Weird problem with my E-Scooter

[Sergey Kirienko]

hey everyone. im pretty new in those forums,
but im using electrical scoolter for more than 7 years now.
im pretty happy with it, its powerfull and stable.

before i explain you guys my problem, i need to put some details into it:
- i have 500w brushless motor, 12.5"
- lithium battery (48v, ~15A) 6 years now, didnt replaced yet.
- controller i did replaced because some water went though.

recently i had this problem when i throttle to the maximum, the scooter starts to gain speed and in some point the whole thing just stops working and the battery indicator shows from 100% down to 0%
when i measure the battery voltage i get 0.5v unless i wait about ~20 minuts or disconnect the battery completly from the controller, then when i connect it right away, it indicates 55.4v battery and then everything works like normal like nothing happened.

first i thought there is a problem with the controller, so i replaced it. but the problem didnt dissapear.

so basically; when i run my scooter without any throttle, everything works fine, but when it comes to higher throttle points, the whole system disconnects.

i was thinking it can be problem with battery, or maybe wires, or is this some common problem that needs replacing the battery protection?

i would like to hear some information about this if that happened to someone else before, please tell me. and the way you fixed it.

 

[Sergey Kirienko]

after i red some articles while wondering in those forums, i understand there is a problem with the battery and needs to be replaced?
am i right or there is any other options?

 

[indianajo]

At 6 years of age, you can have either a tired battery, or oxidized connectors between the battery & the controller. You can check for the oxidation problem by feeling around the connectors when the problem happens: high resistance connections get hot.
A load test on your battery would determine if it is toast, but no bike store within 600 miles of here has a tester. You can tell something by getting into the insulation of the wires from battery to controller, to see if the voltage sags as you ride. However this is typical behaivoir of a tired battery - voltage is okay off the charger but internally high resistance so when you load it you can't get any current, voltage drops. I'd clean the connectors with a wire brush, be sure to disconnect the battery or only touch one contact at a time on the battery side, so as not to create shorts with metal tines. Then if that doesn't improve things, buy a new battery.

 

[Sergey Kirienko]

ok thanks for the information. unfortunately i dont have a tools to check the battery load. but i would like to know if there is a good websites for batteries, not too expensive.

 

[Alex M]

i would like to know if there is a good websites for batteries, not too expensive.

Depends where you are.

From China:
https://em3ev.com/shop/
https://bmsbattery.com/

From USA:
https://lunacycle.com/18650-ebike-battery/