barney55

You all know the story well.

But does anyone know the maximum amp/hr battery that i can put on my 964.

what's to stop me throwing on a 150 A/H or 200 A/H, can the alternator

handle it?

Checked the battery drain normal is .03 amps on the multimeter

(not much i guess).

T I A

elbeee964

I've had no troubles since going to red optima and porsche battery maintainer.
Not what you asked, I know, but there it is.

ltc

Put whatever you want in the car.
The alternator really doesn't care about capacity, just things like shorted cells, etc.
The larger the capacity, the longer it will simply take to full charge the battery....but it's nothing you'll ever notice.

springer3

How long are you letting the car sit between drives? Mine is not a daily driver, but as long as I get it out at least once per month it fires right up. My drain is about the same as your's. I have an Optima red, and do not use a maintainer.

Battery drain is a problem but every battery has internal drain and will go flat even with no external load. Problems with larger battery:

I won't fit. Can you design a safe mounting system??. Most cannot.
Extra weight harms handling, performance, and fuel economy.
Extra cost.
You buy only a few extra days before the battery is dead.

cwrm4

I had the same problem with a newish (18 month) Optima Yellow. Finally, I bought a nice charger, and it spit out an "internal short" error code on the battery.

I replaced that battery with a new Optima Red and now the car always fires right up, even after sitting for a month.

30 mA is roughly the normal drain.

Wachuko

Optima and a battery tender here... yes, I have a hybrid... at least it looks like that since everytime I park it there is an extension cord to it...

Oracle

Buy a trickle charger and in get used to plug it ever ytime... I have a 2 amp that is really good.. Also I have the Porsche but thats a 8 amp and the battery gets a bit warmer... not bad but I rather be gentle with the OEM battery and use the 2A
Make sure the trickle charger is the ones that is sensing the battery and only if needed charges it.. there are the old style that are always on and will fry your expensive battery

barney55

My car has to sit outside in a car park,so no electricity.

Maybe i'll just dump the spare wheel,get a few bottles of the tire repair stuff,

and stick a huge Truck battery on.

Anyone tried that?

JONES199

You guys get a month of sit time out of a Optima Red? Mine is an occasional driver with a kill switch on it; if I remember to switch the kill I may get a little north of two weeks not much more. If I forget the kill two weeks is pushing it. I guess I have some homework to do.

springer3

After a month of sit time on the Optima red, the starter speed is unchanged. My stand-by draw is around 0.030 amps, similar to what others are reporting. I had a boat battery that would still start the boat after sitting for the winter - over four months of idle time.

Batteries can develop internal leakage. Your's must be defective if it gets weak in less than a month.

dfinnegan

Have you diagnosed the drain?

JONES199

I'll have to check but I think this is the 3rd battery in the 6 years I've had the car; just assummed it was normal. Sorry about the hyjacking the thread,

Grigiocorsa

What I have done is to install a switch at the level of the battery so every time I park the car I disconnect the battery …Since I have done that I have no problem even letting the car sitting for long time (more than a month)

Indycam

volkswagen/audi has a nice battery solar panel .

Type volkswagen solar into an ebay search .

Streetfighter

have heard of this happening, but I have been lucky and have not had this issue. My car spends at times a week or even two sitting between drives. Everytime I fire it up I have not had any problems. Personally, I think if you get a good battery that helps.