I got an e-mail from a friend I haven't heard from for ages saying his son found my article on the net.
One thing I noticed is that, in your diagram of multiple batteries in parallel, you have both leads connecting from the inverter/charger to the same battery. I recently read that in a battery bank the two leads should be connected to opposite ends of the bank; i.e. in your "Parallel battery connection" diagram the negative wire should run from the leftmost battery back to the inverter. Otherwise that right-hand battery gets charged and discharged much more than the others.
I've been messing around with off the shelf UPS's lately. Adding larger batteries to them, testing charge times etc. I plan to hook one of them up to solar power to see if I can get stable, reliable, continuous power that's totally independent of the grid.
It's in it's infancy but I'm sure that would make for an interesting follow up article
I am posting for posterity. I think it’s cool to keep a log of battery replacement; and when the unit finally dies one day, I will post a RIP I’m sure.
I have this week, replaced my second set of batteries. This time I only got 2 years out of them. I did not have to revert to battery backup that often during the two year period, so I was surprised when they started dying on me so early.
I think I know why. The dead set of batteries I removed were not true deep cycle batteries.
I can’t remember why I bought them, but it has illustrated that buying the wrong tool for the job just costs you more in the long run. I got 5 years out my first set.
Anyways I now have a brand new, decent set of deep cycle batteries in place and will see how long these last.
Otherwise I'm happy to report to those fellow Icrontians that remember me, that I’m alive and kicking and still using the Same UPS I built over 7 yrs ago
@Winga great to see you!