Long Lasting UPS for Desktop

Anonymous user · ‎2021-06-29

I am looking for a UPS that can backup my desktop (power consumption roughly 250W) for a long period of time (at least 2 hours, the longer the better)
so far the best suitable option i found on the website is a 1500VA back-UPS with external battery pack, but even that is not enough to support 250W load for 120+ min. I was wondering is there any way of meeting my requirement without using big server smart-UPS. ( maybe having 2 external batteries?)
Thanks for the help

-Ryan

Anonymous user · ‎2021-06-29

So you are looking for a upc that is able to produce about 0.5 Kwh or provide about 500 watts for an hour. Actually your desire for 250 watts over 2 hours is better accounting for resistive losses in lead acid batteries. You will need the largest deep discharge battery commonly available. I use an everstart maxx 29. It is rated to deliver 25 amps for 205 min before dropping to 10.5 V. If you ever had this scenario you would have to charge the battery with a car charger to bring it back to full charge. Do not delay the recharge because the battery will sulphate, and be damaged. The UPC supposedly may overload trying to charge such a large battery. Also, do not use both the VLRA battery they supply with the marine battery. Even though they both are lead-acid, their properties cause them both to operate at different voltages.
APC, if I missed the tech info on your power/time graph, sorry. If you have that info on this site you are not making it front page news. My guess is that this battery you use in these APC
's are 10 amp hour at best. So if a UPC did supply 250 watts, that battery will be dead in what, minutes? Shame on you for misleading the public.

See Answer In Context

Anonymous user · ‎2021-06-29

Thanks for the reply

I assume there is no method to satisfy the 2+ hour running time as the UPS is not designed for that purpose. On a not-so-serious note, what would happened if i connect 2 back-UPS in series, in theory shoudn't it work to increase operation time?

-Ryan

Anonymous user · ‎2021-06-29

Hi Ryan,

To answer your question, the BackUPS RS/XS are the only BackUPS line that is capable of handling external battery pack for more runtime, the thing is, that UPS is designed to handle 1 external battery pack only.

Anonymous user · ‎2021-06-29

Hi Ryan,

We honestly, do not recommend the configuration, nevertheless, it will not provide additional runtime nor additional surge protection.

Anonymous user · ‎2021-06-29

So you are looking for a upc that is able to produce about 0.5 Kwh or provide about 500 watts for an hour. Actually your desire for 250 watts over 2 hours is better accounting for resistive losses in lead acid batteries. You will need the largest deep discharge battery commonly available. I use an everstart maxx 29. It is rated to deliver 25 amps for 205 min before dropping to 10.5 V. If you ever had this scenario you would have to charge the battery with a car charger to bring it back to full charge. Do not delay the recharge because the battery will sulphate, and be damaged. The UPC supposedly may overload trying to charge such a large battery. Also, do not use both the VLRA battery they supply with the marine battery. Even though they both are lead-acid, their properties cause them both to operate at different voltages.
APC, if I missed the tech info on your power/time graph, sorry. If you have that info on this site you are not making it front page news. My guess is that this battery you use in these APC
's are 10 amp hour at best. So if a UPC did supply 250 watts, that battery will be dead in what, minutes? Shame on you for misleading the public.