Battery Drain

[mariok]

Hey guys,

just bought an 2004 Avensis 2.4vvti D4 Aut. 3 weeks ago , drove about 130km a day and left it on the driveway for about 3 days. When i wanted to start the engine no luck at all. The lights in the dash went barely on. Charged the Battery for about 12 hours till was showing ok, and i could go again.

I'm been driving with it for a while now ( about 20 km p/day ). Today i thought to measure the voltage of the batt. again and it was showing about 7.5-8.2 volts. Clearly something is slowly draining the Battery. Checked the alternator and it was ok. With engine and everything else off, hanged a multimeter between the Battery and the plus pole and the meter was showing about 0.800A. Asked around and somebody told me to pull the radio out as it could be it. Since i can't do that i just pulled the nr 55 fuse under the dash and measured again. This time meter was showing 250mA, clearly better but still not good.

Now for the techies out there, is this normal ? Anybody can tell where else i should look. Any advice highly apriciated.

Cheers

[Mooly]

I would expect a normal sort of current drain would be no higher than around 20 milliamps, probably less.

You should have no trouble starting even after 2, 3, even 4?? or more weeks given a good Battery.

If you use a meter measuring current like this beware... it's easy to damage the meter. You need to measure the drain with the doors locked, any alarm on (active), and any interior lights off. If you try and lock the doors with the meter in circuit it will probably pop the meter or fuse.

Don't know how the Avensis behaves but on my Auris it's a few minutes before all is off on the dash if you just close the doors...

Also if the Battery is fully charged (I mean fully) then put headlights and heated window on and monitor the Battery voltage (with engine off) and see if the battery holds up. Any cells fizzing ?

[richard.c]

Hi,

You say you checked the alternator, but did you check the voltage at the Battery terminals - when running at about 1500-2000rpm you should see about 14 -14.5v on a normal Battery - there normally is a fuse between the alternator and Battery - that could have blown so the battery is never charged by the car.

If its the original battery after 6 years it could let go anytime - a good battery garage should be able to do a free check / charge test for you.

[mariok]

Thanks for all your answers.

I saw at aa1car.com also something about a certain drain that occurs even during the car is locked and parked. Values from 20-50mA to 800mA for some cars was a normal thing. I don't know, i think i'll go to Toyota dealer tomorrow and have the car checked.

[Mooly]

Let us know the outcome :) Always interesting to hear.

800ma by the way will flatten a Battery very quickly... A brand new 60Ah Battery means you can draw 1 amp for 60 hours, so 0.8 amp is 60/0.8 = 75 hours... then it's flat. 20 ma 60/0.020 which is 3000 hours or 125 days. That's in theory, in practice it would be flat long before that.

And that's for a new Battery... try that with an 6 or 8 year old one :)

[mariok]

As soon as i get the answers from the Toyota technician i'll post it here.

[mariok]

Yep, Battery not holding charge. Replaced two days ago everything seems ok now.

[Mooly]

That's good :)