Flat battery
 

Hi so I have just got my scooby up and running after a year off the road, I bought a new battery for it and keeps going flat overnight or even after a few hours without use, could this be a prob with my immobiliser as this is what some friends have told me? If so how easy is it to get rid of it, I have a 95 WRX with a little key fob immobiliser that u have to touch on a sensor next to the ignition. Many thanks

P.s I'm a girl and don't really know much about cars! :wonder:

Hi there -The way you phrase the problem is interesting and i have some questions:

1) how do you know it goes flat over night/in a few hours? Did this happen only once or are you have re-charging it using a battery charger?

2) You say it goes flat after a few hours 'without use' but if the car is not starting at all what do you deem as 'use'? As in do the lights come on, radio work etc? Do these things kill the battery?

If the car with a fully charged battery is turning over strongly but refusing to start it could be something else like the fuel pump although again that could relate to the immobiliser.

Hi

1. So this happens everyday when I go to start it it always does not start and I have to jump start it then drive it around for a bit to try n charge the battery.

2. So it unlocks fine via the central locking and when I turn the key the dash lights up the radio works and sometimes it almost starts then if I try to start for a second time it just clicks.

Thanks :)

Ahhh ok that makes more sense. It sounds like it could be the alternator rather than the battery. Forgive me if this is something you know but this is designed to charge the battery while you drive. It is driven from the auxillary belt (fan belt as they are sometimes called). First thing is to check the tension and condition of that belt. If it is frayed and/or loose then it won't spin the alternator fast enough and hence wont charge the battery.

The next thing to consider is what you deem as 'driving around for a bit'. A weak battery that has been drained lots (even a new one) needs a really good charge. Ideally using a proper battery charger first but there is no point doing this if the alternator is not working well as the batt will drain away.

If you can stomach an american accent watch this... its on a newer scoob but the principle is the same: .

The belt he is fiddling with/replacing is the one that is in question attached to the alternator.


The other thing to do once you've got it jumped is take the car to a local garage and ask them if they could do a quick check of the belt/alternator. They will use a gauge to see how many vots it is putting out... if it is low on voltage you'll need to replace it, afterwhich you should trickle charge the battery (ideally off the car with a proper charge) but a decent drive might work.

Trust me if it is those things it will be a lot cheaper/easier to resolve than a dodgey immobiliser cause they can be an arse to remove.

P.S Oh and the doors unlocking/radio working is no surprise as these require a whole lot less voltage/amps out of the battery to run compared to the starter motor and fuel pump that gets you going (they are the things that kill the batt currently after you get into the car).

Oh and that is not my vid and the dude has a funny view on which way a clock goes round!

Ok thanks very much I have a day off thur so I think that's I will looking into :) thanks again!

No probs. Hope you manage to get it sorted! :thumb: