My current battery bank was purchased in 2003. Five years of crappy and irregular manual deep cycling has basically ruined them. The sole source of power now for the entire Hive is two sealed glass mat 12ah lead acid batteries vented near the alternate hatch. I know, it's a pathetic situation. I'd be screwed if I had to shelter for more than two days in the present situation.
I have been trying to locate Edison style batteries for months, even searching tips and battery reclamation points looking for discarded older forklift batteries. No luck.
There is hope on the horizon. The coming year is going to see this lithium-ion stuff available in retail at competitive prices. So maybe it's a good thing I waited before sinking another grand into batteries. A deep cycle battery with a charging time of five minutes and an expected lifespan of ten years or more was worth waiting for.
I plan to buy all new lithium ions like these early in 2008 for the Sparkgap quonset and I will be managing their charging via wind and solar around the clock with an embedded custom controller. I have almost all of the computer technology needed sitting around in pieces and fragments at the moment, just waiting for me to bring it all together in one place. I also plan to rewire the entire shelter system with relay controlled 2.1 mm jacks for 12 volt cabling to replace my old auto jack system. One thing important to know about auto jacks for 12 volt is that they stink. The poor fit and contacts inside the typical 12 volt automobile electrical wiring degrades very rapidly in continuous use with loads. The plugs frequently fail from a minor bump or the wrong angle when they are plugged in. In retrospect, like a lot of things in the shelter I just don't know what in the hell I was thinking about when I dropped all this money on 12 volt jack sockets and automobile wiring. It's a terrible system for the electronics and power.
My light, power and computing system early in 2008 is going to be perfect. This is the way I do almost everything in life. I do a first version which is just plain stupid. Then I respond to the feedback I get from realizing it is stupid to get it right on the next iteration. It's fortunate that I had seen shelters similar to the one I have now before (including Firehold Alpha) and had enough information to get the basic design, architecture and layout correct. The internals are still in development. I hope that when I am ready to document what I have done that many of you will be able to benefit enormously from all my initial mistakes. I've made lots. Luckily I got the shelter structure itself correct.