optima battery/ 83 911sc

[nycplumber]

hi guys,

i have a 83 911 sc I want to know what model number optima battery you guys are using. I will be buying a Deep cycle one.

Thank u!

[jetkona]

Here's what I have in my 87 Carrera.

[haycait911]

I also run a red-top. why a deep-cycle?

[billybek]

Deep cycles are typically for RV/ Marine use where small loads pull down on a battery for a long period of time. Not usually what you want in an automotive battery.....

[khamul02]

They are in you have some serious amps

[unclebilly]

Originally Posted by khamul02

They are in you have some serious amps

I'm not really sure what you man by that but a red top is all you need. Your alternator is limited to 55 - 75 amps (depending on what your car is). If you car needs more than 300 Cold cranking amps, you have other issues.

I had a red top in my 91.5 Dodge Cummins Turbo Diesel (there was only one batter on the 1st gen trucks) and it would start that truck at -30°C without being plugged in. My point is that if it would fire up a cold diesel, it better start up your flat 6.

[khamul02]

amplifiers

[billybek]

I think he means amplifiers for the stereo system....

[unclebilly]

Yah but if your amps draw more than your alternator can put out, the size of your battery is just a measure if time before it goes dead... which I guess is why you'd want a deep cycle.

[ljowdy]

One thing to keep in mind, Optima batteries don't like trickle chargers. If the battery goes dead, hit it hard with a high amp charger and it will usually bring it back to life.

[nycplumber]

Thank u!

[Gordo2]

A little follow up on the Deep Cycle part. I don't have one in my car, but do for a 4WD that I own.

The benefit of deep cycle batteries is that they can run electric appliances
- stereo's with amplifiers, winches - or as they are intended: electrical trolling motors and electrical appliances on boats - for a long time with less requirement for a supporting charge by the alt. They pretty much continue to provide a full shot charge to start your motor all the way to the point to where they are dead. You can run them dead and recharge them to full life many times (cycles).

People with high end stereos like them because you can have power a high end stereo (with the car turned off) for long periods and still have power to start your car. People with 4WD's like them because you can run winches, lights etc with the vehicle turned off and still have starting power.

They are normally more expensive than normal batteries - optima yellow top vs. red top. If you don't run electronics with your car turned off, there is little value in buying a deep cycle battery.

Hope this clears it up for you.

Gordo