Friend of mine at work gave me a dead Tenergy 8000 mAh power pack, one of those battery charging units with USB ports.
The PCB is dead but the battery is good. Its a flat rectangular "Prismatic" Lipo, really 2 of them in parallel, about 65mm by 80mm by 12mm. It has a number 666483. After some searching I found this part number at Howell Energy Co. These are 4500 mAh each.
I'm trying to figure out what to do with these bad boys.
I looked at FastTech for cases and PCBs. There is one pair that might work to make a new charging pack (SKU 1434420 and 1323113) but I am not sure this will fit. FT doesn't say what batteries the case works for. In fact they have quite a few cases and PCBs that aren't matched well and the batteries aren't identified.
Any other good sources for similar DIY cased and PCBs? Or any other ideas?
So you have two 4.2V packs but they are glued together and have the mentioned dimensions both together, have I understand this correct?
These power bank circuits are normally made for one cell or some cells in parallel, so you can use one of their circuits in any case which fits, you need only to make holes for charging and discharging sockets….
I am not sure but if these were 9Ah than charging these would take a long time as the most charging circuits seem to charge with less than 1A so it would take more than 9 hours…on the other side you have enough energy for recharging some phones…
Edit: just have looked the one you have mentioned, http://www.fasttech.com/p/1434420 , it says 119x76x21mm this are the outer dimensions and the board has to fit inside too. I would guess your accu will fit it.
Which case is around the cells in stock, maybe you could only replace the electronics…
The two were taped with Kapton tape, which I removed, so they can be separated. The terminals are soldered together though. The case is too far gone to reuse.
I found 4 possible combinations of case/PCB at FT that should work:
SKU 1379400/1323400
SKU 1379502/1323115 (Requires splitting the two batteries, very thin).
SKU 1434420/1323113
SKU 1379501/1323112
And you are right, recharging this pack would take forever, especially if the mini-USB port is used, which I think has a max current of 500mA.
I like the module you found, with the LCD, but I don't see a case that matches. FT isn't good about matching these up.
Yes you are right fasttech doesn’t match these up but I like that they have added these. I like the cases with display, I am not sure for what they are good for but it looks cool…
Mini USB can be used with more than 500mA that is no problem, modern smartphone/tablets have chargers which charge with up to 2A over micro usb.
Why do you always post the skus and not the links? I am lazy…
The cases are indeed nice and have a front plate and they are cheap, but have you thought of using a other box. Maybe some box from sweets or?
If you choose one of the bigger cases, I bet you could also add a led, optics and driver in it…
Whenever I start a new project I create a Word file where I document the ideas, design decisions, math, etc. I put the SKUs in there instead of links, then just copied them here.
One idea is to put the battery in some remote size project box. Possibly add a TP4056 charging circuit, then using it to power something. I suppose I could mount a heatsink on the front, and add a few LEDs with TIR lenses. I sometimes wonder why more flashlights aren't remote shaped rather than round. Any idea what the max current would be from one of these?
Actually I am thinking that with 8 or 9 Ah of power, it might make a good portable bench power supply with CV and CC capability. I'd need to find a buck-boost circuit board that can take a minimum 3V input, and operate at CV or CC. Add some panel meters, banana jacks, and an internal charging circuit and a decent enclosure.
Problem is the minimum voltage is 7V. I suppose I could feed something like this through a boost circuit first, but I'm sure that there is an efficiency penalty.
Edit: I think I could de-solder the terminals and re-wire in series instead of parallel. Then I might want to add a protection circuit. (?)