BMS Battery Alloy Shell Charger Problems

[dnmun]

since it was the ground wire that was burning up the cord, and it finally burned open the last strands of the wire where it was crimped into that grounding lug, it seemed obvious that the AC was going to DC through the diodes and the current was flowing into the case, through the case, to the ground lug, then back to the service ground.

so if it is not flowing through the case, i am not sure how the power is being shorted. did not see scorch patterns.

 

[IBScootn]

Ok, quality has been low, but are there things we can do to improve the chances of these working reliably?

 

[GCinDC]

the less you move it the better!

i toss mine around in my backpack etc, and it seems to be hard on the connectors. The AC plug on the unit, not the part that goes in the wall, but the computer type AC input to the unit seems prone to disconnecting and needs a good push almost every time. This has been an issue w/ all my BMS batt Alloy shell chargers... I should just solder the damn wires.

Cause isn't it hard on the electronics for the AC to connect and disconnect quickly like that? I think one of mine blew after fiddling with the AC plug...

We need someone on the forum to step up and build these units from scratch!

I'd pay more for the reliability, just not $500 for a 1000W charger... Can we keep 'em below $200?

 

[recumbent]

* snip * The AC plug on the unit, not the part that goes in the wall, but the computer type AC input to the unit seems prone to disconnecting and needs a good push almost every time. This has been an issue w/ all my BMS batt Alloy shell chargers... I should just solder the damn wires.

Cause isn't it hard on the electronics for the AC to connect and disconnect quickly like that? I think one of mine blew after fiddling with the AC plug...

True, this has been an issue with my 600 watt unit also, i was thinking to try and spread, or twist the male prongs first to see if it contacts better in the female end, and hold tighter.

 

[Whiplash]

Hey guys, I just had my 400 watt BMS charger go dead. I used it last night no problem but today its a no go. I get nothing as far as lights when i plug in but when I plug in the pack the red light turns on and I get a slight pop at the plug as normal. I checked continuity on the switch and it seems good. I will try to check voltage next on the output. Any help is GREATLY appreciated, I am not afraid of the circuitry, but I am not at all versed in what I am looking at and only recognize a few of the bits inside!

 

[Whiplash]

OK I checked voltage on the output when turned on and plugged in and there was nothing measureable like 200+MV and that's it. So I plugged it in to the bike and it lit the red light so I pulled the plug and checked it again and it was at like 30V and falling to zero after a few seconds. I assume the bike charged the caps and that was all I got but not sure if that helps.... PLEASE HELP!

 

[Whiplash]

Its strange that I get nothing when plugged in as most have something going on it seems. I checked the AC plug and it is fine, I also checked both fuses and they are good. Any ideas?? No obvious burnt or popped caps.

 

[dnmun]

did you measure the voltage in the back end of the charger? put the black probe on the negative output and measure the voltage on the trace that comes off the center leg of the schottky diode. you can post up a picture of your charger if you need explanations. just take picture from the top with the lid off.

 

[Whiplash]

Will do when I get home! THANKS!

 

[Whiplash]

OK here's guts of it I'm not sure what a schottky diode looks like...

 

[LSBW]

Ok, quality has been low, but are there things we can do to improve the chances of these working reliably?

Always amazes me how people would spent 1000-s on equipment, and then cheap out on charger.
Get something decent, at least it won't overcharge your battery and burn your house down in the process.

http://www.mastechpowersupply.com/d...voltage-over-current-protection/prod_111.html

$360 delivered to Canada. Comparable "quality" bms product, $220. http://www.bmsbattery.com/alloy-she...ifepo4li-ionlead-acid-battery-ev-charger.html

for $140 more you'll get fully adjustable, future proofed PS, warrantied and in case of my Konion pack, I can just plug it in and let it charge, without looking at it, thinking if its gonna blow up right now, or when I go to the washroom.

 

[dnmun]

"OK here's guts of it I'm not sure what a schottky diode looks like..."

your thumb is right on top of the schottky diode. the current comes out of the transformer as pulses of electricity and goes through the two outer legs of the diode and comes out through the center leg of the diode. when it gets through the diode it can not go back so it has to go out to the battery after that. the current runs on that trace from the diode out to the choke, which filters out the rf noise from the diode switching on and off so fast, then goes out to the + terminal in the back.

you can see where it say + and - on the back edge next to the fan, and that is where you should be able to measure the voltage. ps, the other little transistor thingy farther over is the voltage regulator that provides the 12V used by the electronic devices in the back end.

 

[Whiplash]

OK I'm on it! THX!

 

[Whiplash]

It looks like I have nothing right there. It seems dead..

 

[dnmun]

measure the AC voltage where it comes out of the back of the AC plug inside on the inside where the wires come off to go to the pcb, the two line leads. i assume you already checked that fuse but it may not be seated.

 

[Whiplash]

Got voltage at the back of AC plug. What's next?

 

[Whiplash]

Oh and my mistake I have .8 volts at the +&- near the fan..

 

[dnmun]

there is a white thermal switch on the opposite side attached to the heat sink next to the npn switching transistors. you should check to see if the AC goes from one of the red wires from the plug to the red wire going over to the white switch. that switch may be open so the AC circuit is not completed. or you can disconnect the power and check continuity from the input through the red wire back through the blue wire to the pcb.

 

[Whiplash]

Can you show me in the pic which wires to check continuity on? I don't see a white switch on the heat sync.

 

[dnmun]

nope, you gotta look for yourself. it is on the other side of the charger from where your thumb is, and connected to one of the red wires.

 

[Philistine]

Always amazes me how people would spent 1000-s on equipment, and then cheap out on charger.
Get something decent, at least it won't overcharge your battery and burn your house down in the process.

http://www.mastechpowersupply.com/dc-power-supply/switching-power-supply/volteq-power-supply-hy10010ex-100v-10a-over-voltage-over-current-protection/prod_111.html

$360 delivered to Canada. Comparable "quality" bms product, $220. http://www.bmsbattery.com/alloy-shell/29-alloy-shell-1200w-lifepo4li-ionlead-acid-battery-ev-charger.html

for $140 more you'll get fully adjustable, future proofed PS, warrantied and in case of my Konion pack, I can just plug it in and let it charge, without looking at it, thinking if its gonna blow up right now, or when I go to the washroom.

Sorry to take this OT to Whiplash, and I would have taken it to PM with LSBW but I wanted to get a public response/discussion on it, are these PSUs for real? I ask because I run several bikes with different voltage, and had always dreamed of getting a Peter North type lab power supply like that, but when I last did a search, I was looking at over $1,000, and that was for a 72v 10a version, on the link given I saw a 100V20A version for $500!!! I nearly creamed my jeans. Normally in websites when they say "normally retails for" you start cackling, but they are being modest in their claims. $500 for an adjustable power supply that can do 100V20amp? Are you kidding? I am dumbfounded. My other question is that the unit I was looking at is this:

http://www.mastechpowersupply.com/d...over-current-protection-220v-ac/prod_112.html

But it has a US plug attached (I want AC 240V as I live in Australia), how can it have a US power plug if it is 220v? My other question is, can I just remove that US plug head, and put on an Aus plug head, and push in 240V? I presume so, but I am confused by the presence of 220V, who runs 220V? I thought Euros ran 230V and we Aussies met them with 240V? I didn't know anyone in the world ran 220V? My other question is, if you use a switching supply like that, how do you know when it has charged? Does it behave like a fixed "charger" in that you set the voltage, then attach the load, and the volts/amps on screen drop until they reach set point?

I am really sorry to take this thread OT Whiplash, because I know you want an answer/help from Dnmun, but I I am just blown away by the price revelation of this post. I agree with LSBW, if that PSU is for real, people should just fight beg and steal to get the extra scratch. I didn't know units like that existed for below $1,800 (and those being 10amp).

 

[dnmun]

that is the code 240V AC plug in the US. if the two line prongs are parallel then it is 120V.

i could never bring myself to pay $500 for a charger when you can get chargers which have adjustable output voltages for 1/10 the cost. but AU is different when it comes to costs. you guys are getting jammed. blame it on the unions and low unemployment.

ps: my 240 here is usually around 245V, depending on the season and how hard the generators in the dams on the columbia river are working. system wide voltage does change with the load. not much but it is a little variable.

 

[Philistine]

Thanks Dnmun,

Just to be clear, I am not being cheeky here, because I totally respect the help you give idiots like me on this forum (I genuinely mean that, I can't recall the number of times I have seen you patiently and thanklessly help noobs through problems, and I have total respect and appreciate the help you give out), but are you saying I can get a lab power supply for $50? Because if so, your ideas intrigue me, and I wish to subscribe to your newsletter.

I realise $500 is a lot of brass, but I am saying that if I can effortlessly turn a knob, and move between the different voltages I run, if it is reliable, I would happily sprout $500. I paid (including shipping) about $300 for a BMS charger which no longer works. I also run RC cars and planes, so if I could just throw a knob and have controlled charging like that... I have never seen (obviously I mean within my sub $800 or so mark) lab supplies that do more than 72volts and 5amps, the idea of something that I can just dial in the voltage and the amps (up to 20amps!), makes me get a rock in my pocket. That was why I was scratching my head, because all prices I had seen were three times that for half the current. I was just asking if it was for real. Because if entry price for total voltage freedom, and current up to 20amps, and it is reliable.... you will never see me on the battery boards again....

 

[dnmun]

i was thinking of bulk chargers that can be adjusted, not power supplies with knobs on the front panel. there are a lot of them on ebay too.

so it does make sense to consider these power supplies if the BMS battery charger cost so much. it does seem like the problems are from poor workmanship though. the choke always seems to be inadequately and improperly soldered onto the pcb which leads to overheating.

but from what i have read now about how the lithium will plate out on the surface of the carbon at high charge rates i would now recommend people charge lipo and the lifepo4 at the lowest rate that they can put up with.

 

[GCinDC]

left bike charging at work yesterday, only to return later and find it uncharged.

here's a quick vid this morning showing how touchy the AC plug is.
[youtube]gSyVBpQ_H0o[/youtube]
shortly after the vid, the lights cut out again.

time to clip the plug i guess and hard wire it...

the primary concern will be securing the cable so it won't yank out. i think rather than use the large plug cavity, i'll drill a hole in the side, and knot the wire on the inside, and probably line the hole with a rubber sleeve of some sort.

is it odd that these models don't have an on/off switch?