D/C Charging System

[Ksoulant]

Good Morning all; I am looking for advice on how to set up my D/C charging system. The batteries are Generator Battery G24, Port and Stb. 8D Batteries and 6-6volt house batteries. When connected to shore power or from the generator, the Genset Battery and the 2 8D engine batteries are being charged from a 50amp 3-bank battery charger and the House bank from the 100amp inverter/charger. The attached diagram is what I have come up with. It looks a little complicated but I believe it is has complete redundancy. If any of the battery banks gives me any problems I can switch to any other bank or all banks for starting. Also the ACR's will switch to charge the lowest of the banks. Are there any drawbacks to this system? Any feed back or comments would be much appreciated. Thanks

 

[rslifkin]

Seems reasonable to me. It's pretty similar to my setup (2x engine batteries and separate house bank). Only thing I did special on my setup was I used ACRs that can be enabled / disabled via a signal fed to them, so the ACRs on mine are only enabled when the relevant engine is running. That way they all charge independently on shore power or generator, but are tied together to charge the house bank from the engine alternators underway.

In your case, I'd drop the 3rd ACR, as the generator battery doesn't need one. ACR each engine battery to the house bank (with or without the ignition interlock at your preference). Generator battery gets charged on shore power or with generator running, but not while motoring (which should be plenty to keep it topped off).

In my case, I dumped the separate generator start battery and simply configured the battery switch for the generator to select between the 2 engine batteries. So normally I leave the port switch set for start bank 1, stbd and generator set to use start bank 2. House switch in my setup is just an on/off. Connecting the house to an engine battery other than through the ACRs requires either moving cables to bypass one of the ACRs or using jumper cables.

 

[DavidM]

There is one common problem I see with your diagram, easily corrected- fusing. There should be a fuse located within 6" of the battery for every wire connected to it. That fuse should be big enough to handle the maximum current of the devices it serves but also be small enough to protect the wire connected to it. That is the fundamental principle of fusing which many do not appreciate.

So..... You need a fuse near the battery for the house panel, move the fuse for the inverter/charger over to the battery not the inverter/charger. Also put a fuse in the circuit to the ACRs, again near the house batteries.

The starting batteries are a little different. ABYC and common sense accepts that you don't need a fuse near the starting battery as long as the wire to the starter is short and direct. But that may not be the case in your installation with lots of on/off/combine switches sending power everywhere. I am ambivalent about this. Maybe others have more concrete arguments.

But I am quite certain you need a fuse at each starting battery for the circuit going to the ACRs.

David