> Still, a laudable goal. Have you checked out various > do-it-yourself sites?
I think I have a cultural inability to search the web, but I certainly did try. That I actually found a single supplier of Li-Ion battery backed-up PSUs for desktop computers suggests that there is the engineering savvy and possibly even a marketplace for such devices. The marketplace itself is not terribly relevant, I'd be satisfied with a higher unit cost if in some way it was possible to add capacity in steps. Being able to build it from readily available components (deep discharge lead-acid batteries are one annoyingly unavoidable expense) is important and one would like modules that can be trusted to last a long time - if necessary by over-engineering them a little. I will have a look at off-the-grid suggestions, but I fear they tend to focus on pre-built modules and in my opinion the hobbyist can focus on issues that commercial companies prefer to avoid, such as quality and long-term reliability. ++L
