This weekend I was getting near the end of an 8 hour print when the power blipped for about a second. I thought – sure am glad I have my machine hooked up to a UPS. Then it blipped again and I though “double glad”. Then it went out totally. The print kept going fine on the UPS for over 25 minutes powering a Mini and an old iMac with core2 duo – although I dimmed the screen as far as it would go, and unplugged the mouse and keyboard too. It wasn’t quite enough juice though – the UPS died about 10 minutes before the power came back.
So I was thinking, I could get an inverter and a deep cycle battery, make a double-ended pronged cord, and then connect the inverter to the same powerstrip the computer and mini are on when the power goes out, relying on the UPS to make that quick switchover and giving me time to haul out a battery, inverter, and a double pronged power cable. I have two worries about this:
would I be feeding power back to the UPS the wrong way so to speak? The powerstrip is connected to an output from the UPS, but when I plug in the inverter, that line will be energized externally from the UPS. Anyway – is that bad? I figure I could get the power strip unplugged from the UPS in 5-10 seconds after connecting the inverter, being careful about the live prongs of course.
I was looking at inverters and there are cheap ones and more expensive “pure sine wave” models. Does it matter to have a pure sine wave? This question is contingent of course, on the answer to #1 being “no big deal.”
The big issue (ask any motorhome owner) is that the deep cycle batteries don’t like to sit unused. Basically if you use a motorhome only a few times a year, you need to replace the very expensive deep cycle batteries every year.
If you use one for a UPS system you need to maintain it (draw it down and charge back up) monthly or even weekly or you will need to replace it every 9-12 months. If you do properly maintain them then you can get 5-7 years out of one.
I think a better (cheaper and less work) would be to just buy larger gel cells or even buy more of them put together. They require much less maintenance and would probably cost less, plus they are safer (no liquid acid to spill).
Funny, I watched that video earlier and it’s what made me think using an inverter and battery might be a better way to go, in particular, the unknown factor of whether the charger in my UPS is a trickle or a float type. I’d rather not have the battery being constantly overcharged, but then, you’d think that would create problems with longevity with the UPS. Still I’d rather not make assumptions.
Hmm, I’m running my Mini on a CyberPower 1350, that also has my MacBookAir’s USB Dock and a full-size DVD Writer attached. The Mini is being driven by my MacBookPro which is attached ti a separate UPS. Maybe I should take the MBA’s stuff off the 1350, just in case? (The MBA is not attached to a UPS, just a constant voltage transformer/filter since it’s internal battery is good for 8+ hours and the only thing on the USB dock that would normally pull power is a 2.5" back-up drive)