We bought the “Fisher-Price Thomas & Friends Ride-On Train” for our toddler, and after some time, the battery stopped charging. It uses a Power Wheels 6V 2400 mAh NiMH battery (Model No. 1102822518 / Part No. 3900-8218). Apparently, this battery was fairly unique (and problematic) to this toy and has since been discontinued. I, of course, did not want to scrap an entire Power Wheels toy that worked just fine except for the battery. ...
After setting the Christmas tree this, a section of the builtin lights weren’t turning on and found two of the wires had been chewed through. I didn’t want to have to throw out the whole tree so I set about fixing it. I wasn’t looking forward to it though as I thought I would have to solder the wires together and cover them with heat shrink tubing… a process that was going to be very annoying under a Christmas tree. I debated just taping them together with some electrical tape but I didn’t want to deal with it maybe coming loose while taking it in and out of storage. ...
This effectively amounted to replacing a battery but I still learned some things along the way. It was thankfully easy to take the rubber case off which I expected to be glued or something but I just had to pull it off. This revealed the main board with the LEDs and the battery tucked underneath. It turned out to be a 18650 lithium battery. ...
Today I learned that the following white connector you commonly see in electronic devices, is called a “JST connector”.