f-32 battery setups/recommendations

[g36]

have a 78 f-32 with starting battery for each engine and original parallel switch and 1 generator and 1 house battery. i would like to have 2 house batteries and keep the engine batteries seperate so not to drain them at anchor but charge all the batteries accept the generator battery when the engines are running. i'm wondering how others are accomplishing this? if possible without having to manually change switches back and forth. maybe a combiner? also at first it appears the 12v for the house is going through the trojan original parrallel switch but i havent gotten that far yet. also what kind of battery charger at the dock are you using? and maybe suggestions on batteries you have gotten good service from? thanks

[g36]

nobody has any suggestions, at least on what brand battereis they have been using thats decent

[jav]

Your setup is quite different than mine. I don't have a gennie but instead have a 2500 watt inverter running off a house bank of 4 golf cart batteries- which serve double duty as the starting batteries from my port engine. This way, they charge off the port alternator. My starboard engine has 2 starting batteries that I run seperatly (different one each month). Lastly, I have one selector switch per engine . Starboard selector allows selection of either starting battery or both together. The port selector switch allows running from the house bank- or as a jump start feature to the starboard bank should the port/house bank get drawn down to where starting is a problem. The inverter is also a dual 3 stage charger (charges both the house bank and the starting batteries) when at the dock. I have disabled my helm jump parallel switch.

[Paul]

I'll give you a basic description of the system in my F-26 single screw boat. It can work in your twin screw application.

I have 2 seperate 12V systems in my boat. The first system is responsible for essentials like cranking the engine, operating the windlass, bilge pumps, nav lights and gauges. No matter what happens to the house bank, I can always rely on the first system to get me home.

The second system is my house bank. This system begins with 2 T-105 Trojan 6V batteries wired in series to give me 220 Ah @ 12V. This system powers the frige, TV/DVD, water pump, lighting, stereo, depth sounder, GPS, Loran, etc. This system also has it's own fuse pannel.

There are also 2 systems for keeping both battery banks charged up. The first is a 70amp alternator. This piece charges both banks at the same time thru a battery isolator. The isolator keeps both systems seperate so that one cant' drain the other when the alternator is not charging. The second system for charging is a 20amp StatPower charger with three bank capability to keep the systems charged when hooked up to shore power. I also have a manual battery switch in case I should need to crank the engine with the house bank. (You never know)

To apply a system like this to your boat, you would need an isolator with 2 alternator capability, a cranking battery for each engine and instead of the manual battery switch, you would keep your cross over switch. You also need to determine how many Ah (amp hours) you need from your house bank. To do this, look at every 12v load you will use daily while on the hook and add them up. For example if your water pump draws 3 amps and it runs for a total of .5 hours per day, the pump requirement is 1.5Ah per day.(3amp x .5 hours = 1.5 amp hours) When you've done this, take that answer and multiply it by the number of days you'll be on the hook and this is your total amp hour requirement. As a rule of thumb, you should not drain your house bank to less than 50%. For example my requirement is 110 Ah and my house bank is 220 Ah.

As far as my generator is goes, I have a 2.5kw Kohler and it cranks from and charges it's own battery. This way when I'm running it to charge my house bank while on the hook, the 20 amps from the charger go to the house bank and not to replenishing the battery that just started the generator.