hogback
New Member
So, I've been running 4x phi 3.5s for almost four years. Never thought I had any issues until recently. My generator almost never kicks on, and in fact my first two or three winters saw no generator activity other than exercise. 14kw Kohler would run for an hour and a half or a bit more. Charging was the standard phi recommendation of 50.5 to 56 for 6min and done. My sccs also are set to the 56 but then hold at 54 if they can. I noticed early this winter that one genny charging session seemed short (I hear it, but don't always think to time it in the middle of the night). Well, the next chance I could, I watched it click on at the proper 50.4 (or something very close to that), and it immediately jumped the battery V to 54.1V, and carried out the whole charge at ~115A for 40-45min. Ran at full current, or very close to it, all the way to 56. So, this is well under the rated capacity, even considering 5 years of use. BTW, I looked back at old logs, and when I first commissioned, the initial V bumped to ~52.8 or 52.9. So that behavior is different, as well as the charging being well under the time needed to fill the bank. I checked what schneider is measuring and it's pretty close to what my fluke was telling me. I also feel like the V sags under load more than it used to, but I haven't got an easy way to check this. Simpliphi is taking the batteries back to have a look for possible warranty. I have not checked any of these four batteries individually for capacity under 0.5C, as they are part of my system and I'm off-grid. They sent me 2x 3.8s "to hold me over" but I'm not sure if I will run with those when I send these four back, or use the rebuilt sunpowers that I'm working on.
Any ideas what could cause this behavior? The jumpiness doesn't seem like a typical capacity degradation, or does it? Something else? Can't see how the bmss could contribute. Charging is all within an Amp or two for all four batteries during the bulk 115A genny charge. Other than the schneider charger, my only 48V charger is a 5A one, so I'm not really set up to capacity check these individually anyways. Any suggestions on what I could do once I've taken them offline, but before I send them back and cross my fingers? I can't see how this is anything other than the batteries if the charger is agreeing with my fluke.
Any ideas what could cause this behavior? The jumpiness doesn't seem like a typical capacity degradation, or does it? Something else? Can't see how the bmss could contribute. Charging is all within an Amp or two for all four batteries during the bulk 115A genny charge. Other than the schneider charger, my only 48V charger is a 5A one, so I'm not really set up to capacity check these individually anyways. Any suggestions on what I could do once I've taken them offline, but before I send them back and cross my fingers? I can't see how this is anything other than the batteries if the charger is agreeing with my fluke.
