I have a pair of Liebert GTX2-700RT online UPSes and they work well; I just replaced the batteries, lubricated the fans, and cleaned the dust out of them a couple weeks ago. They have that sort of standard 4 prong socket on the back for external batteries.
But unlike my two Powerware Prestige EXT UPSes, they only operate with batteries installed. The Prestige EXT will operate as a super power conditioner without batteries which is just as well since it uses 5 x 12V 4AH batteries for 60 volts instead of the more standard and less expensive 4 x 12V 7AH-9AH batteries. These have a 4 pin Molex type of socket on the back for battery expansion. I have considered converting these to use a bank of supercapacitors but I suspect the charge circuit would have a fit charging them from zero volts. I picked these up inexpensively from http://www.refurbups.com/ but I have not seen any deals on refurbished online UPSes there for quite a while now. If your equipment can run on 12 volts DC, then there are less expensive solutions like one of those Belkin 12 volt battery backed up power supplies that some ISPs issue to their customers or something home grown. On Fri, 16 Sep 2016 04:56:35 -0400, you wrote: >Actually the larger SmartUPS series can run for hours providing a large enough >battery string is available I have a SmartUPS RM3000 running data rack >this has 2 external battery boxes and will run everything for 6 hours. > >For TimeNuts applications though I'd recommend a Liebert UPS as this is a >'online' UPS as in input is converted to DC and used to float batteries and >drive a power oscillator for a true sine output and in a power interruption >there is no transfer time or transients on the output > >Content by Scott >Typos by Siri _______________________________________________ time-nuts mailing list -- firstname.lastname@example.org To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.