I found this by searching "808504 controller" on Google images you'll find a picture with the same board markings. It looks to take 48v. I hope this helps
YouTube or Google is your friend. The kit has 2 options I believe. One is for fat bike the other is for standard. Regardless the kit will replace your bottom bracket and crank so compatibility isn't an issue. Just check you bb spacing and double check that it doesn't use a special threading. All...
Unfortunately you can't just replace the cells in laptops like most other things the bms is complicated and if anything goes wrong including disconnecting cells it will shut down for life unless you have a special programmer just for laptop batteries that connects to the contacts. From there you...
I'd double check the voltage with an actual multi meter. The voltage will drop when plugged in and even more with the key on. On my controller the voltage is accurate so I'd trust it. Also the 60% is just the state of charge out of whatever the maximum voltage the controller can handle. For...