How many MCA reccomended for my Merc?

Cricket Too

Lieutenant Commander
Joined
May 14, 2003
Messages
1,732
I have a '99 Merc 250 EFI. Should I being using batts with at least 1,000 MCA or is 800 MCA fine?


Thanks.
 

Cricket Too

Lieutenant Commander
Joined
May 14, 2003
Messages
1,732
Re: How many MCA reccomended for my Merc?

Nobody? What batteries do most of you run, MCA wise?
 

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Re: How many MCA reccomended for my Merc?

I have a 115 4-stroke and it came with a 1000 MCA. So I would assume that is what they recommend. My understanding of it is that Merc engines have to reach a certain RPM to start.
 

1nebel0

Chief Petty Officer
Joined
Nov 28, 2005
Messages
512
Re: How many MCA reccomended for my Merc?

Spend the money on an Optima battery and you will never go back to a wet cell...they will outlast the wetcell battery 5 to one and that will pay for itself alone...most batteries shot in two years and you deal with huge discharges and slow cranking speeds that affects the outboards ability to product a strong spark.. I have 9 boats and will be changing all to Optima now that my friend gave me one that was five years old and works better than a brand new die hard marine....try one and you will see..they are very pricey out of the hole but will save you money down the stretch...
 

Cricket Too

Lieutenant Commander
Joined
May 14, 2003
Messages
1,732
Re: How many MCA reccomended for my Merc?

Thanks Fun Times, that's exactly what I needed to know. My 810 MCA batteries will be just fine.

1nebelO....I had an Optima in my previous boat, it was in the boat when I bought it, had sat there all winter encased in ice. When I got the boat home I pulled it out, cleaned it up and threw it on charge just to check the condition of it, and needed almost no charge at all. I used that battery for the next 5 years and it never ever gave me one single problem and in winter when I would periodically throw it on the charger it wouldn't need any charge at all, even after sitting for 3 weeks to a month at a time.

I went to price them out and they are $260 a piece!!! The reserve on them is low at 50 amp hrs. I got 2 Deka Group 27's 810 MCA and 175 amp hrs each for $120 a piece. I didn't want to drop $500+ and have that little of a reserve. I need the bigger batteries with more reserve capacity. But those Optimas are tough, strong, good batteries.
 
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