Battery Group Size

[mikester]

Spent some time shopping around all the local parts stores for a new battery this morning. I really wanted a Delco side post battery. Just when I thought the only option would be going the local GMC dealer my buddy that owns a shop said his distributor can get them.
That brings me to yet another question for you guys that have done this. Which group ? I know both of my cars came with a 75. The best Delco in a 75 has 700 CCA . If I went to a group 78 that kicks it up to 800 CCA. Seems like a pretty decent difference. I know they both fit. Cars got a standard 78 amp alternator.

 

[Gonzo1970]

My 86 GP Came with the wrong size battery. I didn't know it at the time, but it eventually destroyed it. That's when I found out it was the wrong size.

Went to a Group 75, 700CCA and its fantastic now. Had to do a Duralast Gold.. for $160. I didn't have much choice as the battery took a dump in the middle of nowhere indiana, and that was the only thing around.. At that point, I would have taken a Rual King Exide for $49 (They do have Group 75 batteries for $49, but they're 630CCA). But the Duralast Gold has been fine.. So far..

-Gonz

 

[Longroof79]

Mich,
I've always used a group 75 battery and have never used a 78 series, although we have the option to go either or. The battery tray certainly supports a 78 series size wise. A 75 series battery always looks like it's undersized when it's installed.

 

[mikester]

Mich,
I've always used a group 75 battery and have never used a 78 series, although we have the option to go either or. The battery tray certainly supports a 78 series size wise. A 75 series battery always looks like it's undersized when it's installed.

So Jack, if you had the choice and they were priced close would you go with the larger battery ? 100 more CCA seems to be a decent amount.

 

[Gonzo1970]

I wouldn't.

My Group 75 / 700 has proven to be quite adequate. Now, thats stock, mind you.. If you modified the engine internally (eg. raised the compression) then maybe another 100 would do you some good.

-Gonz

 

[mikester]

I wouldn't.

My Group 75 / 700 has proven to be quite adequate. Now, thats stock, mind you.. If you modified the engine internally (eg. raised the compression) then maybe another 100 would do you some good.

-Gonz

My 406 isnt quite stock. Not that its a big HP, high compression motor but definitely not stock.

 

[spidereyes455]

It's not just about cranking amps in the cold, summer heat and humidity puts a huge strain on batteries too. Not to mention electrical accessories pw, a/c phone chargers, stereo equipment ect. I generally use size 78's in my cars due to the higher cranking amps and larger power reserve should it be needed. I always buy the highest amperage battery that will fit just for peace of mind.

 

[83StreetMachine]

I always use 78s when possible. I usually like to try and find them with dual terminals as well.

 

[Longroof79]

So Jack, if you had the choice and they were priced close would you go with the larger battery ? 100 more CCA seems to be a decent amount.

MIch,
I think I'd go with a 78 the next time I need a new battery. I think for the fact that there's more cranking amps and cold cranking amps, not that it's much of a concern down here..

 

[Gonzo1970]

My 406 isnt quite stock. Not that its a big HP, high compression motor but definitely not stock.

A 406 isn't stock at all.. lol

If I get my way and I put a 6.6L Pontiac 400 in my GP, it would get a 78/800

But I dont see the point with a 305 SBC.

-Gonz