I have had this hp pavilion x360 for about 2 years now and I've noticed the battery life starting to take a dive. I have already ordered a replacement pack but I just can't bring myself to throwing away a semi decent battery just because. So I had an idea, would it be possible to run the two identical packs in parallel and just make some sort of enclosure for it?

I have some experience with making batteries so here's how I planned to go about it;
I know the battery terminates with some sort of multiple pin connection but If I open up both batteries I will have access to the internal protection board itself. I suspect the board will be in charge of balancing the cells, temperature control, over current protection etc. Assuming I connect up each individual cell to it's respective twin in parallel and remove the secondary battery's circuitry, could that work? I know I would be loosing temperature management (of the external pack) and the capacity readings would be all out of wack, but the cells would balance, I think? I would ensure the cells were at the same voltage before connecting them up but I'm curious as to what other problems I'm not considering.

My biggest fear is that the internal circuit monitors how much current is going into the battery when charging it cuts it off if the number is too high, even if the batteries themselves are not charged yet. Then it might drain the batteries to a dangerously low capacity or something.

So does this idea have potential to make a wicked laptop or a small bonfire?

 

I see you battery is flat ... li pol ... ... I would carefully open it up see how the 3 cells are arranged ... test each cell for capacity , maybe just one has malfunctioned , you could replace the cell/s , it would be cheaper . all sizes are available on eBay ...

You should be able to connect any size you like , the electronics will not know or care , it will just take longer to charge.... If you increase capacity in this way temperature sensors are not so important since each cell will work less hard , discharge and charge at a slower pace keeping cooler .

 

You can't connect lithium batteries in parallel.

 

The individual cells all seem pretty balanced, I would have to pop them out and run some sort of cycle test to check for individual capacity. They seem ok though.

Oz gave me some hope but I don't understand why you would say you can't connect lithium batteries in parallel? Whats the limiting factor, isn't this done all the time?

 

I don't understand why you would say you can't connect lithium batteries in parallel? Whats the limiting factor, isn't this done all the time?

After some further reading, I did find hat lithium cells are commonly used in parallel.
But I'm concerned that connecting different or unmatched cells in parallel could cause a problem, and you definitely don't want a problem with lithium batteries.

 

I did the mod and here are the results if any of you are interested.
https://forum.allaboutcircuits.com/...r-your-struggling-laptop.162456/#post-1423878