flat battery!

[Prakesh]

Hi all, I dunno why but my battery is brand new but it goes flat in like 2-3 days when i dont start the car!!

My main question is...........can i jump start with jumper leads? coz ive been told that it shouldnt be done??

anyone???

[Fhrx]

It's a never ending discussion that one.

I have found (both read and heard) you can. You just have to put the earth onto the engine or body rather than the battery?

[ferni]

hmmm i don't understand where this myth comes from that you can't jump fuel injected / computer driven cars?

as for the earth....where do you think the body earth ends up? .... to the negative terminal

To answer your question...Yeah you can jump it no problems - just dont mix up the negative/positive, that will do some damage

sounds like somethings isn't turning off and is draining your battery

car alarm?

stereo?

amp?

if you can't track it down, probbaly worth taking to an auto-electrician?

[Duncan]

It's a never ending discussion that one.

I have found (both read and heard) you can. You just have to put the earth onto the engine or body rather than the battery?

yeah thats a funny bit of it, every car I have jumped from has a very short wire from neg to the car's body somewhere....but most car handbooks say dont jump from the negative terminal?

Anyone know why?

Jumping is safe enough, just make sure the jumper car is running.

But maybe you should also be asking why a brand new battery dies in only 3 days? Maybe an earth leakage somewhere?

[Fhrx]

I realise where the earth ends up, hence the question mark at the end of the sentence...

[wolverine]

i might be writing something a bit silly here, but here goes.. hydrogen gas.

by earthing on the body away from the battery you lower the chance of a stray spark igniting said gas from the battery?!?!

[Edge]

hook up positive to positive terminals on battery first so it will not make a spark - most sparks will come from the positive terminal!

then hook wire from the negative to negative terminal. Negative almost never gives sparks.

hooking to the engine gives a shorter circuit to the fresh battery. So as to bypass the flat one initally. However if you hook it up for 30 seconds direct to battery terminals before trying to start it will work fine.

If you are worried about damage it is because some of the French cars are not very electrical fluctuation tolerant. This is not a problem with Skylines.

Finally the batteries themselves provide capacitance and particularly the flat one will need a short time (about 30 seconds) to recharge before you crank.

When doing a jump start you should have the other cars engine running while the batteries are connected. This helps to keep the voltage stable under load especially the flat battery needing to come up to capacitance - it also prevents the other cars battery becoming flat while you crank the dead one.

If you are paranoid about damage you can get surge protected jumper leads.

In any case I recommend you buy at least 200amp leads with good quality copper wire and copper aligator clamps. Check the conductivity of any old leads you have with an ohm metre before you actually need them. Since you can buy top quality jumper leads at a variety shop for about $7. I got a set of 400amp full stranded twisted copper for that price that are very flexible and nice to keep next to the jack. It would be a good idea to get some new ones. Then you can jump start everyone else

[Craved]

prakesh, what car are you driving? the R33's have the jumping point in the engine bay! thus not going anywhere near your battery direct. the picture on top of the relay box on the drivers side displays how to hook the leads up! cant be bad if they show you how!!!

had similar issue in my car a while back

spent 2 days in an autoelectrician measuring load in amp on the battery wirth the car off, at some points it was almost 5 amps- which is huge. shouldn't be too much more than 0.5A. then disconnect one thing at a time and measure - stereo, alarm, even my turbo timer was drawing 1.3A when plugged in and not running!

just a few ideas

CT

[Edge]

oh yeah my battery is in the front - best you follow instructions as craved pointed out if your battery is in the boot.

[Prakesh]

hey dude, im not sure if this is normal, but my clock stays on when i turn the car off, what do u make of this?

Oh and also, the stereo system has to be turned off manually, it doesnt go off when u take the key out of the ignition.

I do have a rhino system alarm in it and that may be draining the battery but i cant be sure, as u said it might be a wise idea to take it to a auto electrician to get it cheked up.

Thanks for ur help, let me kno if anything else comes up.

Cheers

Prakesh

[Duncan]

Hey Prakesh, I'm not autoelectrician but I'm pretty sure *everything* except the headlights and cabin lights should be off if the iginition is in OFF

[Craved]

Hey Prakesh, I'm not autoelectrician but I'm pretty sure *everything* except the headlights and cabin lights should be off if the iginition is in OFF

Duncans right, they all should be off! i know when i hooked up my head unit originally i had it setup like this too, but drained heaps of power. they may have rewired the clock to stay on too, pretty easy to fix up but can be fiddly to do!!

check the drain on the bat when stereo on normal then check the amps reading after you unplug the HU, if a big change rewire it to save that power-if it's not much then i wouldn't worry too much!

[SKYLINED]

When jumpstarting, surge protected leads are best, so u cant cause a spike and fry the computer/electronics.

Has been known to happen on rare occasions.....

On the topic of the draining battery, sounds like someone needs a clamp meter!!!!

[Prakesh]

Thanks fellas, im going to take it to an auto elec this weekend,

Get this shyt over and done with.

Thanks for all the good info anyways.

Cheers!!!

[cLoWn]

my stereo has to be turned off manually but thats cause some dodgey guy put it in i haven't had the problem with the clock... a good way to tell is just disconnect it and see if your battery still goes flat... also if you have an amp check the power light on it when you turn off the stereo it should only power up when the stereo is on...