My computer UPS (Uninterrupted Power supply ) just started to not give the normal back up time when there was a full power cut , so Ive replace the internal 12 volt DC battery, and all’s well now.

This has got me thinking, if it’s the internal 12 Volt DC battery that gives the UPS its backup time , If I install a second battery 12 volt DC battery in Parallel with the original UPS internal battery will this increase the UPS backup time ..?

Thanks

My computer UPS (Uninterrupted Power supply ) just started to not give the normal back up time when there was a full power cut , so Ive replace the internal 12 volt DC battery, and all's well now.

This has got me thinking, if it's the internal 12 Volt DC battery that gives the UPS its backup time , If I install a second battery 12 volt DC battery in Parallel with the original UPS internal battery will this increase the UPS backup time ..?

Thanks

It will!

But you should check with an power meter that the charging voltage is constant 13.4 - 13.5 volts after you connect the second Battery.

If you use "noname" batteries, you should change them every year but good name like original Panasonic last 2 to 3 years. Importand is a constant charging Voltage from 13.4 to 13.5 volt to get most out of the Batteries.

Cheers.

It will work but best to use a second battery identical to the original.

Naka.

I have 2 Sealed cell type motor cycle batteries in parallel with the internal battery and it works a treat. At least a 100% increase in backup time. My main concern was with recharging all 3 batteries similtainiously but there was no additional heat from the UPS so I assume there is a 3 fold increase in recharge time.

Edited February 5, 200818 yr by bdenner

Yep, as noted above, you'll get a better autonomy time by paralleling up several batteries.

A couple of points worth noting:-

• EACH battery must have its own fuse, lead-acid batteries can generate HUGE currents, we don't want any fires starting do we?
  
• The recharge time from flat will increase, up to approximately 3 times if you have 3 identical batteries (probably less in practice)
  

NOTE that in a parallel arrangement so long as the batteries are all the same voltage, the amp-hour rating does not need to be the same. Interesting information here :- http://www.allaboutcircuits.com/vol_1/chpt_11/5.html

To add to Crossy's post I don't recommend one uses lead acid batteries inside you home or office, they give off toxic fumes and will cause damage if knocked over. 12 volt "Gell Cells" are more expensive but much safer and are available from most motorcycle parts suppliers.

To add to Crossy's post I don't recommend one uses lead acid batteries inside you home or office, they give off toxic fumes and will cause damage if knocked over. 12 volt "Gell Cells" are more expensive but much safer and are available from most motorcycle parts suppliers.

Yeah, agreed.

Sorry for the confusion, in this instance the term 'lead acid' refers not only to the 'wet' (car type) batteries but also the sealed 'gel' or 'spill proof' batteries which are found in UPS units, they both use similar technologies. Wet batteries require good ventilation as the fumes can be toxic (sulphuric acid vapour) and explosive (hydrogen).

How about a 12v car battery? You can get sealed maintenance free ones so allowing for the extra initial charge up time one of these should last all day.

Would that work?

Daffy

You mean like this

Yea! “Monty” That should do it.

Bet you never have to turn your computer off.

Daffy.

The little UPS (3.5KVA) feeds all my computerstuff and fragile equipment in my resort.

LCD projectors, airpumps for the aquariums, emergency lights and the waterpumps feeding the waterpipes.

Over here you can never end up standing under the shower, all soaped up, to then see the power cut out and leaving you standing there all soaped up, trying to get rid of the soap using drinking water

Should last about 8 to 10 hours, but never had a powercut that long yest...

Should last about 8 to 10 hours, but never had a powercut that long yest...

Cool

Are those vehicle batteries, or the special deep-discharge (traction) batteries?

What are you using to charge them, the UPS only or have you got a bit of extra oomph?

I once replaced the internal 12V battery in a standard UPS with a standard 12V car battery. I had to put a small fan on the UPS to keep the electronics cool but after that it worked fine; would keep my PC running for hours without mains. It looked a bit messy though so in the end "she who must be obeyed" put her foot down and I had to get rid of it.

Cool

Are those vehicle batteries, or the special deep-discharge (traction) batteries?

What are you using to charge them, the UPS only or have you got a bit of extra oomph?

Regular vehicle batteries. The UPS works on 48 volt, so I have two sets of 4 batteries which gives me 400 Ah at 48 volts.

Traction batteries would give more endurance (regular batteries' voltage drops below the low voltage setting of the UPS when they are at 30-40%, traction batteries keep their voltage all the way down to a few %), but they are much more expensive! The extra capacity is not needed by me anyway.

Only the UPS charges, it can charge at up to 60 amps at 54 volts. It's not really a UPS anymore, they call them bi-directional inverters. Generates pure sinewave as well!

Switches over just as fast as a UPS, computers don't know what happens, they keep humming happily along...

.... It's not really a UPS anymore, they call them bi-directional inverters. Generates pure sinewave as well!

You nerd you

Thanks guy's for the info, Great stuff..

just wondering , how many of the small USP internal type 12 Volt DC battery's I could in fact connect up in Parallel

to my UPS unit with out causing the electronics in the unit to stop working correctly..?, would it be proportional Eg..

my USP is rated at ... 525VA ( One internal battery ) = about 10 minuets back up time.

would that mean if I installed 4 battery's in total = 40 minuets back up time ..Etc