BMS Battery Alloy Shell Charger Problems

[izeman]

hmmm. afaik the schottky is the 3pin to-220 like one connected to the cool sink. correct?
connected to the middle pin, but i didn't show any voltage.

 

[dnmun]

on the kingpans the output from the schottky diode goes into the choke. there is a big wide trace running from the schottky diode to the place where choke is soldered to the pcb. that is the charger + output.

ok, i looked at the 900W charger the EMC-1000 and the trace is on the undeside so you don't see the trace but it connects to the place where the choke is soldered down so you measure there at the soldered joint.

 

[GCinDC]

i don't want to connect it to the battery before checking the voltage.

fyi, takes some courage, but i just plugged and unplugged my batts in very quickly and then could adjust the voltage. no problems at all.

 

[chroot]

Cell_Man (Paul), He told me that kingpans charger are piece of crap and he stopped offer these piece of sh*t charger. Right now, He is selling LTX chargers offer the 3 switch different voltage set and He mentioned this new charger even allow you tweak lowest and maxmium voltage adjustment. Even said superior quality charger.

60 bucks for this charger. Look bottom 4 LTX chargers

Here the info. em3ev chargers

Example 10S charger

Our NCM/Li Ion Chargers come with a 3 position switch to set output voltage to 42V, 41V and 38V. This enables charging to approx 100%, 90% and 50% SOC. Regularly charging to 90% SOC will help to extend cycle life. Charging to 50% is recommended for battery storage.

Example 14S charger

Our NCM/Li Ion Chargers come with a 3 position switch to set output voltage to 58.8V, 57.4V and 53.2V. This enables charging to approx 100%, 90% and 50% SOC. Regularly charging to 90% SOC will help to extend cycle life. Charging to 50% is recommended for battery storage.

Example 17S charger

Our NCM/Li Ion Chargers come with a 3 position switch to set output voltage to 71.4V, 69.7V and 64.6V. This enables charging to approx 100%, 90% and 50% SOC. Regularly charging to 90% SOC will help to extend cycle life. Charging to 50% is recommended for battery storage.

 

[agniusm]

i have a charger similar to this, thou its a 240W one.

I needed to adjust voltage on it and i have 2 potentiometers near the LED's. I figured one is voltage, other one is for fine tuning. What are those other two near the caps and shunt needed for? Whats their purpose?

 

[dnmun]

the trimpot on the far right next to the led adjusts the output voltage. the one in the middle next to the shunt wire with the little tan cap next to it is for adjusting the current and the other one sets the point where it shift to CV from CC and just runs on the balance current. so it is essentially what sets the balance current.

 

[agniusm]

So, for my to be 10S5P 42V lico pack i set output voltage to 42V or whaterver i want cell woltage to be multiplied. I plug the charger to the battery and measure current, then i can adjust current i want for my pack, right? What then CV/CC should be?
Thanks

 

[izeman]

i don't want to connect it to the battery before checking the voltage.

fyi, takes some courage, but i just plugged and unplugged my batts in very quickly and then could adjust the voltage. no problems at all.

if i plug it in, the voltage of the charger shows the voltage of the battery - what else. connecting it makes the relais click, and after unplugging it, voltage starts to decline slowly. when it reaches 12v (around 30-60s) the relais opens again.
when i measure GND to schottky it gives me -0.5v. yes: MINUS.
i can turn both voltage adjustment resistors as much as i want in both directions, but voltage doesn't change a bit.
any ideas where to start?

 

[GCinDC]

if i plug it in, the voltage of the charger shows the voltage of the battery - what else.

0V.

on a working 900W charger, it will only display 0V until it has been plugged into a battery. then, when unplugged it should display the charger's preset output voltage.

the fact that it doesn't means yours has problems! sorry. what a graveyard this thread has become.

just to see what percentage are still working out there, i created a poll.

everyone, please hit it: Have you had a BMSBattery Charger Fail?

thanks for the links to those other chargers, chroot. unfortunately, they're lower voltage.

if folks know of other working high voltage chargers/sources, please post a link.

 

[izeman]

if i plug it in, the voltage of the charger shows the voltage of the battery - what else.

0V.

0V BEFORE you connect it. of course, as the relais is open, but when you connect it, the voltage is pulled down to a common level, which is battery's level. so when it's connected you can raise the chargers voltage as much as you like, it will not move.
the problem here seems to be that there is NO voltage coming from the charger, and all i see is the voltage stored in the caps.
so any idea where i should start?

 

[dnmun]

the charger has a relay on the output. it is totally normal for there to be no voltage on the output for the large chargers if there is no battery connected.

some of the smaller chargers have a fuse and schottky diode to protect the output from being reversed. those chargers will display the output voltage even when there is no battery connected.

some of the SMPS chargers have a p channel mosfet on the output to protect against reversing the output.

BMS battery does not make these chargers. they are made by EMC or by kingpan.

if you wanna categorize them by failure mode, ask the surveyed if the charger failed because of the new thyristor daughterboard or if they failed for another reason.

most of the kingpan charger problems are because of the change by kingpan to add this thyristor daughterboard and it has led to a spate of charger failures, especially where people use 240v on two wire circuits. so ask them to check if it says 'universal voltage 90-270V'.

from looking at the parts they use to make these big 900W chargers called the EMC-1000 i consider them to be well built. it would cost more than twice as much to just buy the parts to make one and it does take a lot of skill and production control to make it. so if it was made in the USA or europe i expect it would cost about 4-5X what the chinese sell it for. i doubt if the quality control would be better either. that is why they don't make them here.

i think most of the chargers fail because of the inrush current surging on to the npn switching transistors in the front end when the battery is already plugged into the back end. i have tried and tried to explain to people to not plug in the battery first but to them they cannot imagine why it would make any difference and instead they blame poor manufacturing or 'cheap chinese junk'as the failure mode. most of these would never have failed if they had plugged the charger in first. that is why they have the power switch on some of the chargers, to protect the input when it is plugged in to the AC.

 

[izeman]

the charger has a relay on the output. it is totally normal for there to be no voltage on the output for the large chargers if there is no battery connected.

if this is a reply to my post: yes. i know that. just wanted to make sure that i expect no voltage to be there because of the relay. i like to state the obvious in my posts to avoid further replies stating that and this way prolonging the root cause finding

 

[dnmun]

can't make that thing turn on for setting the voltage. i don't want to connect it to the battery before checking the voltage. i followed doc's thread on how to turn the relais on, but i can't remove the board to connect the resistor, as the board is glued to the case. what pins/solder pads on the upper side of the board have to be connected to turn on the 900/1000w type?
help is much appreciated.

this is your original post up. i am not familiar with the resistor you are talking about or what is "doc's thread".

do you have the charger labeled EMC-1000 or is it a different type?

you can measure the voltage in front of the output relay to find the voltage when there is no battery connected. i thought i explained that you would measure at the spot where the choke (the big round toroid wound donut) is soldered to the pcb. that is the output of the schottky diodes.

 

[chroot]

No problem, Cell_Man said that new LTX charger can go high voltage but I haven't ask him how high voltage maxmium yet and however I am going ahead ask him right now.

He mentioned it can tweak lowest and high voltage that's all he said but forgot ask him.

thanks for the links to those other chargers, chroot. unfortunately, they're lower voltage.

if folks know of other working high voltage chargers/sources, please post a link.

 

[izeman]

do you have the charger labeled EMC-1000 or is it a different type?

i can't find the emc-1000 label written on the board. but it's got the very same daughterboard with the blue resistors on it, and it looks exactly the same as all emc-1000 pictures i've seen.

you can measure the voltage in front of the output relay to find the voltage when there is no battery connected. i thought i explained that you would measure at the spot where the choke (the big round toroid wound donut) is soldered to the pcb. that is the output of the schottky diodes.

yes. i did that. i already found a second non working charger (which board was not glued to the the case) and was able to follow traces. measuring at the choke and GND was the first thing i tried. the choke goes directly to the middle pin of the shottky. as said: if there is no battery connected, and the relais is open, then it shows -0.5V.

 

[dnmun]

so no current from the schottky means the front end is not pushing current out of the back.

the ground lead, the - spot where the blue wire connects, is connected to the other side of the transformer and the shunt is part of that ground wire.

so the diode can be open circuit or there is not any switching of the npn transistors in the front end to make current flow out of the transformer.

that would give you no voltage at the choke. that is what goes through the relay.

you have checked the fuse? under the plug?

 

[izeman]

so no current from the schottky means the front end is not pushing current out of the back.

the ground lead, the - spot where the blue wire connects, is connected to the other side of the transformer and the shunt is part of that ground wire.

so the diode can be open circuit or there is not any switching of the npn transistors in the front end to make current flow out of the transformer.

that would give you no voltage at the choke. that is what goes through the relay.

you have checked the fuse? under the plug?

not checked the fuse, but it should be ok, as there are some ac voltages present on the board, and the red and green led are lit. is mt assumption wrong? i would check directly, but am in the office right know so i can't

 

[dnmun]

if the leds are lit your fuse is ok. just checking. you can measure the hi voltage on the front end? it should be 340V from the top of one collector to the emitter of the other one.

base voltage is about 50V. that is where the switch is placed when there is a switch on the charger. to turn off the base current in the transistor.

 

[izeman]

deleted

 

[izeman]

if the leds are lit your fuse is ok. just checking. you can measure the hi voltage on the front end? it should be 340V from the top of one collector to the emitter of the other one.

base voltage is about 50V. that is where the switch is placed when there is a switch on the charger. to turn off the base current in the transistor.

300v dc between collector and emitter of the other n channel bipolar transistor. i guess this was the one you were referring to.
the 'base voltage' thing is confusing me. where shall those 50v be? are you referrring to the switching voltage? afair this should be 50v. so i need to measure 50v dc at the gate? always or only if the relais is closed?

 

[dnmun]

i don't know specifically what voltage would normally be on the base-emitter. just measured that before but sounds like you have hi voltage so not sure why it does not make voltage in the back end. if you can measure the forward bias on the schottky diode you could see if it has burned open. should be .3-.4V forward and open when reversed.

 

[izeman]

hmmm. i don't understand that. connected a switch to close the relais. plugged the charger in. closed the switch. click. measured some volt at the output.
turned the resistors and was able to acchieve some 70v at the output.
i had to turn both volt regulating resitors up to go there. i still can't see which one is what for. couldn't even say that one is fine or coarse.
whatever, suddenly the voltage couldn't be raised any more and started to fall. turning the resistors didn't change anything.
at 12v the relais opened again, and output fell to 3.3?v.
deplugged the charger from main, replugged it, and attached the battery. charges fine with 10a now. strange, strange, ...
but dnmun: no worries, i have several more to repair thanks for your help so far!!

 

[izeman]

i now started to repair the second 900w charger i received broken for free.
i don't know that happened to the boards (maybe the fell to the ground and the board moved inside) causing this:

all the mosfets and schottkys look like this, some pins are even broken.

i repaired the soldered one, plugged in to mains plug and the mains fuse blew. so i measured the fets (GT50J325), and they have a short on all pins. so i removed them and replaced them with the fets from another charger. now it works again.

has anyone seen this before?

edit: ordered 3 of them on ebay, so can repair the 3rd charger for $3.60 each. fakes for sure, but they should do the job.

 

[dnmun]

GT50J325 is an insulated gate bipolar transistor, IGBT. i got them for $4 each from utsource.com since they are $13 from mouser.

 

[izeman]

GT50J325 is an insulated gate bipolar transistor, IGBT. i got them for $4 each from utsource.com since they are $13 from mouser.

'Has anyone seen this' was referring to the bent pins. Not the transistor. The local electronics's shop sells them for $20+.