How many Batteries can i connect with a UPS

[ziaahmedshaikh]

Hi,

I have a 12v 840Watt UPS connected with 12v Solar panels and a battery of 12v (250Amp).

The question is: Can i add one more battery of 12v ( 250Amp) in parallel to increase the backup power ?

in that case i will have Battery array of 12v (500Amp)

Please guide.

[SunEagle]

Hard to say without knowing what the make and model of the UPS.

IMO most UPS systems are designed for the battery that comes with it. That means the internal charging system is balanced for the Ah and voltage of the battery. Unless the company that makes that UPS indicates it can accept a second battery in parallel I would say probably not.

[ziaahmedshaikh]

On its back, the details mentioned are:

Model: Inverx 1000-I
Input: 220Vac-240Vac, 50/60 Hz
Output: 220Vac-240Vac, 50/60 Hz, 4.6A, 1Q;
1000VA/600W

Battery: 12V DC

I purchased this ups 6 years ago in August 2010, no battery came with it. I am running Osaka250s with it for last one year.

[Logan5]

The Inverx 1000-I is a pro style UPS, much different than common consumer grade junk

[jflorey2]

The question is: Can i add one more battery of 12v ( 250Amp) in parallel to increase the backup power ?

IF you charge another 12V battery separately, then add it during discharge so you get longer runtime - then yes, that will work. I would not rely on the UPS to charge it though,

[ziaahmedshaikh]

yeah, definitely ups may not charge both batteries in Power up-time. but i also have solar-panel(s) connected with Charge Controller connected to battery to charge up the battery in day time.

So my question is: Is their any limit of Number of Batteries we can connect in parallel ? (provided that all of them are of 12v dc)

[Mike90250]

in theory, no. In practice, most UPS's don't have a cooling fan, and are expected to shut down from low battery before the inverter overheats.

[Logan5]

You could consider a 19" rack based UPS if a super UPS is what you really need.

[ziaahmedshaikh]

Thank you every one for helping me here. Nice forum though.

[Sunking]

One thing you are not aware of is how and why UPS exist. UPS systems are designed for very short discharge times down to 4C or 15 minutes of run time. Just long enough to get the Site Generator running and taking over. Until commercial power is restored. To do that requires special batteries that can handle extremely high charge and discharge rates. It alos requires Rectifiers aka chargers, to run at 100% duty cycle and have enough capacity to run the equipment and charge the batteries in s reasonable amount of time.

That principle of operation cannot be applied to solar.

[Logan5]

A UPS is a relatively easy thing to build. depending on the size of critical load and average length of outages common to your area. You can do much better building your own system. In my system I use 2 X 110 AH deep cycle batteries wired in series for 24 volts, These batteries and loads are maintained by a Samlex 2415 smart charger. My loads are all 12v and 19v so I have two common sealed step down converters with two different LVD=Low voltage disconnects one with higher set point so as to shed that load early leaving more critical load for the last of the battery power. No solar on this one and it is the least trouble. takes about 2 hrs to shed the less critical load and can run critical several hours after that. critical LVD is set for 23.9v and non critical is 24.2v, Typical bolt on Terminal fuse with Pudenz fuse and fused sub panel for distribution from each step down. 19v step down is for a 23" led display and laptop, not included in energy assessment. My set up does not use an inverter since I spent much effort in purchasing DC powered equipment. I also have a desktop PC with special power supply, it can run directly from 24 volt battery, also not included in energy assessment, I seldom turn it on, but can if needed. I have had no luck converting old or even new UPS's to anything other than what they were manufactured for, don't waste any money trying unless you are working with a rack UPS unit.

[VTSE]

since you have solar panel charging it too..yes you can go ahead and get an extra battery

[Logan5]

seriously? just any battery? as many as I like? please tell me how this is done.

[ziaahmedshaikh]

Yes, but as being said that all of them should be of 12v (if UPS is 12v supported) and you should not depend only on UPS to charge them all. You must have some other additional source to charge them as I mentioned I have Solar Panel(s) connected with Charge Regulator to power-up batteries in day time.

[Logan5]

12v is toy voltage, not sufficient for a powerful long cycle UPS. UPS's do not include solar as it is a poor source of power for maintaining batteries. Until you obtain a professional rack style UPS head unit or learn there is an easier way to do it with a all DC UPS or a 100 to 150 watt pure sinewave inverter, you are wasting your time. and confusing yourself in the process.