Author Topic: EEVblog #397 - Turnigy Accucel 6 Charger Teardown (Read 75177 times)

EEVblog · « **on:** December 11, 2012, 01:25:31 pm »

Inside the Turnigy Accucel 6 Lithium Ion/Polymer/Iron Phosphate 6A Battery Charger.
And a look at the JBC CD-2BB series soldering iron:
http://www.amazon.com/gp/product/B008LZ30Y4/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B008LZ30Y4&linkCode=as2&tag=ee04-20

Schematic: http://www.rcgroups.com/forums/showthread.php?t=1362933
MOSFETs:
MT8103A http://www.mtsemi.com/_control/upload_file/MT8103A.pdf
FDS6680 http://www.fairchildsemi.com/ds/FD/FDS6680.pdf

Dave.

DeepThought · « **Reply #1 on:** December 11, 2012, 03:13:58 pm »

Man, I'm still blown away by that soldering iron. Dear Santa Claus, I was a very nice boy this year...

Dave you mention some firmware hacks. What is done there and where can I find out more? Do you have some pointers for me?
I don't need a new charger per se, but I'm pretty fed up with the menu and software on my current one. Something more flexible would be great. Certainly worth the investment of some 20 quid.
I especially like to have a nicer LiPo charging method for deep discharged batteries. My current one just says "Go away, I'm not touching this. It's dead."
Get them working again with the NiMh constant current (I think) mode easily, just have to watch the temperature and go low on the amps. Drives me nuts.

baoshi · « **Reply #2 on:** December 11, 2012, 03:38:29 pm »

Fantastic video

especially love the schematic analysis part. Frankly I was not expecting the charger to be so well constructed.
A silly question: the dummy load part is directly driven by PWM without any filtering. Is it the best way to discharge a battery? And what's the purpose of measuring back the discharging current from DA1:1 if the mcu is already controlling the current? A safety measure?

Bob

Skippy · « **Reply #3 on:** December 11, 2012, 04:07:24 pm »

I really liked this video.

Silly question: Laptops have multicell batteries in them, right? Do laptops contain all of this multicell balancing gubbins? You don't get these big mosfets in laptops that regulate the charging, do you?

robrenz · « **Reply #4 on:** December 11, 2012, 04:19:36 pm »

That JBC is $16.00 cheaper if you go direct to the Janel website

Dave, if you get a cut from that Amazon link please delete this post.

Plecharts · « **Reply #5 on:** December 11, 2012, 04:28:42 pm »

Quote from: Skippy on December 11, 2012, 04:07:24 pm

Silly question: Laptops have multicell batteries in them, right? Do laptops contain all of this multicell balancing gubbins? You don't get these big mosfets in laptops that regulate the charging, do you?

I have a feeling that most laptops use NiCd battery packs, or at least those I have seen did. You probably don't need to balance NiCd packs, or it does not make that big difference as it does in lithium batteries, where unbalanced pack can lead to big fire easily. Forget it, NiCd and LiIon can look the same...

Dave, what about making it not only regulated load, but also a power supply? I know it probably isn't really precise enough to be a competitor to some more advanced supplies, but it could be a pretty nice power supply for beginners. The unit I have even has auto turn-off on low voltage, so you can even connect it to a battery and make a portable one

lewis · « **Reply #6 on:** December 11, 2012, 04:53:42 pm »

Regarding desoldering:

Dave, get yourself once of these mate, they're awesome: http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-6000-Lead-free-Desolder-Hot-Air-Station-77411

or one of these if you're feeling flush: http://uk.farnell.com/pace/8007-0479/soldering-system-mbt-301-td-100/dp/1279346?Ntt=mbt301

We use them both and they're indespensible for repair work!

For those that haven't seen them, it's a soldering iron with a hole up the middle. You heat up the pad on the PCB, press a button, and an electric pump sucks all the solder out of the joint into a collection tube in the iron's handle. No more manual solder suckers, no more soldering braid, no more pulling out plated-through holes, and they are fantastic for double sided and multi-layer boards. Think of it as a miniature heated vacuum cleaner. Expensive, but once you've used one you'll never ever be without it.

Skippy · « **Reply #7 on:** December 11, 2012, 05:09:32 pm »

Quote from: Plecharts on December 11, 2012, 04:28:42 pm

Quote from: Skippy on December 11, 2012, 04:07:24 pm
Silly question: Laptops have multicell batteries in them, right? Do laptops contain all of this multicell balancing gubbins? You don't get these big mosfets in laptops that regulate the charging, do you?

I have a feeling that most laptops use NiCd battery packs, or at least those I have seen did. You probably don't need to balance NiCd packs, or it does not make that big difference as it does in lithium batteries, where unbalanced pack can lead to big fire easily.

Dave, what about making it not only regulated load, but also a power supply? I know it probably isn't really precise enough to be a competitor to some more advanced supplies, but it could be a pretty nice power supply for beginners. The unit I have even has auto turn-off on low voltage, so you can even connect it to a battery and make a portable one

I'm pretty certain that laptops use Li ion or Lipo batteries.

Things · « **Reply #8 on:** December 11, 2012, 05:10:27 pm »

Hi Dave, funnily enough I ripped apart this chargers bigger brother about 10 minutes before I saw your video!

I'm trying to reverse engineering the cell monitoring circuitry to use in my own projects, but I'm having a bit of trouble understanding how they're doing it.

If you look down near the MUX, you'll see that the BATT- is actually going through a divider into the MUX ... what would be the purpose of this? It seem as if BATT- is never directly connected to ground in the circuit.

Reason I ask is I need to be able to monitor 6 cells individually in my project, but the uC that'll be doing the monitoring will also be powered by the same batteries. I'm worried that the circuit is designed to have the "ground" and BATT- isolated to prevent large voltages on the uC pins.

Could you or someone else possibly explain what's going on here? Would that circuit be suitable when the uC doing the reading is powered off the same battery? Maybe through an isolated DC/DC converter?

Cheers,
Dan

Plecharts · « **Reply #9 on:** December 11, 2012, 05:17:45 pm »

Quote from: Skippy on December 11, 2012, 05:09:32 pm

I'm pretty certain that laptops use Li ion or Lipo batteries.

Oh well, forgot that LiIon sometimes look like NiCd cells.

nitro2k01 · « **Reply #10 on:** December 11, 2012, 05:20:05 pm »

Quote from: Skippy on December 11, 2012, 04:07:24 pm

I really liked this video.

Silly question: Laptops have multicell batteries in them, right? Do laptops contain all of this multicell balancing gubbins? You don't get these big mosfets in laptops that regulate the charging, do you?

As far as I'm aware, most laptop batteries charge the cells in series, but I've seen sense lines going from the individual cell terminals. Presumably they are used for protection circuitry that prevents charging in under/overvolt condition for individual cells. Perhaps these lines could also be used for balancing.

Quote from: Plecharts on December 11, 2012, 04:28:42 pm

I have a feeling that most laptops use NiCd battery packs, or at least those I have seen did. You probably don't need to balance NiCd packs, or it does not make that big difference as it does in lithium batteries, where unbalanced pack can lead to big fire easily.

Which decade are your laptops from? I actually own a Toshiba T2000SX vintage 386 laptop which does have a NiCd cell, but that's about the only time I've seen a NiCd in a laptop. I live i Europe. Maybe most laptops in the US (outside the scope or RoHS) are using NiCd cells and I just never knew, but I doubt it.

T4P · « **Reply #11 on:** December 11, 2012, 05:36:21 pm »

Quote from: Plecharts on December 11, 2012, 04:28:42 pm

I have a feeling that most laptops use NiCd battery packs, or at least those I have seen did. You probably don't need to balance NiCd packs, or it does not make that big difference as it does in lithium batteries, where unbalanced pack can lead to big fire easily.

NiCD batteries in laptops ... what, 10 years ago?

Quote from: Skippy on December 11, 2012, 05:09:32 pm

I'm pretty certain that laptops use Li ion or Lipo batteries.

till today they are still using 18650s 3s2p arrangement with individual discharging leads at least for a 7.4V system with about 4AH, not sure about the larger packs but probably 6.2AH if they are not cheaping out and making the user pay a bomb for cheap chinese cells (The ones i have came out of a ACER laptop ala 2006, a single core AMD Turion 64 MT-40 Acer laptop that was smashed ... don't ask why)

Quote from: Plecharts on December 11, 2012, 05:17:45 pm

Quote from: Skippy on December 11, 2012, 05:09:32 pm
I'm pretty certain that laptops use Li ion or Lipo batteries.
Oh well, forgot that LiIon sometimes look like NiCd cells.

That's a grevious mistake ...

PuterGeek · « **Reply #12 on:** December 11, 2012, 05:53:19 pm »

Those solder and rework stations are way too nice for my wallet!

I bought an Aoyue solder station and separate rework system (refurbished 2702 was $40 less):
http://sra-solder.com/product.php/6363/22/aoyue_2900_lead_free_compatible_soldering_station
http://sra-solder.com/product.php/6681/1/aoyue_2702a_all_in_one_digital_hot_air_rework_station_110_volt

They worked pretty well in the engineering lab at my former employer. I bought them for my consulting/hobby use after I left. The desoldering tips will clog if you don't keep the filter damp and the desoldering trap springs rusted on the work one (now stainless steel).

I like the pistol grip Aoyue desoldering iron better than the straight Pace style. The combo use the same soldering iron tips (integral heaters) and are ready a few seconds after you switch them on.

There is also an all in one but the refurbished 2702 made the separates a little cheaper and adds a little flexiblity:
http://sra-solder.com/product.php/6936/1/aoyue_2703a_all_in_one_digital_hot_air_rework_station_110v

I'm not sure they would last in production use but they're fine for hobby or lab use. They definitely aren't JBC or Pace quality but both of them and some extra tips cost less than the JBC alone.

PA0PBZ · « **Reply #13 on:** December 11, 2012, 07:27:00 pm »

Do I understand correctly that the 'balancing act' works by discharging the cell(s) with the highest voltage and equalizing the cells that way? Looking at the schematic I don't see how it could charge individual cells this way.

Matje · « **Reply #14 on:** December 11, 2012, 07:29:43 pm »

Quote from: lewis on December 11, 2012, 04:53:42 pm

Regarding desoldering:

Dave, get yourself once of these mate, they're awesome: http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-6000-Lead-free-Desolder-Hot-Air-Station-77411

Whoa, they shure are gouging you over there in Britain...

This side of the channel the price for one of these http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-8800-Solder-and-Desolder-Station-123560 is about the same as for the LF-6000 above - in Euros actually, not GBP.

lewis · « **Reply #15 on:** December 11, 2012, 07:42:58 pm »

Quote from: Matje on December 11, 2012, 07:29:43 pm

Quote from: lewis on December 11, 2012, 04:53:42 pm
Regarding desoldering:

Dave, get yourself once of these mate, they're awesome: http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-6000-Lead-free-Desolder-Hot-Air-Station-77411

Whoa, they shure are gouging you over there in Britain...

This side of the channel the price for one of these http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-8800-Solder-and-Desolder-Station-123560 is about the same as for the LF-6000 above - in Euros actually, not GBP.

Yep, sounds about right! Good old Britannia....

JonnyBoats · « **Reply #16 on:** December 11, 2012, 08:38:45 pm »

Dave,

This is another excellent video.

If you re-visit this charger in a future video I hope you show us how you deal with the lifted pads that you indicated could be fixed.

Monkeh · « **Reply #17 on:** December 11, 2012, 08:41:03 pm »

Quote from: Plecharts on December 11, 2012, 04:28:42 pm

I have a feeling that most laptops use NiCd battery packs

Laptops haven't used nicads since about 1980.

ecat · « **Reply #18 on:** December 11, 2012, 08:42:07 pm »

Quote from: PA0PBZ on December 11, 2012, 07:27:00 pm

Do I understand correctly that the 'balancing act' works by discharging the cell(s) with the highest voltage and equalizing the cells that way? Looking at the schematic I don't see how it could charge individual cells this way.

That's my understanding, and yes the cells are charged in series.

Since the maximum discharge current (1A?) is less then the max charge current (6A depending upon the attached power supply), I guess the cycle is:
Charge on, discharge off
Wait until at least 1 cell is is fully charged
Charge off, discharge on
Wait until all fully charged cells <= highest voltage of uncharged cells
... repeat until all balanced and charged?

Balanced charge is just one option. Quick charge ignores the individual cell voltages (?).

I thought the really neat thing about this charger was the ability to calibrate it to within 10mV. Then I bought one, then I bought a Solartron 7150+ and discovered the charger was only 10mV over straight out the box

YMMV of course.

PA0PBZ · « **Reply #19 on:** December 11, 2012, 08:54:13 pm »

I think that the maximum discharge for a singe cell would be something like 200 mA (6 120 ohm resistors, ~4 volts).

EEVblog · « **Reply #20 on:** December 11, 2012, 09:03:43 pm »

Quote from: robrenz on December 11, 2012, 04:19:36 pm

That JBC is $16.00 cheaper if you go direct to the Janel website
Dave, if you get a cut from that Amazon link please delete this post.

I do get a cut, but I don't care where people buy it from. If you can get it cheaper somewhere else then I encourage that.

Dave.

EEVblog · « **Reply #21 on:** December 11, 2012, 09:06:05 pm »

Quote from: lewis on December 11, 2012, 04:53:42 pm

Regarding desoldering:
Dave, get yourself once of these mate, they're awesome: http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-6000-Lead-free-Desolder-Hot-Air-Station-77411

or one of these if you're feeling flush: http://uk.farnell.com/pace/8007-0479/soldering-system-mbt-301-td-100/dp/1279346?Ntt=mbt301

We use them both and they're indespensible for repair work!

Yes, we've always had proper through hole desoldering guns at work (usually the Hakko ones). Never have done enough repair at home to warrant one for myself.

Dave.

ecat · « **Reply #22 on:** December 11, 2012, 09:21:48 pm »

Quote from: lewis on December 11, 2012, 07:42:58 pm

Quote from: Matje on December 11, 2012, 07:29:43 pm
Quote from: lewis on December 11, 2012, 04:53:42 pm
Regarding desoldering:

Dave, get yourself once of these mate, they're awesome: http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-6000-Lead-free-Desolder-Hot-Air-Station-77411

Whoa, they shure are gouging you over there in Britain...

This side of the channel the price for one of these http://www.rapidonline.com/Tools-Equipment/Xytronic-LF-8800-Solder-and-Desolder-Station-123560 is about the same as for the LF-6000 above - in Euros actually, not GBP.

Yep, sounds about right! Good old Britannia....

I'm sure most UK peeps here know this but for any others: If you can find cheaper within the EU then buy it. No import duties, no extra taxes, just a few extra days for delivery. Want to make sure the company you are buying from? Just ask/google around.

UK pricing is often a joke and the situation has to change or many companies will be out of business. Dave mentioned HobbyKing which makes for a perfect example: Earlier this year I was looking for a LiPo pack and charger, looked locally, looked at UK mail order, looked at UK ebay. I remembered HobbyKing and found they had just opened a UK warehouse, the prices were incredible but no stock

. I waited a week, looked again and bought the Accucel 6 charger + the Nano version of the battery Dave shows for around half the average UK price.

Half price! And not on any special sale and shipped from within the UK. No wonder they were out of stock.

ttp · « **Reply #23 on:** December 11, 2012, 10:43:18 pm »

Have one of them for couple of years and it's great, does all my batteries for RC and power tools.

There is hardware mod for it to get serial out to temperature sensor connector, there is a software (forgot the name now) that reads the data from the charger and plots charge/discharge characteristics. I have links at home but I'm travelling now, something to get you started - http://www.rcgroups.com/forums/showthread.php?t=1046318.

DMX512 · « **Reply #24 on:** December 12, 2012, 02:54:58 am »

Quote from: Plecharts on December 11, 2012, 04:28:42 pm

Dave, what about making it not only regulated load, but also a power supply? I know it probably isn't really precise enough to be a competitor to some more advanced supplies, but it could be a pretty nice power supply for beginners. The unit I have even has auto turn-off on low voltage, so you can even connect it to a battery and make a portable one

I had the same idea. I have been wanting to hack my iMAX B6 (basically same as the Accucel 6) into an adjustable power supply, but I haven't got the experience. Sure the output may not be very clean, but it would be a great high current, portable power supply that could be powered from your car (when in the field). I guess it would be similar to Dave's uSupply but with ?0-25V, 0-6A, 50W max output.

If Dave is going to hack the Accucel 6 it into a regulated load, then also try to hack it into an adjustable power supply. Why not put its DC-DC converter to use?

swedeham · « **Reply #25 on:** December 12, 2012, 03:32:56 am »

Very Interesting video since I have a GT 606D witch seem to be the same thing.
The tempsense and serial outport, I have sought after info before but could not find any, but today I found plenty.
The tempsensor that works is a "lm35dz" 0-40 deg C, 0V is 0deg and then 10mV/degC. Hobbyking has it as a product "http://www.hobbyking.com/hobbyking/store/__11777__temperature_sensor_w_futaba_plug_.html"
My electronicsupplyer "elfa.se" has it at half price if you buy 10+ . You may wanna put more than one sensor on your R/C model, ie BEC, motor, battpack .
The serial output seem to need a ttl-rs232 to USB converter "arduino product maybe" or mobile to PC cable (dumpsterdiving job) then you could use a software to view voltages and temperatures.
The software is "Logview" "www.logview.info"

I just saw the video and found this info, so I have not tested anything yet, but the info seems ok .

ttl-rs232 post "http://www.rcgroups.com/forums/showthread.php?t=1046318"

/Mats

peter.mitchell · « **Reply #26 on:** December 12, 2012, 09:49:06 am »

Quote from: ecat on December 11, 2012, 09:21:48 pm

Half price! And not on any special sale and shipped from within the UK. No wonder they were out of stock.

But rememeber, HKs prices are crazy, i don't know how they do it, i buy my heatshrink, silicone wire, nylon screws and nuts from them just because they're cheap and reasonable quality.

Things · « **Reply #27 on:** December 12, 2012, 11:07:33 am »

I can also recommend the ECO6-10 from Hobbyking. It's Hobbyking branded, but Turnigy and HK are the same people, so they're basically identical. It's very similar in layout and components to the one Dave did this teardown on, but with more current handling in mind

nixxon · « **Reply #28 on:** December 12, 2012, 10:23:28 pm »

Quote from: T4P on December 11, 2012, 05:36:21 pm

Quote from: Plecharts on December 11, 2012, 04:28:42 pm
I have a feeling that most laptops use NiCd battery packs, or at least those I have seen did. You probably don't need to balance NiCd packs, or it does not make that big difference as it does in lithium batteries, where unbalanced pack can lead to big fire easily.
NiCD batteries in laptops ... what, 10 years ago?

Quote from: Skippy on December 11, 2012, 05:09:32 pm
I'm pretty certain that laptops use Li ion or Lipo batteries.
till today they are still using 18650s 3s2p arrangement with individual discharging leads at least for a 7.4V system with about 4AH, not sure about the larger packs but probably 6.2AH if they are not cheaping out and making the user pay a bomb for cheap chinese cells (The ones i have came out of a ACER laptop ala 2006, a single core AMD Turion 64 MT-40 Acer laptop that was smashed ... don't ask why)

Quote from: Plecharts on December 11, 2012, 05:17:45 pm
Quote from: Skippy on December 11, 2012, 05:09:32 pm
I'm pretty certain that laptops use Li ion or Lipo batteries.
Oh well, forgot that LiIon sometimes look like NiCd cells.
That's a grevious mistake ...

Here is a picture of the guts of my Acer 14.8 V 4800 mAh battery pack (Model P/N AS07B42) that came with my Aspire 5920G 5 years ago. I cracked it apart last week to replace the 8 18650 Li-Ion cells (4S2P, I guess). The cells are connected as shown on picture with main voltage tap at CL1 and CL5. In addition there are connections to PCB inside battery labeled CL2, CL3 and CL4 as well. The connector to the laptops has 7 pins. There are 2 temp sensors connected to two of the rightmost cells in the photo.

The 18650's I ordered claim to be 4250mAh. Yeah right! If that was correct my battery pack would increase in capacity from 4800mAh to 8500mAh

That would be a 77% increase. I just hope I didn't waste $32.
http://www.ebay.com/itm/350546818332

What does the following text on the battery pack mean: "Never attempt to disassemble or reassemble"?!?

EDIT: Original cells are SONY US18650GR (2400mAh)

rollatorwieltje · « **Reply #29 on:** December 12, 2012, 10:30:05 pm »

Quote from: PA0PBZ on December 11, 2012, 07:27:00 pm

Do I understand correctly that the 'balancing act' works by discharging the cell(s) with the highest voltage and equalizing the cells that way? Looking at the schematic I don't see how it could charge individual cells this way.

That's exactly how most of these chargers work. It just completely stops charging when the difference is too big.

I'm looking at this charger for a while now to replace an old Graupner charger with external balancer, but i'm still a bit hesitant to connect high current sources to dirt cheap Chinese electronics. One of those 3s lipo packs is capable of starting a car...

bitwelder · « **Reply #30 on:** December 12, 2012, 10:48:10 pm »

Quote from: nixxon on December 12, 2012, 10:23:28 pm

What does the following text on the battery pack mean: "Never attempt to disassemble or reassemble"?!?

"These aren't the battery cells that you are looking for replacement"

nixxon · « **Reply #31 on:** December 12, 2012, 11:08:19 pm »

Quote from: ecat on December 11, 2012, 08:42:07 pm

Quote from: PA0PBZ on December 11, 2012, 07:27:00 pm
Do I understand correctly that the 'balancing act' works by discharging the cell(s) with the highest voltage and equalizing the cells that way? Looking at the schematic I don't see how it could charge individual cells this way.

That's my understanding, and yes the cells are charged in series.

Since the maximum discharge current (1A?) is less then the max charge current (6A depending upon the attached power supply), I guess the cycle is:
Charge on, discharge off
Wait until at least 1 cell is is fully charged
Charge off, discharge on
Wait until all fully charged cells <= highest voltage of uncharged cells
... repeat until all balanced and charged?

Balanced charge is just one option. Quick charge ignores the individual cell voltages (?).

I thought the really neat thing about this charger was the ability to calibrate it to within 10mV. Then I bought one, then I bought a Solartron 7150+ and discovered the charger was only 10mV over straight out the box YMMV of course.

If you download LogView (German donorware, IIRC), you get full datalogging capability (activate data out rather than temp sensor) showing everything you could ever want to know about the charging process, down to each lipo cell. While charging and after the charging process has completed, you can view the selected data in LogView (tables or graphs) or access a file with all the data as well. I Usually saved data as CSV files and imported in MS Excel.

Check it out! General info here: http://www.logview.info/vBulletin/content.php?10-english
And some screenshots: http://www.logview.info/vBulletin/content.php?47-screenshots_1

Here is the latest info mail I got from the LogView team October 24th with the title: "LogView 2.7.5.504 Online?":

"Hi LogView friends,

the summer is over, the winter is near, and we can´t get our fingers of ...

a new update for LogView is Online. The actual version is 2.7.1.411.

----------------------------------------------

Changes for this version:

+ new device : Multiplex FlightRecoder

+ new device : Pulsar 3

+ Fix Akkumatik: Akkuamtik-SW 1.09

+ Fixes for OpenFormat

+ keine Nag Screen anymore

+ WDE 1 Fix

+ SM GPS Logger Fix

+ some small other fixes

You will find the download here:

http://www.logview.info/vBulletin/downloads.php

http://www.logview.info/vBulletin/downloads.php?do=file&id=17

Place remarks to the new version here:

http://www.logview.info/vBulletin/showthread.php?6482-LogView-2.7.5.504-ist-Online

If you like to make a small donation for this download you can use this link:

https://www.paypal.com/cgi-bin/webscr?cmd=_xclick&business=dominik%40logview%2einfo&item_name=LogView%20Donation&amount=1%2e50&no_shipping=0&tax=0&currency_code=EUR&lc=DE&bn=PP%2dDonationsBF&charset=UTF%2d8

Have fun with the new version!

Your LogView Team

peter.mitchell · « **Reply #32 on:** December 13, 2012, 02:41:43 am »

Quote from: nixxon on December 12, 2012, 10:23:28 pm

What does the following text on the battery pack mean: "Never attempt to disassemble or reassemble"?!?

You should never attempt it, you should always do it successfully.

Also, if i recall correctly, those cells have about 1.85Ah capacity, you get what you pay for, these on the other hand will provide their rated capacity http://www.ebay.com.au/itm/150936196806.

T4P · « **Reply #33 on:** December 13, 2012, 05:01:09 am »

Quote from: nixxon on December 12, 2012, 10:23:28 pm

Here is a picture of the guts of my Acer 14.8 V 4800 mAh battery pack (Model P/N AS07B42) that came with my Aspire 5920G 5 years ago. I cracked it apart last week to replace the 8 18650 Li-Ion cells (4S2P, I guess). The cells are connected as shown on picture with main voltage tap at CL1 and CL5. In addition there are connections to PCB inside battery labeled CL2, CL3 and CL4 as well. The connector to the laptops has 7 pins. There are 2 temp sensors connected to two of the rightmost cells in the photo.

The 18650's I ordered claim to be 4250mAh. Yeah right! If that was correct my battery pack would increase in capacity from 4800mAh to 8500mAh That would be a 77% increase. I just hope I didn't waste $32.
http://www.ebay.com/itm/350546818332

I'm a little baffled why there is only 8 batteries not 9 batteries but anyway, to get the 14.8V figure they used the two top batteries to gain extra voltage per series bank, the batteries inside are definitely 2400mAH
BTW those 18650s you linked have probably about 2000-2400mAH each if correct and the voltage will quite alot sag under load
and their ESR is much higher therefore will have considerable self-discharge

EEVblog · « **Reply #34 on:** December 13, 2012, 05:14:09 am »

Quote from: T4P on December 13, 2012, 05:01:09 am

The 18650's I ordered claim to be 4250mAh. Yeah right! If that was correct my battery pack would increase in capacity from 4800mAh to 8500mAh That would be a 77% increase. I just hope I didn't waste $32.
http://www.ebay.com/itm/350546818332

I'm a little baffled why there is only 8 batteries not 9 batteries but anyway, to get the 14.8V figure they used the two top batteries to gain extra voltage per series bank, the batteries inside are definitely 2400mAH
BTW those 18650s you linked have probably about 2000-2400mAH each if correct and the voltage will quite alot sag under load
and their ESR is much higher therefore will have considerable self-discharge
[/quote]

The best 18650's are capable of is about 3300mAh, and they are Panasonic NCH18650B:
http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+BA+3+ACI4002+NCR-18650B+7+EU
The A version slightly less:
http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+BA+4+ACA4001+NCR18650A+7+WW

Some ebay 18650's claim up to 5000mAh - bullshit!
I'm thinking about getting a bunch and measuring them vs genuine panasonics.

Dave.

Things · « **Reply #35 on:** December 13, 2012, 05:38:10 am »

Please do Dave!

Also, did you see my previous post? i'd really appreciate if you could explain/have a look at why they do this:

Quote from: me

If you look down near the MUX, you'll see that the BATT- is actually going through a divider into the MUX ... what would be the purpose of this? It seem as if BATT- is never directly connected to ground in the circuit. Is it some way of doing isolation?

Dan

T4P · « **Reply #36 on:** December 13, 2012, 06:02:01 am »

Quote from: EEVblog on December 13, 2012, 05:14:09 am

Some ebay 18650's claim up to 5000mAh - bullshit!
I'm thinking about getting a bunch and measuring them vs genuine panasonics.

Dave.

Yeah, i know about those panasonics it's just the fake ones that never reach the labelling at least on the 3000+ ones, i have seen ultrafire 4800mAH 18650s too and i am definitely going to test them when i get a maynuo load

nixxon · « **Reply #37 on:** December 13, 2012, 07:57:54 am »

Quote from: T4P on December 13, 2012, 05:01:09 am

Quote from: nixxon on December 12, 2012, 10:23:28 pm
Here is a picture of the guts of my Acer 14.8 V 4800 mAh battery pack (Model P/N AS07B42) that came with my Aspire 5920G 5 years ago. I cracked it apart last week to replace the 8 18650 Li-Ion cells (4S2P, I guess). The cells are connected as shown on picture with main voltage tap at CL1 and CL5. In addition there are connections to PCB inside battery labeled CL2, CL3 and CL4 as well. The connector to the laptops has 7 pins. There are 2 temp sensors connected to two of the rightmost cells in the photo.

The 18650's I ordered claim to be 4250mAh. Yeah right! If that was correct my battery pack would increase in capacity from 4800mAh to 8500mAh That would be a 77% increase. I just hope I didn't waste $32.
http://www.ebay.com/itm/350546818332
I'm a little baffled why there is only 8 batteries not 9 batteries but anyway, to get the 14.8V figure they used the two top batteries to gain extra voltage per series bank, the batteries inside are definitely 2400mAH
BTW those 18650s you linked have probably about 2000-2400mAH each if correct and the voltage will quite alot sag under load
and their ESR is much higher therefore will have considerable self-discharge

No surprise that 4 cells @ 3.7 Volts nominal in series gives 14.8 nominal voltage. The remaining 4 cells are simply connected in parallel to the first 4 cells. (4S2P). 4 + 4 cells = 8 cells. What purpose would a 9th cell serve?

When charged, each cell is 4.2 Volts and the pack voltage is actually 16.8 Volts.

T4P · « **Reply #38 on:** December 13, 2012, 10:23:49 am »

11.1V 7200mAH

I'm wondering sometimes why 15.6 acer inchers use 14.8V instead of 11.1V

nixxon · « **Reply #39 on:** December 13, 2012, 11:43:29 am »

Quote from: T4P on December 13, 2012, 10:23:49 am

11.1V 7200mAH
I'm wonder sometimes why 15.6 acer inchers use 14.8V instead of 11.1V

Now I got it

(3S3P configuration)

aargee · « **Reply #40 on:** December 13, 2012, 11:56:45 am »

Quote from: Monkeh on December 11, 2012, 08:41:03 pm

Quote from: Plecharts on December 11, 2012, 04:28:42 pm
I have a feeling that most laptops use NiCd battery packs

Laptops haven't used nicads since about 1980.

Laptops in 1980? What?

I had a Toshiba T1000 from about 1992 that used NiCd battery packs.

As for the Accucel 6 discharging at 1A, I think it depends on battery voltage (total power), my 3S LiPo's won't discharge above 500mA. I think the Accucel8 might have a higher discharge capacity and might be a better candidate for a dummy load hack.

EEVblog · « **Reply #41 on:** December 13, 2012, 12:03:20 pm »

Quote from: aargee on December 13, 2012, 11:56:45 am

As for the Accucel 6 discharging at 1A, I think it depends on battery voltage (total power), my 3S LiPo's won't discharge above 500mA. I think the Accucel8 might have a higher discharge capacity and might be a better candidate for a dummy load hack.

Just put in a bigger resistor and heatsink it as I mentioned.

Yes, if they are smart they will software limit the total power in the discharge resistor.

Dave.

Things · « **Reply #42 on:** December 13, 2012, 12:15:50 pm »

Yes, I'm fairly sure they do monitor it in software. They do for the ECO6-10 at least, which is very similar.

peter.mitchell · « **Reply #43 on:** December 13, 2012, 02:42:14 pm »

Quote from: EEVblog on December 13, 2012, 05:14:09 am

Quote from: T4P on December 13, 2012, 05:01:09 am
The 18650's I ordered claim to be 4250mAh. Yeah right! If that was correct my battery pack would increase in capacity from 4800mAh to 8500mAh That would be a 77% increase. I just hope I didn't waste $32.
http://www.ebay.com/itm/350546818332
I'm a little baffled why there is only 8 batteries not 9 batteries but anyway, to get the 14.8V figure they used the two top batteries to gain extra voltage per series bank, the batteries inside are definitely 2400mAH
BTW those 18650s you linked have probably about 2000-2400mAH each if correct and the voltage will quite alot sag under load
and their ESR is much higher therefore will have considerable self-discharge

The best 18650's are capable of is about 3300mAh, and they are Panasonic NCH18650B:
http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+BA+3+ACI4002+NCR-18650B+7+EU
The A version slightly less:
http://industrial.panasonic.com/www-cgi/jvcr13pz.cgi?E+BA+4+ACA4001+NCR18650A+7+WW

Some ebay 18650's claim up to 5000mAh - bullshit!
I'm thinking about getting a bunch and measuring them vs genuine panasonics.

Dave.
[/quote]

No need Dave, this guy has you covered;
http://lygte-info.dk/info/Batteries18650-2011%20UK.html
http://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html
http://lygte-info.dk/review/batteries2012/Common18650comparator.php

HKJ · « **Reply #44 on:** December 13, 2012, 04:29:18 pm »

Quote from: peter.mitchell on December 13, 2012, 02:42:14 pm

No need Dave, this guy has you covered;
http://lygte-info.dk/info/Batteries18650-2011%20UK.html
http://lygte-info.dk/review/batteries2012/Common18650Summary%20UK.html
http://lygte-info.dk/review/batteries2012/Common18650comparator.php

This guy has been running battery test 24/7 for the last year.

I tested one set of 5000mAh batteries (four for $10), they had about 1000mAh each, but did handle load surprising well.

Brands link TrustFire/UltraFire/etc. can change contents without warning, I did test a UltraFire from 3 different suppliers and got 3 different results, none of them good. This is not really surprising, you can buy the UltraFire shrink wrap from some suppliers and put it on any old battery you have.

A am also working on a test of smaller LiIon batteries: http://lygte-info.dk/review/batteries2012/CommonSmallSummary%20UK.html

Monkeh · « **Reply #45 on:** December 14, 2012, 03:24:50 am »

Quote from: aargee on December 13, 2012, 11:56:45 am

Quote from: Monkeh on December 11, 2012, 08:41:03 pm
Quote from: Plecharts on December 11, 2012, 04:28:42 pm
I have a feeling that most laptops use NiCd battery packs

Laptops haven't used nicads since about 1980.

Laptops in 1980? What?

Okay, so I was off by a couple of years, although they were designed in 79-80.

Quote

I had a Toshiba T1000 from about 1992 that used NiCd battery packs.

And it was five years old then.

peter.mitchell · « **Reply #46 on:** December 14, 2012, 04:35:26 am »

Quote from: HKJ on December 13, 2012, 04:29:18 pm

A am also working on a test of smaller LiIon batteries: http://lygte-info.dk/review/batteries2012/CommonSmallSummary%20UK.html

Wait... are you saying you're that guy? If so, thank you very very much for this great resource of yours!

cwalex · « **Reply #47 on:** December 14, 2012, 11:11:25 am »

I just dismantled a dead asus notebook battery with 6 18650 cells in it. 4 of the cells were reading about 3.9V open circuit and the rest about 3.2V. They all took a full charge individually and so far have remained open circuit at about 4.1V. I haven't performed load tests on them at all but I did put a couple in a torch that draws a bit more than 2 amps and they performed well for the brief time I tested them. I wonder if the charger just decided they were too unbalanced now and decided the pack is bad. I plan to make up a backup system for my adsl modem using them plus some more if I can salvage more. Should be a fun project.

amyk · « **Reply #48 on:** December 14, 2012, 11:33:18 am »

Quote from: HKJ on December 13, 2012, 04:29:18 pm

Brands link TrustFire/UltraFire/etc. can change contents without warning, I did test a UltraFire from 3 different suppliers and got 3 different results, none of them good. This is not really surprising, you can buy the UltraFire shrink wrap from some suppliers and put it on any old battery you have.

All the *fire brands seem to be a "generic", the Ultrafire 3000 have also been known to be recycled cells...

...not even 18650s...

...and not even LiIon:

cwalex · « **Reply #49 on:** December 14, 2012, 12:01:32 pm »

Yeah, I was kind of hoping that at least one of the cells from my dismantled notebook batt would be kaput so that I could take it apart and light it on fire

T4P · « **Reply #50 on:** December 14, 2012, 12:34:27 pm »

Epic fail ... but the charts for that particular battery was quite promising though

Oh, only for the DX ones

SeanB · « **Reply #51 on:** December 14, 2012, 03:14:33 pm »

I just open them and drop them in water, then they react to an inert mass. Nice copper and aluminium sheet inside.

G7PSK · « **Reply #52 on:** December 14, 2012, 06:32:51 pm »

I had a Dell computer come in recently that had a dead NiCd pack it ran Windows 2000 I replaced the battery with a new one which was LiPo and sent it back running XP.

HKJ · « **Reply #53 on:** December 14, 2012, 07:36:23 pm »

Quote from: peter.mitchell on December 14, 2012, 04:35:26 am

Quote from: HKJ on December 13, 2012, 04:29:18 pm
A am also working on a test of smaller LiIon batteries: http://lygte-info.dk/review/batteries2012/CommonSmallSummary%20UK.html
Wait... are you saying you're that guy?

Yes.

Quote from: amyk on December 14, 2012, 11:33:18 am

All the *fire brands seem to be a "generic", the Ultrafire 3000 have also been known to be recycled cells...

Some of the *fire brands are sometimes acceptable batteries and at other times they are not very good.

Quote from: amyk on December 14, 2012, 11:33:18 am

It is surprising that it is economical feasible to make this kind of fake batteries.

SeanB · « **Reply #54 on:** December 15, 2012, 05:01:38 am »

Scrapped electronics provides the battery inside, and then the case is cheap along with the assembly. If you get spare cell casings as scrap then it is easier and cheaper.

metalphreak · « **Reply #55 on:** December 15, 2012, 11:56:59 am »

Hey Dave,

Have you ever used one of those electronic vacuum pump desoldering irons?

http://www.ebay.com.au/itm/150830114062?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I just received this one I ordered and... its fantastic

Will see how long it lasts but it seems to be built ok.

Might do a video on it tomorrow, and show how easy it is to desolder the LCD from my turnigy charger

cwalex · « **Reply #56 on:** December 15, 2012, 12:17:45 pm »

Quote from: metalphreak on December 15, 2012, 11:56:59 am

Hey Dave,

Have you ever used one of those electronic vacuum pump desoldering irons?

http://www.ebay.com.au/itm/150830114062?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

I just received this one I ordered and... its fantastic Will see how long it lasts but it seems to be built ok.

Might do a video on it tomorrow, and show how easy it is to desolder the LCD from my turnigy charger

I would love to see a video demo

If you have a faulty PC motherboard can you try it to desolder some of the large caps to see if it would work? If you don't have a m/b I can send you one! Just PM me you address.

metalphreak · « **Reply #57 on:** December 15, 2012, 12:33:28 pm »

Motherboards can be tricky, because they have such a massive ground plane. I have plenty of boards here which I was planning on taking components from

Part of the reason why I ordered it.

T4P · « **Reply #58 on:** December 15, 2012, 01:05:00 pm »

I always thought the handheld ones were nasty
It vibrates massively doesn't it? An Aoyue 474A doesn't cost much more and is much more powerful in terms of vacuum pressure

cwalex · « **Reply #59 on:** December 15, 2012, 01:45:29 pm »

Quote from: metalphreak on December 15, 2012, 12:33:28 pm

Motherboards can be tricky, because they have such a massive ground plane. I have plenty of boards here which I was planning on taking components from Part of the reason why I ordered it.

Yeah, that is why I was interested in a demo of it. If something can do that it is definitely worth the money. Are you going to try it on a board with large ground/power planes?

ttp · « **Reply #60 on:** December 16, 2012, 10:49:52 pm »

Quote from: cwalex on December 15, 2012, 01:45:29 pm

Quote from: metalphreak on December 15, 2012, 12:33:28 pm
Motherboards can be tricky, because they have such a massive ground plane. I have plenty of boards here which I was planning on taking components from Part of the reason why I ordered it.

Yeah, that is why I was interested in a demo of it. If something can do that it is definitely worth the money. Are you going to try it on a board with large ground/power planes?

I bet it won't be good enough to remove eg. capacitor from motherboard, you need a lot of heat for that. I find a solder pot full of molten solder best to remove parts from PCBs with large power/groung planes, just put the board on top and pull the part before it gets hot. Preheating the board works well too.

metalphreak · « **Reply #61 on:** December 17, 2012, 01:14:33 pm »

Doesn't vibrate much at all. I made sure I got the one with the twin diaphragms in the pump. Make a fair bit of noise as you'd expect.

Motherboard with massive ground planes (which is fine when wave soldering...) and lead-free solder = mediocre results. Just like a regular iron, it takes way too long to heat up. I did manage to pull off a few heavy duty inductors with it though %-B

Works great for regular stuff. If it's a job you can do with a soldering iron and a regular solder sucker, you can do it with this, but its much easier

Overall, it works fine, but I wouldn't classify it as a "Must Have" tool. You can get by with a $10 manual sucker for the odd occasion when you need to clear some through holes or whatever.

Tried to get a video of it in action but its really hard on my (currently messy) small workbench with the camera between you and the tools. Battery in the cam went dead before I got any usable footage. I have some time off next week for the holidays so I'll see if I can get back into taking some vids.

ryansoh3 · « **Reply #62 on:** December 23, 2012, 01:20:09 pm »

Hi guys, here's my first post:

First, I would like to thank Dave for this tear down. It was first tear down of something I actually owned!

Anyways, I'm having trouble activating the USB communication feature for the charger.
My setup is as follows:

Charger side:

UART converster side:

Anyways, when looked through via a crude scope, I basically see the TTL signal shown below:

I can't figure out what's wrong with this setup and it's driving me crazy. Thanks for your help guys.

Cheers!

McMonster · « **Reply #63 on:** December 23, 2012, 02:14:39 pm »

Quote from: ryansoh3 on December 23, 2012, 01:20:09 pm

I can't figure out what's wrong with this setup and it's driving me crazy. Thanks for your help guys.

I'd start by connecting the grounds (the third pin on the charger side I guess) of the charger and serial converter together.

ryansoh3 · « **Reply #64 on:** December 23, 2012, 02:37:32 pm »

Thanks for your reply.

I do have the ground connected, shown in the picture via the grey cable. The purple's Tx/Rx. Cheers!

PA0PBZ · « **Reply #65 on:** December 23, 2012, 03:11:48 pm »

The signal looks ok to me, is this from the charger or from the pc?

aargee · « **Reply #66 on:** December 24, 2012, 02:10:08 am »

I thought that was the thermal sensor connector, maybe one-wire data flow?

I wasn't aware the Accucel had serial comms support.

- Rob

ryansoh3 · « **Reply #67 on:** December 25, 2012, 01:47:26 am »

Quote from: PA0PBZ on December 23, 2012, 03:11:48 pm

The signal looks ok to me, is this from the charger or from the pc?

It's from the charger, and I've confirmed that the UART adapter is working as well because when I short the Tx and Rx leads, it loops what I type in Termite right back to me.

Quote from: aargee on December 24, 2012, 02:10:08 am

I thought that was the thermal sensor connector, maybe one-wire data flow?

I wasn't aware the Accucel had serial comms support.

- Rob

It doubles as a temperature sensor and a TTL/RS232 serial output, which is selectable in the config menu.

Thanks for your replies.

PA0PBZ · « **Reply #68 on:** December 25, 2012, 10:15:22 am »

Quote from: ryansoh3 on December 25, 2012, 01:47:26 am

Quote from: PA0PBZ on December 23, 2012, 03:11:48 pm
The signal looks ok to me, is this from the charger or from the pc?

It's from the charger, and I've confirmed that the UART adapter is working as well because when I short the Tx and Rx leads, it loops what I type in Termite right back to me.

Baudrate? Does the bit time from the charger and the pc looks the same on the scope?
Or maybe level? Maybe you have to invert the signal from the charger?
Although you should see something on your terminal if any of this is wrong...

One more thing: I think the charger puts out a TTL signal level, did you take that into account?

ryansoh3 · « **Reply #69 on:** January 04, 2013, 03:52:34 am »

Thanks for your replies. I just got my hands on a scope and here's the output from the UART adapter when I type something in Termite/Hyperterminal:

And from the hobby charger:

The only thing I notice is that the charger has a slightly slower resting voltage.... could that be causing a problem?

Thanks!

PA0PBZ · « **Reply #70 on:** January 05, 2013, 12:54:13 pm »

Can you show the same on the PC side?

ryansoh3 · « **Reply #71 on:** January 05, 2013, 01:21:37 pm »

Yup, the first picture shows from the PC/UART adapter output, and the second one shows the hobby charger's output.

(Didn't know that meter was for bullcrap

)

The UART adapter reads its own signals without a hitch, but doesn't seem to receive the charger's at all.

SeanB · « **Reply #72 on:** January 05, 2013, 01:33:58 pm »

Select a lower baud rate, probably 2400 will work.

PA0PBZ · « **Reply #73 on:** January 05, 2013, 04:06:08 pm »

Quote

Yup, the first picture shows from the PC/UART adapter output, and the second one shows the hobby charger's output.

Sorry, I was thinking RS232 but you use a USB converter so there is no RS232 side.
What happens when you just connect the TX and RX pins here, do the characters you type get echoed on the screen?

Quote

Select a lower baud rate, probably 2400 will work.

AFAIK the charger works at 9600 baud.

ryansoh3 · « **Reply #74 on:** January 05, 2013, 04:08:05 pm »

Yup, if I short the Rx and Tx pins, I what I typed is echoed and comes back to Termite/Hyperterminal, so the UART adapter itself seems to be working properly.

Things · « **Reply #75 on:** January 05, 2013, 04:19:52 pm »

Interested to see how you go with the UART. I was tempted to try this with my ECO6-10 too, but don't have any USB-TTL adapters on hand. I believe I read somewhere that the parts needed in the charger for it are unpopulated? Not sure how true that is ...

ryansoh3 · « **Reply #76 on:** January 05, 2013, 04:26:26 pm »

Some earlier versions of the Accucel-6 were missing a connection from the board to the Temp sensor/USB out and had to be manually connected via a wire. However, the newer versions already seem to have UART output when the output mode is selected to USB, not the temp. probe.

Check if your charger has a menu that allows you to change between the two outputs, and then we should take it from there.

Cheers!

Things · « **Reply #77 on:** January 05, 2013, 04:34:23 pm »

Mine actually has a physical mini B USB port on it, even with USB written above it, but I believe I read in the manual somewhere that it's actually a RS232 output. Kind of odd using a USB connector in such a case.

ryansoh3 · « **Reply #78 on:** January 05, 2013, 04:38:13 pm »

Ah, I see, I just looked at some reviews of that charger and it stated that the USB output doesn't work.... $:-\$

Perhaps you can probe it to see if it's outputing anything at all?

PA0PBZ · « **Reply #79 on:** January 05, 2013, 04:38:20 pm »

That was going to be my next question, if you in fact set the thing to USB. But since you show a scope picture of the output at least something comes out of the charger, so I guess the setting is ok and you have no missing parts... Oh man, I'm a bit out of options now, everything looks ok, it just doesn't work. $:-\$ You did set the baudrate at 9600 I guess? and no parity, 8 bits and one stop bit?
Could you post the output of the charger on the scope again, but then a bit more stretched out? I want to decode it by hand and see what it sends...

PA0PBZ · « **Reply #80 on:** January 05, 2013, 04:39:59 pm »

Quote from: Things on January 05, 2013, 04:34:23 pm

Mine actually has a physical mini B USB port on it, even with USB written above it, but I believe I read in the manual somewhere that it's actually a RS232 output. Kind of odd using a USB connector in such a case.

I read somewhere that there are in fact chargers with a built-in RS232-USB converter.
Hook it up if you dare!

ryansoh3 · « **Reply #81 on:** January 05, 2013, 04:40:36 pm »

Yup, everything "should" be working...

I'll take some shots right away. Thanks for your offer!

Things · « **Reply #82 on:** January 05, 2013, 04:50:14 pm »

Quote from: PA0PBZ on January 05, 2013, 04:39:59 pm

I read somewhere that there are in fact chargers with a built-in RS232-USB converter.
Hook it up if you dare!

Have tried plugging it in, but no response from the PC

ryansoh3 · « **Reply #83 on:** January 05, 2013, 04:55:28 pm »

Here are some screenshots of the output from the charger:

Zoomed in:

Cheers!

PA0PBZ · « **Reply #84 on:** January 05, 2013, 07:26:47 pm »

The resolution is not good enough to really decode what is being sent, and after a bit of googling I think that it is not human readable anyway.
Did you ever try logview? http://www.logview.info/vBulletin/
For the rest I'm out of ideas, I'd love to get it on my bench and find the obvious thing that we are overlooking, but for now...

ryansoh3 · « **Reply #85 on:** January 06, 2013, 04:40:42 am »

Gotcha, thanks for your time.

I'm going to order another USB to UART/RS232 adapter that has a different chip and lets see how that goes...

Mad Professor · « **Reply #86 on:** March 11, 2013, 11:07:51 am »

I got my self a Turnigy Accucel 6 charger just over a month ago.

Over the weekend I was looking at seeing if I could connect it upto my computer so I could plot some battery cell discharge curves.

But I can not find anywhere in the settings to change from temp probe to usb interface.

I have seen posts else where saying that the usb interface is no longer selectable, and that some versions of the board already have data to usb ic on the back of the board, but it not populated.

I have taken my Turnigy Accucel 6 charger apart and the pcb seems to be yet again another version.

I am not sure what is going on with the 6pin header at the bottom of the board, but it's tied in with the push buttons.

TP1,2 & 3, Looks interesting, this might be the RX, TX, GND for the microcontroller, I will have to get my PicoScope out and have a look when I have some free time.

Best Regards.

AmmoJammo · « **Reply #87 on:** October 27, 2013, 02:40:26 am »

Same same, but different?

This is a PoliMax branded charger, its similar, but different... Very similar to the one Dave took apart though

The two holes next to the DC jack are for hard wired charge cables with alligator clips

RossK · « **Reply #88 on:** September 27, 2015, 07:02:45 pm »

I've started the process of designing my own S2 balancing LiPo charger (yes for "fun" ... that and the cheap one that came with my hex copter is trying to murder batteries) so I've been going through the schematic with a fine toothed comb and have some additional insights to share. I'll start with the most obvious bits worthy of additional mention and go into the less than obvious bits.

Circuits like this one abound in this design. They serve 2 obvious purposes.
1) Allow the MC to force the system 'off' / give the MC the ability to act as a safety officer - however, this role (of safety) is best handled in analog when dealing with so much energy
2) Ensure the circuit is in a known, and safe, sate on power up, before the MC code has a chance to take control of its ports.

It took me a couple of minutes to understand this one - I've never built an RC filter so integrated with op amps - but that's what this is. It uses the time constants of the many distributed caps and resistors to create an RC filter system which converts the PWM signal into a, mostly, analog current target.

In simulation I observed some significant overshoot - in actual application I would ramp the PWM up to avoid damaging overshoots. Overshoot can also be reduced by increasing R24.

In the simulation the observed current drops to 0 with every cycle but this may or may not be something which happens in the real world. This can be reduced to oscillation by increasing PWM frequency (I used a 10kHz signal).

Frankly I wouldn't use this circuit - I'd use a much more strait forward PWM into a 2 stage RC filter which sets the target current (target sense resistor voltage drop).

This circuit has only one job and it's not at all obvious at first - Dave even missed it in the video. This circuit is here to protect against reverse battery hookup - nothing else. As far as I can tell it has no part in the constant current or constant voltage processes. It doesn't even cut the circuit if the battery leads were to be shorted to each other - there must be a negative potential for it to turn the FET off. How negative depends on the potential of the buck/boost cap - the more voltage in that cap the more negative this needs to be ... e.g. about -5v when the buck boost cap is at 15v. This isn't as un-safe as it may sound because once the cap is discharged enough the FET will be turned off (assuming that the buck boost isn't running).

Another point Dave missed on this one in the video is the feedback loop. It doesn't take the long way around - it's just being used as a compariator. There is no valid way for this circuit to ever get 14% of BAT- to be equal to 19% BAT+ (and we really don't want that anyway!).

I hope others find this helpful - if I have any other revelations I'll share them as well, and if I actually build a charger I'll share it in its own thread

sk2593 · « **Reply #89 on:** January 22, 2016, 03:20:00 am »

Good Job RossK.

Has anybody else noticed this? I am looking at the circuit design and none of the chips/ICs are specific for Lithium Ion or NiMH or any other battery chemistry. They seem to be general purpose OpAmps, and DC to DC convertor circuits. It looks like the MCU is the primary driver of the charging algorithm.
Would it be in theory possible to design a battery charger that can work with any chemistry(essentially future proof) The software in the MCU can be reflashed/upgraded via a smart phone app or something. In theory is it possible?
I know there are some out there who have hacked the Micro Processor and upgraded firmware.
See the link below:
https://groups.google.com/forum/#!topic/cheali-charger/WkkV64jA56Q

Monkeh · « **Reply #90 on:** January 22, 2016, 04:13:54 am »

Quote from: sk2593 on January 22, 2016, 03:20:00 am

Good Job RossK.

Has anybody else noticed this? I am looking at the circuit design and none of the chips/ICs are specific for Lithium Ion or NiMH or any other battery chemistry. They seem to be general purpose OpAmps, and DC to DC convertor circuits. It looks like the MCU is the primary driver of the charging algorithm.
Would it be in theory possible to design a battery charger that can work with any chemistry(essentially future proof) The software in the MCU can be reflashed/upgraded via a smart phone app or something. In theory is it possible?
I know there are some out there who have hacked the Micro Processor and upgraded firmware.
See the link below:
https://groups.google.com/forum/#!topic/cheali-charger/WkkV64jA56Q

Not cool.

sk2593 · « **Reply #91 on:** January 22, 2016, 04:53:15 pm »

Not following?

Monkeh · « **Reply #92 on:** January 22, 2016, 05:46:49 pm »

Quote from: sk2593 on January 22, 2016, 04:53:15 pm

Not following?

Second accounts are kinda frowned upon: https://www.eevblog.com/forum/crowd-funded-projects/cofounder-needed-for-battery-charger-startup/

Although when it's so obvious...

sk2593 · « **Reply #93 on:** January 22, 2016, 06:32:29 pm »

Can you please explain on the merits of the question? I am not an expert and I don't claim to be. Like everyone else I am trying to learn here. My first account had personal info hence the new account.

samsmock · « **Reply #94 on:** January 26, 2016, 06:46:53 pm »

Sorry to up a semi dead thread.

Not sure why, but my stinking charger smoked.

I attached a pic of it and the part that apparently went. I've looked at the schematics, but I can't seem to find the part that matches. It appears to be one of the mosfets that's placed everywhere on the board.

Can anyone help me figure out what part it is? Or if the other parts that are listed elsewhere are compatible?

The Markings are:

DT4110
DD52M

mikerj · « **Reply #95 on:** January 29, 2016, 10:50:24 am »

It will either be VT13 or VT15 from the original schematic, the switching MOSFETs that form the buck/boost converter. It's not easy to see which one it is from the pic, but should be easy for you to work out. If one side of the MOSFET is connected to ground it's VT15, an N channel device and equivalent to an IRF7413. If one side of the MOFSET connects to the 12v power input, it's a P channel device, and equivalent to IRF7424.

AndreyS · « **Reply #96 on:** June 25, 2017, 08:29:30 pm »

How about showings guts of Turnigy Accucel-6 80W?
They released new version with usb port. I assume MCU is not atmega, hence it should be similar to imax b6 v2. Or it isn't?
Can anybody show its guts?

AndreyS · « **Reply #97 on:** June 25, 2017, 08:37:17 pm »

I searched a lot for differences. Thats what I found:
imax b6 mini. All photos are here in comment section:

imax b6ac. Some photos are here in comment section and some are here
But all what I could find about Accucel 6 80W is this:


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