Trickle Charging and Batteries

I get three guesses for a quarter. Your potentiometer is shorted, your zener diode has cratered or one or two of your diodes have bit the dust. Me thinks its time for a closer look see, in the isles of your local supplier for a new one. Cost to repair out weighs the purchase.

Cheers

Hmm .... seems to me either the charger doesn't want to provide the 120 mA or the batteries just don't want that much any more. To test the charger, replace the batteries with a dummy load and see if it can deliver 120 mA. If it can, then at least one of the batteries is dying.

Once you identify the problem, you can take appropriate action.

Grae

As far as I know a 300 AH battery will need more like 1200 mA current for trickle charge. Probably the trickle charger out put is defective or the sensing circuit is malfunctioning.

bioramani

Dear all

Regarding this issue,I discussed with our protection engineer.He told "the batteries will not take current when it is fully charged".But I am not satisfied with this answer.

1)Then I take all cells readings with RMS multimeter and hydro meter after switching off battery charger.

2)The voltage is in the range 2.040V to 2.060V and specific gravity is in the range 1190 to 1210.

3)Then I put the charger in boost mode(3 ampere) for 4 hrs.

4)After 4 Hrs,I put the charger in trickle mode.The trickle current will not raise above 40 mA but the DC voltage raises above 120V and simultaneously the over voltage alarm comes.Hence I set the voltage 120V not bothering about trickle current.

I dont know where the mistake is.Please share your views.

And I thanks to our members who share their ideas.

Regards

gova

Kindly furnish following information:

1)Your battery charger is it automatic one with auto control feature.

2) Please indicate the make of the charger.

3) when you select the boost mode the charger is charging the battery at 3/4 amps but in trickle mode it is not charging beyond 40 mA, there should be controller inside the battery charger which is restricting the trickle charging current .Please explain how are you varying the trickle charging current?

Dear sir

1)Battery charger is not automatic.It is manual only.

2)Make is "power aids".

3)Usually we set the trickle current at 120mA.but now we cant raise above 40 mA.

4)there is no problem in raising the boost current.

5)In our substation,for a feeder fault,LT supply also damaged/burnt.After this incident only,the above things happened.

please share your views

regards

gova

I think yours is TNEB SS.

Normally Power aid Battery chargers, they give one potentiameter (variable resistance) in the circuit, which will vary the trickle charging current, in your case the potentiameter is not working, therefore you are having this problem.

Dear sir

you are right.This is TNEB SS.Your guessing tells your Experience.

I got your point but to ensure further i put this question again.

1)Is this statement correct.

"when battery is full charged condition,it will receice only required amount of trickle current say 40mA eventhough we increase the potentiometer Knob".

Regards

gova

Yup, your right. However a potentiometer does not increase the amps but lowers resistance to increase voltage to the zener diode threshold cut off voltage. Sounds weird, but the feed back from the batteries is compared to the input and the minimum might be 40 mA. I can't really say, but try disconnecting the battery pack and check the output voltage whilst turning the potentiometer. You should see a full swing from start to finish, if there is a gap or stoppage anywhere, the problem is with the potentiometer.

Cheers