Starting Battery for Optimax

[Optimax Man]

Curious if anyone is using a deep cycle battery for their optimax. Mercury states not to use deep cycles and requires you have 1000ca and 800cca. If you are using a standard marine starting battery, not deep cycle, do you have any issues running down your battery using locators or running lights for extended periods of time?

[marine_man]

The reason merc recommends what they do is because the amperage draw is huge with a dfi engine. Based on the discharge rate, I doubt a deepcycle would hold up long enough.

If you move around a bit with your rig, you should have no problem running down the battery with lights or locators... the alternator charges at 60 amps at WOT... you should be just fine.

The other risk with using a deep cycle is low voltage problems with the computers. Use what mercury recommends.

[ChuckN]

I was just faced with this same question last week. My battery could not handle fishing all day with livewells, graphs, etc. It was a cheap battery at that, and I'm thinking that was my case.

I asked a Mercury mechanic and he explained it just as Marine_Man did, so I won't repeat what he said. Not recommended...

[PerchJerker]

I have an Opti and a 1000 amp starting battery. I've never had an issue with it running down even though I run a bunch of stuff off that battery.

[anordqu42]

I have an opti that is VERY touchy when it comes to starting. I know some of it was bad batteries, but even with a brand new 1100 ca battery it won't start always. If I go more than a week without running it, I need to make sure to charge it overnight. But even sometimes that doesn't help!! I've learned to always have a backup plan or two with this motor; some times I can get it started by first starting my kicker and using it to put more juice to the battery. I also carry a jumper pack (you know, like one you'd have in your car) and attach it directly to the motor (that has worked every time). And before the jumper pack I used jumper cables between the trolling motor batteries and Opti (does not work if I go between batteries).

To answer your question, yes, I have gone long periods of using electronics/livewells and the motor has started up just fine, as long as I've been using the boat regularly.

One thing I should mention is that my battery is up under the console, and I think if it closer to the motor I wouldn't have as much of an issue.