Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Merc 90 Repower - Battery

Posted by swist on 08/15/15 - 5:26 AM
#1

So when repowering from a 2004 4-Stoke (carbs) to current model (2015 EFI), recommendation seems to be that battery have at least 1000 CCA capacity. Old one did fine on a 500 CCA battery.

But I don't need to get this motor off to a bad start, so I did get a 1000 CCA battery.

Can someone tell me where all this juice is going? Yeah, it's got a fancier computer and fuel injectors, but all else would seem to be equal - not enough to need twice the capacity. Or?

Posted by gchuba on 08/15/15 - 8:26 AM
#2

The manufacturer's CCA rating would be based on the amperage draw of the starter/staring of the boat. Gets hot quick.They do not want any overheating. Did you cross reference the cable sizing for the new motor?
Garris

Posted by swist on 08/15/15 - 8:28 AM
#3

Looks the same as the old.

Posted by Phil T on 08/15/15 - 3:04 PM
#4

recommendation seems to be


That's a bit squishy.

I would have the dealer show you the Mercury documentation for the new motor that specifies the minimum cold cranking amp (CCA) rating.

I recall it is the Verado family of Mercury outboards that require a minimum of 1000 CCA.

Newer outboards are very fussy and will not start without a minimum amperage.

The battery requirement is not about capacity but rather the ability to discharge high amperage over a prolonged period.