No power when disconnected from AC Adapter

Here is a guide for replacing the battery:

Microsoft Surface Pro 4のバッテリーの交換

Here is a link for the battery on ebay ($40).

Hi,

Sorry, I don't have a solution but some info may help.

Unfortunately, I don't believe it's the battery. Every pro 4 that I've come across (over 20 units with this issue) that has had a battery "go bad" by swelling or physical damage was not repaired by a brand new aftermarket (or oem used) battery. I have tried 3 different suppliers (although the packaging is almost identical to one another) and none have repaired any pro 4's with the swollen or physically damaged battery. The pro 4 will usually say "plugged in, charging" or "charged" with an accurate battery percentage. I can adjust my brightness settings but not the power settings.

I had one pro 4 that the battery just went bad internally, swapped it with an aftermarket battery and all was good. (I tried an oem battery just to see if there was a difference but there wasn't - oem worked as well.) In this case, the bad battery would quickly switch from "0% charging" to "100% charged" with the bad battery.

I've done everything on the internet from drivers to rewriting the bios and nothing seems to help which makes me believe it is damaging or shorting something on the motherboard when the battery damage happens.

If anyone with any insight on this could help, I'm sure all of us would be very grateful.

Thank you,

Any updates to this issue?

if you look under the middle left can on the board, there are 2 black diodes that are identicle to each other. Some say replace only the top, some say only replace the bottom. I replace both every time and 99% of the time it works. Only time it don’t is when the issue is further down the line from my experience.

I did the replacement myself. I also had the issue you’re facing the first time I tried. What you probably facing is that your replacement battery is missing part of the required circuitry related to charge control.

I bought mine from AliExpress and it had exactly the same model number, but its board was different from the original one. I searched a lot and found a picture (attached) showing the two battery boards, then I compared the original board from my surface to the one that came with the new battery. That was my case.

I carefully (very carefully) removed the board from the old battery and soldered it on the new one. Voilá… I’m typing this from my surface running on the new battery. Hope that can help you.

I am experiencing this same exact issue. In my case, I am using a ifixit battery, replaced 6 months old, worked great until now.
Able to use the computer only when is plugged in, and performance is mediocre, something definitely affects performance.