Rapid battery discharge

[aston rover]

My 75 gave me an early morning call (7:00 to be precise!) from the alarm siren. It wouldn't disarm from the keyfob, had to stop it by unlocking the drivers door with the key. Low battery voltage became apparant from the dull interior lights and non-functionality of everything else! Battery voltage was around 6.7V. The battery-backed alarm sounder had must have thought the battery had been cut by a car thief as the discharge rate was so quick.

Yesterday I had been messing around with nav computers, but can't see how this would have disturbed anything.

Last night after getting petrol I noticed that the interior central locking switch was not functioning - Could a partial short/insulation breakdown on the switch be the cause?

Any thoughts or pointers greatly appreciated.
Thanks

[aston rover]

Sorry forgot the vital stats

03 Rover 75 Conn SE 2.5V6 auto

Just had the central locking switch apart, sems ok...

[JohnDotCom]

If it has the Hi Line TV Sat Nav and you had that on, that can drain the battery completely in about 4 hours if no engine running. (its difficult getting off the Beach sands when that happens believe me).
Also the Battery itself is always a good bet fir weird power faults. Stick it on Charge then see if/how quick it drains.

[Christopher]

I fitted a new aftermarket HU a few weeks back and spend a good 6 hours cleaning and polishing R70 ... with the radio on (as I would have with my Harmony) ... result? Next morning clicketty-clack and light-show and no start ... uncle Ken to the rescue and one jump-start later battery was up and running (thanks Ken :D) I've bought a battery charger now to leave the battery on charge overnight should I ever do it again. :o:o

[aston rover]

Thanks for the replies chaps. Charged the battery for about 2 hours & car started ok. I'm pretty sure the drain was nothing I'd done/left on as I gave it a run last night, came home, locked it, left it. Alarm sounds about 9 hours later, battery down to 6V.

I've recently fitted a BM24 tuner. On a few occasions when I've turned the ignition off the output from the HK amplifier has kept going for a few minutes, then turned off. Never used to happen with the standard R75 tuner module. I'm wondering if the BM24 unit is suspect, and is not powering down properly.

The car is now with with my ex-MGR dealer for a check over.