(Well, this is sort of a power supply.)
I have a couple of old omnismart Tripp-Lite UPS units (700PNP and 850PNP) which have been sitting unused for about 5 years. They were all functional when taken out of service. When plugged in one of them doesn't light up at all, and the other one lights up, but not surprisingly, the failed battery light is on. (And stays on, even if it is left plugged in for a couple of hours.) Now the funny thing was I had to clean out another group's storage area at work a few weeks ago and they had a couple of APC UPS units of about the same size. I don't know the history of those units, but there too one of them would light up when plugged in (and the failed battery light eventually went out, so I guess it charged up) and the other would not light up at all. Yes, reset the breaker on the unlit ones and it didn't make any difference.
Pretty sure in the 3 failure cases the internal lead acid batteries were dead (failure light) or good and dead (no lights), It seems unlikely to me that the electronics failed just sitting around. Do UPS units tend to stay dark if the battery is beyond hope? If so, how do they tell? (Detect a short, open, or something like that?) Yes, there were still batteries inside all of these units.
I have a couple of old omnismart Tripp-Lite UPS units (700PNP and 850PNP) which have been sitting unused for about 5 years. They were all functional when taken out of service. When plugged in one of them doesn't light up at all, and the other one lights up, but not surprisingly, the failed battery light is on. (And stays on, even if it is left plugged in for a couple of hours.) Now the funny thing was I had to clean out another group's storage area at work a few weeks ago and they had a couple of APC UPS units of about the same size. I don't know the history of those units, but there too one of them would light up when plugged in (and the failed battery light eventually went out, so I guess it charged up) and the other would not light up at all. Yes, reset the breaker on the unlit ones and it didn't make any difference.
Pretty sure in the 3 failure cases the internal lead acid batteries were dead (failure light) or good and dead (no lights), It seems unlikely to me that the electronics failed just sitting around. Do UPS units tend to stay dark if the battery is beyond hope? If so, how do they tell? (Detect a short, open, or something like that?) Yes, there were still batteries inside all of these units.
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