Strange Battery Drain !

[RS2junkie]

Hi, Hope someone can advise...

Parked the RS2 yesterday after a 15 mile trip and left the sunroof open so the alarm triggered. When I went back to start it the batter way dead, not a peep !. Jump started it and it ran fine, shows 13.5 - 14v on the gauge and I am getting no batter warning light. Checked the battery voltage and I get 12.13 v

Had a new alarm fitted and also tidied up the stereo wiring, perhaps something has been disturbed.

Where do I start, can someone please tell me what check to do ? Is there a common fault I don't know about

The battery is not new, is it possible that it could fail, from normal to dead in about 5 minutes ?

Help ??

Paul

[rj scotty]

When batteries start to die they can do strange things. In my experience battery drains are nearly always interior lights some where.

To find a drain place an Ammeter in circuit lock the car and wait a while, should settle down to a mater of milliamps anymore and something is still "on"
Find somebody with a battery "drop" tester to see what sort of condition it's in.

A new decent battery from the likes of Varta is about £80 delivered

[driftin jo]

I don't think you have gone from fully charged to dead in 5 mins and if
you have you will have killed your battery, a good battery would need a
500 amp load to kill it in five mins. I suspect the battery has been taking a battering
with a high parked drain for some time, probably since you had your alarm fitted.

You need to check the current drain with a multi meter with the car locked,
you should not have more than ~30 mA .
I suspect that you will see something like 300 mA drain. Once you have done this it's just a process of elimination buy pulling fuses etc. to find what is causing the drain.

[Thecrispynoodle]

I have now had 2 cars which suffered from battery drains when not in regular use due to current drawn by aftermarket alarms, both times I only managed to resolve the problem by fitting a Bosch battery which copes significantly better with these conditions than anything else you can buy including the supposedly high quality Halfords own brands. This doesnt mean to say that you havent got a problem somewhere that needs sorting but that it is entirely plausible if you use the car infrequently and for fairly short trips that it is solely down to the battery not being able to recharge fast enough, and putting a Bosch in will do no harm at all (apart from on your wallet unfortunately). A mate of mine at work also pointed out (after I had bought a new Bosch battery...) you can buy dash top solar panel car battery chargers that plug into your cigarette lighter socket which might be a cheaper way of giving your existing battery a helping hand. Follow the advice in the posts above to see if you have an abnormally high drain that needs locating, but dont be surprised if the alarm alone is causing the problem.

[Donald Smith]

If the central alarm module is taken out or bypassed,your car will not start.This happened to me.12 volts at the starter,but the car would not turn over.You mention that you played around with the alarm.