Battery Drain

[Critical_Mass 10]

Hi guys/gals.

 

I took my rado off the road in October, where it will be sat in the garage for a number of months, but it does get started every so often.However, i have noticed the battery will go flat after a couple of week. I went to start it yesterday and found that the battery was that flat the digital display on the dash wasn't even showing the time, so ive had to stick it on charge. This is the first time its been so flat the dash isnt displayed, but normally the car will not start due to lack of battery power.

 

It does have an aftermarket thatcham alarm fitted (cannot remember the make at the mo), but with it being in the garage locked away, i dont set the alarm but the immobiliser will set on its own. My question is, would the immobiliser being on and nothing else make the battery go flat after a couple of weeks?

 

If not how do i check if something else is draining the battery?

 

Cheers

 

Gaz

[davidwort 0]

If the stereo/alarm/immobiliser just draw a fraction of an Amp when off, a couple of weeks is enough to drain a standard battery, either fit a high Amp/hour one , e.g. diesel battery, or isolate the things that draw current completely.

Does your alarm have a key to kill it completely?

A digital multimeter that can measure current can be placed in-line on the battery, just don't operate the central locking or turn the ignition on, that will pop the meter's internal fuse.

If your car isn't run much then your battery will degrade quicker than a daily driver too.

[Critical_Mass 10]

Cheers David. Yes there is just the immob and stereo (memory) drawing power. As long as it is normal for it to drain in a couple of weeks thats ok. I didnt get a key with my alarm, ill check the siren to see if theres a switch for a key on there.

 

As i say the car will be off for a matter of months, possibly until next october ish, could it be that i will possibly need a new battery sometime them?

 

I'll check the current across the battery and see what it reads.

 

Thanks again David

[davidwort 0]

what you need, is to set a multimeter to amps (usually a different connection for at least one probe, not all multimeters will offer this) then connect it 'in-line' between the +ve lead for the battery and the +ve terminal on the battery.

IIRC mine was using about 0.01 Amps which adds up when you work out the amp/hours over several weeks.

First time around I replaced a battery, thinking it was getting old and tired, but looking into it a bit more (and a new flat battery later!) I worked out a couple of weeks was quite a drain for any battery, I have a hefty 70 odd amp/hour battery now seems to last a bit longer than the old ones, I tend to put it on trickle charge if it has more than a week without running though or the starter struggles (I do have a newish high compression engine though.)