BMS Battery Alloy Shell Charger Problems

hopefully the time was not wasted and the repair will be successful. good luck.
 
izeman said:
It will not be worth it money wise - that's for sure ;)

i will go look on the other disc to see if i can find the white paper on the 3842 since it will help you understand it. the Rt/Ct on pin 4 is how the oscillator establishes frequency. resistance and capacitance in parallel. the 3842 runs at higher frequency than the kingpan type, orders of magnitude higher and the 3842 has internal slewing of the frequency so that the frequency of the oscillator wavers back and forth so it doesn't remain at one frequency and create emf type interference.

the little caps are ubiquitous and you may find one on some other stuff that is dead. you should verify that the zener on the gate drive is still and intact diode and did not short out or burn open when it was exposed to overvoltage. if the mosfet died, it may be dead too.

i had just always assumed that those parts were the opamp and fan transistor, even though i had learned that the fan signal comes off that pn junction device attached to the screw on the IGBT and runs over to the 16 pin IC on the daughter board. it shoulda registered before i got out the magnifying glass to try to read the UC3842. almost impossible to read it so deep down in the charger too with the sunlight reflecting off the magnifying glass. but when i recognized that, i kinda knew what i was looking at then.

post up a picture of the traces underneath too. i bet one of those big power resistors next to it, i think one is 22R, is for the current sense on the source leg of the mosfet. so then a trace would come off of it and go back to pin 3 on the 3842.

lotta work for sure, you did pretty good getting the 3842 out and cleared almost all the solder which is very hard imo.

the parts will be on ebay. you might be able to find another mosfet to substitute for it if you don't find the 1808 on ebay.
 
i think you can make it work again. you need to test all those diodes around it to be sure they are still functional since the current surge may have gone through one of them and burned it open, not likely they are shorted. the resistor on the left above the 3842 looks burned too so check that one to see what resistance it has now, before putting new parts in place.
 
Anyone reading this thread who has an EMC-2000?

I have a more comprehensive question here:

http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=29096&start=175#p1053945

Just wondering if any one else has pictures of a working EMC-2000 , around this portion of the board...from both sides

Also created another thread but I will move that content to this thread.




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I have (had) a fully working BMS battery Alloy shell charger. Been using it for a few years, no issues.

I need to know which direction to turn the current adjustment pot to reduce the current..and I can't test it as I seem to have killed it

I had turned its voltage down and current up when I first bought it.two years ago. Originally it was set to about 1770 Watt and i had adjusted it down to about 1500 watts. It was 148 volt 12 amp, I adjusted it to 83 volt and 20 amps.

It has been perfect ever since ...till a day ago when I thought I'd 'up' the power a bit, at least get it back to about 1700 watts, so I brought the current up a bit.

No problem it worked fine while the battery was under charge But after I fully discharged the battery and putin back on yesterday..bang. the mains plug fuse blew, the ring main and the main home CB' all tripped.
Looks like the input bridge rectifier has shorted, two diodes are now direct short, one from positive to an AC pin and the other is the negative out to the other AC pin

So before I even start to attempt a repair, I really need to know which direction to turn the pot to reduce the current again.
In the pictures below it is Pot number 4,



1......LED Red/ Green W501
2......Voltage W0411...I think, hidden under white 'gloop'
3......Current End of charge W401
4......Current W402
5......Voltage W503
6......DISPLAY CALIBRATION CURRENT
7......DISPLAY CALIBRATION VOLTAGE


POTS ANNOTATED.jpg
file.php


file.php
 
High Neil, I have a new bmsb alloy 900w I'm just getting ready to fire up.
I am gonna turn down the current a bit first, although I haven't concluded which pots are current.

They are all named, so once I figure it out I'll confirm which way is up/down.
100_1400__1433087159_73_187_98_129.jpg
left to right pcb locations: w4011, ?, 402, 401, 501, 503


EDIT= descriptions I came up with so far (left/right)
All the trimpots except '?' are marked with what looks like 'tx, 121, 502'. 'Out' or counterclockwise= increase.

1. coarse voltage,
2. ? Without it properly set charger kept stopping midcharge. It does seem to affect the fan too. (when I finally got it to stay charging, I turned this one out until the fan shut off when charge was done and unit was cool.)
3. coarse current
4. fine current
5. tunes when you want the light to go green I guess. I just tuned it to go red/green starting with current drop below 2a, then it goes solid green by 1a, (about 3 minutes before full charge on this 20s 5.8ah pack) I adjusted it after cv started and current dropped mostly off.
6. fine voltage
 
Well after about 15minutes of scanning threads and posts to no avail I got the ballz to just start fiddling with it.
Youtube to hook up multimeter for current- it's been awhile lol. Found some leads that wouldn't melt too.

So for the 900w alloyshell pictured, turning 'in' or clockwise reduces the setting. All the trimpots except '?' are marked with what looks like 'tx, 121, 502'.

I'll update if I figure any of the others out.
 
Well, I'm not surprised- I started playing with the other trimpots while charging, keeping careful track of their settings. I managed to get the charger to hit the set voltage limit sooner, (assuming I'd found the voltage limit pot) after reversing the change with no effect, I started farting around like a 5 year old and now the thing is so outa wack I have no clue how to get it back on lol.

If anyone has set one up from scratch, please let me know, or point me in the right direction- Cuz right now that's where I'm at :cry:
 
At least I made notes when I did my first tinkering...unfortunately I lost the notes:(

What I did was wind all the way to one end, feel for the clicks, some of them don't stop turning when they reach the stop, they have an override ratchet system. Count the number of turns and make notes..and don't loose the notes!
 
Oh snap! Yeah, that's as far as I got- I can tell when the pot is out the whole way with a little click, but found nothing when turning them in. I'm up shitcreek now :lol:

You're not aware of any coverage of the basic setup of these chargers on here? Even knowing for sure which pot is which would be helpful.
 
No sorry, not seen anything .

I'd probably start with voltage with it powered up with no battery connected.

if id does not give an output with no battery you may need to measure from the input side of the output relay.

The voltage you set will be the absolute max voltge you want

Then with a fully depleted pack, adjust the current to the max you want.

but leave a margin. My 2000W unit was seta a the maximum the factory would set it at of he 2kw unit . this was about 1770 watts, so i 'd not set your 900 to more than about 750 watts.

so if you wanted 75 volts you would set max current to 10 amps
 
Thanks man! That was so easy to find the voltage pots once I found the spot to measure it. I picked two legs :shock: of the square relay thing. Turns out the first and last trimpots are for course and fine. I'll be updating the original post whenever I get this all sorted.

Also, I'd look a little deep at that inverter. The charger shouldn't even be able to tell if its true sine or not. The ones that don't modify the sine to 100% are just less efficient and start to hurt electronics the shittier it is at matching the ac sinewave, yes? (this is just my extremely basic understanding from what I've heard)
 
Well I have two or three others, of lower power ratings, and also a bigger one of maybe 2.4kW..but not sure if that is working.

I may rig them all up and see what happens so if the charger works off of any oof them
 
Well, I am so spoiled with the gophert supply. If bmsb could just supply some instructions for the dam thing it wouldn't be that bad, but still gophert is waaay better for multiuse and adjustment. Too bad I couldn't find more than a 60v version.

In order my findings with the 900w charger.

-First pot is definitely coarse voltage,

-second is weird. Without it properly set charger kept stopping midcharge. It does seem to affect the fan too. (when I finally got it to stay charging, I turned this one out until the fan shut off when charge was done and unit was cool.)

-third and fourth are current adjst.

-fifth finetunes when you want the light to go green I guess. I just tuned it to go red/green starting with current drop below 2a, then it goes solid green by 1a, (about 3 minutes before full charge on this 20s 5.8ah pack)

-Sixth is fine voltage adjustment.
 
you could go to the 2kw thread. seems like the w501 etc numbers do correspond to what you found

http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=29096
 
Thanks guys! I'll read thru it (yep, same pcb locations- lol I was even on that thread and missed it) and look for further explaination of the 'led adjustment' and the (at least right off-the-bat) unmentioned '?' trimpot.
I'm guessing that is the ccw you mentioned izeman- makes sense that it adjusts 2 limits, cuz it was confusing me and my 2$ multimeters lol.

I like the idea of bypassing that "*$^%*&#&$" load sensing relay too.
 
Well, some 'success,

I removed al the IGBT output transistors and stuck in any old bridge rectifier I had kicking around.

The main board seems to power up..well at least the LED front display panel becomes live .

Not sure what to check to see if the switched mode / driver section is working ..dnmum ? any clues on what to check ? where to check?
 
New rectifier and IGBT's arrived and fitted.

All working correctly again.


One thing to note...

THE VOLTAGE CONTROL potentiometers,m work non intuitively, anti clockwise to INCREASE voltage. I thing the current is the same but can't confirm that now
 
Oh well guess I spoke too soon.

No magic smoke been emitted yet..but I feel it wont be long.

Inside this unit is a third LED..never sen it light up before.

Tried to top up my nearly fully charged pack just now..and this other red LED started flickering red, the charger was margin noises I had never heard before, the output voltage display quickly started rising to over 100 volts..from its set point of 83.2

Quick disconnect and power off. Restart and all OK...

but I am guessing that these pots that we had assumed were 'Fine and Course' for voltage, are a lot more than that.

Second attempt at charging..with output voltage reduced and the red 'other ' Led quickly stared flickering and the output voltage and current went to zero. but charger still OK, like some auto shutdown.

So it is either that when I did the intial damage I coked more than I thought, or the setting up has been screwed by my 'pot fiddling'

Nothing to loose now so will keep trying
 
Hi Neil, you could be right about 'course' and 'fine'.
The '?' pot standing vertical on mine that's unmarked seemed to be the key for me though.
I had wild high volt 'surges' or the charger would go into cv lower than it was set for.
I think I lowered the setting, started charge, then increased the setting little by little until it would stay charging to the set limit, then after current dropped the whole way I lightly adjusted back down cuz the fan stayed on.
 
nutspecial said:
Hi Neil, you could be right about 'course' and 'fine'.
The '?' pot standing vertical on mine that's unmarked seemed to be the key for me though.
I had wild high volt 'surges' or the charger would go into cv lower than it was set for.
I think I lowered the setting, started charge, then increased the setting little by little until it would stay charging to the set limit, then after current dropped the whole way I lightly adjusted back down cuz the fan stayed on.

the fan is not controlled by the CV setpoint trimpot. the fan on the EMC-1000 is turned on when the heat sink warms up and turns off when the heat sink cools off.
 
dnmun said:
the fan is not controlled by the CV setpoint trimpot. the fan on the EMC-1000 is turned on when the heat sink warms up and turns off when the heat sink cools off.

Same with the EMC-2000..but fan operation does have an effect on output. When the fan kicks in the regulation goes wild for a second, voltage goes up current goes up, then it settles again. It has done that since new. Bad design I guess rather than anything that can be adjusted out.
 
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