The batteries I use for the system are SLIGC115, 4 in series for 24V...
(wow just realized I posted an erroneous reply on another thread, but anyway)...
Every time I put them to a test, I get the following:
Within 10 minutes, the UPS units (APC SmartUPS 1400) are complaining vocally that the batteries are dead... still pumping power almost a half hour after alarm, but why the alarm?
I'm using 2ga wire as interlinks, with a 100A master link between the two 12V 'halves', and 50A glass cart fuses with 10ga wire going up to the units (there are two).
The batteries are rated at 120 minutes @ 75A, which I'm pretty certain I'm not hitting, probably closer to 20A or so total, and they are bitching up a storm. They're golf cart batteries for christ sake.
More details available upon request, but rest assured, the wiring is not getting hot, and as far as I can tell, there might just be some parasitic loss in the 50A fuse holders? Dunno.
Next step is to wire up a meter across the main output terminals of the batteries and see what is happening there. I have a feeling since these are brand new (about 4 months old?) that the batteries themselves are not the problem, and it's something in the distribution wiring.
Think some uber caps bypassed with several progressively lower value caps, right down to bypass (say 4700, 3300, 2200, 1500, 1000, 470, and finally a few 0.1uf ceramics) might help with this, right at the boards in the UPS units?
I'm at a loss here. I think I'm going to run them this time until the system drops offline to see just how long they take to go truly dead, but I'm convinced (without more measurement) that the wiring is the problem.
Ideas?
Steve