What size (power) battery do I need?

[Emission]

I've never bought a battery in more than 20 years of driving -- I'm a complete newbie when it comes to this stuff.

My '86 Turbo is sitting in the garage with a bad battery. It's on a trickle charger, but it won't hold more than 7.62 volts when unplugged. The original owner purchased the battery from the local Porsche dealer back on 9/27/2001 (more than 7 years ago). I think it is an OEM Porsche battery (white in color, with no real markings anywhere).

I think it is time for a replacement.

My car is always garaged, never outside in the cold, and I drive it 3-4 times a month. Like I said, it sits on a "Battery Tender" trickle charger when in the garage.

I want to get an Optima battery, as I hear good things. What model do I need? How many CCA and AMP Hours? I assume I will have to make an adapter plate for it...

Thanks in advance,

- Mike

[afterburn 549]

I use the Pc 680 will start dwn to below freezing...8.5 .1 C/R most like them and they are small !

[RSBob]

I went through the same thing not that long ago and did many searches and came back with a perpetual Porsche favorite. If you like dry cells, you might want to try an Optima Red Top. Available at Costco/Sams Club and many others. Well made, lots of cranking power, an no bad acid flashbacks, man.