Increasing runtime on an electric handwarmer

[dealgrabber2002]

Hello,

I recently purchased an USB hand-warmer for my wife. One came defected due to the USB not working properly but it charges and works well. The company sent me a replacement and told me to keep the defective one. But the battery doesn't last long on these things.

My question is, can I remove the battery from one and stack it on top of the one that's working perfectly. Solder the 2 batteries together, then connect it back to the wires according to - and +, will that increase the runtime?

 

[poguy]

Is it a single cell or multiple cells in series? For a single cell, yes you can put them in parallel.

Multiple cells in series is a bit more complicated.

 

[ChrisGarrett]

If you solder the two cells in parallel, how will you be able to charge them internally, or even externally? The internal charging module is meant for one cell, no?

Chris

 

[dealgrabber2002]

It's a single cell. It's not like the 18650 li-ion. it's somewhat shaped like a pop-tart in a aluminum foil. Wouldn't charging be the same but takes longer to charge due to the increased capacity. Isn't it parallel increases the capacity, while series increase the voltage?

 

[dealgrabber2002]

If you solder the two cells in parallel, how will you be able to charge them internally, or even externally? The internal charging module is meant for one cell, no?

Chris

It has USB output for charging phones and a micro usb port to charge the powerbank itself, so soldering the batteries together will not block the charging port.

 

[ChrisGarrett]

It has USB output for charging phones and a micro usb port to charge the powerbank itself, so soldering the batteries together will not block the charging port.

No, I'm just wondering if the BMS (battery management system,) or charging module can handle the extra cell, is all. I don't fiddle with this stuff too much, but it's something I wondered about, is all.

I don't know, one way, or the other.

Chris