EEVblog #751 - How To Debunk A Product (The Batteriser)

[GeorgeOfTheJungle]

If the 15µA quiescent current figure is right, that's 131 mAh per year.

[amspire]

If the 15µA quiescent current figure is right, that's 131 mAh per year.

Which is excellent if you want to power a circuit with a single 2200mAh NiMH battery. Lithium Ion batteries are great, but AA and AAA batteries are better for devices that you want to use for the next 30 years. A chip that has 15uA idle current and that has over 90% efficiency from sub-milliamps to 500mA battery current would make it easy to make devices running of a single AA battery.

A chip that is comparable is the LTC3528 but with a single battery input it is around 80% efficiency, needs a 4.7uH inductor rather then a 2.2uH inductor (2.2 uH is a sweet spot currently for inductor size vs current capability) and has a lower current capability. It also costs about $3 in quantity so it would seem that the Batteroo chip is much cheaper.  When you are talking about a chip that has under half the losses, double the current and under half the price of the best that Linear Technology can do, you are talking about an impressive effort by the Batteroo chip design company.

[Delta]

That does indeed seem an impressive little IC.

But how many of the professional design EEs on here have ever thought "I really need a DC-DC converter that will output between 1.35v - 1.5v with an input down to 0.6v for this project"
I would put my money on zero.

What a waste of effort.

[Fungus]

The fact is they do have an IC, there is nothing in the LT range that comes close,

I'm guessing LT simply haven't made any effort in that voltage range due to lack of demand.

If they can tweak this to output 3.3V or something like that then they might have a product.

[GeorgeOfTheJungle]

The problems of this "invention" IMO are:

1) That it cuts your power supply from 100% straight to 0 without notice.
2) That you no longer can know how much juice there's left in your batteries.
3) For not much gain in total mAh (minus those 131mAh per year) as you can see in the discharge curve of a batt.

[Fungus]

The problems of this "invention" IMO are:

1) That it cuts your power supply from 100% straight to 0 without notice.
2) That you no longer can know how much juice there's left in your batteries.

Not true. The output actually goes down from 1.5V to 1.3V. If you're designing this into a product then you can have a battery indicator.

3) For not much gain in total mAh (minus those 131mAh per year) as you can see in the discharge curve of a batt.

Even so, if you can get this efficiency with a single AA battery and a higher output voltage then you have a competitive chip.

The Batteroo battery clips are useless, yes.

The Batteroo chip? An interesting design but currently crippled due to the constraints of their useless product.

[PA0PBZ]

The output actually goes down from 1.5V to 1.3V. If you're designing this into a product then you can have a battery indicator.

If you build this into a product you can measure the input, so...

[Hensingler]

I'm guessing LT simply haven't made any effort in that voltage range due to lack of demand.

If there was a valid application for this Batteroo chip it would already have existed. The closest thing with presumed valid application are fixed 1.8v output parts like the chips Batteriser used in their patent applications.

[amspire]

I'm guessing LT simply haven't made any effort in that voltage range due to lack of demand.

If there was a valid application for this Batteroo chip it would already have existed. The closest thing with presumed valid application are fixed 1.8v output parts like the chips Batteriser used in their patent applications.

Removing the Batteroo's optimisation for its battery cell boosting role from this chip would not be hard, and then you end up with a chip that outperforms anything TI, LT, AD, ST, Microchip and Maxim can currently make. To say that a company like LT doesn't make their chips better because people like spending over 3 times the money for a lower efficiency and lower capacity chip that needs a bigger and more expensive inductor does not even begin to make sense.

It would seem that these big companies do not make a chip that technology-wise is as good as the Batteroo is probably - they can't right now. Whoever designed the chip is very talented and skilled.

Batteroo's chip decreases the output as the battery voltage decreases - that will just be the wiring if the feedback resistors. The Batteroo chip lets the output voltage drop by 100 to 200mV in burst mode - that will be resistors setting the hysteresis of a comparitor. The Batteroo chip has two parallel supplies - it would be dead easy to make a lower power chip that only has one supply. Whatever company owns the design of this chip is sitting on something that is valuable and is most definitely very useful.

[bktemp]

I'm guessing LT simply haven't made any effort in that voltage range due to lack of demand.

If there was a valid application for this Batteroo chip it would already have existed. The closest thing with presumed valid application are fixed 1.8v output parts like the chips Batteriser used in their patent applications.

Removing the Batteroo's optimisation for its battery cell boosting role from this chip would not be hard, and then you end up with a chip that outperforms anything TI, LT, AD, ST, Microchip and Maxim can currently make. To say that a company like LT doesn't make their chips better because people like spending over 3 times the money for a lower efficiency and lower capacity chip that needs a bigger and more expensive inductor does not even begin to make sense.

The high efficency is probably because of the agressive burst mode:
Unlike most other converters, the Batteriser stepup seems to run at a fixed duty cycle (or maybe fixed peak current) regardless of the load current. When the target voltage is reached, it shuts down until a much lower threshold. This results in a rather large output voltage ripple. Most other manufacturers instead try to keep the the ripple in PFM/burst mode to an acceptable limit.
The ic may have a high efficency, but 1.5V output voltage with a rather large, load dependend ripple makes ist useless for most applications using the voltage for some analogue circuits.

[GeorgeOfTheJungle]

The high efficency is probably because of the agressive burst mode:
Unlike most other converters, the Batteriser stepup seems to run at a fixed duty cycle (or maybe fixed peak current) regardless of the load current. When the target voltage is reached, it shuts down until a much lower threshold. This results in a rather large output voltage ripple. Most other manufacturers instead try to keep the the ripple in PFM/burst mode to an acceptable limit.
The ic may have a high efficency, but 1.5V output voltage with a rather large, load dependend ripple makes ist useless for most applications using the voltage for some analogue circuits.

That would be a good topic for another EEVblog vidjeo.

[Fungus]

The high efficency is probably because of the agressive burst mode:
Unlike most other converters, the Batteriser stepup seems to run at a fixed duty cycle (or maybe fixed peak current) regardless of the load current. When the target voltage is reached, it shuts down until a much lower threshold. This results in a rather large output voltage ripple. Most other manufacturers instead try to keep the the ripple in PFM/burst mode to an acceptable limit.
The ic may have a high efficency, but 1.5V output voltage with a rather large, load dependend ripple makes ist useless for most applications using the voltage for some analogue circuits.

That would be a good topic for another EEVblog vidjeo.

Yep. There might be another Batteroo video after all....

[amspire]

I'm guessing LT simply haven't made any effort in that voltage range due to lack of demand.

If there was a valid application for this Batteroo chip it would already have existed. The closest thing with presumed valid application are fixed 1.8v output parts like the chips Batteriser used in their patent applications.

Removing the Batteroo's optimisation for its battery cell boosting role from this chip would not be hard, and then you end up with a chip that outperforms anything TI, LT, AD, ST, Microchip and Maxim can currently make. To say that a company like LT doesn't make their chips better because people like spending over 3 times the money for a lower efficiency and lower capacity chip that needs a bigger and more expensive inductor does not even begin to make sense.

The high efficency is probably because of the agressive burst mode:
Unlike most other converters, the Batteriser stepup seems to run at a fixed duty cycle (or maybe fixed peak current) regardless of the load current. When the target voltage is reached, it shuts down until a much lower threshold. This results in a rather large output voltage ripple. Most other manufacturers instead try to keep the the ripple in PFM/burst mode to an acceptable limit.
The ic may have a high efficency, but 1.5V output voltage with a rather large, load dependend ripple makes ist useless for most applications using the voltage for some analogue circuits.

Batteroo claim the BTR004 is a PWM device and I would be amazed if this were not the case. Trouble is, the PWM mode would only work between 100% load and about 10% load and we do not know what 10% load is because I don't believe anyone has tried to test for a 100% load at various battery voltages.

What the chip does seem to have is far superior switching devices to all the other big companies. I have no idea if they use an internal boost converter to provide extra bias voltage for a gate drive, whether they have mosfets that turn fully on at 0.6V, or whether they are using super beta transistors for switching, but whatever they are doing, they seem to get better efficiencies at low battery voltages then the competitors in spite of running at a fast 1.4MHz clock rate.

After some initial characterizing of this device, everyone got bored and stopped testing the chip. A pity as the details could be quite interesting.

The aggressive burst mode is because they can with devices designed for batteries, and the fact that there is a cost to each burst in that when the burst ceases, they switch a resistor across the battery for a period to dampen ringing. This is pure resistive loss, so they will have done everything they can to maximize the burst period.

Do other manufacturer switch burst mode have this resistor? I haven't looked, but the Batteroo may have a particular problem in that the clip forms a nice rf loop with the battery.

Some of the things I do not recall being tested in this forum include:

• Max output current vs battery voltage
• Burst mode vs voltage - is there a voltage at which burst mode ceases?
• Temperature vs load (using the reverse substrate diode as a temperature sensor).
  
• Is the chip thermally protected?
• Reverse substrate diode temperature versus current (since when a batteroo turns off in a multi battery device, current passes through the reverse substrate diode and it is near impossible to thermally protect it)
• Can it switch on under full load? (The way the Batteroo is used, the device usually switches on at no load)
  
• What is the minumum startup voltage?
• Efficiency vs battery voltage for a full sweep of load current from microamps to 100% load. (Would be a big task)
• Does the device latch up if battery voltage is applied as the substrate diode is conducting in a reverse direction?
• Switching resistance (by measuring the coil to -ve voltage when the coil switch is on) at different batt. voltages.
• In burst mode, does the pulse width vary with battery voltage?
• For the AA cell (that has 2 inductors), is it running as a 2 phase converter?
• RF radiation

On the Batteroo technology page, they claim the Batteroo can switch on at 0.6V I think, but I assume they mean that as long as the device is on, burst mode can still work fine from 0.6V. If it did actually turn on at 0.6V, that would be impressive.

Doing all these tests would be a massive job, so I cannot blame anyone for not bothering. Batteroo has always gone out of its way to avoid specifications. The point is that technically, the Batteroo is a pretty decent effort. That means that there was some excellent engineering work done. Doesn't stop the final product from being mostly useless and unnecessary.

[forrestc]

It would be great to have a version of this same chip with a higher output voltage. Something that could run down to 0.6v and could step it up to 3.3v or 5V at over 200mA, and yet only consume 15uA when there is no load. That would allow the battery to be permanently connected to the converter, and it would not need to be switched off. The 5V circuit will have its 5V continuously, so it can have conventional soft power ON.OFF switching. It would not be technical difficult (unless the chip is designed for under 3.3V maximum - which it might be to maximize efficiency). If Batteroo, or the company who designed this chip released a higher output voltage version, it would probably have better specs then anything else on the market. We have no idea about issues such as reliability.

The part you're looking for is a MCP1640.   I agree with many who say that the best kept secret of the Microchip  (of PIC processor fame) is the strength of their analog product line.

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.  Not quite as good but close.  There's also a cheaper 175mA version...

Edit:  Looks like the MCP1640 is specced at 800mA typical 'input current limit'.  Which means that at as an example 1.2V in, you'll only get 100mA at 3.3V. 

[amspire]

The part you're looking for is a MCP1640.   I agree with many who say that the best kept secret of the Microchip  (of PIC processor fame) is the strength of their analog product line.

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.  Not quite as good but close.  There's also a cheaper 175mA version...

Edit:  Looks like the MCP1640 is specced at 800mA typical 'input current limit'.  Which means that at as an example 1.2V in, you'll only get 100mA at 3.3V.

I will get some to try them. It is 500KHz and with a single NiMH, it is pushing it at 100mA 5V output, but that is fine for Arduino-type projects. About 60c price. Idling, it will use about 25% of a NiMH battery in two years - that is about as good as I really need. Efficiency is 50% to about 83%.

If you only need about 20mA output (from a 0.9V flat AA cell) or up to 200mA with two AA cells, chips like the AIT 7350 and the Seiko S-8354 have been around for over a decade and work very well. They get better efficiency them the Microchip part. I think this $1 board has either the AIT of Seiko chip, but I couldn't work out the SMD code (E5 OD). Idle current is pretty good.

This board I believe has an AIT type IC. http://www.ebay.com.au/itm/DC-DC-Adjustable-Boost-Converter-Power-Module-Step-up-Modules-500mA-Green-/401156413129

Looks like there is a shortage of brand new designs - perhaps when it comes to switching converters, designers like the tried and true chips they have been using for years.

[Brumby]

To me it is no surprise that a chip such as the BTR004 has not been done before.

The requirements have dictated a narrower area of operation than how a general purpose chip would have been designed - and I feel these conditions allowed for improvements in other areas, such as efficiency.

Herein lies the fundamental reason why no such chip had been produced before.  Aside from some obscure
situation, the application could only ever be for a single cell booster, which puts it straight into the 'let's suck as much as we can from a battery" arena.  Some quick assessment of batteries and battery operated devices would have shown this really didn't make a lot of sense.  Sure, the converter could do the job, but was it a job worth doing?

It took Batteroo and crowd funding to take a shot at it.

[janekm]

To me it is no surprise that a chip such as the BTR004 has not been done before.

The requirements have dictated a narrower area of operation than how a general purpose chip would have been designed - and I feel these conditions allowed for improvements in other areas, such as efficiency.

Herein lies the fundamental reason why no such chip had been produced before.  Aside from some obscure
situation, the application could only ever be for a single cell booster, which puts it straight into the 'let's suck as much as we can from a battery" arena.  Some quick assessment of batteries and battery operated devices would have shown this really didn't make a lot of sense.  Sure, the converter could do the job, but was it a job worth doing?

It took Batteroo and crowd funding to take a shot at it.

Perhaps (back in speculation-land, sorry, it's just too much fun to speculate  ), this is how FitiPower got the job.

Batteroo:
Can you make us a chip that can draw 2A from a dead battery?
LT: Eh... You do realise that the internal resistance of the battery will too high to draw 2A once the battery has been discharged that much, right? Also it'll cost $300k
Exar: Eh... You do realise that the internal resistance of the battery will too high to draw 2A once the battery has been discharged that much, right? Also it'll cost $200k
FitiPower: We can make you chip that draws 2A from low impedance power supply at 0.6V. It will cost $100k and will be done in 1 month.
Batteroo: FitiPower, you got the job!

(1 month later)
Batteroo: FitiPower, where's our chip, we promised everyone we will deliver the Batteriser next week?
FitiPower: We have taped out in one month as promised, prototypes will be back from the fab in 3 months, mass production in 6 months

[amyk]

The IC Batteroo is using does seem to be a customised IC with the internal fixed voltage divider for the 1.5V output. If it is a custom IC, there is no need for any proper datasheet to be made. To have a block diagram for the Batteroo webpage, someone might take an old datasheet for a similar chip and edit it.

And so what if the block diagram shows two outputs from the driver blocks? That is completely fine. If you use a triangle, that is what is going to happen, and it is just a block diagram. As a block diagram, it is as informative as many other block diagrams I have seen in professionally produced datasheets.

Look carefully. What I'm saying is that it seems someone took the FP6711 revision 1.0 datasheet (which Fitipower themselves don't even have on their website anymore) and used an image editor on it, badly. The wire jumps (not there in the original block diagram) are assymetrical. Lines don't butt correctly. The output of the Error Amp, which is missing an input, is the most ridiculous example of this. If it was based on the FP6711, wouldn't Fitipower or Batteroo have access to the actual "source" document the datasheet was created with, and the actual schematic files, etc.? If it wasn't, surely they'd have something better they could use, even if it's an internal document they might have to redact parts of? It would take far less time and look much more reasonable to use a schematic editor (does anyone on their team even know how to use one...? ) to draw the BTR004 schematic consisting of 5 parts, than try to edit an existing image of a schematic.

I also just noticed the block diagram has an oddly-coloured 1-pixel line on the left and bottom, and what appears to be a band/gradient around the borders. That's... a screenshot. Because Fitipower's PDFs have that trivial-to-circumvent "do not copy" DRM bit set.

I don't doubt that they have a working boost IC. I am just completely puzzled by how they're doing it. Maybe I should ask Fitipower...

[Someone]

Some of the things I do not recall being tested in this forum include:

• Max output current vs battery voltage
• Burst mode vs voltage - is there a voltage at which burst mode ceases?
• Temperature vs load (using the reverse substrate diode as a temperature sensor).
  
• Is the chip thermally protected?
• Reverse substrate diode temperature versus current (since when a batteroo turns off in a multi battery device, current passes through the reverse substrate diode and it is near impossible to thermally protect it)
• Can it switch on under full load? (The way the Batteroo is used, the device usually switches on at no load)
  
• What is the minumum startup voltage?
• Efficiency vs battery voltage for a full sweep of load current from microamps to 100% load. (Would be a big task)
• Does the device latch up if battery voltage is applied as the substrate diode is conducting in a reverse direction?
• Switching resistance (by measuring the coil to -ve voltage when the coil switch is on) at different batt. voltages.
• In burst mode, does the pulse width vary with battery voltage?
• For the AA cell (that has 2 inductors), is it running as a 2 phase converter?
• RF radiation

On the Batteroo technology page, they claim the Batteroo can switch on at 0.6V I think, but I assume they mean that as long as the device is on, burst mode can still work fine from 0.6V. If it did actually turn on at 0.6V, that would be impressive.

Doing all these tests would be a massive job, so I cannot blame anyone for not bothering.

Most of it is pretty easy when you have the right tools, for instance:

Efficiency vs battery voltage for a full sweep of load current from microamps to 100% load. (Would be a big task)

With a multi channel SMU this is entirely automated and then collects a lot of other data (including some of those on your list) when you can interpret it well 

[bktemp]

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.

You have fallen in the common trap: Never stop reading at the first page of a datasheet.
If you look a the footnotes of the specs it tells you the actual truth:
"IQ is measured from VOUT; VIN quiescent current will vary with boost ratio. VIN quiescent current can be estimated by: (IQPFM * (VOUT/VIN)), (IQPWM * (VOUT/VIN))."

So for 5V out and 1V in, Iq drawn from the battery is around 0.1mA! That is much higher, but still ok for many applications.
MCP1640 is a great ic because it is cheap and works well. I have used it in many projects. Typically I use it as a soft power switch: The on/off button pulls the enable pin high for a short time before the microcontroller takes over. This reduces the current when powered down to around 1uA.
If I need a low power microcontroller powered on permanently, I prefer a 3V source like a CR2032 or 2x AAA batteries without any voltage regulator at all.

Some measurements on the Batteriser have been done in this thread:
https://www.eevblog.com/forum/projects/batteroo-testing/
Based on those measurements and observed waveforms it doesn't look like PWM mode at all to me. Instead the converter seems to keep operating in burst/PFM mode over the full load range.

[amspire]

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.

You have fallen in the common trap: Never stop reading at the first page of a datasheet.
If you look a the footnotes of the specs it tells you the actual truth:
"IQ is measured from VOUT; VIN quiescent current will vary with boost ratio. VIN quiescent current can be estimated by: (IQPFM * (VOUT/VIN)), (IQPWM * (VOUT/VIN))."

So for 5V out and 1V in, Iq drawn from the battery is around 0.1mA! That is much higher, but still ok for many applications.

If you look at fig 2.1 in the datasheet, it shows that with 1.2V in, 5V out, the quiescent current at 20 degC is just over 20uA. I am hoping it is right. I have ordered some to try. 0.1mA would be pretty pathetic. I did look at Note 3 and it doesn't seem to make much sense. I guess I will find out when I test it.

MCP1640 is a great ic because it is cheap and works well. I have used it in many projects. Typically I use it as a soft power switch: The on/off button pulls the enable pin high for a short time before the microcontroller takes over. This reduces the current when powered down to around 1uA.
If I need a low power microcontroller powered on permanently, I prefer a 3V source like a CR2032 or 2x AAA batteries without any voltage regulator at all.

The main place I want to use the regulators is making small pieces of test gear. From experience, you can keep using gear like this for 20 to 40 years, and that is why I don't want Lithium. Also AA/AAA batteries means if the batteries go flat, you do not have to wait for batteries to recharge. Since devices like this are often used infrequently and often only for short periods, I like the idea of running off one AA battery.

Some measurements on the Batteriser have been done in this thread:
https://www.eevblog.com/forum/projects/batteroo-testing/
Based on those measurements and observed waveforms it doesn't look like PWM mode at all to me. Instead the converter seems to keep operating in burst/PFM mode over the full load range.

If you look at this post from that thread, you will see the sawtooth wave from the burst mode at 100mA. At 500mA, there is no sawtooth. That means at 500mA, it has to be PWM mode.

https://www.eevblog.com/forum/projects/batteroo-testing/msg1101667/#msg1101667

The 1 A waveform just looks crap. Not sure if this is the AAA battery.

[bktemp]

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.

You have fallen in the common trap: Never stop reading at the first page of a datasheet.
If you look a the footnotes of the specs it tells you the actual truth:
"IQ is measured from VOUT; VIN quiescent current will vary with boost ratio. VIN quiescent current can be estimated by: (IQPFM * (VOUT/VIN)), (IQPWM * (VOUT/VIN))."

So for 5V out and 1V in, Iq drawn from the battery is around 0.1mA! That is much higher, but still ok for many applications.

If you look at fig 2.1 in the datasheet, it shows that with 1.2V in, 5V out, the quiescent current at 20 degC is just over 20uA. I am hoping it is right. I have ordered some to try. 0.1mA would be pretty pathetic. I did look at Note 3 and it doesn't seem to make much sense. I guess I will find out when I test it.

Look at the caption below fig 2-1: "FIGURE 2-1: VOUT IQ vs. Ambient Temperature in PFM Mode."
Yes, the marketing departmant achieved their goal: They fooled you to think the ic is much better than it actually is.
Somewhere in the datasheet there is a description of the internal operating mode:
The ic starts up using a free running clock controlling the switching transistor. Once the output voltage is high enough, it switches over to normal operation mode, powering all of the internal functions from the output voltage. Therfore all internal supply currents are sourced from the output voltage. Once the ic is running, the input voltage can go much lower than at startup (0.35V if the output current demand is low).

I did a quick measurement using a MCP1640 and a MCP1640C (both PFM mode) with a 680k/392k voltage divider generating slightly over 3.3V and no output load.
The power consumption is fairly constant around 100uW over the full input voltage range.
This gives an equivalent total current consumption including all losses at Vout of 100uW/3.35V=30uA.

Some measurements on the Batteriser have been done in this thread:
https://www.eevblog.com/forum/projects/batteroo-testing/
Based on those measurements and observed waveforms it doesn't look like PWM mode at all to me. Instead the converter seems to keep operating in burst/PFM mode over the full load range.

If you look at this post from that thread, you will see the sawtooth wave from the burst mode at 100mA. At 500mA, there is no sawtooth. That means at 500mA, it has to be PWM mode.

https://www.eevblog.com/forum/projects/batteroo-testing/msg1101667/#msg1101667

The 1 A waveform just looks crap. Not sure if this is the AAA battery.

It is hard to say if it is really in PWM mode. If you look at the cursor marking the zero load output voltage (at that level the boost converter turns off in burst mode), at 500mA and 1000mA this voltage level is never reached. Maybe the ic operates at full duty cycle barely reaching the nominal 1.27V. At 1000mA it does not reach the target voltage at all.
The AAA batteriser uses only a single step up while the AA batteriser uses both channels in an interleaved mode.

[amspire]

Look at the caption below fig 2-1: "FIGURE 2-1: VOUT IQ vs. Ambient Temperature in PFM Mode."
Yes, the marketing departmant achieved their goal: They fooled you to think the ic is much better than it actually is.
Somewhere in the datasheet there is a description of the internal operating mode:
The ic starts up using a free running clock controlling the switching transistor. Once the output voltage is high enough, it switches over to normal operation mode, powering all of the internal functions from the output voltage. Therfore all internal supply currents are sourced from the output voltage. Once the ic is running, the input voltage can go much lower than at startup (0.35V if the output current demand is low).

Ah! you are right. The only figure you need to know is the input quiescent, but they give a graph of the quiescent current drawn from the output if you apply a voltage to the output greater then the regulated voltage.

They got me! 

That does make the PFM mode of this chip pretty bad.

At least it does have a chip enable, and it does (I hope) reduce the quiescent current down to about 1uA.

[forrestc]

The MCP1640 has 19uA Quiescent current, operating voltage down to 0.65V, 1000mA current.

You have fallen in the common trap: Never stop reading at the first page of a datasheet.

Yeah, I posted, and about 5 minutes later saw what I had done. 

I use the MCP1640 in various applications where the iQ when on isn't that important - usually it's shut down when idle which has a very low current.   I'm also typically stepping up from a pair of cells (2.4V) to 3.3V so the efficiency is better.   I went and re-glanced at it and fell for the marketing drivel since I know how good it is in my applications.   Still, a very decent part for single-cell and 2-NiMH applications.

[Luminax]

It would seem odd if Fitipower were the designers of the BTR004... If you're Batteroo, would you pick an IC designer that noone has ever heard of, for your one shot at getting the custom IC that you need for your "world-changing invention"?

Would you put one over that Battero will not just do exactly that?
After all if their goal was really getting a proper custom IC for their 'world-changing invention' instead of the scamming merry-go-round that they took us and their investors on, they would've heed Dave's advice way back when... that it's just not feasible?

I don't understand this current wave of conspiracy theories. Yes, obviously Batteroo is marketing their product with wildly inflated claims, and is probably using dishonest marketing methods like bought votes and "customer" statements. There are many good reasons to distrust them.

But the battery sleeves are working boost converters, right? They are apparently designed around a custom IC which is made by an OEM who has a track record in boost converter ICs. Where's the problem here? Again, the claimed benefits are wildly inflated, but why would the miniaturized boost converter itself be "not feasible"?

Time to move on and let Batteroo fade away in silence, I'd say...

I guess I either have misworded my reply, or you have misunderstood it, either way I would like to make a few of my points clear :

1) Nobody who have followed this thread from the start has ever doubted, even in the slightest, that the product will work as a boost converter
2) The 'not feasible' in my statement above refers to batteroo as a whole that, while the idea of making that small of a boost converter is probably good and novel, is not really practical due to space restriction, most devices already have their own boost converter, et cetera, et cetera. Hence the feasibility here refers to batteroo as a whole.
3) I would like to not be lumped with conspiracy theorist, kthx. I'm sure everybody by know realized that they ARE scamming, and I dutifully challenge anyone not thinking so.
4) If the conspiracy is concerning Fitipower, what I'm trying to say is that, it's not below the Batteroo corps to utilize a no-name IC company if it achieves their goal, mainly try to spend as little and get as much money in as possible.