Static Current draw on battery
 

Does 45 mA draw on the battery with the car shut down seem unusual?
It's a 2 yr old Optima Red top. I've been charging it every five days or so because the engine seems to crank slower each day. Checked the ground strap from frame to transmission. With engine running at 2000 rpm and lights on, voltage at terminals is arounf 14 V.

Your charging voltage seems about right. 45ma means that it would pretty well drain your battery dry in 1,000 hours (40 days), assuming 45 amp-hour battery. I assume from your user-name that you have a 1990 or newer C2? Are you measuring the current draw with alarm on? I know they use some current (my 993 uses more power with alarm on). Your numbers don't seem really out of line.

I hope you don't need a new battery, but if you do, these are great:

www.rockracingbattery.com

Best I've ever used (but pricey). I use the 1236 in my 73RS racer and after 5 years it's better than any other new battery I've used. I might recommend a slightly larger model for a newer car with more electrical accessories though (1257)...

Some questions about using16V batteries:
What damage would the higher 16V voltage do to stock CDI/coil systems?
How could the voltage regulator (output: mid14Vs) recharge the battery?
What would that do to 12V radios and alarms etc....? Are all the older, stock, wires rated for such?
Please educate us on the conversion process. Thx.

C2: Make sure the battery is disconnected from the chassis when charging so the charger doesn't spike the vehicle electronics/etc, and make sure it stays at ~12.6V a couple days later after the surface charge has been absorbed.
Two years isn't much, but it may be time for a new battery.

It's on an 86 coupe. Not many bells and whistles. The C2 is a rowing ergometer.

One other detail. Early in the year I connected the battery charger backwards for an instant and there was some current, but it was not plugged in. Someone at work thinks I may have damaged a rectifier in the alternator.

The two models I mentioned (1236 and 1257) are both 12V models. I don't recommend the 16V versions for a Porsche...

Re: Static Current draw on battery
 

fwiw.. i finally bought a simple battery load tester. A bud said spend the $90 on a snap-on. I only used it once on my 911 but it told me exactly the % of max current available.

I would not worry about having damaged the vehicle.

The worst thing that could have happened is the battery saw a large current spike. They do that all the time when you turn the key.


My 88 draws 90 milli amps