Need a schematic for a belkin F6C120-unv. All functions of the unit work fine other than the charging circuit won't keep the batteries charged. Runs about 24.7 volts, but keeps getting lower as the batteries run down with A/C power active. The batteries run down to 50% after 3 or 4 hours. The diagram view shows the charging circuit kicking in periodically, but the voltage is not high enough to charge. The fuses check out ok. Have tried 2 new sets of batteries. Both sets work fine in another UPS that I have. Steve

Here is a link for the batteries . And look in the yellow pages any computer repair shop should do fine.

http://www.batterysharks.com/Belkin-F6C800-UNV-p/F6C800-UNV_UPS12-7_x2.htm?gclid=CLWpnJeZrbwCFelxOgodOjMA4A

If they cannot hold the charge or do not charge then get rid of the thing and get a new one. Should be much cheaper than when you bought the one you have now.

Cradle and contacts are fine. Cradle circuit is nothing but a reed relay and few wires, relay closes on proximity to robot's body, therefore no voltage on contacts before robot is close to cradle.
There is a thermistor inside of battery, and mine was bad. I removed it and now I am charging the battery from my bench power supply at about 220 ma current, overnight, and it works. Probably the solution is to get a new replacement battery, but the one with the thermistor inside (OEM), easily recognized by the third wire, and all should be fine, assuming that nothing else is wrong with charging circuit or power adapter (12v/1A)
Hope this will give you some ideas of where to poke.
Once successful, please post your solution.

if its a Brand New out of box, it may require at least a couple hours charge. thats what we do when we move our servers around.

-mk3ride

I just replaced the batteries on my Belkin F6C900-UNV. They died just short of 3 years of use, which is what I would expect. My unit contained two 12 volt, 4.5 amp-hour batteries that were connected in series. When connected in SERIES (one battery's red terminal is connected to the other battery's black terminal), the two batteries behave as if they were one 24 volt battery. Therefore, this UPS is designed to charge a 24 volt battery. When replacing the batteries, you cannot use a single 12 volt battery. This will fry the battery. You can use either two 12 volt batteries connected in series, or one 24 volt battery.

I measured the charging voltage of my two new batteries (connected in SERIES), and find it charging at 24.6 volts. This is an ideal float voltage to maintain these sealed AGM (absorbed glass mat) lead acid batteries (13.2 volts per battery). The replacement batteries are similar to the originals, each measuring about 2.7x3.5 inches and 4 inches high and rated at 12 volts, 5 amp-hours. They can be purchased for $20 or less each, so for $40 I now have a fully functional UPS, good for another 3 years.

Unplug it and open it up. Check the batteries with a load tester of the same voltage, like a car lite bulb. If the batteries are good, check that the connectors are tight on their fittings. I had to squeeze the ends on my Cyberpower unit with a pliers to make it tight enough to work right. If the batteries are dead and you can't charge them, contact BatteryBob.com, he gave me good service.

Check the manufacturer's web site for upgraded software on your UPS. This sounds more like a software problem.

If you've got nothing my guess is its something more than the battery as it should still be able to draw power if its plugged in. If its within the warranty period (3 yrs, I believe). Go to the belkin webpage and to their ups support and start the process to return it and get it fixed/replaced. A couple months ago I had a F6C500-UNV that suddenly died on me just like yours - no nothing. It cost me $13.00 or so bucks to ship the broken unit to Belkin; a week or two later I got a brand spankin' new F6C550 or whatever they currently sell in that same voltage area back from them. The cost to RMA the broken unit was much cheaper than even buying a new battery for the old and now discontinued unit.

Very likely, "would this also explain why none of the indicator leds are working?"...the dead batteries are your problem. you can try this test, since you had it opened: 1.) disconnect internal batteries, label the wires by terminal location. 2.) connect (2) 12 volt car batteries to same exact wires that you just disconnected, noting correct polarity. 3.) power up UPS. if everything ok, then buy 2 replacement batteries for UPS. if not ok, buy new UPS after through search inside UPS reveals no blown fuses or other faults including poor wire connections.

that´s pretty strange and i would say that the batteries aren´t properly charged, try to let them charging over night without any load. good luck