Maintaining UPS/car batteries

[murtaza.ajmi.3]

@murtaza.ajmi.3 it was nice talking to you on phone, I scrapped the plan of running fridge on UPS and bought a used APC SUA 1000

The person whom I bought from did not have any idea about configuring it. Since its a 24V design I will add 2x120AMP batteries on it. I want it to charge the batteries at 12amps and charging cut off should be 29 volts and what should be the cut off, I suppose 22 volts? How do I set these parameters?

U r very welcome. .. u purchased the ups without upgrading or wot? ... cuz without upgrading ur ups is of no use ... configuration or upgradation or software calibration is the main thing that makesur apc ups talk with ur batteries. .. kindly check with the vendor if he has upgraded the ups r not ... if not thn it wont charge ur batteries timely n as apc is micro processor based so it ll not give u ur desires backup ... setting parameters means numerous commands is to be made in ups so tht it ll give u backup with hi rating batteries. .. by default its charger is 1 to 3 amps ...

[siraj_7]

@murtaza.ajmi.3

He told me that it is already done, he did not do it in front of me. He said it is already programmed to take care of large battery bank. But I asked him to precisely set it to 12amps since I will be adding 2x120 amp batteries. He said it takes care automatically. Can you please tell me the procedure to do it or a reliable place where I can get it done in Karachi. Model is APC SU 1000 NET

[whiteangel]

Thanks @whiteangel I am not going for fridge backup because it is increasing the cost incredibly. I am only going for 3 savers and 3 lights and bought APC SUA 1000. Now the questions is that I am going to purchase 2x120 AMPS batteries tomorrow. The person is a AGS battery dealer and told me that AGS supplies 1250 gravity acid, should I trust AGS 1250 acid and go for it or can you let me know a more reliable source of better quality acid. I will be using AGS tonic to top up batteries later since the poster of the thread has found it to have TDS of 005.

If its coming from AGS, then I would recommend you go for AGS electrolyte.

About the guy claiming that the APC will automatically set charging current depending on battery... A UPS can't detect the AH of a battery, you need to configure the max charging current in the settings depending on AH rating of battery. What I would suggest is to check the charging current with a DC clamp meter. If it is not charging at the required rate, then go for adjustment.

[siraj_7]

@whiteangel Thanks!

How to check the charging current?

By attaching the meter to the red and black wire coming from the UPS without the battery
OR
By attaching the battery bank and then putting it on battery terminals. The battery bank will be in series so it will be connected in parallel or series?

If its coming from AGS, then I would recommend you go for AGS electrolyte.

About the guy claiming that the APC will automatically set charging current depending on battery... A UPS can't detect the AH of a battery, you need to configure the max charging current in the settings depending on AH rating of battery. What I would suggest is to check the charging current with a DC clamp meter. If it is not charging at the required rate, then go for adjustment.

[Zyrak]

Ammeter is connected always in series. If u go through the thread for last 1 week posts,u will get the idea of how attaching ammeter.

[whiteangel]

@whiteangel Thanks!

How to check the charging current?

By attaching the meter to the red and black wire coming from the UPS without the battery
OR
By attaching the battery bank and then putting it on battery terminals. The battery bank will be in series so it will be connected in parallel or series?

If your UPS is 24volts connect batteries in series to get 24 volts

For checking charging current clamp the meter on red wire coming from UPS. Make sure clamp meter CAN READ DC AMPS. Most clamp meters just read AC amps. I use UNI-T UT203 it can measure up to 400amp DC current.

[talhawaleed]

Ok frnds leave it and tell me one more thing.I attached pannel ammeter in series between the batteries. And what i know is that current remains same in series circuit i.e the current passing from first battery =current passing from ammeter=current passing from 2nd battery.
Now during charging my clamp meter shows almost 13.5 -14 A of current passing through the batteries whereas the ammeter is showing 30A.check the pic below.

Analogue AMP-Meter is an alternating current meter whereas Uni T 204 has an option to measure DC current that?s why reading on analogue is showing an error.

[siraj_7]

thanks @zyrak @whiteangel
@whiteangel can you tell me the price of this Uni T 204. Alternatively for a cost effective and permanent solution is it possible to connect cheap DC analogue amp meter and volt meter permanently in the battery wire loop so as to get reading whenever I want by just having a look at the guages.

Something likes these:

[whiteangel]

UNi-T 203 is about Rs.2500

For the current measurement I am using this. It reads DC voltage and current with the help of a shunt resistor. But it only works one way. Either you can check charging current or you can check current being supplied by the battery during loadshedding. It can't measure both ways.

[siraj_7]

@whiteangel Thanks

What is the approx. cost of this setup and can we install two of these which will tell both charging current and battery output.

UNi-T 203 is about Rs.2500

For the current measurement I am using this. It reads DC voltage and current with the help of a shunt resistor. But it only works one way. Either you can check charging current or you can check current being supplied by the battery during loadshedding. It can't measure both ways.

[Zyrak]

thanks @Zyrak @whiteangel
@whiteangel can you tell me the price of this Uni T 204. Alternatively for a cost effective and permanent solution is it possible to connect cheap DC analogue amp meter and volt meter permanently in the battery wire loop so as to get reading whenever I want by just having a look at the guages.

check my setup at post #2570
one current is being checked at one time. either charging or discharging.

[whiteangel]

@whiteangel Thanks

What is the approx. cost of this setup and can we install two of these which will tell both charging current and battery output.

This will cost you about Rs.500-600. I bought it online. You can install two displays with one shunt resistor for measuring current both ways. I just think it is unnecessary. If you really want to know how much how much current battery is supplying during loadshedding, you can switch the yellow and black wires connected to the shunt and it will show you the current draining from battery.

[siraj_7]

@whiteangel Thanks!

I am looking for a setup in which I don't have to fiddle every time, just pass by and glance at the values on the displays.

Charging current and battery supplied current during load shedding.

[Zyrak]

U can get ammeter from electrical accessories shop.it will cost u 250-300. Get it of 60A range

[Zyrak]

This type of ammeter is easily available from electric shops

[Zyrak]

This type...

[siraj_7]

Hi @zyrak so basically the current is looping through this ammeter, will this affect the system's efficiency since the current has to pass through this ammeter as it is connected in series.

[sherry56]

Siraj bhai according to my knowlege it will not effect the efficiency of the system as its jst measuring the current and current in series remains the same.

[Zyrak]

Hi @Zyrak so basically the current is looping through this ammeter, will this affect the system's efficiency since the current has to pass through this ammeter as it is connected in series.

not any bcz ammeter is always in series so it has very less resistance, so energy losses are not very much high. also the ammeter, i showed in pics is capable of measuring both AC & DC current. also no matter what is the direction of current in outer circuit, its needle will deflect in same direction. i am personally using it and experiencing it since years. it has bridge rectifier circuit within it and thats why, can be able to measure and show the current in same side deflection. u can personally experience it

[siraj_7]

@zyrak

So during load shedding the reading will mean ampere drainage from the battery

and during electricity from the wall, the reading will mean charging amperage

Please confirm and also tell me what do I tell the shop keeper that I want what? AC/DC Ampere meter that can be connected in series?