Finding the Faulty Battery

Usually a voltmeter and a power resistor should do it.

If you can safely measure each battery voltage under full UPS load, then you won't need the power resistor.

If you can only measure the batteries under no load, then add a power resistor in parallel with the voltmeter. Scale the resistor to load an individual battery at the normal discharge current.

Weak/bad battery will be usually be easy to find under load.

Dear anand,

Thank u very much for your reply.

We do this type of conventional method only. My request, is there any monitor or display unit to ensure the heathiness of the individual battery in a bank.

(Any advance method)

Please explain.

V.Jayasankar

Dear Jayasankar

There are advance battery monitoring solutions available which can provide a variable discharging current, inform available Ah etc. Since these are expensive capital investment therefore most of the people monitor individual cell voltages, manually, and then decide the battery health.

Thanks and regards

Ashok Toshniwal, Bangalore, India

Suspect the one that doesn't answer at roll call...

The one that doesn't bite when kissed...

The one that doesn't make the meter jump...

uh...thinking... you should try too...

Everybody jumped on ANDY GERMANY but the point he made about one battery failing ,then another, then another is usually very accurate. Overcharge shortens battery life considerably. I think Triplite brand is the worst in my opinion. If your UPS is over 3 years old, consider your batteries, if they're sealed lead acid, to be fully used. Most of the better UPS' have auto tests that will spot he total pack getting weak, but not individual batteries. You'll still need to load and meter them individually.

Who did? You are the only one who has replied since I posted......

An Electrical Testing company such as those certified by the Intenational Electrical Testing Association (NETA) normally performs these test using the EXPENSIVE equipment mentioned. Look for the nearest one on the neta.com site.

You can measure the battery impedance and find out the faulty battery online.There are many suppliers for battery impedence testotrs like Megger,Doble etc... this can be done online.

There is a Cell Watch System available that will monitor the batteries.

If you are using a system that has deep cycle car or rv type batteries, you can use an automotive battery tester. just hook it up, apply the load and it will tell you if it passes or not.

That is what I used at one place that I worked at. I would go around about every 6 months and test, replacing those that failed.

My Cyber Power UPS has a program called 'Power Panel Plus'. It uses a special series type conductor to the computer. Research that program to see if they offer a generic system.