Backup Power

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preshan

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Hi guys i just installed a 3kva ups on my tank and have decided to only plug the return pump , resun waver and 2 seios on controller to this ups so that
i can get the longest backup time in the event of power failure.
what do you guys think
how long backup time would this ups have
there are 16 batterys 7amps each on the ups
total watts used is +- 200 watts

Preshan
 
did you buy it from EJ?
 
No i got it from a customer who didnt want to spend money on repairing it
so i put in new batterys and charger card
 
I would also connect a small heater just in case.
 
I am in the process of investigating solar power backup.
 
we get lots of power outages, just bought a 5.5kw generator for checkers to keep things going, will run all my pumps just without the lights
 
Hey edd welcome to MASA.
 
Oh my system i had a system that ran off a 24v backup kit and it ran my system for +/- 12-14 shours with everything and 36+ with just a pump and heater
 
mekaeel said:
guess we all need need to start investing in a genarator to be on the safe side
Click to expand...
This is a very good idea. UPS back ups are fine for short power outages, but when you start getting to the 1, 2 or 3 day outages you will find you will need a generator. The problem with a genny is they are very noisy.
 
Preshan, post how many watts your return pump and seios are drawing, and i can tell you exactly hopw long your back up will be.
 
From his message it looks like total power consumption of 200 W. With 16 battries of 7 Amps ea would be 112 amp hrs. Based on this, backup would last abot 4.5 days. I agree with Viper, I would add a heater, but even with a 200W heater backup should last for two days easily.
 
Your discharge current on that load with a bank of 16 12V batteries would be 1 Amp. So in actual fact, you'll get about 12 hours max.
 
Surely if you have 16 batteries of 7amps ea, you have 112 Amp hrs. If you are drawing 1 amp per hour roughly ( 200W / 220V) that is roughly 112 hours?
 
Your discharge current of 1 Amp is only because you have so many batteries in series. If you had a discharge current of 1 Amp on 12V, then yes, you would get huge back up. To work out discharge current, divide the watts of the load by the total voltage of the batteries in series.
 
But why would you put the batteries in series? Your invertor converts 12 DC volts to 220 volts AC. By putting batteries in series you have 192 V DC . Not what you want.
 
The invertors in UPS's aren't 12V. They make them to suit the total DC bus.

UPS manufacturers as a rule of thumb do not make their UPS's with all the batteries in parallel. With large units, you would have two banks of betteries in series, and parallel the two.

Even if all 16 of his batteries were in parallel, his discharge current would be 16.66, and with one 12V 7ah he would only get about 25 minutes or so.
 
I would rather have a small genny, but you would need a UPS to regulate the output of it. A 1 kVA Line interactive UPS, and a genny with and AVR is the answer.
 
I need to spec the size of the genny for the big tank also might as well then run fridge and freezer as well.
 
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