whick Optima Bluetop? D31M or D34M?

[kdiddy]

okay, I meant to do this last year but never got around to it but this year it's getting done before the season even starts.

For cost's sake I'm not going to jsut use a basic Perko switch set up to run two batteries, Bluetops.

Because of size considerations I'd like to go with the smaller D34M, but I I want to make sure I've got enough juice for my needs.

Basically one would be a starting battery and use while engine was running, and the second would be switched on while anchored and just playing stereo (which is fairly large and probably draws decent amount of power)

I assume the answer would be to play it safe and go with the larger batteries, but, how much wopuld I be sacrificing for the smaller one?

Could I use one of each?

thanks

[mgswed]

RE: whick Optima Bluetop? D31M or D34M?

I am considering this as well. I know it was a while ago but does anyone have any recommendations on which blue top to buy? Thanks -MG

[NautiqueJeff]

RE: whick Optima Bluetop? D31M or D34M?

Go with the bigger one if you can fit it into the space you plan to use. I think that's the D31M. I have that one, and it sits on its side under the rear seat. So far (about one year) it has been wonderful.

[Labatt911]

Battery

I believe I used the 34. Instead of the switch, I bought for $50 bucks at west marine a two cell battery isolator. All you do is hook up the batteries together and run a wire from the back of you alternator to the center post on the isolator. That way you never have to worry about turning the switch and draining the wrong battery. And the batteries will charge each other when the boat is running. Just hook all of your stereo equipment up to the second (auxillary battery). I too have only used the set up for about a 1/2 a summer. It has worked great.

[mgswed]

RE: Battery

Thanks for the info. -MG

[Mikeski]

kdiddy,

We have been discussing battery/alternator upgrades lot this winter on other wakeboarding websites. It seems like 200-240 amp-hours works pretty well. To get this much reserve capacity you will need 4 of the smaller blue tops, three of the larger blue tops or two golf cart batteries. The battery isolator will drop your charging voltage so you might want to consider a battery combiner from Yandina. I am almost done with my battery upgrade, here is a schematic of my system. My only regret is going with the 150A combiner, I wish I would have went for the larger 200A+ unit.