in calculating the AH for the battery we consider the load current and back up time. with correct dimensioning that should not happen!

it is however not advisable to use batteries with different AH ratings together. this could damage them. so since your ups has an internal battery adding a different rated battery would definitely cause trouble.

additionally some UPS are not designed to support extended autonomy. those that are, can normally be ordered without batteries to allow battery bank dimensioning. (this is most likely to be done by your supplier though!)

and finally, batteries have a recharged time limit to avoid damage! so, such a small UPS would require an external charger to protect the batteries. the limit is usually around 8 to 10 hours.


Recommendation.

Get a slighly bigger UPS i suggest 1 KVA. from this range, extended autonomy is usually possible from my experience.

A battery Bank with 26 AH batteries would give about 1 back up time at full load. Actually a little longer. For this range of batteries the UPS should be able to recharge without requirement for external charger.

please note: ensure that you determine the input voltage requirement of the UPS so as to get the correct no. batteries.

1 KVA can back-up, up to 4 computers.

and remember to get the online UPS to avoid feeling the black outs and brownouts etc....:)






> Date: Tue, 16 Nov 2010 09:02:36 +0300
> From: muriukin@gmail.com
> To: skunkworks@lists.my.co.ke
> Subject: [Skunkworks] Power fluctuations and UPSes
>
> @Hellen. You said that i can add a battery bank. I have a question, a
> 650VA has 7AH battery, if i was to replace it with a 100AH battery or
> more would the UPS meltdown due to heat generated by extended
> operationi or it will be just fine?
>
> On 16/11/2010, hellen masita <hellenmasita@hotmail.com> wrote:
> >
> > Hi David,
> >
> > there is one other option i see.
> >
> > The types of UPS in the market can fall in two broad categories.
> > 1. line interactive
> > 2. online
> >
> > i work with DELTA UPSes and they are the latter type. the difference?
> >
> > online UPSes allow power to go through the UPS into the equipment whether or
> > not the mains are working while line interactive kick in once power fails
> > (blackout, brownout etc....)
> >
> > line interactive UPSes therefore usually need a few seconds to minutes to
> > kick in unlike the online UPSes which just switch supply to battery and
> > continue working without effect. no dip in power, no flickering.
> >
> > add to this the double conversion technology available in such system and
> > you get filtered/Clean power free of spikes and noise.......
> >
> > i suggest, you look for an online double conversion ups of the same rating.
> >
> > one last point, to get extended back up time does not necessarily require a
> > bigger ups. if the UPSes you have serve your requirements then than is the
> > right size of ups for you. what you need is to dimension a battery bank that
> > can support longer back up.
> >
> > that,s my take!
> >
> > Date: Mon, 15 Nov 2010 09:30:41 +0300
> > From: daudi.were@gmail.com
> > To: skunkworks@lists.my.co.ke
> > Subject: Re: [Skunkworks] Power fluctuations and UPSes
> >
> > Thanks guysSo if I understand correctly:a higher VA power will give me more
> > time to back up etc if power fails completely
> > my situation where the comps reboot each time the power fluctuates in
> > probably because the UPS circuits are damaged and nothing to do with the VA
> > power of the UPSTherefore to deal with my situation I should be looking for
> > a UPS with extra strong circuits rather than higher VA?
> > On 15 November 2010 09:02, Kenneth Ndirangu <kendirangu@gmail.com> wrote:
> >
> > David,
> >
> > You probably need to clarify how the office is wired.
> > Seems to me like each ups is sitting on a different power source (different
> > phase and different breakers).
> > It's common with kplc in cases of 3 phase supplies to have a brown/blackout
> > on one phase only.
> >
> >
> >
> > some ups have high voltage sensitivity and transfer capabilities that makes
> > them capapble of working with a varying input voltage including brownouts.
> >
> > When selecting a ups, count your pc's determine how much runtime u want then
> > go for it. In the long run it's easier t handle 1 big ups instead of many
> > small ones. but a 650va ups on a desktop pc is just enough time to finish up
> > and shutdown safely.
> >
> >
> >
> > hth
> > Ken
> >
> >
> > On 15 November 2010 08:05, Job Muriuki <muriukin@gmail.com> wrote:
> >
> >
> > There is a difference in the two UPSs. The higher the rating in VA the more
> > power can be provided
> > to yo PC so it lasts longer. Just multiply that value with the power factor
> > of your UPS for APC its
> >
> >
> >
> > about 0.6 to get power in watts. For the reboots its the circuits in the UPS
> > that are giving in.Where are you located? I noticed some of my routers in
> > upperhill are rebooting especially yesterday.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
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