BMS Battery Alloy Shell Charger Problems

no, down on the pcb. the black wire goes to the the trace that goes over to the left under that cap, so connect that black wire on the pcb to the red wire on the middle trace.

cut the wire off about 7mm above the surface so when you fold it over to that adjacent hole, it is not too long and touch something else. but the cap is farther over. there is nothing underneath to short out on the pcb.

you have to pull the insulation off the wire from the top with some pliers and the bare wires will lay on top of each other, then solder it down and you can remove the thyristor board too. cut a hole in the label where the screw is and put your screwdriver in through the hole. you have to hold the nut. save the parts for some other project.

the latching output daughter board is by the output. the wires go by it where it stands up, in your picture the second wire tie is next to it. grab it at the top and rock it back and forth until it breaks off. if you damage it however, don't blame me. but that is what we remove for the lifepo4 chargers. ping and paul shoulda told you that.

also, i am now thinking that the reason we see so many of these chargers with the npn switching transistor blowing up may be cause of the inrush current putting a huge voltage spike on the transistor when it first hits. on some of the chargers (the big high power, more expensive models) there is a separate switch to the high voltage so the charger can be left plugged in and turned off with the switch. that feature is a real bonus because it saves the damage to the npn transistors.

but anyway i think for those chargers without a switch, then install one of my ICLs inrush current limiters, where it has the thermistor spot next to the red wire on the right.
 
I'm welcoming others input on this too

Dnmun:
(im not the most electronics experienced guy)
So looking at the picture below cut B and C and solder them together... I don't see why I need to cut them so short, plus if i leave them a little longer I could reattach the thyristor board some day...

Aaand Im also cutting wire A and taping the end. And removing the latching daughterboard.

Oh and uh... what voltage should i be reading across B and C, the way it is, powered on?

BTW are there others in this thread fixing the same problem/mod as me? which user/what page about...

When you say your ICL does this mean you sell stuff?
 

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the reason to cut it short is so that after you pull off the last bit of insulation it will be bare wire. if it is as long as the distance between the two through holes then you can push the strands over on top of each other and solder it together laying flat on the pcb. just like a jumper wire. i use a jumper wire when i repair these IF the pcb is already pulled outa the charger. since yours is still glued in then it is easier to just use the stranded wire, soldered together, as the jumper. so you are soldering C to B in your picture. you can unsolder A from the hole in the pcb and remove it altogether.

you will never put the thyristor board back. they should never have put it in. i have warned ping and jimmyD about them, it has caused a lotta charger returns to ping already. i have had two burn out on me and cargo tom had both of his chargers burn up because of them.

the lattching output daughter board needs to be removed if you are gonna balance charge wit that charger. the latching output daughter board turns off the charger when it reaches final voltage. this is the right thing for lipo since lipo cannot be overcharged since it has no BMS.

lifepo4 has to continue charging at a low rate at the final voltage in order for the cells to all balance to the same voltage to fill up.

so remove that little daughter board too. remove it by pushing it back and forth until those legs at the bottom break off. it doesn't take much. save the parts for something else later. i have a big bag full, who knows what to do with them. the little caps may be useful and there is an opto on the latching output board, and some resistors and the thyristor too.

but do those two things, that should get your charger into a stable long term fix.

i have some of the ICL inrush current limiters that i sell to people who have the other type of switch mode power supply SMPS using the mosfet on the input to switch. these burn up fast because of that type design and on some of the chinese chargers will usually fail within a a few hours. that is why i bot a bunch to help people fix their chargers.

some people will work on their charger but most are just too unable to do stuff so they just throw the charger away. kinda a mental laziness, some people never fix stuff since they can just buy something new. i fix everything. so i have parts to fix these things, chargers and BMSs and batteries.

i try to help people but mostly they just never reply, first they ask for help and then just disappear when i try to get them to analyze their problem. like it is too much bother for them to measure stuff or look at something so i can give them accurate advice, but they just ignore it because they would have to do something. like they expect some kinda free advice where they don't have to do anything to help. it is really hard to diagnose electronic problems over the net. some are just too lazy to even measure the cell voltages on their battery. makes me feel like trying to help people is a total waste of my time.

anyway, i am now thinking that the reason so many people are having problems with the npn swithcing transsitors in the front end on these low end chargers is because of the inrush current when the charger is plugged in. that causes a voltage spike on the transistors that can cause them to short out and blow up.

the higher end, bigger chargers do not have the problem since there is a switch on the high voltage. so the charger when plugged in does not have the inrush current creating a spike on the transistors because the DC voltage on the front end is already stable when the switch is turned on. for the larger chargers this is critical because the currents are so large at start up but they can get away with it on the low powered models so they cheap out on the switch.

so using an ICL on these cheaper low power chargers would make the transistors last longer and less chance, in fact there would be no chance, of failure from the inrush current created voltage spike.

i have sold some of the ICLs that i bot, saved about 8-10 chargers so far.

i just came to this conclusion while working on a buncha chargers the other day. i have two with the npn switching transistors burned up. but installing the ICL on the pcb while it is in the charger requires some effort. you have to unsolder the jumper that is across that place where they have marked for the ICL (i think it says Rth) and then solder the new ICL where the two holes are. or you can cut the jumper, stand the two pieces of jumper up vertical and then solder the thermistor legs to the jumper legs.
 
but do those two things, that should get your charger into a stable long term fix.
Yeah I'm pretty happy about the prospects of fixing my charger so easily. Ping and cell man want to tell me its dead because they sell chargers, and save time by not helping me fix it... I guess leaving the thyristor board in is a win-win for them too, they don't have to remove it and they're chargers die after some time so they sell new ones. Anyway I love fixing my own stuff especially when it means saving $100+ on a new charger.


some people will work on their charger but most are just too unable to do stuff so they just throw the charger away. kinda a mental laziness, some people never fix stuff since they can just buy something new. i fix everything. so i have parts to fix these things, chargers and BMSs and batteries.

i try to help people but mostly they just never reply, first they ask for help and then just disappear when i try to get them to analyze their problem. like it is too much bother for them to measure stuff or look at something so i can give them accurate advice, but they just ignore it because they would have to do something. like they expect some kinda free advice where they don't have to do anything to help. it is really hard to diagnose electronic problems over the net. some are just too lazy to even measure the cell voltages on their battery. makes me feel like trying to help people is a total waste of my time.
It is mental laziness sometimes but most are just unable to proceed because they don't understand the electronics terminology (rectifier, thyristor, draughtboards etc...) and then feel bad using up your time asking for clarifications. And it can be very really tricky for us noobs to figure out descriptions of what needs fixing on top of figuring out what the terminology means, and, for example, which of the two seemingly identical red wires to cut etc... I couldn't follow anything when I first started reading the thread, but I have a background in engineering and I have repaired circuit boards before, so I kinda know how to articulate exactly what I've not understood. In making things understandable to noobs, whenever a description is refering to a picture, that picture needs to be identified like "pic 1". many little clarifications like that are needed. They prob just want to see written "let me know all your specific questions" or something

If I turn on the charger first, The spark isn't very big when I connect it to the battery, so I think my npn switching transistor thingys should be alright without the ICL thingy.
 
the thyristor daughterboard is there to allow the charger to work on either 120 or 240. they used to have switch for selecting the input voltage, but started using this thyristor board recently because people don't know how to flip the switch. the higher end chargers all still have the voltage selector switch.

i think i have talked ping out of buying more of these 'universal voltage' chargers from kingpan so hopefully they will not be around much longer. they charge him extra, 5% for the thyristor board but it results in many chargers dead and returned to him so he is losing money on it.

he doesn't make money by cheating you, he makes money by selling good products and backing them totally so his reputation will sell his batteries for him. i consider him an excellent businessman and totally honest and sincere person.

he is just stuck with having to sell these chargers because that is what kingpan supplies him with.

the latching daughterboard is there to turn off the charger when it reaches final voltage as i said. this latching output board is needed for lipo but if you have lifepo4 or in your case konions then the pack will not balance because the charger turns off. i thought that was the problem you started out with. this has been a known problem for three years. you have to remove the latching output board if you want to use the charger to balance the pack. you should remove the thyristor and solder the wires together to reduce the chance of it burning up on you.

the ICL is on the input AC, not the output. the reason your charger sparks when you plug it into the battery while the charger is unpowered is because the capacitors on the output of the charger suck a ton of current from the battery when the connection is made. the reason i recommend adding the ICL is to reduce the voltage spike in the front end. to make the charger last longer. of course you don't have to do any of this either.
 
The more I mess with these things the less I like them - Bloody unreliable, good for low currents/small packs but I sent another pair to hell yesterday trying to charge a 6Kwh 44S Lifepo4 battery at only 4A! God I hate them.

Time to get serious methinks. I've got some evil lurking that will make all of these BMS battery chargers look like the unreliable expensive toys they are. I'm working on a 6KW 160V three phase charger for when 1Kw charging is just too slow :mrgreen: And its smart enough to know if its being fed 3 phase or plain old single phase 15A, and not attempt to draw 30A from a 15A socket :twisted: And that is also PFC ~ so no tripped breakers if they are the right size.

Probably way too overkill for most people here bar a few.
 
dnmun said:
the thyristor daughterboard is there to allow the charger to work on either 120 or 240. ...

Well I removed the latching daughterboard and it will charge the battery through the discharge leads at 1.6A, Charger voltage 58.8V, battery resting voltage: 57.7V. looks like the charger is working now :D

However it does not charge through the charge leads of the BMS... so I guess I have a BMS problem too... Another thing that Im not sure is normal is when I measure the battery voltage from the discharge leads I get 57.7V and when I measure it from the charge leads I get 57.3V.
 
do you have a picture of the BMS? is it the ping or from BMS battery?

ping and paul shoulda told you about the latching output. i will eventually get a picture up for the thyristor jumper. i thought it was obvious since they are right next to each other and no traces in between them. you don't need the other red wire which is for a 240v AC line voltage, you use only 120 anyway. so you can take it out.

after speculating for a few days i am really certain that adding an ICL to these chargers which don't have the power switch is important.

i just looked at greg's charger and i realized it doesn't have switch either. i have a KP series charger right here with a switch, 300 watt, but greg's is 900W so iwould have expected a switch. but they are economical designs.
 
The Stig said:
However it does not charge through the charge leads of the BMS... so I guess I have a BMS problem too... Another thing that Im not sure is normal is when I measure the battery voltage from the discharge leads I get 57.7V and when I measure it from the charge leads I get 57.3V.
dnmun said:
do you have a picture of the BMS? is it the ping or from BMS battery?

The battery and the 14S 40A Li-ion BMS are from Paul/cell-man, here is a picture and specs: http://em3ev.com/store/index.php?route=product/product&path=42&product_id=75

Yeah I thought ping/paul should have been able to tell me something because the charge curve of Lifepo4 is quite different from konions. I hadn't told either of them where I got the other product from. So do Ping and Paul hang out?

I got the impression you need the thyristor board for powering the charger with 240VAC. Since I travel to europe I think i will take the chance and leave it in. If there is a guide to installing the ICL please feel free to link it. How much is one?

Here are some pics that kind of show the cell-man BMS and battery installed in a little frog battery case, I'm pretty happy with it, esp once I figure out the charging situation:
IMG_20130208_223911.jpg


IMG_20130208_223759.jpg

Caption: the little red wire going into the cell balancing plug goes to a 24V battery level indicator, which is isolated by a push-button switch.
 
dnmun said:
did the BMS allow you to charge before you added that wire to the sense wire plug?
I just tested it, It doesn't make a difference if that little red wire is in the balancing plug or not. It leads to an open switch anyway.

I had discharged the pack a bit, then when I plugged the charger into the charge leads it was charging for a bit at about 2.3A but now I can't get it to accept a charge again. the pack is at ~57V
 
dnmun said:
most likely one of the cells is at the 4.2HVC and it is shutting off the charge. you can measure the voltage of each cell right on the sense wire plug.
Did that, they are all at 4.0-4.1V

I just discharged it again at 5A for a minute and now I'm charging in the charge leads steadily at 2.4A, 58.1V. Will edit this with updates soon... Maybe its just a very cautious BMS...
 
i see 58.5V@1.4A so it is still trying to balance them. you could even adjust the charger voltage down a little from 60 to 58.8-59V and i think it will balance and less time spent at the 4.2 cutoff level because it will go into balance mode at a lower voltage. jmho.
 
dnmun said:
i see 58.5V@1.4A so it is still trying to balance them. you could even adjust the charger voltage down a little from 60 to 58.8-59V and i think it will balance and less time spent at the 4.2 cutoff level because it will go into balance mode at a lower voltage. jmho.
Yeah I've adjusted it to 58.6v. That's the charger voltage your seeing:) The BMS cuts off at at about 57.3v and is now sitting 57.5v.
 
you would see the 50mA of balancing current if they were still charging in balance mode. it is cut off for HVC on one of the channels. but it seems like it is close to full. that was cheap for a lipo BMS.
 
This might be of use to anyone with a 900W BMS Charger.

Email from BMS or ecitypower
Hi sir,

Sorry for the delayed reply , did you measure the battery voltage ? Is it at normal voltage ? If it is ok, please measure the voltage according to the pictures i sent , the blue is positive , the black is negative , connect the charger to ac power , don't need to connect battery ,sorry to cause any inconvenience .

Regards
Bin

img0965vv.jpg

img0966fa.jpg


Little history, my 1 week old 99.84V 900W bms charger wont charge at all, I still need to measure the voltage by following their instructions above with the pics, will do it in the morning.
 
Here is a recent chat with BMS, Epowercity:

me: i will check later in the morning, thanks for the pics, what should the volatge read if i do it this way
Sent at 1:51 AM on Thursday
sales3: i am not sure about the voltage values , it will be transferred to our engineer , who know whether it is ok or not
me: okay once i measure the voltage I will send u an email with that info, tnx
Sent at 1:54 AM on Thursday
sales3: ok , bye
me: tnx bye
Sent at 1:58 AM on Thursday
me: hi just measured 10.V
by following on the pictures u sent
Sent at 2:17 AM on Thursday
sales3: ok , can you also send us some pictures of the charger ? We need the inner pictures , especially the pcb , hope it will not make any inconvenience .
me: one sec, i will take them now
Sent at 2:21 AM on Thursday
me: uploading pics right now to gmail
sales3: ok
Sent at 2:25 AM on Thursday
me: pics sent
Sent at 2:28 AM on Thursday
sales3: ok, let me see.
Sent at 2:29 AM on Thursday
sales3: wait for a moment , we are checking
me: ok
Sent at 2:35 AM on Thursday
sales3: Is there a new order in future ?
me: I just need a charger for my pack, thats all i need, sorry
Sent at 2:44 AM on Thursday
sales3: we think the control PCB(the small pcb in charger) is broken , we can send a new charger and that pcb to you , but you may pay the shipping cost , what do you think ?
Sent at 2:49 AM on Thursday
me: so you will send a new charger and pcb? but I pay the shipping
?
sales3: yes , is it ok ?
me: how much is shipping?
Sent at 2:53 AM on Thursday
me: I need a 99.84V 8 amp charger AC voltage 240V, french plg type
sales3: same as the last one . about $70, can you do me a fever ? Could you measure the two site on pictures i sent before ? To see whether they are connected , the multimeter has a Buzzer switch , it can check the connections .
Sent at 2:58 AM on Thursday
me: yep they buzz, its connected. sounds good

Short story, they want to send me a new charger, plus new pcb and I just pay shipping $70... :D ....I said stick it!!! Ya get what you pay for!!!! learned my lesson on this one.
 
what was the voltage when you measured it at the two points circled?

if they will send you another for $70 why would you not do that?

they offered to send it even if you did not show the old one was broken?
 
dnmun said:
what was the voltage when you measured it at the two points circled?

if they will send you another for $70 why would you not do that?

they offered to send it even if you did not show the old one was broken?

10V, I just have a feeling that after reading this thread and the problems people have had with BMS, that I am throwing more $ away.

I had sent them a video and close up pics earlier, and they believe the pcb is bad. $70 for shipping, that's a joke and on top of it they use FedEX which in turn sent me a bill for 35 euros after they delivered it for custom taxes. Screw FedEX

Probably going to go with nice Mastech dc psu
 
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