Fan running drained battery

[Fatbloke]

Hi All
Last night the radiator fan kept coming on when the car was off. It wasn't to do with a regen. It was running really fast, faster than when it's doing a regen. This must have kept going overnight as today the battery was completely dead.
I got it running with a jump starter pack and ran it for a while then tested battery voltage with the engine on and off and it seemed fine. I also tested with a wee load tester and it said the battery was good but needed charged. Its on charge now.
The fan didnt come on when I was testing it or since it's been charging.
Any idea what could have caused the fan to kick off? It's never done it before.
Cheers
Dave

 

[Fatbloke]

Tested battery again after full charge. Voltage and load test fine.
Used car today, no issues. Regen started and cruised on motorway and regen cleared. No fans running.
No idea what caused the fan issue but all seems fine. Nothing really standing out with vcds scan.
Hope it doesn't do that again.

 

[strtnz]

Only thing I could think of is a relay stuck in contact, and when the battery has drained the contact has been released so it's not drained the next time you've had it on. Strange one either way.

 

[Fatbloke]

Yeah very strange. Seems absolutely fine now. Will keep the jump starter in the car for another few days just in case.