In investigating batteries, I wanted to upgrade my power somewhat, so I started looking at batteries larger than the L16s, and with a longer lifespan, so I don't have to do this again in 8 years. The Surette batteries looked interesting, and eventually that's what I settled on. The large Surette batteries came with a 10 year warranty, have a 15 year lifespan, and are field maintainable. Individual plates can be replace with just a wrench, making these easier to maintain for long life.

I started trying to figure out how many batteries I would need by writing a spreadsheet that calculated out my power requirements, with adjustments for inverter inefficiencies, temperate compensation, and reserve capacity, I discovered I could use either 24 smaller batteries (like the Trojans), or 8 or 12 larger ones for my 24 volt DC system. I finally went with the 8 - Surette 6CS-25PS batteries, at 825 Amp hours at a 20 hour rate.

The only downside to using the heavier batteries was they weighed 318 lbs apiece! This was obviously going to be a project requiring some planning. Since Surette makes the batteries on order, which takes about a month, I got my order in while the weather was still good, hoping the batteries would arrive during the prolonged decent fall weather we'd been having. Once winter comes, the chances of getting a large truck down the road is pretty slim...

Once the batteries were ordered, I had two project to do first in the power shed. The first was to add a propane heater, so on cold nights I could keep the batteries warmer. Batteries loose alot of efficiency below 41F, and the shed deep freezes like everything else. When it got down to -38F last winter, there was almost no power. I removed an unused heater from the entry way, and removed all the poorly installed propane piping (15 feet worth) back to the source. I then used this same pipe with a few elbows and replumbed the existing propane pipes in the power shed. Replumbing was rerouting the existing pipe, which stuck out in the middle of the shed, to follow the all, so I'd have room to build a new battery box. I then added a T for the new heater with a cut off valve.

Classically while starting this, the weather changed, and got back to the usual cold and snow. Once I got the heater installed, I could now keep the shed warm, which made the rest of the project more comfortable than the previous rewiring project. I had also added lights, don't know why I didn't think of that in phase 1... Anyway, I started to get worried, waiting, waiting for my batteries to arrive.

Now that the shed had heat, I build a new floor in the other half of the shed, which has a dirt floor. Once this new floor was built, I made a ramp, and slid all the L16s (at only 130 lbs) to the new spot, one at a time. I was so glad I had left extra long cables to the DC disconnect when I wired up the batteries during the intial rewiring project phase

At this point, I was back in demolition mode, as I ripped out the old battery shelf, which was poorly constructed anyway, and way too high off the floor as well. Then I constructed the floor of the new battery box with 4x4s for supports, and 2x6 oak boards for the floor. I then added a thin sheet of 3/4 plywood to the floor to make it easier to slide the batteries around. The floor was 60 x 52 inches square.

I added the back wall and the side wall, since these would be inaccessible as soon as a few batteries got put into place. On this side wall I added conduit for the cable coming out of the box, and the air intake. I had bought a power vent, and was going to use that to help with hydrogen outgassing. I figured with a propane generator and heater in the shed, I should be extra careful about outgassing from this larger battery bank. Finally the new battery box was ready, and I went back to waiting, waiting, and watching it snow.

Eventually I had to go out of town for a work trip, and Murphy's law strikes, the batteries arrived while I was gone. I managed to make arrangements with the trucking company to hold them till I got back, as the roads weren't in very good shape anyway. They didn't have a 4x4 truck, and it was that 4x4 only access time of the year by now.

Finally the moment of truth had arrived, and we were all about to find out if we'd be able to move the batteries once off loaded. I arranged with some friends for help, and we'd try the brute force technique of battery moving. I'd learned at Rainbow Gatherings that if you put project phase enough bodies into a project, you can move anything. I've seen people carry piano's for 4 miles uphill, lift school busses, all sorts of things, so I figured it was time for a moving party.

I had to start by shoveling a long path for the truck in 2 feet of fresh snow, to get the truck close enough to the power shed to make this doable. Without 4x4 drive, the truck slid a lot, we all pushed a lot, and it got where I wanted it. The driver was being very helpful, and understood the closer he got to the shed, the easier this was going to be. He managed to get around to the back, where we could unload on the cement patio, and it was a level path tothe shed with no more obstacles.

He had brought a wheel ramp, but we quickly discovered that even though they were 318 lbs, two people could manhandle them around pretty easily. We slid them down off the pallet, and loaded onto a hand truck. Hand trucking them into the power shed was interesting... It was as much sledding as rolling... The snow and frozen ground turned out to be be great for slidding the batteries around. We offloaded all the batteries, and the truck only got stuck twice on the way out.

At this point I was feeling less stressed out about our ability to move the batteries. While rerouting the cables through the new conduit, we moved the old batteries to the garage, where I'll hook them up again as a temporary power source. I had previously built a ramp up to the sill of the shed's door, and made a continuous floor across to the battery box. Moving the batteries in (up an iced up ramp) turned out to be pretty easy.

After that, 2 hours of wiring, and all systems (12VDC, 24VDC, and 120VAC) were fully back on line. Other than trying to move them, I like the Surette batteries, and with a 15 year life span, I look forward to not doing this again in 8 years. Later in a bright and warm shed, I finished the battery box by building of the remaining two sides and a top.

Part three of this 3 phase project was building a much larger photovoltaic array. That project is described here.