How to House Bank

[motion30]

I am soon to take delivery of a new to me 44' trawler twin cats and 8k westerbeake gen set 1 inverter with a 100amp charger and seperate 40amp charger It has 7 8ds flooded cells all batteries are less the 2 years old I need opinions on the best setup for a house bank set up and starting bank set up I plan on upgrading the stock alt to maybe 100amps or better I want to have a good set up for live aboard and anchoring out for extended stays I will have as much 12v appliances as possible (12v tv, fridge, stereo ect) ,,,,,ok opinions and why please
thank you

[motion30]

nobody?

[Tia Bu]

Maybe it's because this thing sounds like it has so much juice it's hard to imagine having any problems- although I can remember cruising on a boat with a similar setup and waking up the first morning without enough juice anywhere to crank an engine, a generator, or hoist the anchor.

One thing I find handy on my boat, which has a much smaller and much simpler setup than the one you describe, is that the battery bank is switched so that it is in three zones of equal amp/hour capacity. You can run off one zone, any two, or all three at once. I don't remember seeing any battery switches on the market that allow you to switch between three batteries (or three groups of batteries). A previous owner of my boat made this setup by using two separate battery switches.

It works out that each zone pretty much has enough capacity to handle the boat for 24 hours at anchor. This is very useful for cruising. If the voltage starts to get low, I can switch to another zone and still have one zone untouched for starting the engine later. That way I don't have to wake up the wife or other passengers for charging right away.

All three of the zones are the same kind of deep-cycle batteries. I don't have a separate battery for cranking.

If you set up the batteries this way, you might want to try to plan your appliances and usage so that a typical 24 hours of consumption is no more than 1/6 of your total battery bank's amp/hour capacity. (You shouldn't draw your batteries below 1/2 capacity, and each zone would be 1/3 of the total amp/hour capacity in the bank.)

Although it sounds like you have three independent sources for charging the batteries (two engines and a generator), you might want to consider adding some solar as a backup. I did feel pretty silly sitting out in the anchorage in that trawler with an engine room full of dead batteries.

A lot of cruising sailors try to set up enough solar and/or wind generation to meet, or nearly meet, their 12 volt demands while on anchor. But most of the trawlers I see out there seem to rely on primarily on their generators for charging while at anchor.

Also, for what it's worth, I didn't exactly plan all this setup out in advance. It took a a year or so of fiddling with loads, wiring, batteries, charging schemes, etc., before I sort of learned what the boat would do and settled into a happy balance. In the beginning, I was a bit baffled and frustrated by it all.

Hope this is of some help.

[Hyprdrv]

I'm not a fan of separate battery banks unless they are doing separate things. For instance I would have separate batteries for the Genset and the individual motors and maintaining a charge through maybe the Xantrex Echo Chargers from the house bank. I'm also not sure what your 2 separate chargers are doing. Is the 100A charger shore? What is the 40A connected to, the Genset? Does the Genset have auto start and stop? Do you have any low voltage alarms? I believe the most important thing is having enough juice to start either a motor or the genset so having these separate from the house bank would be a consideration.

Steve in Solomons MD
Lagoon 410 SE

[Pete7]

I would be tempted to do nothing for the first couple of months and then see if anything needs changing. After all if might be a very good set up now so why fiddle with it.

Pete

[btrayfors]

Hard to answer without knowing the specifics of your present setup. Pete might be right: do nothing until you determine how the boat is now set up and how it works.

In the abstract, with seven 8-D flooded batteries I'd probably think about one dedicated 8-D for each engine and for the generator, leaving four 8-Ds which I'd set up as a single house bank. That would give you a total capacity in the neighborhood of 800AH which should be enough.

The generator powering the inverter/charger with 100A charging capability could maintain the house bank. Depending on how it's set up, the smaller 40A charger, powered by the generator simultaneously with the inverter/charger, could maintain the three dedicated start batteries.

That's just theoretical though. Need real specifics and experience to do much more in the way of recommendations.

Bill

[motion30]

AS far as I can tell each motor has one 8 d for starting the starb motor battery also starts the genset The 40 amp charger was installed when the inverter charger died The alt on the motor seem to be small 55amp or so I am thinking the genset deserves its own battery maybe combine everything else into a giant house bank maybe one 8d to start both motors How big of a charger will i need for the shortest gen set charge time? These are flooded cell batteries

[donradcliffe]

A lot depends on your refrigeration setup. A 12v refrigeration system will be one of the biggest loads on your house battery, but a 120v refrigeration system will mean that you have to run the genset a couple of hours a day and will have excess charging capacity.

Does the boat have a propane or electric stove?

[motion30]

electric stove but it will not get used much I have gotten along great with a micro wave and gass grill for the past 4 years, hell I hardly ever use the stove in my condo while on the dirt It has a large norcold fridge and freezer Guess I will need a battery monitor to