Help with electrics -no ign lights-no anything

[oberonspacefruit]

checked and cleaned earth wire.
it started and lit up with a jump cable.
which means
a-my battery charger is fooked.
b-my battery is fooked.

when it was running i turned it off anthen tried to start it. the lights came on but not enough power to start it- so its deffo a battery issue.

i suspect my grips have drained it- but why would it not bump start?

does it need a bit of power to bump?