Hello everyone, i'm new here, first post Hope i'm not doing it wrong, and yes i did use the search function first

So my "problem" and help request is to take the working battery from HTC One mini 2 (broken screen), and put it into a working HTC One mini 1 that has a dead battery. Yes i know for 20$ i can get a replacement... but why pay when you can have fun for free? hahaha

What i know:
The batteries are same physical size, actually the mini 2 is 1mm smaller in thickness if i remember right.
The connectors themselves are not the same. So no easy swap.
Mini 1 battery is 1800mAh, Mini 2 battery is 2100mAh.
Both batteries have a + and - tab that goes to the "charging board?" and they are at equal distance.

What i don't know:
Mostly everything advanced about batteries, volts, mAh, charging boards (BMS?) and so on.

So my questions are:
1. Can i take the "charging board" from the mini 1 battery 1800mAh, and put it on the mini 2 battery 2100mAh? Will it charge it full or stop when it hits 1800mAh? Or will it just not charge because it doesn't recognize the battery?
2. Or should (could) i unsolder the ribbon with the connector, from Mini 1 battery board and do a wiring (since pins are inverted on mini 1 from mini 2 and thus connector would be upside down) to solder it to the mini 2 board?

Simplified questions:
1. Will the board from the mini 1 1800mAh battery, recognize and fully charge the mini 2 2100mAh battery if i swap the boards?
2. Will the mini 2 board and battery work in the mini 1 phone if i swap the connectors?

What would be the "safest", and would there be any difference?

Heads up: The mini 1 is known to have the battery die (shuts down with 40% battery left) i'm wondering if it's because of the "charging board" (BMS?) And therefore wouldn't it be better to use the board from the mini 2 which seems to not really have issues over time (mini 2 has been used 2 months before screen broke) if that is possible of course? There is written V01 on the mini 1 board, and V02 on mini 2 board. Updated board? doesn't kill the battery?

If you need more pictures or close ups on the chips i can try and take some and post.

Hope someone can help Hope it all makes sense otherwise ask me anything and i'll try to answer.

Images:

Mini 2 and mini 1 connector side by side.

Side by side comparison with text on both batteries facing up on top 4 pics, 2 lower pics are both from backside.

"Pinouts" from board to connector.

 

The chances are the charger pcb won't charge to fully capacity using a different mAh battery, as the algorithm will be wrong. I would swap the cells over to your desired design and see what happens...

 

The chances are the charger pcb won't charge to fully capacity using a different mAh battery, as the algorithm will be wrong. I would swap the cells over to your desired design and see what happens...

I wouldn't bet against that but if both batteries have the same number of cells and chemistry, then the terminal voltage is how the charger determines cut off. There is a chance that it will be ok.

 

Thanks for the fast replies

So if i understand it right, the best chance to get it to work would be to not switch the boards, but just switch the connectors?

So the 2100mAh battery still has the original "charger board" and thus will most likely fully charge?

 

Small update... My soldering iron died. Soo i might just buy a new phone and then fix this one when i buy a new soldering iron.

Any help is still appreciated. If any one can explain more in detail why one thing or the other would or wouldn't work it would be nice

I'll post an update when i get to work on it again in case any one else can use this info

 

Keep the original charge pcb and fit the bigger capacity maH battery to it,..