Xantrex UPS

[Tom Metro]

Rich Braun wrote:
> ...the Xantrex Powersource 400 units I bought last year have
> been a very satisfactory purchase.  I still get hours of backup
> time with them (...I think it was 7 or 8 hours...). 
> 
> Nothing I've ever bought before those has come anywhere close.

That's because a typical UPS is designed for short duration use. There 
can't be anything all that magical about these devices - they're just 
trading off VA rating for run time length. You should be able to get the 
same effect by purchasing a UPS with a much higher VA rating than you 
need. It'll end up having the same amp-hour rating on the batteries. 
(Though in theory a device designed for long run time should be cheaper 
due to being able to use cheaper, low current components in the inverter 
circuit.)

I looked these up when you mentioned them before and Best Buy was 
charging $150 for a 650 VA unit. That's 2 or 3 times the price of a 
competing 650 VA unit. I'd be curious to know what kind of batteries 
they have inside, and how the run time would compare to a 1000 VA unit 
powering the same 50W load.

If long run time is really your goal, you'd be better off using less 
expensive UPSs in conjunction with a gas generator. You can get 1000 to 
2000 watt generators imported from China these days for $130 to $200. 
With the generator you can keep refilling the tank for days or run time. 
(Of course a generator is a tad less convenient. You can't exactly stick 
it in a corner in your office.)

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/

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