Meatball964

SUCCESS!! I guess in my impatience to get it started the first time i did'nt give it enough run time with the cables attached (sorry for the frantic posts & did imention how cold it is today?).
What pisses me off is this is a one year old Optimum Red Top (off the group buy) that i religiously attach my Battery Tender whenever i'm not driving the car. Hopefully it can be saved.
For the battery to die "mid-drive" like that i have to suspect a bad alternator. I'm charging it up (while in the car), once complete will test, then start car & test. I'll post results.
Thanks for all the knowledge guys...really.

P-daddy

Time lapsed.....2 hours from initial post til now. Best forum on the net!!

AOW162435

A properly-functioning alternator should keep the car running - even with the battery pulled from the car. Or so I've always thought.

If the battery had sufficient power to start the car for your drive home, I can only assume the alternator stopped producing shortly thereafter. At that point, the only way the car will continue to run is on battery power alone.

The Whatever battery my 993 came with gave up the ghost in early 2006. I installed the correct Interstate battery and have had no issues since. That's 6 years. Replacing a car battery every year is beyond my comprehension.


Andreas

IXLR8

Not a good idea.

A battery doesn't need a lot of capacity to start, it needs low internal resistance. The capacity part is what keeps it running. My alternator belt went some 100 miles from home and the only reason I made it home is because I had a new battery. It had a Reserve Capacity of 120 minutes and I got home in well under that. As a battery gets older, the internal resistance increases and the capacity and reserve capacity decreases.

I feel the same way if they don't last at least 10 years, but then there are factors beyond the owner that determine that.

mongrelcat

Dudley

This post reminds me of the RS pulley that was the popular mod a few years ago. The lower alternator output meant that the battery was always in question when driving in stop and go traffic for extended periods.

User 122821

I have had way too many issues with Optima batteries myself or with friends. It seems to be hit or miss with them. I've switched back to group 48 full size batteries from Interstate or Johnson Controls.

Quadcammer

interstate are made by johnson controls and thats what I have.

badabing

Agreed. Unfortunately, for many years my winter storage arrangements necessitated me leaving the car locked with the alarm armed and no place to plug in a tender.

After several months the alarm would flatten the battery. Add a few more months of a completely discharged battery sitting in relatively cold temps and you have a battery beyond resurrection.

IXLR8

I'd remove the battery in that case.

deekay911

[QUOTE=IXLR8;9270783]
A battery doesn't need a lot of capacity to start, it needs low internal resistance. The capacity part is what keeps it running. My alternator belt went some 100 miles from home and the only reason I made it home is because I had a new battery. It had a Reserve Capacity of 120 minutes and I got home in well under that. As a battery gets older, the internal resistance increases and the capacity and reserve capacity decreases.QUOTE]

Capacity is a function of current drawn and time...hence stated in Amp-hours or mAmp-hours. Your 120 minutes would be very variable depending on the current drawn, lights being used, heater motor, demister etc etc. I'm sure everyone would intuitively know that if you running on reserve it makes sense to turn off everything not needed to give you the most 'time'..

993/907

Two batteries in my '95 since new.
No battery tender.
Probably do the third battery this year, just to be safe.

Ish993

+1

IXLR8

Battery Capacity rating on a battery in Ah is defined at a certain C rate or X hour rate.

Reserve Capacity The reserve capacity of a battery is defined as the number of minutes that it can support a 25 ampere load at 80°F until its terminal voltage drops to 1.75 volts per cell or 10.50 volts for a 12V battery. Thus a 12V battery that has a reserve capacity rating of 100 signifies that it can be discharged at 25 amps for 100 minutes at 80°F before its voltage drops to 10.50volts.


Thats for sure as I didn't even power a window down in the middle of summer.

Academictech

[QUOTE=S2K993;9270667]SUCCESS!! (sorry for the frantic posts & did imention how cold it is [QUOTE]

Took my son in the C2S to his hockey game in Shelton CT this am....1degree F wind chill @ 7am...finally some winter like weather! But no snow

Before alternator, check both battery terminal leads...things tend to shrivel up below zero