I tried firing up my PS4 for the first time a while, and the controller battery was dead. I tried charging it using multiple chargers, but it just wouldn't take a charge. Since I've been watching the occasional youtube video about repairing electronics and stuff, I wanted to try replacing the battery myself. It would be cheaper than buying a new controller. In theory I could buy just a new PS4 controller battery, but that would take weeks to deliver if it arrived at all - shipping batteries is apparently rather complicated right now. Plus this would actually still be cheaper since I had everything I needed lying around anyway.So I watched a video by NSC Mods, which made it look simple enough. It was a little more complicated for me since I wanted to use a 14500 battery in an AA battery holder, meaning I would need to cut a hole in the back of the controller (well, in retrospect I could have just glued the battery holder onto the back and just drilled a small hole for the wires, but this is good too). So I disassembled the controller, ripped open the battery pack and pulled out the battery's internal board.
Luckily the battery holder just fit in the gap between rear board and the molded details.
So I cut a rough, undersized hole and sanded it to the final fit. I probably took a little bit off the side ribs when sanding, but I probably didn't really need to. I did have to remove the old plasic battery housing the was screwed on top of the main board, but that shouldn't cause any issues, and I replaced the screw to make sure the board was supported.
I soldered the battery holder to the battery board, but nothing seemed to happen when I inserted the 3.7V 14500 battery and pressed the Playstation button. So I tried removing the cables and soldering them again with the opposite polarity, but still nothing. I reversed the polarity again, made sure the battery was fully charged, then tried plugging the controller into the PS4 and pressing the Playstation button again.
Luckily this time if finally turned on! I epoxied the battery holder in place, carved out a little bit more relief to make it easier to pry batteries out (this Nitecore 14500 battery is a few mm longer than a normal AA and was pretty hard to remove from the holder once it was in place), and the result was... well, I was happy with it!
The controller seemed to be working just fine. The battery didn't exactly help the ergonomics, but it actually wasn't too bad, and it hasn't been getting hot in use or anything - I can tell since I keep touching it while handling the controller.The dashboard showed the controller as having a full three bars of charge. After several hourse of use (maybe three hours, give or take?), it finally dropped to just two bars of charge. So I plugged in the controller to see if it would start charging, and it... didn't. Well, that's OK since I can just remove the battery and charge it normally.
Out of curiousity however I finally decided to try to search for a different cable to see if the cable was the issue. Luckily I found one, and... the controller started charging.
Um. I'm... starting to think there wasn't actually anything wrong with the old battery. Oops.
Oh well. Truth is, I enjoyed the process (when I wasn't cursing the process), it was kind of exciting and it was really satisfying to see it actually work. I'm embarassed to admit that it gave me a sense of accomplishment, and a little bit more confidence in my tinkering skills. So I'm happy. I also really like being able to pull out and swap batteries in electronics, rather than having to wait for them to charge, so I think in some ways this is an improvement. The Nitecore battery I'm using is rated at 1000 mAh, which I believe is the same as the original PS4 controller battery, however there are higher-capacity 14500s available, so that's nice.
