Battery Capacity Load Tester

[rjr10234]

Gentlemen,

I have a battery bank that feeding UPS and i would like to do the capacity load test for it, but I would like to have the following result as will the Amp, Voltage, expected live time and condition of the battery bank. So please if any one has the idea for designing this load tester with mentioned specification i will be so happy to have such information and design review.

Thanks

 

[k7elp60]

battery test and load bank

What is the voltage and the amp/hour capacity of the batteries? To test the batteries, they have to be fully charged and discharged at a constant current to the cutoff voltage. The time it takes to get to the cut off voltage times the discharge current is the capacity of the batteries. A load bank can be constructed or purchased. The specifications depend upon the batteries to be tested

 

[rjr10234]

Thank you for your replay

The total battery voltage 125 Vdc and the voltage per cell 2 Vdc. Amps depend on the load and the total battery cells 60. So please if you have any idea for designing such device I would like to have it.

 

[k7elp60]

load test

From you recent post I understand the batteries are Lead Acid type. These batteries also have a capacity such as 5A or some marking as to
the capacity. This is an important charastistic as the discharge current for the load tester is set to some value to discharge these batteries. Once I know the capacity in amps of the batteries I can better advise you.

 

[rjr10234]

The capacity of the batteries as follow:

8 hr 25.0 Amp, 1.75 Vdc, 05/03 A this is the first type and the second type is :

100 Amp hr

So is this information enough and I wash if i could get capacity load tester and also it should be enable to give me the complete information about the battery conditions.

 

[Nigel Goodwin]

The capacity of the batteries as follow:

8 hr 25.0 Amp, 1.75 Vdc, 05/03 A this is the first type and the second type is :

100 Amp hr

So is this information enough and I wash if i could get capacity load tester and also it should be enable to give me the complete information about the battery conditions.

Presumably (from what you said earlier), all these batteries are connected in series to give 120V?.

When connecting batteries in series it's vital that they are all identical, mixing different batteries will result in the weaker ones going flat first - once they do the other batteries will reverse charge the flat ones, with dry cells this causes them to 'vent' leaking corrosive chemicals everywhere. With lead acid cells I'm not sure what will happen, but it certainly won't do the batteries any good!.

A reasonable load for testing would be 10% of the rated Amp hr, so for 100 Amp hr, 10A would be a good choice. A simple (and cheap) way to do this would be a 110V 1000W electric fire element - it might not give exactly 10A, but it will be close enough to make a decent load - in any case, you would be advised to monitor the current as well as the voltage during the tests.