My 84 245 GLT just killed it’s 3rd Sears battery in 2 years. I noticed for a week or two it’s sort of stuttered when starting, like it just barely got enough power to turn the engine over. Then one day I go out and it’s just dead.

AAA and the Sears guys both tested the cars charging system and said it looked fine. The meter in the gauge cluster is reading plenty of juice too. Apparently the last battery developed bad cells, and I’m assuming that’s what happened this time too (same symptoms). But I’m sure I’m not just having bad luck with faulty batteries. Obviously something in the car is killing the batteries. One guy mumbled something about "maybe it’s the diodes" but I don’t know what he’s talking about.

So what does this sound like to you guys? I’d hate to replace the battery only to kill it again in 3 months. I’m thinking either the wiring harness or alternator, what do you guys think?

Thanks!

The electrical suggestions are very good but it could be mechanical. Is the battery bolted down correctly? If the battery is loose in there it can bang around and damage a cell. Do you drive on a lot of rough roads? If you do again the impact can damage the battery. When I worked with a Mechanic in his shop we replaced a lot of bad batteries that were fairly new but not bolted down. We would always insisted on brackets but a lot of the Jiffy shops will not.

Good Luck and Happy Brickin'

Brian
86 240GL 142K miles

Yeah, definitely check the amp draw on the battery when the car is off.

In my case, a rebuilt alternator fixed the problem. It killed a few batteries in a couple of months. Each time they tested the battery, they said, "oops- bad cell!" New brushes/regulator on the old alternator did not fix the problem.

Greg

Those are great ideas. Another suggestion: measure the current between the disconnected wire and the + battery terminal. Make sure everything's turned off in the car before doing this or you risk frying your meter. If the load is more a few milliamps somethings draining the battery besides the clock and memory circuits in the ECU and the radio. Like the horn relay example but they don't draw enough current to blow a fuse. Most of these problems drain the battery faster than a year's time but they may be a factor.

Good Luck!

Stave L 3-240s in Charlotte, NC

Your regulator could be allowing too high a charging rate and burn out the battery.

Other than that you might have a relay sticking. I had that one time and it took 2 batteries to realize what the problem was. It turns out the horn relay had one set of contact that closed just enough to drain current, but not actuate the horns. I found it when I was changing the battery and happened to hear a very small click.

I suggest that you don't depend on AAA or Sears to track down Volvo
electrical problems. Get someone who really knows Volvo electrical
systems because they have their own peculiarities.
If your amp light stays on with the engine shut down, it most
certainly is a problem with your isolation diodes.

You didn't say whether it is a Bosch or Motorola/SEV/Marchal system
which makes a considerable difference in how you approach the problem.

One thing you can do is to either install a battery switch and turn it
off or just disconnect one of your battery cables any time you shut the
car down for any length of time. If this helps, it verifies that it is
a wiring or charging system problem.

Sears batteries are variable and it may be that you did get a run
of defectives but I doubt you would have 3 bad ones in a row.

What voltage was your charging system putting up?
Should be between 13.5 and 14. Much over that and you will damage the
battery by overcharging.

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George Downs Bartlesville, Oklahoma