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Post by mediadogg on Nov 7, 2019 16:48:29 GMT
After a recent home theater reconfiguration, I wound up with a nice Cyberpower UPS being unused. I was thinking about experimenting with connecting a charge controller to the UPS internal batteries, so that I could optionally charge the UPS from solar with spare gear that I have lying around.
I have successfully used multiple charge controllers on the same battery, and with using a battery tender along with a charge controller. To me, using a solar charge controller in parallel with the UPS internal battery charger would be essentially the same thing. I know that charge controllers can work in parallel. I'm just wondering if a consumer grade UPS charging circuit would be robust enough to not be affected by back-feeding.
Anybody with thoughts or experience that would point out something that I am overlooking?
By the way, I have seen a bunch of the Youtube hacks out there. I have more confidence in the advice I would get around here.
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Post by tattoo on Nov 7, 2019 17:17:21 GMT
Man I wish I could help you but I have no idea........
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Post by alixthedark on Nov 10, 2019 2:50:52 GMT
you can charge your battery from multiple power sources no problem. a ups is just an inverter unit and a battery maintainer charger so there shouldn't be any noise in that system that the cc can't handle.
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Post by mediadogg on Nov 10, 2019 4:16:03 GMT
you can charge your battery from multiple power sources no problem. a ups is just an inverter unit and a battery maintainer charger so there shouldn't be any noise in that system that the cc can't handle. Yes, I did mention that I was familiar with that in general, and actually use multiple CC's in my setup. But I am not so sure that a consumer grade UPS battery maintainer / charger has been designed to cooperate with anther unit, since they are usually self-contained. So, I was hoping to hear from somebody who has actually done it successfully, or who knows the internal design of a typical consumer UPS. Got any more specific info? Oh, and thanks so much for taking the time to reply!! |
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Post by alixthedark on Nov 10, 2019 6:49:06 GMT
I've used an apc ups as an inverter before but not my current setup. back then I was using a chinesium cc unit, but I don't know if it's even comparable. the apc unit I had had fast switching diodes and generated decently clean signals. I have no idea about the charger though.
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Post by alixthedark on Nov 10, 2019 6:51:17 GMT
I had to solder the wires for the warning reset button so it wouldn't tell me there is no ac coming in constantly. lol
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Post by mediadogg on Nov 10, 2019 13:18:32 GMT
I've used an apc ups as an inverter before but not my current setup. back then I was using a chinesium cc unit, but I don't know if it's even comparable. the apc unit I had had fast switching diodes and generated decently clean signals. I have no idea about the charger though. Ok, then! Good info. At least we know that the CC connection didn't fry the charger. Thanks for that! |
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Post by Upton O'Good on Nov 15, 2019 0:05:03 GMT
Hi Mediadogg, I'm no expert on this at all, but I've been thinking about this type of thing too. Been wanting to do something similar to power our satellite internet devices at the ranch during our (unfortunately) rather frequent power outages. A couple years ago, I picked up a free UPS with a dead SLA battery and used a larger 35Ah AGM SLA battery instead of the little (stock 7AH?) one as the battery source. This works really well and runs the sat modem, router and VOIP for cell phone service for a really long time when the power goes out. My concern with doing this was that I suspected the duty cycle of the charge circuit in this little UPS might be beyond the design specifications when used with a larger battery. In addition, I imagine the charge current the UPS provides is probably not optimal for the larger battery either. So, I was thinking about adding a charge controller and a solar panel to get even more run time (at least during the day) and maybe a more appropriate charging current when the sun is available to help out. These are the things I have thought about so far: As I understand it, many charge controllers go through an equalization charging phase. During this phase the charge controller provides a higher voltage than it usually applies during the other phases of charging. I suspect this may be an attempt to reduce sulfate deposits on the battery plates, I'm not sure. I think my charge controller does this once a month or something. If I had two charge controllers (the one in the ups and one the solar) would this happen twice as often (as they would be likely out of sych)? Maybe I should disable the equalization charge on the solar charger? The two charge controllers might have different thresholds. So, one may decide the battery is charged and the other may be in a different phase (float vs. boost as an example). With my limited knowledge, I don't think it will matter, as the charge will be determined by the "higher" of the two. But to be honest here, I'm not sure  . Just things I've considered when thinking about it..... Upton |
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Post by mediadogg on Nov 15, 2019 18:38:41 GMT
Good thoughts. I have mainly considered the real time aspect of charging conflicts, thinking that each charger is looking at "now" and not doing anything that doesn't make sense relative the current SOC of the battery. But I had not considered time-based things, such as monthly equalization. There are a couple of guys here that know a lot more about that sort of thing. I hope they chime in. One way to possibly control it would be to use the load output of the CC to control a relay to shut off the AC input to the UPS during the day. That prevents a direct conflict, but that still would not stop a dual equalization event from happening, assuming that both chargers are set up to do that.
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. Just things I've considered when thinking about it.....