If you do not need 48 volts, why not get something like this and use a marine battery for trolling 

You can use 12 Ga wire if you fuse it at 30 Amps. Install the main fuse inside the box, as close to the battery terminals as possible. This way it will protect the wiring if you get a short where the wires exit the box. It's best to have a main fuse and several smaller fuses protecting individual circuits.
There are a lot of chargers available on the market. I would get one designed for SLA batteries. For a generic charger, keep charging current at or less than 10% of total battery capacity (This is a general rule but check this with the battery manufacturer). This is what I do with a single SLA battery, used to power my radio when camping.

More info on that Dohikey please.

Your going to need some sort of buss so you pull equally from the batteries. Charging is going to be challenging.
what kind of box are these going in?

Looks like it's this.

https://www.amazon.com/Newport-Vessels-Trolling-Battery-Center/dp/B01AE2TG7G/ref=sr_1_1?ie=UTF8&qid=1487517696&sr=8-1-spons&keywords=newport vessels smart battery box&psc=1&tag=vglnk-c102-20

Good info.

Not really. You can put one of those fuse blocks on the outside of the box if you have multiple circuits and need to power them all from the battery.
Keep it simple. You really don't need a bus bar for the batteries. simply daisy-chain positive and negative terminals inside the box. Use thicker gauge wire if you are concerned about equalization. There will not be a significant voltage drop in the daisy chain circuit to be worried about equalization. Lead-acid batteries are not as picky as some other type of batteries. Keep it simple.

I'd agree, especially if the batteries are of like type and comparable age.

I would occasionally disconnect the batteries and check the charge status of each to ensure they are all close in voltage. If one battery is low, it will pull the charge down on the others and cut run time substantially because it represents an increase in loading on the remaining batteries and literally contributes a negative number - worse than nothing. Found this out the hard way...

I refurbished an old battery box a few months ago and converted it from 48V to 12V.  It used to be a battery backup for a Siemens phone system.

Attached File


I bought one of these B+D battery charger/maintainers at HD : http://www.homedepot.com/p/BLACK-DECKER-2-Amp-Waterproof-Battery-Maintainer-BC2WBD/205431808

I just leave it plugged in all the time.  It came with an attachment that had ring terminals.  I chopped those off and added PowerPoles. This little charger has been more useful than I ever thought it could be.  I use it to test batteries from small UPS systems.  If I connect it and it starts charging, then the battery is generally good.  If it stops immediately, I send it to the recycler.  I drag the battery resistance meter out a lot less now.

The box has a DC breaker on it.  I think 10 or 12 amps.  Enough for doing portable stuff.  I can even run the IC-7300 at full output power and it never trips.  The IC-7300 runs for several hours listening and even doing transmission it takes a while to get the voltage to drop too much for reliable operation.  I'm going to be getting one of the KI0BK Low Loss PWRGate (LLPG) devices so I can connect both the power supply and the battery at the same time, keep the battery maintained, and allow instant switchover if AC or the power supply fails.  He's got three separate devices that would be killer if they were in one box.  The LLPG, the solar controller, and the RigWalker distribution.  If he combined them I'd buy today!

Eventually I am going to go the route of the other posters that use automotive/marine batteries for their backup.  Lots of AH there for cheap!