Sometimes they become so discharged that they can't recharge. I think a typical battery charger has to detect some voltage to be able to charge it. A trick is to connect a good battery to it in parallel, and attach the charger to the good battery. Optima recommends this in their instructions.Preferred: Fully automatic “multi-stage” or “multi-step” chargers, which monitor the battery and charge it as necessary. Multi-stage maintainers will charge at varying voltages and varying amperage (rarely exceeding two amps). Some of these multi-step chargers are also capable of being regular battery chargers (seven amps or more).
OK but not preferred: Traditional “float” chargers provide constant voltage with tapering amperage to the battery even when it is fully charged. For float charging, we recommend 1 amp max, 13.2-13.8V.
sounds like the alternator is failingThe last 2 outings I've had problems, both times after a rest stop it failed to start but started right up when jumped.
In reviewing my logs tonight I noticed last year my voltage would vary from 13.6 to 13.8 while driving but in todays log it varyed from 13.1 to 13.3. Also in checking the log tonight my voltage (with the ignition on but not running showed 12.33 volts but it did start. I'm thinking I dropped below what voltage was needed to start out on the road.
Andrew.......Good point on sloshing corrosive stuff around when on the track. If I go to another Optima I think I'll try the red top this time for it's higher cranking power. Before I was looking for more reserve capacity but there lots of choices.
Alfajay which red top did you get 20 years out of?
Optima Batteries - Auto Parts Warehouse
Well, it's the kind Optima was selling in 1994 (when I took the picture below I saw that the "94" square had been pulled from the sticker on the battery - so I exagerated - it's only 17 years old). I have heard that the Optima company changed hands once or twice, and that subsequent owners lowered the quality standards. My point being that whatever model I bought 17 years ago probably isn't available today.Alfajay which red top did you get 20 years out of?
This was my experience as well. For a daily driver with a good charging system they seem to work okay. But for something driven less frequently with a not-overpowerful alternator (like my '91 Spider) they seem to degrade a lot faster than a standard lead acid cell. Likely this is due to the fact that they're less tolerant of low charge states.I have had mixed results with my Optima red tops, I think they don't last as long when the car just sits, but if you drive it enough they seem to do well.
Humm.....didn't think of that? The first time it wouldn't start was the second time I took the car out that day. The first time out the battery tender showed a full charge.sounds like the alternator is failing
Thanks Eric........I can check this via the laptop.Many chain auto parts stores (Advance Auto or AutoZone) will test them for free (keeping in mind they are hoping to sell you new parts...).
Or a simple voltmeter can be used. Connect it to the battery. A well charged battery should show ~ 12.6V with everything 'off'. Then start the car and see what it shows with the engine running ~ 2000 rpm. It should be 13.6-14.6V. It should remain fairly steady when you increase the rpm's. (It may return to battery voltage at idle.) If it reads higher than 14.8 the battery might be getting overcharged (can 'boil' away the electrolyte). Less then 13.4V may not be enough to re-charge the battery.