I rebuilt the battery for my G4 DLSD and I cannot figure out why it is not working. What am I missing?

[CircuitBored]

I have rebuilt the battery for my DLSD with new 18650 cells but sadly things are not going quite to plan. The current situation is that I have the battery fully reassembled, voltages are good, the operating system sees it as fully charged and healthy, but the machine will not actually run off the battery. It shuts off the second I pull out the power connector.

The replacement cells are very similarly spec'd to the originals, only a little bit larger (2500mAh instead of 2100mAh).

This DLSD has no PRAM battery but is otherwise stock and works fine, save for a dodgy DVD drive. I really don't have a lot to say, unfortunately.

I am rather confused by this issue as by all accounts the battery should be working (even the charge level indicator button works and shows full charge). This post is sort of a hail mary so please let me know if you have any tips or ideas for things to try.

 

[3lectr1cPPC]

It’s likely the BMS. Most lithium ion batteries will prevent the battery from working after new cells are installed, partially for legal reasons and partially because of greed (they’ll sell more new batteries that way). I wouldn’t know anything about how to fix it though unfortunately.

 

[CircuitBored]

It’s likely the BMS

I feared as much. What a shame.

 

[joshc]

Does this help?

https://www.reddit.com/r/batteries/comments/tk0twj

 

[CircuitBored]

Does this help?

Sort of! Sadly that thread is about the battery from a different unit so the pinout may be different but it's good to know that there is a "trick" required to get the pack to wake up properly. Whether or not the net result of that is the same as installing the pack and powering the laptop is still to be established, of course.