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Question about Belkin (F6C1500-TW-RK) (F6C1500TWRK) UPS System

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Belkin F6C1500-TW-RK discharged new batteries, won't recharge

Belkin F6C1500-TW-RK. Replaced batteries for first time in 4 year old UPS. Batteries were new, 12.5V via multimeter before installation. Turned unit on, monitoring software indicated 24.5V and 82% capacity. Left plugged in overnight with no load, capacity dropped to 70%. Decided to use anyway (needed the outlets!), now dead after two days. Multimeter reads 3.5V and 1.5V; batteries obviously not charging. Measure only minimal current and voltage directly from internal UPS leads (red and black wires) with batteries disconnected, but of course can't actually turn the unit on this way (current even drops slowly when I press and hold the power button). Any suggestions for further check or repair, including disassembly? Any way to rule out defective batteries? I have no other means to charge.

Posted by walletless on

  • walletless Jan 26, 2011

    Belated addendum: I sent the new replacement batteries back to the vendor, they checked them out, said they were fine, and sent them back to me fully recharged. I tried them again in the UPS, same problem.

    Belkin generously offered to charge me an arm and a leg to ship the unit back and pay for repair (out of warranty), but I declined and have since bought a new APC UPS. I think the Belkin unit has a design defect (intentional?) that permanently damages the UPS if the batteries die and the unit is left plugged in.

  • Dave Johnson
    Dave Johnson Mar 25, 2017

    Same failure mode here. I beleive the "IG0" and "IG1" components eventually fail from thermal stress (PCB all around the big heatsink they are bolted too is dark brown discoloration, in my case 8 years worth - which I call pretty good :), resulting in draining batteries to complete exhaustion (usually destroying them) and unit appears dead. Haven't performed any further troubleshooting. If anyone tries to fix, let us know.



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This sounds like a battery issue...I would have the unit and batteries tested at your nearest batteriesplus store...

Posted on Aug 04, 2010

  • aburt Jan 19, 2011

    FYI - just had same problem. Same UPS (Belkin F6C1500-TW-RK). Replaced batteries, plugged in, no load, died w/in 48 hours. Can't turn on. I don't think it's a battery issue we're seeing here.



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