Battery Banks

[EdHouston]

Anyone see any issues with this simplistic wiring diagram?

[SailingSeaDragon]

My only comment is.. I believe one large battery bank is better than two smaller banks... My logic goes like this... Battery life is drastically shortened by drawing a battery down more than 50%. So if I two (2) 250 amp banks (total 500 amps)... You will need to monitor your batteries and switch banks after using 125 amps, not many amps... With one 500 amp bank I can use 250 amps before firing up the engine and recharging...

The problem becomes more pronounced on day two or three of a cruise -- it is difficult to charge a battery bank beyond 85-90% of capacity without an extended time on a "trickle charge" (most likely shore power or hours of motoring). What this means is, when out cruising a 250 amp bank is more like a 215 amp bank...

Just my thoughts...
Garner

[dutchie]

The problem with two parallel connected battery banks is that if one cell is bad it will drain both banks, special when on cell internally shortcuts all the power of the other bank goes over the other bank, with will cook the already bad bank with the potential danger off accumulating enough H2 gas for a big explosion. Thats why the different battery banks should always be insulated by a battery isolator. 

[SV THIRD DAY]

The approach on THIRD DAY is simplicity, so we have a starting battery and then a house bank of 5-group 27 wet batteries.  This system has worked well for our cruising needs where we rely 100% on our batteries for everything.

I wouldn't want to split my house bank due to charging issues as Garner states.


Rich

[Atavist]

I have the exact same set up as SV Third Day, and have no complaints either. 

One large parallel bank is better IMHO... just do a monthly check on fluid levels to make sure everything is where it should be and you shouldn't have any problems with one bad battery pulling the rest down.

[wedelstein]

Rich, where do you stuff 5 batteries. I have a dedicated starting battery and 2 group 27 house batteries. I use engine powered refrigeration so I have to start the engine daily. I have a seperate dedicated alternator for the house battery.

i am considering adding a 12 powered refrigeration system. If I do that I think I will want more house batteries. If so where can you put extra batteries on the P 365.

[SV THIRD DAY]

Two in the Star sail locker, One in the Port, and two under the cabin floor just forward of the bilge.

BUT....I will be moving the three Sail Locker batteries to the Bilge area later this mounth to get them out of the HEAT generated by the engine in the sail lockers when motoring.

Rich

[wedelstein]

I put the new fuel tank under the cabin floor. There is not place there for batteries but I can work on the front of the engine.