Battery Question

[HPSimpson]

I have 1996 Dodge Cummins diesel, after siting for six weeks both Optima 34-78 battery's read about 9. 75 amps. The truck will not start under this condition, would this be consider normal for setting this long.

 

[B.G. Smith]

Mine sits in the driveway sometimes that long, a little quick I would say. bg

 

[nickleinonen]

with the batteries charged up and in known good condition to start the truck, unhook both batteries and in series with one of them put in a multimeter set to read amperage [0-10a scale] and see how much your paracidic draw is [idealy next to none, but less than 1a (0. 5a-0. 75a) is a good number to shoot for with computers on newer vehicles]. . then start pulling fuses to see which circuit is drawing too much...



or it could be that your batteries are beginning to show their age... ?

 

[HPSimpson]

The batteries were bought in February 2005, I will tried unhooking and see what the draw is on the batteries.

Thanks

 

[JWChessell]

I parked my '03 with new batteries for 93 days; did not disconnect the batteries; connected a 1-amp solar charger (1-amp under optimum conditions). When I returned, both batteries were D-E-D dead -- nothing would light up. Took about 1/2 hour with a jump-connection to another car, idling its engine, to get the batteries up enough so that when the other car rev'd his engine, the truck started.

 

[Loren]

Did you mean 9. 75 volts? If you are reading 9. 75 amps with the truck shut off, those batteries will go dead in a matter of a day or two.



It sounds to me like something is drawing too much power when your truck is off. My 1995 has sat for at least six weeks on several occasions without drawing the batteries down that much. Nick’s advice to pull fuses is good. As he said, it’s also possible that one of your batteries is dying, but they shouldn’t at that age. I am still using a pair of Optimas that I bought in January 1999.



Optima batteries don’t self-discharge very fast, so I suspect there is a load on them. The only time I had my batteries go dead (in the 2000 truck) was when I left for a 4-5 day trip and left the interior lights on. I couldn’t believe that those few little bulbs would deplete two deep-cycle Optimas, but they did. A charger brought them back, and so far they are still good batteries.

 

[HPSimpson]

Battery problem

I disconnected both batteries and re-charge slowly the right Optima came right up, the left after two days still would not fully charge. I replaced the left battery and fully charged before starting the fuse check. Then went though each fused circuit to find what was causing the draw. The after market alarm system drawings 1. 75 amps while in the on mode, with disarmed draws . 92 amps. Since I keep the truck inside fence area I have pulled the 20 amp fuse, and only install when I park some some place else.

Thanks for the help.

 

[Loren]

Paired batteries

Just a reminder: Your two batteries are a set. They need to be matched.



As a general rule, I would not replace just one of them. Replace them both and use the one good one for some other vehicle.



If you can’t spare the change for a pair of Optimas right now, then you should ensure that your replacement is at least the same type and size as the older battery. Do not mix types.



If you do mix battery types, ages, sizes, etc. , you can expect that one battery will cause the other to fail.



Glad you found the problem with the alarm. I would never have thought that those systems would draw that much power.



Loren