Wiring additional batteries

[ready123]

People will tell you that it is heresy, but I use deep cycle batteries for my engine starting batteries, which also power my house loads.

I changed the group 27 starting batteries to group 29 deep cycle from Wally World, which are the biggest ones that would fit in my box (without modifying it too much). I run a few house loads off of them while at anchor overnight, like my anchor light, and reading lights. I do not run an inverter or anything with a high current draw. I'll run the generator for maybe 30 minutes before bed to cool-off the fridge, which brings the battery charger online to top-off the batteries too. In the morning the batteries are still fine. While the alleged not-for-starting batteries do a fine job of, well, starting their associated engine with no problem, as a matter of course I use the emergency start feature to parallel the batteries when cranking. By paralleling them, each sees half the draw they would otherwise. It should be noted that if I was cranking big diesels my thoughts would be different. For the last two years, my deep cycle batteries have cranked my small block V-8s just fine. Since it never sees house loads, I have a bona fide starting battery on my generator.

I can't argue with that plan..... it is not the ideal and your generator means you have a good backup should the starting batteries drop too low. Lack of a generator does require careful attention to the battery state of charge IMO.
As they say there is more than one way to skin a cat! Apologies to fellow cat lovers.

[vickyb]

The batteries in my boat are not originals.. I have twin Merc 260's...Not sure what batteries I need for that. One site says: 375 cca/475 mca/90 Ah
Which of these batteries would be equivalent?: http://www.canadiantire.ca/en/search-re ... ne+battery
Not sure if Canadian Tire is a good option for getting these batteries. Only reason is its more accessible to me vs a Marine Store.

Right now I would use this one, buy two one for each engine if it were me.
http://www.canadiantire.ca/en/pdp/group ... -VxCvldWSo
That will cover you for the day trip excursions you described then at a later date you can put in a dedicated deep cycle circuit for the fridge, stereo and any other heavier load while out.

Where are you located?

Michael,

So I would use one of these per engine?

[ready123]

You need to replace that bad battery as a minimum..... having two means you are starting from a better position.
If you have a two bank charger you can get away with only replacing the bad battery.... single bank do both.

[vickyb]

People will tell you that it is heresy, but I use deep cycle batteries for my engine starting batteries, which also power my house loads.

I changed the group 27 starting batteries to group 29 deep cycle from Wally World, which are the biggest ones that would fit in my box (without modifying it too much). I run a few house loads off of them while at anchor overnight, like my anchor light, and reading lights. I do not run an inverter or anything with a high current draw. I'll run the generator for maybe 30 minutes before bed to cool-off the fridge, which brings the battery charger online to top-off the batteries too. In the morning the batteries are still fine. While the alleged not-for-starting batteries do a fine job of, well, starting their associated engine with no problem, as a matter of course I use the emergency start feature to parallel the batteries when cranking. By paralleling them, each sees half the draw they would otherwise. It should be noted that if I was cranking big diesels my thoughts would be different. For the last two years, my deep cycle batteries have cranked my small block V-8s just fine. Since it never sees house loads, I have a bona fide starting battery on my generator.

The book that I recommended in an earlier PM covers a lot of what you are addressing.

Thanks for the message and the information. Very helpful. I have actually ordered that book and am waiting for it to be delivered Thank you again

[vickyb]

Hello Michael,

Not sure if I have a 2 bank charger but maybe I do because on my power panel in the galley, I have a gauge with a toggle switch for Battery 1 and Battery 2. Battery 1 is hooked up to Starboard side battery, Battery 2 to Port side NOW, it wasnt when I bought the boat and the wires were just hanging loose.... does that mean I have a 2 bank charger?

[ready123]

Hello Michael,
Not sure if I have a 2 bank charger but maybe I do because on my power panel in the galley, I have a gauge with a toggle switch for Battery 1 and Battery 2. Battery 1 is hooked up to Starboard side battery, Battery 2 to Port side NOW, it wasnt when I bought the boat and the wires were just hanging loose.... does that mean I have a 2 bank charger?

That sounds like a Voltmeter which allows you to see each batteries state using the toggle switch.... print the State of charge photo I posted earlier to keep on board so you can see the level of discharge while at anchor by using that toggle.... you want to stay above 50% as a minimum. You will then be able to see how much you are using while out by using that toggle...... Trojan factory wiring often puts the bulk of the load on one engine, starboard I think.
You have a 3 bank charger as mentioned in PM..... not related to that toggle switch.