Review: cheap 18650 mobile power bank

EDC Gear for Flashlight Carriers USB Power Devices
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It’s hard to see in this picture but the white bank with the bad chip is a lighter(newer?) shade of white then the white banks with the good chip. Perhaps this signifies that the bad chips were used in a new batch where there is a slight variation in the plastic used?

(it’s the 1st one on the left.)

here’s a pic of the white bank w/ the bad chip

Man, my batch order contained ~80% of the ones with bad chips. It seems the is much protection PCB soldering onto 18500 cells in my future (I might not even have enough of these.)

Anyway -> for the banks which I will keep for personal use I am contempting whether or not I want to make a notch in the lid (before closing) in order for future cell removal.

On the ones intended for gifts -> I haven’t decided if I want to do this. + Using protected cells in the “bad” chipped ones only partially addresses one of it’s downfalls. I would not use high drain devices on the such as tablets. I fear the drain will be too high for some of the components. Unless one had already ordered these I would recommend getting a different type of power bank. What a hassle.

Heck I might not even gift the ones I have here if the “good” banks still turn out to be junk in repeated usage. I’ll think it over before giving these out.

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I’m awaiting a shipment of five of these as well (from BIC). Did you guys contact them and ask for a compensation?

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I bought another two from another ebay seller.

I got a black and a white one and sadly both contain the FM6316CE-based circuit inside. But something else is different to the one that broke down for me before, they contain SS34 diodes instead of SS24, maybe something else is different too?

Can anyone confirm that the ones with SS34 diodes are also bad for them? (over discharging possible?) If not I will probably just try to use it normally and get a refund if it breaks.

But before really using them I will measure some things before they break again. Maybe just parts of the circuit are missing, as there are quite some free pads on these small boards(?). In my opinion, what also looks suspicious is this 0 ohm resistor.

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I’ll pop mine open tonight and check em out

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My unit (blue from BIC) has ss34. It was overcharging and shorted and burned before I did a discharge test.

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OK, and I also re-read these thread and dchomak’s also did over-discharge, from his pictures he also has SS34….

I will then start experimenting I guess, trying to replace the 000 Ohm (which actually connects the GND of the device) with 1…5 Ohm or something and see what this does, or rather thinking more about what could help….

But I probably should ask for a refund anyway.

The best would be to get the real circuit diagram or board layout of these little CHD-XS V1.1 board / pcb as it might contain some missing parts for these unpopulated soldering pads. Someone good at googling this? Maybe it can be found…

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Just a heads up -> BIC’s CS responded to my partial refund request very promptly & just offered me a refund of more than 50% of my order total (consisting solely of these power banks.)

As this pretty much seemed to be a cut and dry case of this power bank’s manufacturer opting to now produce the units with unsafe chips -> BIC goes on my list for good vendors.

For the record, I am not affiliated with them in any way and I have sent very little $ overall towards their way.

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All 20 of mine arrived today…and all 20 have the 6136 chip. Brilliant. To those who have said they have no overcurrent protection, I shorted a usb cable through my multimeter and it was trying to push 5A. I only wanted to test one but the results were certainly concerning. My Ruinovo 6x-18650 box cuts before the multimeter refreshes past 1.5A, and requires a push of the hardware button to reset the breaker.

Dissappointed

EDIT: Also, no over-charge protection either, I’m filing a dispute with the vendor so I’m sacrificing a laptop pull and I want to see how high it will charge it.

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Hm interesting one of the new FM3616CE based ones (with SS34 diodes in my case versus my previous with SS24) does have the blue led become more and more dim after the battery reached 2,5V. After that with a multimeter I saw it going down to about 2,38V when I disconnected it. By now the cell has recovered to 3,72V (still rising, this was just minutes ago…).

To say something positive, the FM3616CE might actually try to keep the cell at 2,5V, by cutting-off at 2,5V - but with a bad implementation that already begins to discharge again at 2,50…01 V so you could say, disregarding production variance and temperature dependence that maybe means something between 2,45 or 2,55V for that barrier…
Anyway, this would mean, each time the battery goes above 2,5V, it will again be discharged for at least one pulse of the FM3616CE’s internal boost converter, grinding down the battery to a certain voltage, until it won’t even recover to 2,5V anymore! Then it will probably really stop to discharge… but that might maybe be too late for the cell, I know electronics but I am not a battery specialist. Maybe someone else who knows more about batteries can even say that this is perfectly fine? But I am suspecting it is not, as the current will be quite high, for a 5V 1A discharge, this will already mean a cell discharge current of at least 2A, not counting the conversion losses.

To those who don’t know what I mean with “pulse”: The FM3616CE is very probably doing a DC/DC buck conversion for charging and a boost conversion for discharging, these kind of converters have a certain operation frequency in which they operate, for more details, see [1] below - basic electronic understanding is still required though.

In the end:
Maybe (just maybe) this is also just a lack of circuitry and the FM3616CE itself is actually quite good: Some resistors, diodes, capacitors, whatever might be missing…. When looking at the CHD-XS V1.1 circuit board, there are still multiple unpopulated parts and one 0 Ohm resistor. Maybe it would actually work if all/the correct parts would be populated……

Additional Information: I did only check for discharge cut-off doing all this, not for overcurrent protection so far!

Maybe I am experimenting more at another time. This is already over the limit of my time making sense to me (expect if I would buy 100+ and rework them, which I won’t be doing…), at least at the moment it is still fun as a short pastime :wink:

[1] DC-to-DC converter - Wikipedia

EDIT:
Ok I also verified that it is not overcurrent protected at all :-/

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Any way to fit a protected 18650 cell in it ?

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The larger cells with Chinese circuit won’t fit for sure - there isn’t enough space between plastic walls supporting the contacts to fit the cell even without the contacts. I don’t have any smaller protected cell but I don’t think you can make it fit either.

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I got 5 of these, each different color, and ALL have the BAD chip, chinese shit.

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I learned about the “Charger Doctor” and bought one from BIC. Costs $3 and I love it!
Here is the BLF review

And here is the $3 link to BIC

http://www.buyincoins.com/item/34684.html

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Those powerbanks all fail on discharge protection because of a missing IC. This can clearly be seen on the pictures posted by alphazeta.

I have the original schematics/datasheets laying around here somewhere, its a bit of a mess, as they’re all in chinese.

Regards,

doc

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I bought 3 of those:

http://www.ebay.com.au/itm/161228941965

They are also based on the 6316, but have the additional IC (protection IC) equipped. They disconnect at 2.5V and keep the bank disabled until external charging power is connected from the outside.

Regards,

doc

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What is the chip identifying markings (the protection IC)?

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According to the datasheet the protection chip should be DW06D. I have one battery bank from dealextreme which has an FM6316 and a chip marked CT2105 and it cuts off at aroung 2.6 volts.

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Check out the price, then check out the second pic!
On sale!, regular price was $29.99

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Has anyone recently received this (or any) power bank with the ETA9635 good chip?

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Upon seeing this thread i contacted buyincoins a few days ago and they told me that this model is the one with the ETA9635 chip.