How to Detect Bad Battery

[rahul_sanghavi]

bad battery relationship to internal resistance

Hi

I have some problem during my project that how to find Bad Battery.
I sense Battery voltage only.
Is it Possible to find bad battery indication using only Battery voltage ?

Regards
Rahul

 

[dreamteam]

bad battery voltage

Battery is a current source, so you have to check the voltage through a load. Checking only voltage without load won't be enough to detect bad Battery.

 

[cmosbjt]

how to detect a faulty battery

use so call Reset IC or voltage detection IC to sense the battery voltage.

 

[Hoko]

detecting bad battery

You can measure its internal resistance and open-voltage.Hioki 3560 is capable of battery measurement.

 

[IanP]

bad battery internal resistance

First of all, battery is a voltage source (in theory it should supply infinite current at the same voltage level, but in reality because of its internal resistance it is not the case).
Sensing voltage only does not give you definite answer.
What battery testers do (HIOKI 3560 is a good example) they measure (close to)shorcircuit current for, say, 1ms. And if you combine these two values, current and voltage, you will be able to assess a battery. This test can be performed during normal operation.

 

[platonas]

bad battery detecting

You can connect a load on u r battery that can draw an appriciable current i.e. for a 12V 7Ah battery try to draw a current between 5-15A. If there is a large dip in the voltage across the load then the battery is not ok. Considering a 12,5 to 12,8 open voltage, at load this sould not fall below 12,3 to 12,6 according to initial voltage. (This is just an example and values are not based on manufacturers data) Usually faulty batteries could measure less than 12V at such loads.
Simillarly you can operate with other battery voltages.
Carry an experiment with good battery and use the results as an approximate reference. Certainly, this method will give a rough result since the load is connected for a short period, usually anything less than 10 secs.

You will not get an indication of the capacity of the battery but only on its approximate condition.

 

[rahul_sanghavi]

bad battery indications

Hi

Thanks "platonas"

Regards
Rahul