Timmy06

Hey guys,
So everytime I left my car sit overnight...The battery die and ?I have to jump start it...It only really does it when I let it sit for several hours...I've charged and tested the battery and, it should be ok, its a yellow top optima battery...Any help???

BigWillieStyles

How cold is the area you store the car?

Do you have any other problems?

Buy a new battery and see if this fixes it.

Timmy06

I usually sits in the garage...Prolly mid 50's or 60's....
-No other problems...less than 3k on the engine...
-Buying a new battery today!...Hopefully it does the trick...

ahad

getting a new battery shud do the trick...i had similiar probs when i bought my car...changed the battery havent had a prob since...

dblboinger

iTrader: (3)

How old is the battery? If it's old it might be the culprit, but before I bought a new battery I'd try a couple things to see if something with your car caused the battery to fail.

I can tell you now, some people are going to flame me over this approach, but I can assure you it has worked for me on more than one occassion and I have NEVER damaged anything. Never-the-less this manner does theoretically run some risk of damage to certain electronics, in particular anything computer controlled....i.e. your ecu and most newer car stereo head units. I have done this on several occassions and never had problems, but this is your decision. If you wish to try read on. If not, then take your car to a competent electrical shop and have the entire system evaluated before you buy a new battery.

You need to find out if there is a current draw when the car is shut off. You can do so by simply disconnecting and reconnecting the battery. If you get a spark when you reconnect the battery then something is drawing current (you may see a very small spark if you have anything that has a memory, i.e. your ecu or a car stereo with memory). The more current, the bigger the spark. Then to isolate what "branch" of the wiring is at fault repeat this same test but remove one fuse at a time until you notice a decrease in the spark. I would try toeliminate the branch that powers the ecu first and then leave it disconnected until you finish. Once you find out what branch the draw is on you can start disconnecting things one at a time until you find the cause.

If you don't find a current draw, then it's a good bet your battery is shot, but take it with you when you go to buy a new one. Most places can easily test a battery to tell you if it's bad. Of course you can do that yourself too. Connect a voltmeter across the battery terminals and turn on your headlights. With the lights off the voltage should be around 12.6 volts. When you turn your headlights on it should stay fairly close to that value and it should stay there for a fairly good amount of time. If it drops below 12 then you've probably got a bad cell (maybe more than one depending on how much it drops). Also, start the car and see what the charge voltage is...it should be 13.8-14.4 volts. That tells you your alternator is recharging your battery. If it's less than 13.8 volts with the car running try revving the engine a little to see if it comes up, especially if you got aftermarket pulleys installed. If it stays below 13.8 regardless of the rpm's then you may have a weak alternator too

If you just run out and buy a new battery it may work fine for a while, but before long you might start seeing the same symptoms again and by then you might have ruined the new battery you just bought. Don't just fix the symptom, find and fix the problem

Good luck.

Audie

Buckman66

Not a flaming Audie as your basic method is OK, but relying on a spark as a measure is very basic and unreliable.
Ensure everything in the car is switched off , doors and boot closed.!! disconnect the battery earth lead and connect a multimeter in series ( set to amps, not milliamps ) )i.e. one lead on the battery earth terminal and the other on the disconnected earth lead. If your car is drawing power it will register on the meter. Then remove each fuse in turn and check the meter to see if the power consumption stops. With this method there is no issue of power surges or spikes.


Bob ( UK )

Timmy06

Um...So I just found out that my boost gauge light was disconnected...
-Not the whole thing but the ground came disconnected and the power was still entact...
-Could this be the problem?

dblboinger

iTrader: (3)

Nope. Loose connection = reduced or no current flow, not a dead battery.

dblboinger

iTrader: (3)

Thanks Bob. I'll give you that using an amp meter would be safer for your electronics, but I was going for the quick and easy method. Like I said, I've done this more than once and never had any damage from it. The circuits will get the same surge regardless of how power is interrupted, but by using the meter connected in series you eliminate the repeated interruptions therefore it would be safer. Just make sure the meter is capable of the current you might encounter or you'll damage your meter.