Steam Deck/ Battery Replacement and Battery Testing

Good day everyone

I recently purchased a steam deck from a third-party company because I live in a country that isn’t supported by valve shipping services. (one week since purchased)

About a week in using my steam deck the battery stopped working. The device would not turn on unless it was plugged in.

The story goes as follows:
One night I was downloading 2 games at 150 GB, and not wanting to stay up and wait I proceeded to leave my Steam deck on overnight on the charger dock while I went to sleep.

When I woke up, the back of my steam was very hot and I quickly took it up from its dock and plugged it out. The device imminently shut off without any warning. I let it cool down and held the power button for 3,10 and 60 seconds and it still would not turn on. Hence, I plugged it back in to see if I would get a white light and it automatically turned on by itself before I even got a chance to press the power button. The device booted up normally and I was relieved until I plugged it out and it immediately shut off once again.

I quickly contacted the seller explaining to them the issues I’m having with my Steam deck, I told them I am returning it and they rejected to take it back from me. They were trying to blame me that I must have dropped it or done something bad (Which is false).

I contacted Steam support and I explained my problem to them their response was due to how my device was purchased and the country(Caribbean) i’m in doesn’t have Steam support they are only able to provide online troubleshooting services. (nothing that they recommended to me worked) I tried battery storage mode, holding down the power button, and charging it overnight all to my endeavor.

I did my research, and I found people who have had similar problems, luckily for them they lived in the US where they had RMA. They concluded that the culprit behind this issue is a faulty steam deck battery that needs to be replaced.

Currently, I am planning to buy a steam deck replacement kit from Ifixit. However, before that, I want to test my current steam deck battery with a multimeter to make sure that is the problem and not a faulty chip on the motherboard.

Does anyone know how to properly check a steam deck battery with a multimeter?
Does anyone have any similar issues?

OP in case this still helps or for any one else who may need this info: I checked my Steam Deck battery by putting my Multimeter in voltage mode. Put red probe on red wire of the battery plug, black probe on black wire on the battery plug. A good charged battery should read around 7.5-8V. A bad one will give no reading or a very low one