Something drawing power from my battery???

[blacktop]

Ok! This is starting to piss me off big time!

4 weeks ago i realized my Altanator was dieing in my 4WD, so i took it to my local Mechanic and he changed it over with a new Bosch item, now every f**king morning my battery is flat as a sheet of paper, i took it back to the mech and he replaced the regulator and tested! told me all was fine and that the problem was "my battery is not in good condition thus it was destroying my regulator thus drawing current from my battery" I think this is bullshit! cos i go to start my car this morning and once again FLAT!!!

It is a dual Battery setup, i have never had an issue before with starting my car, as i think the duel setup is linked when starting my car, but now i can't even jump it off my other battery i don't even think they are connected at all.

When the car is running both batteries show charge from the Altanator, when not running it was showing a draw of about 3.5amps, With the new regulator it was showing a draw of about 0.5 to 1 amp.

Why the hell is my car drawing power from my battery when it is not turned on?
this mech tryed to blame it on my shit battery but before i changed the altanator i replaced the main battery with a brand new one.

This problem of the car drawing power from the battery only started when he changed the altanator.

does any one have any ideas of what is happening?

cheers
Brendan

[ian]

hi
do you have an under bonnet light that comes on when you open it ?if so check to see if the switch is fully breaking the curcuit ,, may be a long shot
ian

[pauljones1976]

Your mechanic may have a point. If the battery has been run dead flat or overdrawn it's possible that some of the cells in it may have warped and become short circuit. This will allow current to flow and flatten the battery continuously.
Take the battery(s) to a battery shop and get them tested first before you spend money and time trying to fix things which may not be the problem.
Cheers,
-Paul.

[Squid]

Yeah a fucked alternator will often destroy a battery (even a brand new battery), bend the cells beyond useful condition and the battery won't hold charge.

Hydrometer test ftw here... it will tell you most of what you need to know! Failing that charge it up with a charger, leave it disconnected and see if it has held the charge the next day... if the cells are warped it won't hold the charge.

A visual inspection can also reveal bent cells, but it isn't very accurate

[blacktop]

The mech lent me a Brand new battery on Wed and this battery is Flat today, my other battery is telling me it should still be ok it shows 11.5V and was load tested at 200amps Its not great but it should still be enough to start the car.

That means the batteries aren't to blame!

[pauljones1976]

In that case I'd be seeking a second opinion, preferably from someone with experience with twin battery installations. Usually a good battery shop will help you out - they will probably get a sale in the future anyway. The investment into looking at an alternative professional might well be worth it in the long run. Trust me, I've persevered with mechanics before who don't know their stuff properly and it cost ME, not them. I do pretty much all my work myself now for this reason - I'd rather learn at my own cost rather than paying them to do the same!

Good luck!
Cheers,
-Paul.

[Dazza]

It could be a faulty alternator that your mechanic fitted. I have heard of diodes in an alternator shorting out and draining the power from your battery. If the only thing your mechanic changed was the alternator and your battery is now loosing charge overnight it has to be something to do with the alternator

[slide86]

you can do a current draw test to see if there is a circuit in the car drawing current.

use a multimeter in series with the -ve side of teh battery, put the multimeter on amps.

monitor it and pull fuses one by one, if the current suddenly drops after pulling a fuse that normally shouldnt have power when the car is off you know that circuit has a fault

[Grega]

slide86............brilliant suggestion

[lexsmaz]

I agree with slide86 but i would do it on the positive terminal of the battery, & make sure your multimeter can read up to 10 amps ... ( i'am sure you know how to do it but just in case you need to take the battery lead off the battery & hook up the multimeter in between the + battery lead & battery + post, like slide86 said in series ) also i would disconnect the alternator wires including the battery lead to the alternator & test for a discharge .. I suspect the alternator could be the main cause of your problem ...

[clubagreenie]

How are the dual batteries connected? With a manual isolating switch or one of those little black boxes that are supposed to manage charge/discharge?

If the later and it's failed then you can have all the problems you've mentioned.

[Sam_Q]

jaycar sell a product that has a fuse shaped end and if you plug it in it reads the current..

[2TG KE35]

if one battery is fucked then it draws charge off the other causing that to die as well.

happened in my mates dual setup in his bravo

that might be your problem. just my 2c.

[Jorrs]

faulty alarm causing a current drain overnight ?
incorrect alternator wiring ? i had both of these issues that were causing a drain of the system and the car would be flat every day, it ended up killing my brand new battery as well.

[blacktop]

Thanks for all the suggestions guys! + Rep to all

Think i may of sorta figured out the problem today

A long long time ago the previous owner had for some reason bypassed the Battery light in the dash thus sending to much power to the regulator and killing it, i didn't even know the car had a battery light! so got all the wiring fixed up and put 2 brand spanking new batteries in today so i will see if this fixes the problem. if it doesn't fix the problem there will be a very cheap 4X4 in the for sale section cos i have had enough of it!!!

Thanks again for all the help