Replacing my truck batteries, how important are CCA numbers?

It does - darn kid never remembers to turn down the volume.

 

Maybe it means you can crank it too long and then can mess the starter up? That would be the only thing I could think of that would do damage. But I agree with you just spit balling. Ha Ha

 

That's quite possible. You can crank a long time with good batteries. Somewhere on my laptop I've got a cold start video of my old KW. I had that Cat rolling over a good 4 or 5 minutes (intermitently) before it actually stayed running.

 

My thought was because it was talking about the CCA @ cold temps, that maybe having too much CCA and the higher load of a cold motor might actually result in too much load on the starter causing physical damage. After all, the lower resistance of cold temps will let the starter make more power if the amps are there.

 

Very true. But on the other hand, when voltage starts to drop off, the starter will suck up more amps to compensate. That'll generate more heat too.

 

The blower fan will draw more amps if you hold the squirrel cage stationary, thus popping a fuse. The fuse limits the available amps.

A starter will draw more amps as it tries to turn over a cold engine with good compression, as opposed to a warm engine with poor compression and loose oil tolerances. There isn't a fuse between the battery and starter.

 

There's no doubt the benefit wouldn't last long, especially when you consider that all those types of calculations use Kelvin, so it's not the huge temp change it looks like in Celsius or Fahrenheit.

 

That's pretty much what I was driving at.

 

No you dont, arcing upon completing a circuit doesnt care if its negative or positive first, the circuit is being completed, it will flow current, ergo sparks

 

Which is why you want the ground on jumper cables well away from the battery unless it's a quick hook/jump/go.