The BM235 does not accept lithium batteries

[IanB]

On power up the display says "Inp Err" and then flickers and beeps continously.

Well, that sucks.

(Note: two fresh alkalines at 1.6 V each are OK, but two fresh lithiums at 1.8 V each are obviously too much for it.)

[Muttley Snickers]

I just tested mine a number of times with 2 AA Energizer Ultimate Lithiums temporarily hooked in and also got the InEr message momentarily with a series of beeps and then the meter simply returned to normal operation, both the batteries were at 1.798 prior to testing.

Both of my good variable power supplies are in bits at the moment, perhaps you could run it on a supply and check at what voltage this starts to occur. 
 

[EEVblog]

Reply from Brymen:

I was talking to engineer and was advised that BM235 battery voltage can not be more than 3.5V out of its current design. The reasons are:
 
1. Input warning detection uses a comparator inside main chip. While A or mA/uA input terminal is without being plugged-in by test lead, the compared signals are from battery voltage and from a fixed voltage around 3.6V. If battery voltage is more than 3.5V, that comparator may misjudge and display “InEr”.
 
2. The maximum working voltage of BM235 main chip can be only 3.6V.   
 

[alanb]

Ian - Energiser were trying to help you by supplying alkaline rather than lithium! https://www.eevblog.com/forum/chat/annoying-energizer-marketing-scam/msg1031514/#msg1031514

[joeqsmith]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

[TheBay]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

I think this will get lost on some here mate

[2N3055]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

Don't switch it on! Blow it up!!

[rstofer]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

I think this will get lost on some here mate

You mean he really didn't do that?  Hm...  Lost on me!

It sounded like a neat way to get a bench meter without all the cost.

[joeqsmith]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

I think this will get lost on some here mate

You mean he really didn't do that?  Hm...  Lost on me!

It sounded like a neat way to get a bench meter without all the cost.

I read on the internet that batteries are DC and the wall outlet is AC and to convert from AC to DC I needed something called a diode.  I drove to Radio Shack and the guy there looked at me funny but sold me one that's good for 4A.  I stuck it in line with the cord but the meter still won't turn on.   Before you ask, I tried the diode both ways.  It just doesn't seem to work.  I'm running out of things to try. 

I have attached a couple of pictures showing how it is setup.  My soldering seems fine and looks to be making a connection.   

[RGB255_0_0]

On the meter it says CAT IV 300V, so maybe it needs 300V?

[whitevamp]

On the meter it says CAT IV 300V, so maybe it needs 300V?

I read on the internet that there is a cat IV telephone networks cable is this what i need? and will it work to 300v?

[joeqsmith]

On the meter it says CAT IV 300V, so maybe it needs 300V?

I think you are onto something.   I am pretty sure it has something to do with the voltage going in.  I read a little more on the internet and they use something called a capacitor to smooth out the rectified DC.  I could not figure out what it would need so I went back to Radio Shack and found a capacitor that is about the same size as the two AA batteries that came with the meter.   The guy at Radio Shack was no help.  Don't they train these people?

Soldered the cap in there but when I plugged it in, the capacitor blew out a bunch of confetti paper.  I think it was a Chinese knock off.   

[sotos]

On the meter it says CAT IV 300V, so maybe it needs 300V?

I think you are onto something.   I am pretty sure it has something to do with the voltage going in.  I read a little more on the internet and they use something called a capacitor to smooth out the rectified DC.  I could not figure out what it would need so I went back to Radio Shack and found a capacitor that is about the same size as the two AA batteries that came with the meter.   The guy at Radio Shack was no help.  Don't they train these people?

Soldered the cap in there but when I plugged it in, the capacitor blew out a bunch of confetti paper.  I think it was a Chinese knock off.

For your soldering, try this tool it's much better than yours.

[Len]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

A pulse generator might work. I don't suppose you happen to have one?

[StuUK]

  thanks for the giggles

[TheBay]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

I think this will get lost on some here mate

You mean he really didn't do that?  Hm...  Lost on me!

It sounded like a neat way to get a bench meter without all the cost.

I read on the internet that batteries are DC and the wall outlet is AC and to convert from AC to DC I needed something called a diode.  I drove to Radio Shack and the guy there looked at me funny but sold me one that's good for 4A.  I stuck it in line with the cord but the meter still won't turn on.   Before you ask, I tried the diode both ways.  It just doesn't seem to work.  I'm running out of things to try. 

I have attached a couple of pictures showing how it is setup.  My soldering seems fine and looks to be making a connection.

You need to swap those fuses for a nail/screw or wrap them in baking foil. It will work then.
See when a fuse goes it's because that's the fault, the fuse. So put a bigger one in or use methods above. This is what I see and what I hear all the time so must be right.

[MosherIV]

Soldered the cap in there but when I plugged it in, the capacitor blew out a bunch of confetti paper.  I think it was a Chinese knock off.

That is because you are doing it wrong. You need a transformer to reduce the voltage. Make sure you get it the right way round 

Alway good following your work joeqsmith 

[Johnny Electron]

So I just tried running the BM235 right off the wall socket to I don't need to change out the batteries and the stupid thing does not work!!  What a POS!!  No fault codes, or anything on the display.   I checked the fuses and they are not blown..     Now what do I do?   Does Dave do repairs on these?

I think this will get lost on some here mate

You mean he really didn't do that?  Hm...  Lost on me!

It sounded like a neat way to get a bench meter without all the cost.

I read on the internet that batteries are DC and the wall outlet is AC and to convert from AC to DC I needed something called a diode.  I drove to Radio Shack and the guy there looked at me funny but sold me one that's good for 4A.  I stuck it in line with the cord but the meter still won't turn on.   Before you ask, I tried the diode both ways.  It just doesn't seem to work.  I'm running out of things to try. 

I have attached a couple of pictures showing how it is setup.  My soldering seems fine and looks to be making a connection.

OMG I can't stop laughing!  Thank you Joe! 

[The Soulman]

I read on the internet that batteries are DC and the wall outlet is AC and to convert from AC to DC I needed something called a diode.  I drove to Radio Shack and the guy there looked at me funny but sold me one that's good for 4A.  I stuck it in line with the cord but the meter still won't turn on.   Before you ask, I tried the diode both ways.  It just doesn't seem to work.  I'm running out of things to try. 

Jeeeez silly people at radioshack, 4A is way to much current for such a meter, better get 33 mA diode. 

*Waning not to be attempted by any noob* 

[Hydrawerk]

WTF

[2N3055]

I think it's about time to issue a warning for those that didn't get so far (and hence never will  ) that this is  satirical topic... LOL...

My favorite is "... Before you ask, I tried the diode both ways. .."  LOLOLOL  Good one ,  Joe!!

[joeqsmith]

    We all laugh and think no one would ever do such a stupid thing but back when I was in school, I had a friend who wanted to use a car stereo in his bedroom (we were not old enough to drive).  He wired up a line cord right to where the battery hooked in.  He had it apart at school to show what had happened.  But to his defense, he never took any courses in electricity (they actually offered this back then) and he did not have a meter of any sort.  He though it was a one size fits all when it came to electricity. 

[IanB]

And meanwhile, BM235 meters everywhere are going to be prematurely ruined by leaking alkaline batteries...

[MacMeter]

Glad I searched before asking if my new EEVBblog BM235 could take 1.8v lithiums. I just tried it, same NG results. I put in some Energizer MAX AAA's, supposedly "leak proof" guaranteed, doubt that means much. While I've read how some poo-poo the idea that alkalines can leak, when you have a remote or other device become ruined because of an inexpensive battery, it's no longer theory, but reality. After a power outage years a go, I was opening all my remotes and other battery devices only to discover a few with old leaking batteries. I can't speak for others, but it then occurred to me how many devices I had put away thinking I'd be using them again, but the years go by quickly. That's when I switched to buying and using all Eneloop rechargeable batteries. Granted, some up front costs, but cheap insurance for many remotes and other devices, some of which are too old to find replacements for.

Very few devices don't care for the lower NiMH lower voltage, and work fine. On those devices I use the more expensive disposable store bought lithiums. Since this meter does not function with those, the QUESTION is now:

Are there any downsides to using NiMH rechargeable AAA's in this meter?

[IanB]

I haven't tried it, but if it works I can't think of any reason why not.

[MacMeter]

I haven't tried it, but if it works I can't think of any reason why not.

Thanks, I just want to avoid the inevitable leaking battery. After my bad past experiences I avoid alkaline batteries like the plague!

[mtdoc]

To get it to work with lithium batteries you just need to use a reverse batteriser.

[kcbrown]

I'm just glad Joe clued us in on the meter not working directly from the mains.  It was going to be the first thing I tried ...

 

[MacMeter]

To get it to work with lithium batteries you just need to use a reverse batteriser.

I caught up on most of the "batteriser" videos, what a nightmare, though highly entertaining and educational. There was one poster that in their opinion Dave might be a bit harsh, but considering not every potential buyer of those devices is not reading this forum, I think it's a great public service. If you are making outrageous claims for a product, you have to back them up, or face the music, and maybe get BUSTED! That's part of Daves appeal, I'm sure I would have bailed out on that stuff, far earlier, but to Daves credit, he pounds them for FALSE advertising and bogus claims, we need more of that for all products these days.

[texaspyro]

What I have done in such cases is to install a series schottky or even germanium diode in series with the lithium cells.   I used some very thin double sided copper foil strips (from old Aerotech "copperhead" rocket igniters).  Solder diode to each side of the copper strip and slip it between a battery terminal and the battery contact.  Tuck the diode in whatever nook or cranny you can find in the battery compartment.

The Copperhead igniters (aka crapperheads) used a conductive pyrogen.  One end of the strip was dipped into the pyrogen and the other end clipped to the launch controller using a clothes pin like thingy.  One major problem was when they sheared the strips off a larger sheet you often got short circuits along the shear.   I've also used the strips to insert things like current meters between various spring loaded connectors (like cell phone batteries).

[rstofer]

I haven't tried it, but if it works I can't think of any reason why not.

I wonder if the low battery voltage detection of 2.5V will get in the way.
Spec is in User Manual...

[IanB]

I wonder if the low battery voltage detection of 2.5V will get in the way.
Spec is in User Manual...

It doesn't seem to be an issue. I tested it with a pair of completely discharged* NiMH cells and even with the low battery indicator showing the meter still read accurately on voltage, resistance and diode test ranges, even with the back light on.

* I discharged the cells individually to the point that a 10 ohm load caused the cell voltage to drop below 0.35 V

[MacMeter]

That's an ideal "IanB", I could try running the new 1.8v Lithium AAA's down in a flashlight to maybe 1.6v to get to the under load limit of 3.0 volts. Or just go with the NiMH black Eneloops

[IanB]

Note that the low battery indicator doesn't show up if the cells are charged, so I think regular Eneloops will work fine. White Eneloops will be better than black Eneloops for low drain applications like this.

[MacMeter]

Note that the low battery indicator doesn't show up if the cells are charged, so I think regular Eneloops will work fine. White Eneloops will be better than black Eneloops for low drain applications like this.

Thanks, I have a bunch more of the white Eneloops, so I'll use those!

[Dan666]

Hi,
I'm new to the forum, but I've been following the eevblog YT channel lately, and that sparked an interest in electronics in me.
I used to have a cheap MultiMeter (actually I still have it) which I replaced with a Brymen 235 after discovering about it from eevblog itself.
As I'm trying to get rid of non-rechargeable batteries in my electronic devices, also because I fear leakage as someone suggested already, I'm using two Eneloop AAA batteries in my BM2335.
Today I was toying around with the EF functionality and from time to time the battery symbol appeared. It sounded strange to me that the batteries were already low, so I discharged them in the charger, and they still had ~630mAh (on a max of 750mAh).

I don't know if it's a quirk happening on the EF mode or what... my question, finally, is the following:

Is it OK to use rechargeable batteries with the Brymen 235 ?

cheers,
Danilo

[rstofer]

You should probably read through this thread where the battery issue is discussed at length.  The BM235 is very picky about battery chemistry (voltage).

The right answer, of course, is to read the manual and follow along.  In other words,

Batteries:
1.5V AAA Size battery x 2
240 hours continuous on Alkaline
NOTE: Lithium AAA's may need to be drained a small amount before use to drop the
initial terminal voltage.

Page 18 of the manual I downloaded from Dave's store:
http://www.eevblog.com/files/BM235-Manual-EEVblog.pdf

[Dan666]

You should probably read through this thread where the battery issue is discussed at length.  The BM235 is very picky about battery chemistry (voltage).

But I've read this thread, that's why I replied to it... You were talking about higher than expected voltage batteries, whereas a ni-mh is a bit lower but still within the range of voltage a non-rechargeable battery can provide.
Of course basically I don't know much about electronics, so if my questions seem stupid, it's because I still have much to learn...

The right answer, of course, is to read the manual and follow along.  In other words,

Batteries:
1.5V AAA Size battery x 2
240 hours continuous on Alkaline
NOTE: Lithium AAA's may need to be drained a small amount before use to drop the
initial terminal voltage.

Page 18 of the manual I downloaded from Dave's store:
http://www.eevblog.com/files/BM235-Manual-EEVblog.pdf

Yes, the non-eevblog (the one I have) one comes with the paper manual, which I've read thoroughly more than once, including the part about batteries, which BTW is a bit different, no words about lithium batteries or hours of usage.
It doesn't say anything about rechargeable batteries, but it says:

Low Battery: Below approx 2.5

which means that a ni-mh will be shown as low quite early.
I just wonder if the readings are still within specs in a low battery scenario...

[IanB]

I think Eneloops should work OK with the BM235, but I have not done extensive testing with my own meter. If you wait until this evening, I will have a chance to do a few experiments and report back.

[Dan666]

I think Eneloops should work OK with the BM235, but I have not done extensive testing with my own meter. If you wait until this evening, I will have a chance to do a few experiments and report back.

Well thanks!
In any case, the first thing I did after having received the meter was swap out the batteries for the eneloop, so I know it works with them, I just wonder if they fall short on duration and/or if its measurement are off when the batteries are low (which in case of the eneloop would be when the batteries are still quite full)

Nonetheless, this is a very nice meter, and if I compare it with the the other crappy one I have, it's light years ahead of it!

ciao,
Danilo

[MacMeter]

You should probably read through this thread where the battery issue is discussed at length.  The BM235 is very picky about battery chemistry (voltage).

But I've read this thread, that's why I replied to it... You were talking about higher than expected voltage batteries, whereas a ni-mh is a bit lower but still within the range of voltage a non-rechargeable battery can provide.
Of course basically I don't know much about electronics, so if my questions seem stupid, it's because I still have much to learn...

The right answer, of course, is to read the manual and follow along.  In other words,

Batteries:
1.5V AAA Size battery x 2
240 hours continuous on Alkaline
NOTE: Lithium AAA's may need to be drained a small amount before use to drop the
initial terminal voltage.

Page 18 of the manual I downloaded from Dave's store:
http://www.eevblog.com/files/BM235-Manual-EEVblog.pdf

Yes, the non-eevblog (the one I have) one comes with the paper manual, which I've read thoroughly more than once, including the part about batteries, which BTW is a bit different, no words about lithium batteries or hours of usage.
It doesn't say anything about rechargeable batteries, but it says:

Low Battery: Below approx 2.5

which means that a ni-mh will be shown as low quite early.
I just wonder if the readings are still within specs in a low battery scenario...

Bear in mind, Dave updates his online version of the manual, when he is alerted to any new info supplied to him, as well as what newer versions of the firmware may have fixed or changed. Unfortunately, you are stuck with whatever the firmware is that's currently on the meter when you buy it, as it's not user updatable. I have not switched to NiMH batteries yet, so I can't help there, and I may end up preferring to drain down some primary lithiums as an alternative. I do agree however with concerns over alkalines leaking, no matter the supposed expiration dates or brands, as it's hard to differentiate these days between clones and fakes. Every device in my house is either lithiums or NiMH, as I've experienced and lost devices that had bad leaking batteries. Shame the BM235 can't handle off the shelf AAA lithiums at 1.8 volts, but it's a fine meter.

[sequoia]

You should probably read through this thread where the battery issue is discussed at length.  The BM235 is very picky about battery chemistry (voltage).

The right answer, of course, is to read the manual and follow along.  In other words,

Batteries:
1.5V AAA Size battery x 2
240 hours continuous on Alkaline
NOTE: Lithium AAA's may need to be drained a small amount before use to drop the
initial terminal voltage.

Page 18 of the manual I downloaded from Dave's store:
http://www.eevblog.com/files/BM235-Manual-EEVblog.pdf

Just got low battery warning on my (EEVblog) BM235, so decided to try some Energizer Lithium cells on it.

I discharged each battery first for 10 mAh @ 100mA (360 seconds), then checked voltage after an hour or so and it was ~ 1.65V.

Not sure how Lithium batteries behave (?), have to see if battery voltage will creep up slowly enough to trigger the overvoltage after few days....

[MWisBest]

Just got low battery warning on my (EEVblog) BM235, so decided to try some Energizer Lithium cells on it.

I discharged each battery first for 10 mAh @ 100mA (360 seconds), then checked voltage after an hour or so and it was ~ 1.65V.

Not sure how Lithium batteries behave (?), have to see if battery voltage will creep up slowly enough to trigger the overvoltage after few days....

Once they're drained even slightly from a fresh pack they should be fine. I drained a pair at ~2mA for 5 minutes, they've sat at 1.7V for days since.