Battery cut relay (any auto elec's out there?)

[_R_J_K_]

Hi all,

Basically what's happening at the moment is that I have a car with some battery drain. It destroys batteries, to the point where they won't create a circuit when you put them on a charger (maybe my charger isn't powerful enough or something).

Anyway, I was wondering if anybody has put a relay or similar in that completely cuts the battery automatically when the car is shut off, and to connect the battery you have to push a button on the dash. I want this to be automatic so that it can't be forgotten to be turned off by whoever is driving.

I've been trying to find some kind of diagram for the last couple of days, but I'm not good with circuitry so I don't know what the setup is called. The car is carbied so there's no computer to be harmed. I'd find the leak with my multimeter, but I have to find a new 10 mA fuse, and I'd rather just do this to prevent any problems down the track.

 

[Nut Kracker]

Hi,
Give me a little time and I will have a isolation diagram for you.
MAYBE !!!!!!

 

[IBLOWN]

You do realize if you do that, it will run poo for about 80 kays each time you turn the key off until the ecu re-calibrates?

Why not just put a quick connector on a trickle charger so its easy to just plug in when you get home?

 

[hakhawk]

or find the drain source and fix it

 

[Nut Kracker]

You do realize if you do that, it will run poo for about 80 kays each time you turn the key off until the ecu re-calibrates?

Why not just put a quick connector on a trickle charger so its easy to just plug in when you get home?

Nah. he said it's carby'd No BCM or ECU

 

[Tree cutter]

Your battery charger must be one of those charge and maintain ones. They wont charge your battery when the voltage gets really low. You can make your charger work by connecting another battery or small booster back to your battery for a few seconds when you turn on your charger. Cheapest easiest way to stop your battery draining would be to use battery terminals that have an isolation switch in them so you just pop the bonnet and turn the connection on or off. Better still would be to buy a new fuse for your multi meter and find the short or whatever is left turned on.

 

[Nut Kracker]

Hi all,

Basically what's happening at the moment is that I have a car with some battery drain. It destroys batteries, to the point where they won't create a circuit when you put them on a charger (maybe my charger isn't powerful enough or something).

Anyway, I was wondering if anybody has put a relay or similar in that completely cuts the battery automatically when the car is shut off, and to connect the battery you have to push a button on the dash. I want this to be automatic so that it can't be forgotten to be turned off by whoever is driving.

I've been trying to find some kind of diagram for the last couple of days, but I'm not good with circuitry so I don't know what the setup is called. The car is carbied so there's no computer to be harmed. I'd find the leak with my multimeter, but I have to find a new 10 mA fuse, and I'd rather just do this to prevent any problems down the track.

This diagram will isolate the accessories at the battery when your car is off. I don't think the leak would be comming from the starter motor.
All you have to do is realy splice a relay into the other wires from your battery.
Depending on the current draw and how many accessories you have will depend on the amperage of the relay(s).
You might have to put more than one relay in.
Remember that this suggestion will isolate "everything" except for the starter, including head and tail lights.
I've only suggested this as a possible quick fix.
As the other guys have said and I agree, get the voltage leak checked out as soon as you can, it may lead to other problems.
Here it is any way. Remember that this is just a suggestion and I take no responsability for loss or damage to property or persons.

 

[_R_J_K_]

Finding the drain source is a bit tricky at the moment. Before I blew my multimeter fuse, I could tell the car wasn't pulling large amounts of power from the battery while it was off. It's being caused by some kind of short somewhere that doesn't arc consistently (sometimes it even shorts when I give the car a bit of a rock by hand), I have my suspicions with the wiper motor.

Continuous slow charging isn't really an option because of the unpredictable nature of the leak (It's not slow and continuous). It could drop dead while it's out and about which is what I'm trying to get around. Funny thing is though, I jumped the car with one of the dead batteries in it and took it for a spin, didn't make a difference to the state of the battery.

Cheers for the diagram Nut Kracker, I knew it wouldn't be too complicated. :spot on:

If you're all wondering too, it's a 4A-C Corolla I'm trying to setup for someone to learn in. I only paid $300 for it, so it has it's fair share of problems to begin with.