Why the hell won't my car hold a charge?!
 

Ok, so my TT Z is my second car, and I only drive like once or twice a week. But, EVERYTIME I go to start it, the battery is either completely or almost dead. This means that I have to jump the car if I want to use it. Considering this car is my play toy, thats a lot of extra work just to enjoy a little driving.

So, my question is this: What is draining the battery on my car so badly?

More than likely you have something draining the battery. Get a voltmeter and disconnect the negative cable on the battery. Connect the voltmeter leads between the negative battery post and the cable. If you get a voltage reading, something is staying on in the car.

If you do get a voltage reading, then it's a "search and destroy" mission. Start pulling fuses until the voltage reading disappears. Once you have located the circuit, that's where the "search and destroy" comes in.

Good Luck

PS..Another possibility is that you have a dead cell in the battery. Bring the car to Auto Zone or Advanced and have the battery loaded tested.

You'll want that Volt, Ohm, Milliamp meter in the current setting rather than the voltage mode. Modern cars will always draw some amount of current to keep things like the ECU and radio's memory fresh and the remote door locks working. A typical load ought to be a couple of watts - 100 to 200 milliamps. You're likely drawing 8-12 watts from your description - which will show up as 750 to 1000 milliamps of current flow. Any more than that and your battery would be dying faster.

When I faced this I found that the fancy cap for my after market stereo was putting on light shows in the sub-woofer compartment all night long. The spiders in there were partying like it was 1999.

:icon21::icon21::icon21::icon21::icon21::icon21:

I'm in the same boat as you but run my Z a couple of times a month so I have a trickle charger installed. I run the cable up from the battery and out near the windshield washer on the passenger's side. I pull into the garage, connect the trickle charger and then put the car covers on.

Hasn't failed since. Good luck.

Paul, wouldn't disconnecting the battery cable take care of any draw, other than shorts? Just curious. And LMAO on the spiders. OP - how old is the battery? As far as shorts, check mods such as audio first - that is generally where the problems occur, on aftermarket stuff.

It is possible that the battery just does not hold charge any more, So grab a new one and perhaps buy a trickle charger for the storage time.

Have the battery checked out first. How old is it?

most likely your battery is just going south. buy a new one. and as previously posted, if you rarely drive the car a battery tender would be a wise investment.

Yes but a short would show up rather quickly.

Pulling the negative cable from the battery and then connecting the VOM between the battery terminal and cable forces all power coming from the battery to flow also though the meter. When set to the current mode the meter will measure the current in amps/milliamps. SOP is to always start with the highest current scale and work your way downwards. Many VOMs have a third jack for the (+) cable to measure high current loads and normally it's labeled 10 AMPS or 20 AMPS, the negative test lead stays in it's normal jack while the positive lead is moved to the high current jack. With the car still having some juice after a week the load it's "that" high like leaving the headlights on ... but rather something smaller like leaving a dome light on (8-12 watts).

I am having the same problem with my car right now. the only way to get the car going is by jumping the battery. i also tried putting another battery but the car did not want to turn on. even thoe it had power inside the car. it wont hold a charge and i only use it on the weekends.

:icon17:

That's what I was thinking. Especially if the battery is old. I upgraded to an Optima Yellow Top a few years back. The car sits for 2 weeks at a time now, and it starts like a champ everytime...

Battery is like 3 months old.

What kind of batt did you get. Here at the shop i sell interstate and i RARELY have any problems with selling them. But if i get a customer come in with a problem and then i check and see it's like an autozone duralast batt...that right there would be the problem.

Example tho i had this ladies bmw that i threw in a big mtp 93. Now i know the batt was sitting a while b4 i sold it, but her car started fine no problem and it showed cahrging well plus my machine said batt was good. 2 days i get a call that the car was dead and she needed a jump. I drove myself nuts checking everything out only due to when she drove here each time the damn batt would charge and hold just enough for it to say good when checking it. But over night was dead next morning. So i replaced it regardless and so far 3 weeks its good. I even called her to make sure. So it also depends on how the shelf life was on the new batt you bought.

I had the one in my 300zx last about that long.

my SR20 240 always used to have a dead battery after a few days of sitting. I sold it like that :icon17: charged and good for 72 hours of course

What do you guys think about these battery trickle chargers I found on ebay.
ebay#330311300790 #320339579844 #270353907107

I'm seriously thinking about buying one of the above.
So far I like the Wildfire, all one unit that just plugs into the wall but the Carson Engineering is 3 amps.

get a c-tek charger...they make good stuff.

I'm having the same problem :suicide: It started when I put Two 12 inch Rockford Fosgate P3's w/ 850.2 ZX Kicker amp in the car. I dissconnected everything and I haven't had a problem since. But I want to rock the subs so I'm thinking about putting one of those shuriken audio batteries to run off the main one. I was told that would fix it :dunno: So if by coincidence you realize that this started happening when you installed a system, this is your problem.

Hi same problem here, I got my z for a week or so. This is my first manual car and I've been stalling and having to restart my car every time I screw up my clutch and 1st gear timing. After those initial days of learning manual, I've gotten pretty comfortable driving manual. But now the car won't start. I charged the car for like 10 min thenjump started the first time it did turn on and I drove it around for like 30 min or so to charge it. So after that I went home and didn't turn it on again until this morning. I started once and it worked, but I left something in my house so I turned it off and when i came back out and tried it again, it didn't work.

I'm wondering if learning manual in this car caused this problem?

Any help appreciated, thanks!