Power fails, need to stop and stat again

[SeanG]

Hi, I have an urban mover re branded in Ireland as Kenbay bike. I have an on going problem of loosing power even though the battery still has a good charge. I used to think it was related to the rain but happens in the dry as well. If I brake and start again the power kicks back in. It also kicks back in if I don't break and let the bike slow to near stop. Bike is 2 1/2 years old.
Any ideas?

Thanks Sean.

 

[NRG]

Failing battery.