My guess is you're out of luck. I'm assuming your UPS has VRLA batteries which discharge after about 6 months. As for plugging it in, that shouldn't be a problem unless there was something wrong with the UPS to begin with. Good luck.
I've have a UPS that hasn't been powered up for 2 years. Does anyone know if it will still work? I'm not sure if I want to plug it in and take a risk of anything happening.
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