Is my Optima a gonner?

MGN54 · 06-08-2003, 04:07 PM

Hi,
I put an Optima in my 88 Carrera about 6 years ago. Great battery! Over the past two years the car has become a garage queen. (Tired of it getting dinged at work!) Anyway, I don't keep it on a trickle charger and charge the battery on occasion for a weekend drive. Put it on a 10amp auto charger yesterday and charged it for about 24 hours. Battery was registering almost 13 volts when I disconnected the charger to go for a drive after dinner. Car turned over slow but started. Took it for a spirited drive and pulled back in. Tried to restart and no go. Bummed. Is the battery toast and time for replacement? Or, do I need to charge it at higher amperage? Guess I can't complain if I need a new one. Just don't want to purchase a new one if I just need to give it more of a jolt!

Mark

bell · bell's Garage

change it, sounds bad to me......and don't run the car until you do, bad batteries will destroy alternators

911pcars · 06-08-2003, 04:31 PM

Don't automatically throw it away without first checking to see if it's just discharged. More good batteries are discarded because of this.

Optima batteries (mine anyway), don't reawaken from a discharge like other batteries. I've discovered it needs a jolt from a large, quick-start type charger, the type found in repair shops and service stations. The Optima dealer told me about this.

Perform a quick charge for 1 hour or less (do not overheat the battery). At this point, the battery should be warm but receptive to a trickle charge (overnight should do). Use a battery conditioner (slow trickle charger) when the car sits for period of time. If your shop is doing this, ask them to test the battery after charging to see if it's okay.

Sherwood Lee
http://members.rennlist.org/911pcars

widebody911 · widebody911's Garage

Optima batteries have a convoluted recharge dance which must be followed. Something like charge @ X amps for Y hours, sacrifice a house cat and sprinkle it's blood on the positive terminal, then charge @ X amps for N hours, etc, etc

The exact incantation is probably available on their site.

Randy Webb · 06-08-2003, 04:45 PM

"it needs a jolt" -- Right -- or use use another battery (briefly) then go to the trickle charger. Worked for me.

pwd72s · 06-08-2003, 05:54 PM

What's wrong with taking the car for a few hours drive? Plug in a volt meter, or hook up a mutli meter reading volts. In time, you'll know if it's battery...or something else.

911pcars · 06-08-2003, 10:04 PM

Porsche alternators don't seem to like being battery rechargers, at least for amounts needed to recharge the battery. It's better to use a fully charged battery with the somewhat nervous charging system we have rather than stressing the alternator and it's electronics with excess current output.

The battery is primarily needed to crank the engine for starting. Once the engine is ON, the alternator supplies the majority of voltage and current to the elec. system. A voltmeter hooked up to a defunct battery will still read around 14+ volts in a good charging system so this isn't going to tell you much until you try to start the engine one or fifty miles from home. This method is highly inconvenient although good for personal exercise.

It's better to take the battery to a reputable battery/electrical shop where they can test the battery. "Old-fashion" battery testing methods required the battery to be charged before testing. This can be hazardous to test techs as the gases produced in a charging battery are explosive. Modern test equipment is able to test battery capacity even though it's discharged. This is infinitely safer for the operator and to surroundings (engine compartment, paint surface, etc.)

Sherwood