Back-UPS RS 800 Not charging

[Agent24]

Re: Back-UPS RS 800 Not charging

Yes I am in the process of getting my hands on an ESR meter so that is why I was wondering if that would be a fair enough test.

Going for the capacitance test first is more suited to non-polarized capacitors.

ESR measurement is a better test for electrolytics most of the time. But some can fail with reduced capacitance while the ESR stays OK! Also you can get excess leakage current problems too...

[budm]

Re: Back-UPS RS 800 Not charging

You can use 2A 250V fuse in other from factor to test out the function first, this style of fuse can be found at Mouser or Digikey.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

I got a fuse and soldered two wires to where the fuse came from and attached the fuse to the wires with cables so I could replace it if it blew.

There was no change in performance even with the new fuse. The fuse did not blow and you can see where the voltage is in the picture and it is slowly dropping.

[stj]

Re: Back-UPS RS 800 Not charging

you could have just soldered in the correct fuseholder.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

you could have just soldered in the correct fuseholder.

Yeah I know that but I live by a small town and I was searching to just find the correct rating. This is just for testing.

[budm]

Re: Back-UPS RS 800 Not charging

So at what test point that you are showing the 23VDC? How about the voltage on cap #3 which has 1.1V on it.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

So at what test point that you are showing the 23VDC? How about the voltage on cap #3 which has 1.1V on it.

I have retested the voltages on the capacitors that you pointed out in this picture. All of the voltage tests were done with the replacement fuse connected while the board is on and connected to AC power. The batteries are also connected. These are the voltages I got from testing the two terminals on each capacitor with my multimeter set on DC volts.

1 - 22 vdc
2 - 6 vdc
3 - 3.8 vdc

It may also be worthwhile to add that the battery drops by 0.4 volts and starts dropping a considerably large amount faster if I disconnect the jumpers that are holding the fuse. The voltage also goes up about 0.4 volts and the speed of voltage drop also slows after I reconnect the fuse.

[budm]

Re: Back-UPS RS 800 Not charging

So far we do not see any 28~29V dc power source for charging the batteries yet, the highest one is the 22VDC, and we also do not get the charging voltage all the way to the fuses to charge the batteries either. This is not easy to trace out the connection.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

Would me removing the transformer and getting clear shots of the traces help at all?

[budm]

Re: Back-UPS RS 800 Not charging

I do not think so, what I need is to be able to see real closed up pictures that I can trace the connection from the two green fuses to see where it goes to. I look around at the computer recycling place and did not find any APC RS or CS 800, I found CS350, CS500 but the boards are not the same as yours. I will keep an eye for it.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

What I need is to be able to see real close up pictures that I can trace the connection from the two green fuses to see where it goes to.

Well the traces go under the transformer and through the board to the other side so I will try my best to get some good pictures of the traces.

I looked around at the computer recycling place and did not find any APC RS or CS 800.

I wish I had one of those places near me.

[canadaboy25]

Re: Back-UPS RS 800 Not charging

Well I fianally got the transformer removed and the main trace from the two fuses go straight to the large capacitor between the two heatsinks.

There are a few other small traces leading off to different places. If you need me to get pictures of those too let me know.

[ThePCDoctor]

Re: Back-UPS RS 800 Not charging

Many years ago now, I was given an APC brand, 600VA, UPS with dead and leaking batteries. (2x 6vdc gel-cells).

APC brand is the only one I've tested that WILL accept much larger batteries, like car batteries.

My own replacement batteries for the above mentioned UPS.



In case of a short circuit inside the UPS, the UPS and batteries are protected by a 30A quick blow fuse, in-line. (as seen in the photo).

In the case of the 800, mentioned above, I'd just replace all questionable parts.
The total bill would still be less than $5.

If those original batteries are 6vdc each, they CAN be replaced with a single 12VDC battery. That's basically what I'm doing.

Good Luck!

The Doctor

[kc8adu]

Re: Back-UPS RS 800 Not charging

looks like something i would do.oh wait id did that about 7 times here.
the newer apc units are junk.
old metal cased ones i hang on to.
in the o.p's case the charger got killed by a shorted battery.
wish i had one like it here to autopsy.probably easy fix.

[MarieShaw]

Re: Back-UPS RS 800 Not charging

Thanks For Solution.

[Kiriakos GR]

Re: Back-UPS RS 800 Not charging

All APC UPS always need fresh working batteries so the device to pass it self test (at boot up), and then it starts charging them.

Simple as that.

[brethin]

Re: Back-UPS RS 800 Not charging

All APC UPS always need fresh working batteries so the device to pass it self test (at boot up), and then it starts charging them.

Simple as that.

Not all APC UPS do a self test. I have a few old APC UPS (metal cases) that will function fine with worn batteries, they will just not provide the backup time a new battery would.

[kc8adu]

Re: Back-UPS RS 800 Not charging

all mine do.
when you hit the power button it turns on the connected loads to the line then about 10 seconds later it goes to battery for a test.tells you if the batteries will hold up the load.
if it fails you get an annoying beeping.

[brethin]

Re: Back-UPS RS 800 Not charging

all mine do.
when you hit the power button it turns on the connected loads to the line then about 10 seconds later it goes to battery for a test.tells you if the batteries will hold up the load.
if it fails you get an annoying beeping.

Then I would guess your units are not old. Like I said the old units I have don't care about the battery condition to work they just don't give much time when the unit inverts. I do have 7 newer units that do perform the self test and will not work with a degraded battery.

[budm]

Re: Back-UPS RS 800 Not charging

Since it does the self test when it is first turn on, now once it is on, disconnect the batteries to simulate fail batteries or fail charging circuit to see how smart the system really is to see what kind of warning you will get.