APC BACKUPS-RS550 not charging battery

[clearchris]

Re: APC BACKUPS-RS550 not charging battery

If you left this idle for a year, it's likely your batteries are dead. Lead acid batteries do not take well to being left idle, just like in your car. I have a UPS that I'm not using at the moment, but I leave it plugged in. Best case is these batteries last 2-5 years when plugged in all the time. Dead UPS are always avaliable because the batteries go so quickly.

[Curious.George]

Re: APC BACKUPS-RS550 not charging battery

If you left this idle for a year, it's likely your batteries are dead. Lead acid batteries do not take well to being left idle, just like in your car. I have a UPS that I'm not using at the moment, but I leave it plugged in. Best case is these batteries last 2-5 years when plugged in all the time. Dead UPS are always avaliable because the batteries go so quickly.

Note that "leaving it plugged in" can result in the battery being cooked by the UPS (many UPSs don't flat the batteries properly) so that, when you actually NEED it, you find the battery is toast (and, likely "bulging" -- often to the point where you can't easily get it out of the case!)

UPSs try to recharge batteries too quickly (and too cheaply!) on the premise that they may be "needed, again" in short order. It would be nice if the UPS could NOTICE the line conditions (i.e., how often there ARE outages and what their durations are) and adjust this policy accordingly.

For example, if you encounter brief "power flickers", then the battery is carrying the load for really short periods so charging it "more gently" is likely not going to increase your risk of it being insufficiently charged to handle the NEXT flicker (this of course depends on the average interarrival times of those events -- but the UPS can determine that empirically!)

Similarly, if the battery is deeply discharged by prolonged outages -- but they are infrequent -- then it can still opt for a gentler recharge (or, perhaps a quick influx of charge when power first returns but then switching to a slower charge rate to let the battery cool)

[jinu_j]

Re: APC BACKUPS-RS550 not charging battery

If you left this idle for a year, it's likely your batteries are dead. Lead acid batteries do not take well to being left idle, just like in your car. I have a UPS that I'm not using at the moment, but I leave it plugged in. Best case is these batteries last 2-5 years when plugged in all the time. Dead UPS are always avaliable because the batteries go so quickly.

I had swapped the old battery with a new battery. But the problem continued.

[clearchris]

Re: APC BACKUPS-RS550 not charging battery

Did you check the date code on the "new" battery? Depending on where you get them from (don't get from amazon or ebay) they might not turn over quickly. Lead acid batteries go fast when they aren't hooked up to power...

[Thorsten Freak]

Re: APC BACKUPS-RS550 not charging battery

does anyone have a schematic drawing on 640-1172A-Z-REV05 printed circuit board an a APC Back-UPS PRO550?

Mine isn't charging the Batteries properly

cu Thorsten

[redwire]

Re: APC BACKUPS-RS550 not charging battery

For your 550, I only find bits pieces here: https://www.elektroda.pl/rtvforum/topic3529704.html
I have this schematic for APC 640-0259_REV05 which is I think is Back-UPS RS500, BR500i. No charging - electrolytic capacitor C7 22uF 16V usually bad. Check R28 runs very hot.

It is unfortunately different, 550 using IC2 TYN278PN and some add-on TL4 board with two 22uF 400V for C12. IC2 does not need the usual 22-47uF cap there on pin 2 BP/M.

[theone111]

Re: APC BACKUPS-RS550 not charging battery

I have a similar problem with an APC BR550GI Pro UPS
https://www.se.com/il/en/product/BR5...ckups-pro-550/

[theone111]

Re: APC BACKUPS-RS550 not charging battery

does anyone have a schematic drawing on 640-1172A-Z-REV05 printed circuit board an a APC Back-UPS PRO550?

Mine isn't charging the Batteries properly

cu Thorsten

Any luck finding and fixing? I have the same model and problem.

[elbass7]

I have the APC BACKUPS 650 with a similar problem...however, it won't turn on the battery backup outlets, even with the unit connected to good 120VAC power. Just makes a ringing noise, which sounds like an inverter, but no power comes to the outlets. Only 3.45 volts are trying to charge a 12 volt battery. I took the battery out and charged it on my car charger on the slowest setting and it seems to hold a charge. After charging I can connect it to the UPS and with the unit unpluged from the wall, it make the same ringing noise. The green power light comes on, but pushing the on button does nothing.
Any help would be appreciated on next steps.

Eddy B

[redwire]

Start a new repair thread, your model is different.
Mods, I would move it