Chromebook doesn't turn on occasionally

Acer chromebook doesn’t turn on. Its not an issue with power adapter. I opened the back cover and disconnected the battery cable/wire and reconnected it. Then it starts working for few hours. After few hours it doesn’t turn on again, I don’t even see any light for power/battery. I’ve to open back cover again and remove/reconnect battery cable.

Has anyone experienced this? Is battery an issue? Is cable bad? or something else? Btw, chromebook works on battery as well and battery lasts well.