Dual Battery Configuration

[Brent Headberg]

I've read many of the articles from the archives about BATTERIES, but I didn't see anything about mixing Starting Batteries with Deep Cycle Batteries.The 2 batteries in my Hunter 335 are matching batteries, and as far as I can tell they are AGM...no holes in the top to inspect or add water. In any case, they are shot...only holding about 50% charge, and I want to replace them. Here's what I am thinking:1 Marine Cranking Battery for the engine.1 Deep Cycle Battery for the house.Attach the 50amp Battery combiner that West Marine sells.Anyone have any input?Cap'n BrentS/V Elena Lua

 

[Steve Dion]

2 battery system

Brent:If you have a two battery system, you might as well just get two deep cycle batteries. If you are at anchor leave the switch on one or two but not on both. I have never seen any value in having a starting battery but other may see it differently.There is a battery switch from Blue Sea that can act as your switch and combiner which I think is a lot better than all of the wires that the West Marine device offers. I think the Blue Sea part is an 8080.

 

[Daniel Jonas]

combiner

Steve,I agree that he should use two of the same type of battery. This is better for charging purposes and there is enough cranking amps in a deep cycle marine battery to handle the engine start. However, the Blue Seas 8080 does not provide a "combiner", it just allows one to parellel the batteries if necessary. In fact, the label on it is "emergency cross connect". Which is a little misleading if you want to regularly charge the batteries on the "both" setting of a conventional battery switch. I'm pretty sure you meant combine in the parellel sense, just wanted it to be clear.I think that the combiner can be a great idea if one is not willing to manually switch a multiple battery system for charging/use and monitor the same. I would use the 8080 with a combiner,and an 8062 without.Dan Jonas (S/V Feije II)

 

[Bob Fuller]

My two cents

My '90 33.5 had the same configuration as yours. After much research and planning, I ended up paralleling the two starting batteries under the aft birth, adding two Trojan 6V golf cart batteries(from the golf cart company) under the port quarter berth, new Blue Sea shut off switches, new Blue Sea Parallel switch, a West Marine 50 Combiner, a two bank battery monitor, a Balmar regulator, rebuilt the Alternator to connect to the new regulator, and all new 2/0 wiring and appropriate fuses. Two things came out of this for me since I did all the installatiion myself: I have an excellent understanding of my Primary 12 V system, and I have had no problems with drained batteries while cruising on the weekends as I use to when I did this about 1.5 years ago. If you need any info. let me know.Bob FullerS/V Frolic Some

 

[Steve Dion]

Thank you Dan J!

Dan:I suppose that is why some use and Echo Charger in the circut. I had forgotten about that part.