Battery power

[66toaster]

I'm in the Phila., PA area. How many CCA does a '73 coupe need? Car came with a battery @ 800CCA. I'm partial to Interstate. Their website shows the battery for this car @ 590CCA. Is that sufficient or should I continue with the extra CCA? Car is in an unheated 2nd floor building garage. Thanks.

 

[HB Chris]

The Interstate is a Group 47, around 450CCA I think. The BMW Exide battery is also 450CCA, 50Ah. Both work fine in my coupe. With the permanent magnet starter from the e30 M3 they crank the engine even faster.

 

[deQuincey]

I use a 70Ah battery
That is the maximum size that the original tray can hold