Strange issue Bamboo GT Not turning on or charging

Hi all,

Been having a strange issue with my board. I got it off gumtree and upgraded the battery pack due to the terrible battery degradation on the board when I got it (it was getting only about 40-50% of its range potential). Bought the new R2 remote and everything was going great with the board for a number of months, amazing range, then one day the board would not turn on at all.

The power light doesn't blink blue at all when I turned it on, remote wouldn't pair, etc.

The charger didn't work at all, led charge light didn't turn on, etc.

So I left it dormant for a number of months as a "future me problem".

So I've recently opened it all up during COVID to see if there's a loose wire or something blown up, but all looked completely okay, nothing burned out or shorting that I can see. The battery pack is wrapped up.

I plugged in the charger after fixing everything up and making sure there wasn't a loose wire or anything and it started to charge up again! Great I thought, must have just been a loose connecter. Then it stopped charging again after about 3-5 mins .

I then tried turning it on and off and it would randomly just turn on for a total of about 30 seconds before turning off again. I can't say there was any sequence I could get it to I got it to turn on again and managed to pair the remote and spin the wheels for a bit, but it didn't last long again. When it connected it showed a full battery on the board and then just cut out again.

I'm kind of stumped as to what the issue could be.

Any ideas would be greatly appreciated

Are there any steps to diagnose what's going wrong that I've missed? I've read a lot about the BMS being unreliable on these boards, could this be the explanation?

 

The BMS isn’t unreliable, it’s just not designed for 18650s. It’s either motor controller or bms.. both around 125$ 3rd prty, or $200+ from evolve to diagnose. But, with the 18650s, they may/may not even try to help.

 

Where can I source these parts? eBay? Here?

Would you replace the BMS or the Motor controller first? Any idea how I might be able to diagnose further with a multimeter?

If I replace the BMS is it likely to fail again given I have 18650s? Anyway to fix it more permanently other than going back to the terrible flat pack batteries?