My use case is something along the lines of: "I want to be able to have a KWh or two available as backup power, with a load that won't exceed more than 400W sustained with peaks of 700W for a couple of seconds." If I really really stretch my brain out, I guess I could see maybe needing to run an average load of 300W for several hours -- let's call it 8 hours which gets me to 2.5KwH (the actual capacity isn't my question unless it matters in the end - keep reading I guess)
I *think* that the old APC Smart-UPS SMC1500 that someone was kind enough to give me will meet this requirement -- the data sheet (linked below) says it'll push 900W/1400VA which is well above what I need.
I've also got a local supplier who has a bunch of used Valence batteries, in both the 12v and 24v flavors. The UPS is a 24v model so I think I could *either* 2s or 2s2p of the 12v varieties, or do 2p/4p of the 24v ones. In any case, let's assume for this discussion that I could get my hands on "several KWH of 24v battery capacity".
Now, the questions...
1) If I do end up with a bunch of capacity, will the charger that's in the UPS be able to charge these guys? I should note that I'm not asking if it can charge them QUICKLY, I'm just trying to understand if there's some threshold at which point the battery bank is "just too big" for the charger to work at all, or if there's some other non-linear behavior I need to consider. The UPS spec sheet says that the rated charge power is 73W, so needless to say this might take a LONG time to recharge, but that's not a concern. It's only a concern if the UPS won't be able to charge them at all, in which case I'd be limited to a single discharge cycle (oops).
2) are there concerns with the UPS itself running this load for an extended period of time (several hours, maybe even a day)? I know that the el-cheapo UPSs are not designed to run for hours on end, but I **think** that the SMC1500 is pretty robust and is designed to handle heavier, more sustained use... though I have no way to confirm this. Thoughts on this part would be greatly appreciated.
I also have access to a slightly different UPS, an APC SUA1500... the specs on it look very slightly higher in terms of capacity and charger, etc -- but I think they're more or less the same design at the guts.
https://www.apc.com/us/en/product/download-pdf/SMC1500
https://www.celltech.se/fileadmin/u...sbara/Valence_Modules/XP_Module_Datasheet.pdf
https://www.apc.com/us/en/product/download-pdf/SUA1500
I *think* that the old APC Smart-UPS SMC1500 that someone was kind enough to give me will meet this requirement -- the data sheet (linked below) says it'll push 900W/1400VA which is well above what I need.
I've also got a local supplier who has a bunch of used Valence batteries, in both the 12v and 24v flavors. The UPS is a 24v model so I think I could *either* 2s or 2s2p of the 12v varieties, or do 2p/4p of the 24v ones. In any case, let's assume for this discussion that I could get my hands on "several KWH of 24v battery capacity".
Now, the questions...
1) If I do end up with a bunch of capacity, will the charger that's in the UPS be able to charge these guys? I should note that I'm not asking if it can charge them QUICKLY, I'm just trying to understand if there's some threshold at which point the battery bank is "just too big" for the charger to work at all, or if there's some other non-linear behavior I need to consider. The UPS spec sheet says that the rated charge power is 73W, so needless to say this might take a LONG time to recharge, but that's not a concern. It's only a concern if the UPS won't be able to charge them at all, in which case I'd be limited to a single discharge cycle (oops).
2) are there concerns with the UPS itself running this load for an extended period of time (several hours, maybe even a day)? I know that the el-cheapo UPSs are not designed to run for hours on end, but I **think** that the SMC1500 is pretty robust and is designed to handle heavier, more sustained use... though I have no way to confirm this. Thoughts on this part would be greatly appreciated.
I also have access to a slightly different UPS, an APC SUA1500... the specs on it look very slightly higher in terms of capacity and charger, etc -- but I think they're more or less the same design at the guts.
https://www.apc.com/us/en/product/download-pdf/SMC1500
https://www.celltech.se/fileadmin/u...sbara/Valence_Modules/XP_Module_Datasheet.pdf
https://www.apc.com/us/en/product/download-pdf/SUA1500