tafkai

any radio will take power full time . they have a permanent 12v to keep your settings stored (stations etc.) will not be taking more than your clock , so forget about it !!!
like adrian says ........... cold + battery =

btw. adrian , what is your new avatar ??

Indycam

nose of a race car from above .

The power/amps for a radio turned off will be tiny , not battery draining in 2/3 days .

MARC A. 964 C4

Don, "Porsche Battery Maintainer",....Exactly that model!.. So, for my garaged sleeping beauty, the trickle charging has worked great. This option is provided throughout Europe, and std.equip. on the new Porsches being sold by, Porsche Antibes, Fr. I had no other options as to where to buy it, I asked them, I bought it, and it solved the problem.. I also had a drain from the useage of my soft top, did a modification, and one less problem again. All the best, Marc

DarrylH

Although it sounds as if the old one is knackered, if a new battery also dies quick deaths, I'd start the "find the drain" process. There are so many creative ways these cars find to kill batteries...

andrew911

I had a drain in my HVAC control a year or so ago. Had it refurbished by Otto's of Venice (they are a shop in California- I pulled it out and mailed it to them) and that did the trick. Now my car can sit for weeks and still start. Now that it's getting colder and also because once the salt is on the road my car won't be driven I've got the Porsche battery maintainer plugged in (it's called the Charge-o-mat- in the link posted earlier it's called the "porsche battery maintaniner"- seems they now have a Charge-o-mat II which is the more expensive one on that link and still have the regular Charge-o-mat).

Anyway, try to find your drainage problem, and once you get that solved, use the charge-o-mat if the car will sit for more than a few weeks (i.e. the winter or whatever). My old '87 and '78 911's would literally sit for a couple of months in the garage and start right up, but nowadays modern cars seem to have more of a constant draw (at least the 1990 (964) 911's and newer, and a bunch of the modern Ferrari's)- most of the people I know by me with these cars use some form of a battery maintainter in the winter as opposed to pulling the battery, but it's up to you. If you store your car outside I'd recommend pulling the battery since no electric and much colder temps outside...and up by you it's a lot colder than where I live.

Good luck with it!
-Andrew

Red rooster

I bought a ACI charger/maintainer here in Canada for about $80.
Batteries left off charge for any length of time will sulphate ,so lose capacity and then be scrap.
I tried the lighter socket method but was unhappy with the small voltage drop to the battery so wired in a lead/connector straight on the battery. The hood needs to be open a little anyway for possible fumes.
The maintain voltage required depends on the battery constuction .As a rule of thumb , new type , sealed batteries need more volts to initial charge and float charge than the old vented type.
A low spec voltage regulator in the alternator could mean the battery never fully charges.
Problems, problems !!!!

Geoff

Indycam

Hiya DarrylH
"Although it sounds as if the old one is knackered, if a new battery also dies quick deaths, I'd start the "find the drain" process. There are so many creative ways these cars find to kill batteries..."

I don't see any proof that the old battery is knackered . I don't know if the battery is bad or its not getting charged or its being drained . Batteries are cheap but putting a new one in and then killing it by under or over charging it , gets pricey . If it was my car I would pull the battery , charge it up
and then test it .

If ya ever get down to the middle of california look me up .

DarrylH

I guess that reference to low cold cranking capacity got me figuring the battery had seen its last. But as you say, it would be best to go back to first principles and confirm its death, rather than assume it. My bad. FWIW, I have a deep-discharge battery in my car now - and I've had it go flat for various reasons often enough that it's paid for itself several times over. But I'm down to a 16ish milliamp resting drain - for now! And thanks for the offer - never can tell...

Indycam

No "bad" , just a couple of guys kicking ideas around . No right , no wrong . Just talkin . And ifin a beer or two , thats good fun .