BMS Battery 400w charger help

mxer

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Nov 28, 2010
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My trusty 3 year old (it's done me well) BMS Alloy Shell Charger is not working


I bulk charge my 50v (set to) Lipo for 3 years without an issue switching on first (red light) plugging in my 50v lipo pack (green & red). fan cuts in charging commences.

Now when I switch on the charger I get a solid red light that instantly fades away to nothing, re-switching gets me a solid red light again but by the time I go to plug my lipo pack in it's faded away again.

I've tried everything, plugging lipo first gets me a solid red but that's from the pack, no fan kicking in, nothing?.

I took the charger apart and can see No obvious burnt areas or traces?...no puffs of smoke no burn smells, Nothing??.

Ive changed fuses,wiggled wires,checked voltage to the board from the kettle lead?.all good.

It's like it initially takes in voltage the fades away?..

Can anyone Help or have had a similar experience? I'd hate to give up and throw it out as there's nothing obvious to me that looks faulty?.

Any help or advice would be greatly appreciated with many many thanks in advance..

Update: I have asked over at Endless but after searching about I have no fix so also looking at a new plug and play charger @ 50v (4.17) BMS Battery no longer make this charger, so pretty desperate to find a solution..

Cheers All
Last edited by mxer on Thu Feb 23, 2017 7:47 pm, edited 1 time in total.
 

Danidl

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My trusty 3 year old (it's done me well) BMS Alloy Shell Charger is not working


I bulk charge my 50v (set to) Lipo for 3 years without an issue switching on first (red light) plugging in my 50v lipo pack (green & red). fan cuts in charging commences.

Now when I switch on the charger I get a solid red light that instantly fades away to nothing, re-switching gets me a solid red light again but by the time I go to plug my lipo pack in it's faded away again.

I've tried everything, plugging lipo first gets me a solid red but that's from the pack, no fan kicking in, nothing?.

I took the charger apart and can see No obvious burnt areas or traces?...no puffs of smoke no burn smells, Nothing??.

Ive changed fuses,wiggled wires,checked voltage to the board from the kettle lead?.all good.

It's like it initially takes in voltage the fades away?..

Can anyone Help or have had a similar experience? I'd hate to give up and throw it out as there's nothing obvious to me that looks faulty?.

Any help or advice would be greatly appreciated with many many thanks in advance..

Update: I have asked over at Endless but after searching about I have no fix so also looking at a new plug and play charger @ 50v (4.17) BMS Battery no longer make this charger, so pretty desperate to find a solution..

Cheers All
Last edited by mxer on Thu Feb 23, 2017 7:47 pm, edited 1 time in total.
Obviously it's not charging. How many pins are there on the output lead from the charger to the battery pack?. Is there a DC voltage on these when disconnected from the battery pack but also connected to the mains?
You indicated that you checked voltages around the charger...How?
Many of these power supply chargers will have fuses with wire ends soldered like resistors in line with the input transformer, it would not be obvious that it will have blown. But a. Resistance measurement should given the clue. Don't do that measurement however when there is mains voltage applied.... Life is short as it is. I am not requesting that you publicly answer these questions, but when you do answer them to ,might be close to a solution.
If there is an electric ,continuity failure in the power supply you can probably fix it but
If there is an electronic failure in the power supply, you probably cannot fix it. Even simple switch mode power supplies where the primary switcher is at mains voltage are not suitable for casual repair. Most chargers fall into that category.
 
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mxer

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Nov 28, 2010
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Really appreciative of the input Danidl.

There's nothing on the 2x output Anderson connectors of the charger plugging in switched on. The LED light lights up initially on the charger then just fades away??

I'm thinking it's the power supply end, I have checked voltage to the board(240v there) to eliminate kettle lead,switch, and fuses but where to trace from there is beyond me and a little scary switched on, lol..

I like the idea of testing components but unsure what to check or how, I do have a multi meter.

If it helps, this happened to me a week ago, but I managed to shock it back to life by plugging the battery pack in which with a bit of wriggling firrd up the fan and charging commenced. But now I've nothing, not even if I plug the battery in this time..

Like I said I've tried most sequences now as nothing to lose as it's dead, opened up, cleaned, dusted, wiggled, still nothing.
 

Danidl

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Really appreciative of the input Danidl.

There's nothing on the 2x output Anderson connectors of the charger plugging in switched on. The LED light lights up initially on the charger then just fades away??

I'm thinking it's the power supply end, I have checked voltage to the board(240v there) to eliminate kettle lead,switch, and fuses but where to trace from there is beyond me and a little scary switched on, lol..

I like the idea of testing components but unsure what to check or how, I do have a multi meter.

If it helps, this happened to me a week ago, but I managed to shock it back to life by plugging the battery pack in which with a bit of wriggling firrd up the fan and charging commenced. But now I've nothing, not even if I plug the battery in this time..

Like I said I've tried most sequences now as nothing to lose as it's dead, opened up, cleaned, dusted, wiggled, still nothing.
....
The potential good news is that there was life after death in a manner of speaking... That you did get it to momentary charge after jiggling connections. That would suggest an electrical rather than electronic fault. . A loose connection, dry solder joint.
There would typically be 100 or so connections on a small PCB and failure of any one will result in non working.
In a number of these supplies, a capacitor is used to supply an initial charge to a clock situated on the low voltage side of the transformer. This is supposed to kick-start the process. The clock then switches on and off the power transistor situated on the live mains side of the transformer and this then supplies the continuous power to the clock and then powers up the output. Voltage measurements at the output are used to alter the switching rate of the power transistor and thus regulate the voltage
I would closely examine the board for dry joints, without any power attached. A dry joint might be greyer than silvery and you might wiggle any wires protruding. Using the multimeter as a low voltage continuity tester between connections you expect to be made. You cannot use it to measure the resistance of components in circuit, unless you are sure there is no other possible parallel path .
I would be reluctant to suggest you make any measurements of voltage either AC or DC when mains voltage is present. Actually making that stronger... I am actively advising you not to take any measurements on the exposed board with mains present
 
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mxer

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Nov 28, 2010
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Fantastic thanks again, I have ordered another one albeit different, waterproof apparently, lol. I take no fan on the new one? Don't know if that's a good thing?.

In the mean time I will test to destruction as nothing to lose, I like your thinking, I'm the same about it must be something simple? As no burnt traces smells crackling, so should surly come alive again, I'll strip it of it's shell tonight and post some pics for ideas to prod/test, cheers..
 

Danidl

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Fantastic thanks again, I have ordered another one albeit different, waterproof apparently, lol. I take no fan on the new one? Don't know if that's a good thing?.

In the mean time I will test to destruction as nothing to lose, I like your thinking, I'm the same about it must be something simple? As no burnt traces smells crackling, so should surly come alive again, I'll strip it of it's shell tonight and post some pics for ideas to prod/test, cheers..

Fan present or not does not matter. I prefer fanless finding the frequency really annoying.
Electronic components can fail silently and with no external physical damage, so absence of damage is not evidence of no damage.
If you get it working you can locate it at the other end of your commute and get extra zip on the return journeys.
 

mxer

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Nov 28, 2010
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HaHa your a clever chap Dan. Top stuff that's exactly what I intend to do, Cheers

:)
 

mxer

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Nov 28, 2010
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It's ALIVE!!!..



Don't know what yet, but it's something fixable. Going to replace 3 pin, fuse, switch connector block as this area has had a lot of use to and from work.

Thank you Danidl for giving me the inclination to investigate further, Top man, cheers.
 
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Did you check the hidden fuse next to where where the kettle lead plugs in and the fuse in the plug?

OK, I see you got it working.
 

mxer

Pedelecer
Nov 28, 2010
92
10
Yes thanks d8veh, I'm thinking a cold solder on 1 of the many connections to the block.
If I move it it won't work, move again and lights up like a Christmas tree, so faulty connection somewhere, I'll replace the lot hopefully curing it..
 

Danidl

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It's ALIVE!!!..



Don't know what yet, but it's something fixable. Going to replace 3 pin, fuse, switch connector block as this area has had a lot of use to and from work.

Thank you Danidl for giving me the inclination to investigate further, Top man, cheers.
... Working out better than anticipated. What I would now recommend is to power it up an then to gently poke each wire and component with a plastic or wooden stick. Eg a toothpick, a straw, bic Biro sleeve or similar and see can you replicate the fault. That will isolate the area and a little soldering, on the disconnected board should see you right for another 3 years.
Looking at the picture, it looks that a number of the components have very little solder and might have come adrift
 
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