Battery drain or bad battery? Options

[tornik550]

Due to a new baby, I haven't been driving my car much. I have found that if I let my car sit for three days or so, the battery voltage will be so low that the starter will not turn. The alternator cranks out 14 volts when running.

I made several changes prior to noticing this. I suppose there could be something which could be causing battery drain or my battery could just be going bad. I suspect this may have been going on for a while however I drove the car frequently so I didn't notice.

If I change the battery with an external charger while it is still hooked to the car- it will charge to around 13volts then by morning it will read around 12.33 volts.

I obviously do not really understand batteries. Is there a way to determine if I have a battery problem or a drain problem.

[pcar916]

On batteries you can generally depend on the specification. If it says it's a 48 month battery it will likely last that long and not much longer. There are exceptions of course, but wet-cell batteries are a very tried and understood technology, which makes them fairly predictable.

One thing folks don't do enough these days is make sure that the fluid level in them stays up to the "rings" and above the plates. If your plates are showing the battery is killing itself. Get it up to the correct level with distilled water and charge it immediately. If it's too far gone or a cell is bad then it's just a core toward a new battery regardless of the electrolyte level.

I have a battery cutoff in my car and the Optima battery is 10 years old. I expect it to die anytime but it still holds a good charge and won't give up so far. Now that's weird.

But at least I don't have a clock (or anything else for that matter) constantly draining the battery.

Once it's fully charged, if you run it by a your FLAPS they usually have a tester that'll report it's condition. You can also check the electrolyte yourself with a specific-gravity style battery checker.