Battery draining problem

[Tim M]

Hi

On my Moggie the battery seems to drain suddenly intermittently. It is running a dynamo and I think the Voltage Regulator is faulty so have purchased a new one. The battery is new. Might this do the trick? Thanks

[bmcecosse]

It may - if the old Reg was faulty and 'sticking in' at times - but the Ign warning light would then be ON when you switched off... Was it ??

[Tim M]

No, the light was off.

[bmcecosse]

Well I doubt it is the Regulator... Look elsewhere..

[Trickydicky]

It is possible that your "new" battery may be faulty, was it happening before you replaced it?
Is the dynamo charging the battery, it should read 13.5-14v across the terminals when revving the engine.

[simmitc]

Does it go flat whilst running or only when switched off? Have you checked that it is the battery (voltmeter on terminals, or hydrometer)? If it is just the electrics on the car fail, but the battery is OK, then it could be a loose connection - was the new battery fitted correctly? When it goes flat, does everything stop working, or only some things? Is a courtesy light switch sticking on? All sorts of possibilities, need a bit more information.

[Tim M]

Thanks for the replies. I have now tested the voltage across the terminals as the car was being revved and all seemed to be working well. When the battery dies the whole car gets knocked out but the culprit could have been my five year old who has been into the car and put the lights on!

I have the new voltage regulator anyway so I'll save it for a rainy day as all sorted for now. Thanks everyone again.