Engine Start Battery Size

[charles_reed]

The usual answer is to ensure that the CCA value is higher than the starter motor requires. All the Yanmar ones up to 4-cylinder state 200 A. I have not found values for Volvo but assume something similar. However, the battery may need to supply this current for some time and it may not be fully up to charge, so some leeway is needed. The 13 Ah of the RF900 was OK under ideal conditions but not otherwise. The 38Ah of the RF1100 seems to be plenty.

That's because they all, from the 2GM20 to the 3YM30 use the same starter motor.

 

[vyv_cox]

That's because they all, from the 2GM20 to the 3YM30 use the same starter motor.

But it must surely take more current to turn over a 4 cylinder engine than a 2 cylinder?