Time for new batteries

[Black Snow Slide]

My boat came with 3 batteries. 1 as a start battery and 2 as house batteries. This fall was the first time I gave them any care and was shocked as to what I found.

My start battery is a 750CCA start battery. This battery has a constant draw as the Carbon Monoxide detectors (2) are always on and can not be turned off.

The two house batteries are the same 750CCA start batteries. These batteries get drained due to Refrigerator, lights, stereo, blender, and all the other 12 volt goodies. I have a built in charger in the boat that is always pluged in.

The Interstate Batteries are toast and am wanting to replace all three with Deep cycle batteries. I am starting a Volvo 5.7L GI-F. A friend of mine has the same motor and starts his with his a deep cycle.

I was thinking Optima blue tops. What is your ideas?

 

[JoLin]

Re: Time for new batteries

Here's what I think:

Marine starting or hybrid battery for the motor, deep cycle or hybrids for the house. Keep 'em separate- the way you use power you might find yourself stranded. Exercise better care and oversight of the batteries you install.

Develop better energy management habits. I pre-chill the fridge on shore power and only run it off the dock when the boat motor is running. The rest of the time it's turned OFF. It's an amp hog. I make good use of my carry-on cooler.

Easy on the lights, or change them over to LED's. A D-cell camping lantern also does a good job of lighting the cockpit. Night vision works great- you'd be amazed how little light you need if you give your eyes a chance to acclimate to the dark.

Turn down the stereo. That big-*** amp you're driving was giving me a headache, anyway

'Course, you can always install a couple of 8D's as your house batteries, but the boat might list a little to one side

 

[trendsetter240]

Re: Time for new batteries

Some good advice from JoLin on how to be power smart.

Personally I would recommend a dual purpose starting/deep cycle for your starting battery. Get something with 1000MCA or around 750-800CCA and at least 115 Minutes of reserve capacity.

For the house batteries a single 8D deep cycle battery (expensive) or two group 31 deep cycle batteries with at least 110AH (Amp Hours) capacity each.

My opinion is that the AGM and Gel Cell batteries cost more than the improvement they provide. Stick with middle of the line quality flooded lead acid batteries for the best bang for your buck.

Cheers!

 

[Greg Mrozinski]

Re: Time for new batteries

Black,

Jolin and Trendsetter make good points. If I may add a few additional notes. Batteries are expensive so do a little homework before you buy. First calculate what your total power consumption is when you go out...add up all the Amps you will be drawing using the frig, stereo, amps, lights, etc. Take that number and multiply it by the total hours you plan to run all these things. That gives your total amp-hr requirement. Now, deep cycle batteries are rated at an average 20 hour Amp-hr rating. For Group 27-31 batteries it runs around 80-110 Amp-hrs. Normally you don't want to take your deep cycle batteries below the 75% drain level. So actually than you only have about 60-80 Amp-hrs per battery. So, if want to run say 20 Amps than you will have about 3-4 hours run time on each deep cycle battery before you have to recharge. So an all day outing turns out to be only about 8 hrs on two deep cycle batteries. Not much really if you want to do an over nighter as well.

Speaking of charging, how do you plan on recharging the deep cycle batteries? Most OEM alternators are not capable of adequately charging deep cycle batteries, especially AGM and Gel cell versions. So if you plan on starting your engine to try to recharge the house batteries you will have to run your engine at nominal speeds for a very long time to recharge. Not practical. Also different types of batteries have different charging profiles. Most OEM alternators do not contain the proper voltage regulaters to charge deep cycle batteries. Also, if you decide to go with AGM or Gel cell deep cycle batteries, make sure your on board shore power charger can handle those types of batteries. If not you will ruin your new expensive AGM/Gel batteries in a heartbeat. Most newer style chargers are type selectable and some can even charge multiple types in the same system.

As far as your CO dectors go, you can rewire them to run off the house battery(ies) or install a separate breaker to isolate them and you can then turn them off when you want to. You didn't mention an on board generator so you may not need them on all the time.

Batteries and charging systems are not easy and require a good deal of thought before moving ahead with changes and upgrades. You don't want to be dissappointed in performance and waste your money. Good luck with your purchase and I hope that what I said helps and not confuses you further.

 

[Fl_Richard]

Re: Time for new batteries

I would avoid running the CO detector batteries with the house set. With proper battery etiquette the starting batteries should never be dead and propane appliances often operate without any power so CO protection should always be operable.

 

[Black Snow Slide]

Re: Time for new batteries

I went to 2 different places to buy the Optima battery today and one wanted $280. and the other was $278. I found them on line at Summit Racing for $200. but wasn't comfortable with the policy for handling warrantee issues if one arises. So I went with my number 2 choice. The Diehard Marine Platinum 2 size 34 m. It is a AGM construction witch is the same as the Optima. Weight they are the same. CCA they are very close. The warrantee is much better with the Diehard. 3 years no question replacement. They were on sale this week for $189 after trade. Not bad. I Really hope I made a good decision.

 

[JoLin]

Re: Time for new batteries

You're going to get as many opinions as there are members here

If that's the kind of battery you wanted to spring for, be happy. Sounds like you got a good deal on them.

 

[Greg Mrozinski]

Re: Time for new batteries

Definitely a good price. They will be fine. Let us know how they work out for you.

 

[Black Snow Slide]

Re: Time for new batteries

Installed the batteries yesterday and all is good. I took out the little trays that hold them in and cleaned underneath them and reinstalled with 5200. Turned on the main power and she became alive. With all the rain we are receiving in southern New England, the arc is ready just in case.

I got an e-mail from a guy with a pic of his engine compartment. He has 8 of these batteries for Start/ House/ Generator. He has had them for 3 years on his live aboard. He described his boating and usage as " heavy duty with no breaks." Ill let you all know how long they last but don't be mad for me digging out this thread years from now.

Thank you to all who contributed. Black Snow Slide