DEAD BATTERIES IN 308's - NEED HELP

Something is defintiely wrong!

You need to get some numbers here.

1. Voltmeter on the battery, car off. Should be 12.5 approx.

2. Voltmeter on the battery, car at 2000RPM. Should be 13.5 to 14.2 approx. This tells you if alternator is working.

3. Car completly off, with an ammeter (curent measuring device) capable of reading, say, 5 amps without frying itself. Disconnect the negative battery terminal. Put the ammeter between the negative battery post and the now disconnected battery terminal clamp. You're now measuring current draw across the battery. You're looking for say 50ma (50 milliamps) or there abouts. Anything greater means a light is on, or your alarm system or keyless entry is really pulling juice, etc.

These three metrics will in all likelihood enable a conclusion as to what your problem is.

You can get a Multimeter from Radio Shack.

 

If you are realy having this problem after only three days, the fellow who told you about getting a volt meter is right. However, if you are not driving for longer than that,and your alarm system is on, it will definitely run your battery down. You might look into a battery protector. I have had a Lotus Esprit and a 360 Modena. Both require a protector. Allstate and Deka are two brands which can be had for around $50.00. It is reassuring to see that little green light on when I want to go for a drive. Luck.

 

VERY SIMPLE BLACK HORSE


YOU HAVE SOMETHING ON, WHILE THE ENGINE IS OFF, DRAWING CURRENT

CHECK ALARM, POWER AMP FOR RADIO (IF YOU HAVE, RADAR DETECTOR, ETC)

A BATTERY SHOULD READ 12.5 VOLTS OR BETTER WITH NO LOAD ON IT...AFTER A COUPLE OF DAYS, CHECK THE VOLTAGE..IF LESS THAN THAT, YOU DEFINETLY HAVE A LIVE CIRCUT ON CONTINOUSLY..


BUY A CHEAP DIG MULTIMETER FOR 20.00, PUT IT ON DC VOLTS, RANGE 0-100..DCV .AND OBSERVE

GOOD LUCK,
BRUCE

 

I disconnect the battery ground during Winter and have a trickle charger on; remember the battery cable is about 12'-15' feet long, which adds to current draw from clock etc.

 

My car alarm, clock, etc. will eventually discharge the battery in my 308 over about a month of not driving the car if the battery is in good shape, and in a shorter time if the battery is a little tired. Most car batteries do not hold up well if they are not regularly used and are repeatedly killed.

The basic problem is that I don't drive my 308 enough, especially this time of the year. I have this same problem with some other cars as well.

Accordingly, I installed a marine "combo" battery (exide blue top spiral cell) and I keep a "smart" charger on it (a charger with various state LEDs that turns off and on at "smart" sensed intervals -- so it won't trickle charge the battery to death). This type of battery doesn't mind being charged repeatedly, being used infrequently, and it cranks just fine. It's a "combo", or compromise, between deep cycle and cranking plates.

I installed a marine cigarette lighter female socket with a spring loaded and rubber gasketed cover behind my front license plate, and I wired it directly to the battery through a 10A fuse. I pull into the garage and just plug in the "smart" charger lead onto which I installed a male cigarette plug.

Kind Regards, Chris

 

I had a similar problem,but,my battery didn't die in just 3 days. It usually takes about 2 weeks. So, I bought one of those new Optima Batteries,and installed a Battery Tender on it. And,you need to have that plugged in to an extension cord. Now,whenever I go to start it,she fires right up. (BTW. The reason that I might not start up my car for 2 weeks is that I live in the Midwest,and it's very cold out. My car is in a garage,but,it's still cold ass out here,and I think that it's probably more damaging to start it and run it in super Cold weather,than to just let it sit for a couple weeks.) But,hey,Spring is just around the Corner.

 

I installed a battery master switch from Flaming River. It kills everything in the car including the clock.(I don't use it anyway)

To keep important accessories energized like the alarm and the memory in your radio tap into the battery with a separate fused circuit that by-passes the master switch. With many of the new batteries you will find four terminals, two top posts and two side terminals. On my 308 I run the car off of the top posts and accessories off of the side terminals. A properly functioning alarm shouldn't drain your battery.

I am also in the process of installing a 1 gauge, two terminal, slip connector (NASCAR style) to the battery and mounting the connector in the grill or under the bonnet so I can jump/charge the battery without pulling the washer bottle, spare and access panel. Found the slip connector at NAPA. Rated at 750 amps continuous.

I haven't had a dead battery yet.

DJ

 

My 308 QV already has an OEM battery master disconnect, as probably do other 308s. It is in the negative cable right by the driver's side headlight. A hefty silver plated contact cable connector that you can simply pull out to disconnect the battery (without taking out the spare). Push it back in when you want to reconnect.

Just lift the front hood and stand on the driver's side by the lift arm. Look down between the headlight and the spare tire compartment. The connector has a red plastic body.

I only use it when working on the car, since I like my alarm and clock to run when parked...

Kind Regards, Chris

 

I had a similar problem on a Mondial QV. It was a slow drain from a 12volt source which appeared to be the clock and/or the cigar lighter courtesy light.
If you don't already, when you garage the car turn your battery connection off (there is a switch in the battery compartment where the ground is.). See if that helps.

 

My 308 has sat often for more than a week, but always has started. Does sound like a drain from somewhere.

 

My 308 sits for two or three weeks in heated storage during winter, and when I go to start has plenty of juice. I believe you are leaking.

 

When I bought my 308, it must have had a crummy battery, as the car would be dead after 1 week of sitting. It was the clock. I used to have disconnect the battery strap on the left of the spare tire. I put a new battery in it, and the car starts everytime now.