Cranking batttery Merc Pro xs 250

What cranking batteries are you guys using? The last few times out fishing at night I haven't been able to crank my boat after running my electronics and lights for just a little while. The battery is only about 8 months old but Im thinking it may just be too small after researching it a little bit. Its a interstate with 750 cold cranking amps and a series 27. Im hoping its simply a battery issue because after I charge it all night it instantly cranks up.
 

FishingwithRusty

Active member
i was always told the optimax needed 1000cca. i run a 31 series oddessy agm

hearing about guys piggy backing a smaller 12v battery to help with the bigger electronics
 

jbh3

New member
IMO, you're going to need to move to one of the dual purpose group 31 AGM's. The Batteries Plus X2 or the big Odyssey are really good choices. Both are expensive, but have good warranties. The Deka/East Penn from Sam's has decent #'s at a more reasonable price and may get the job done for you. FWIW, Merc recommends a minimum 1000 MCA's for the engine alone. You need the big numbers for cranking amps and RESERVE CAPACITY to run all the accessories and still be able to start and run your big engine. Best of luck in your decision.
 

Strato-G

Active member
Its a little added weight if you use standard batteries, I went to 2 31 series linked for cranking & electronics and live wells..... emoGeezer emoUSA
 

Rob Lee

Member
I have a 225 opti-max and use optima blue tops. 900 cca. I have two birds helix 10 mega si gen 2. No problem. In fact, just recently replaced batteries after eight years. Still using one of the old ones in rv. Pricey, little bit.
 

273vindicator

New member
Go to batteries plus and get you a group 31 and you will be very pleased I have an optimax and run into the same issue and boat has never went dead again since the switch
 

fischnrod

Active member
I have nothing on my cranking battery but the standard stuff when I turn the switch on , everything else is on my trolling batteries. I don't have all the new electronics like everybody else either I can't afford them emoGeezer
 

silvertalon

Active member

silvertalon

Active member
fischnrod - 1/20/2018 8:47 AM

I have nothing on my cranking battery but the standard stuff when I turn the switch on , everything else is on my trolling batteries. I don't have all the new electronics like everybody else either I can't afford them emoGeezer[/QUOTE

]Sears has a group 31 on sale right now for 150. Its a 750 cca and has 155 reserve cap. If you run 2-4 locators and 2-4 pumps in summer, you need a lot of battery. I can prove that when I once had to throw back 24 pounds in a CBA when I got stranded. - Blue top, Exide Megatron, Deka. Size (group 31), and reserve capacity are paramount. Plan to spend 225 plus for the best. . Its better than carrying 2 batteries. I just bought a Megatron agm, and the reviews say 'you just can't kill it'!, I always carry a 700mca jumper booster that is light weight. Optimax reguire a min of 650 cca (1000 mca). The reason is the PCM (ECU), the computer module. It requires at least 500 amps to fire the motor (ignition).
 

Carl

New member
Go get the duracell 31agm from sams and dont look back. I battled the battery with the pro xs for a few years. This battery is around $175
 
+1 on going to a group 31 battery. Weigh the merits (there are many) of AGM, gel, and all the other fill media options carefully. In the end you should keep in mind those 'aw sh**' moments when the battery dies and you need a replacement now. I stayed w/ wet cel batteries for this reason - I can get one anywhere. My Wally World batt was $80 and, on average, lasts 24 months.

If you decide to go to a different fill medium be sure your charger(s) is compatible.
 
Something else to consider: get a Weego. It's a portable charging/jump starting device you can buy from TW and other outlets. Gives you 20-something jumps from one charge (advertised, prob a few less than that in reality). Tons of peace of mind for $150 (pro model). Fits easily in the glove box. If you fish lots of TXs and use all of your toys it's a must-have item.
 
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