Charger do not work (probably tried to reverse polarity)

[Tyro]

Hi, I am writing here for the first time i think, but am reading the forum for the while. I hope you can help me with your advices. I have a 16s2p lifepo4 battery pack and charger for it for a while. Until i didn't finished my frame i have not used them yet. Yesterday I tried to power charger to AC and look it makes voltage in the output or not. It didn't (o to be truthfully it gave ~2.3V). As I have finished first ebike for my dad with 8s1p pack and bought charger for it i know - even unloaded charger have voltage in the output. I think i have reversed polarity when tried to charge pack. I thought output have to be loaded to give more volts. When I turn it on the red power led lights, the red/green led is off, fan is working, output ~2V. I do not leave turned it on for a long time, because the capacitor exploded once after doing that. It is changed to new one now. Checking with voltmeter found few interesting thinks which are listed if comment of photos. I think there is somewhere error with charger logic, because i can find >+63V on board.

Where I have to start checking? There are some photos of charger.

Changed capacitor is next big from reel. The diode in middle shows resistance to both ways while other shows resistance only to one side and unlimited to another. I tried to desolder and check - it looks to be fine when not in schematics. I do not know how to check triodes.

Back side of charger. There are ~+63V within blue wire and next side of reel.

IMG_20120322_224444.jpg (138.81 KiB) Viewed 199 times

[DAND214]

Have you dhecked the voltage in the battery? That charger will show next to nothing without a load that is below the set oltage. The relay next to the cap you replaced cuts all power when it hits the set voltage.

I have one that looks like that charger and it wouldn't charge as the battery was above the cutoff voltage. There are three trim pots I see the one by itself will adjust the cutoff voltage.

Not sure if this is helpfull but if you have 63v at the relay but not ot it is because it's not being energized.



Dan

[Tyro]

My battery voltage is 53.2 V. I have tried to connect to charger's output 60W bulb lamp, and there was no effect on charger. Now as I said works only one led from two, and I think other one should light red or green?

[DAND214]

Did it ever work?

[dnmun]

you must know for certain if you reversed polarity or not. it seems that you must have or you would not have mentioned it.

why did you remove the diode? the charger is functioning, since it has 63V on the output, you need to analyze the circuit that turns on the relay and see if reversing the polarity could damage something in that circuit.

try turning off power to the charger, apply voltage of correct polarity to the output, and then check to see if the relay will function. it should click when you apply voltage to the output.

[Tyro]

I got this charger together with 48V 20Ah Headway pack. Seller says it worked. Chargers cable do not have marks plus or minus, tester showed nothing to me too (zeros).

why did you remove the diode?

Because power with tester goes to both ways. Not only from anode to cathode. But diode is fine, i put it in back.

try turning off power to the charger, apply voltage of correct polarity to the output, and then check to see if the relay will function. it should click when you apply voltage to the output.

I tried - yes, relay didn't worked. I measured that relays magnet pins are shorted inside. Today i changed the reel with new one, but nothing solved. Connecting battery pack to charger I do not hear reel connecting sound.

I am getting nervous

[dnmun]

what is a tester? do you have a voltmeter and do you know how to use it?

the relay coil should appear as a dead short since you are measuring the resistance of a copper wire. a dead short.

one set of contacts would be open and the other should be closed. i assume your relay is normally open and then closes when the battery is attached to the output. did you ever connect the battery to the output while the charger was turned off and listen to see if the relay clicked? before you replaced the relay?

[Tyro]

what is a tester? do you have a voltmeter and do you know how to use it?

the relay coil should appear as a dead short since you are measuring the resistance of a copper wire. a dead short.

one set of contacts would be open and the other should be closed. i assume your relay is normally open and then closes when the battery is attached to the output. did you ever connect the battery to the output while the charger was turned off and listen to see if the relay clicked? before you replaced the relay?

Sorry, "tester" is the same voltmeter, but that's slang in our language I know how to use it.

Coil was really shortened - resistance between coil contacts was 0 Ohms, tried to connect charger to battery or use 9V battery directly on reel to force contacts to close, but was no sound. Now there is sound how contacts closes.