# Trouble shooting Elcon Charger & MiniBMS



## Coulomb (Apr 22, 2009)

jlanman said:


> I converted a Ford Ranger to electric 12 years ago using a ElCon PFC 3000... I have had no issues until now. The charger will not activate in spite of the pack low charge state.


I don't think that Elcons have been around for 12 years, but if the Elcon is old (say over 5 years), then the usual mechanism of the MOSFET protection capacitor going high internal resistance with age may have kicked in. The capacitor that they use is longer life than the cheapest option (it is rated for 105°C), but in my opinion it should really be a longer life part. Of course, that would add a dollar or two to the cost of manufacture.

Do the LEDs still come on? There is the red/green LED, but sometimes you can also (or instead) see the red LED from inside shining through the yellow sticker. Though I'm unsure how that works with a 3 kW charger, which has two 1500 W chargers in one box.

It is possible that the charger is OK, but the BMS isn't telling the charger to come on for whatever reason. In this case, there IS a way to temporarily force the charger to come on. You need to short pins 1 and 3 of the 7-pin connector. Unscrew the plug, and use a good flashlight and/or a head magnifier (etc) to see the tiny markings on the front of the connector. You need to short pins 1 and 3 with a short piece of wire. The pigtails of a 5 W resistor are about the right diameter. If the resistor is of low value (say less than 100 Ω), then you don't need to cut the leads off the resistor, use both ends.

*WARNING!* All these pins are connected via low impedance to the negative end of the pack, so isolate the pack from the charger somehow before doing this, and be cautious. Using an insulated-handle pair of needle nosed pliers would be a good idea. If possible, use the blue cap to cover the 7-pin connector with wire inside to make the whole thing safer.

If you want to have some assurance that you have the right pins before shorting anything, you should see 11-13 VDC from pins 2 to 3 (3 being positive), when the charger is switched on (not necessarily charging). Shorting these pins together is not good, and will likely burn up an SMD fuse inside the charger (not terribly convenient to get to), which your BMS likely needs to see. So be cautious with this test too.

[ Edit: had the 12 V pins totally wrong (sigh!). The charger is enabled by pulling enable (pin 1) high, not low. Needing to connect pins 1 and 3 is still correct, fortunately. ]


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## Coulomb (Apr 22, 2009)

This is what you will be looking for (below). I managed to photograph the tiny stamped numbers with the correct light and plenty of zoom. But note that this is rotated from the "normal" position, so don't assume yours will be the same.










To make sense of the colored markings (you don't need to), see this post.


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## jlanman (Dec 23, 2012)

Thanks for the very prompt and helpful reply. You caught my charger age error. It is 6 years old. I guess my age affect kicked in. I took the 12 from the invoice date and failed to make the subtraction. The single LED does come on green. It flashes red a couple times if I disconnect and reconnect the AC power. I had found the pin 1 and 3 force start info.; but, wasn't sure it was a good idea. I plan to order a new connector for the test now that you have provided some valuable insight. I'll be back after it arrives and I have learned more.


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## Coulomb (Apr 22, 2009)

jlanman said:


> The single LED does come on green.


Ah. That's the most important piece of information. 

The charger thinks that the battery is full. Assuming that it really isn't, that means it pretty much has to be the resistance divider measuring battery voltage.

So it probably has to be R10 on the main board (likely actually 2 through-hole resistors in series), or R8/R9/D8 on the daughter board. Possibly C10. R10 is by far the more likely. It's likely to be about 150kΩ total (as 2 x 75kΩ) for a 144 V model, with R8 and R9 being 3.6kΩ and 2.0kΩ respectively. These will differ from the schematics, which happened to be for a higher voltage model. With luck, you can probably replace the R10s without taking out the main PCB (which is a time consuming pain).


Edit: you might also check R20 (main board) and R34/R35 (control board) which measures the charger output voltage.


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## jlanman (Dec 23, 2012)

OK, great info. However, I need some direction as to how to ID the boards and specific resistors assuming they may not be marked. I'll request a schematic from Elcon as I only received a very basic user's manual at the time of purchase.


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## Coulomb (Apr 22, 2009)

jlanman said:


> I need some direction as to how to ID the boards and specific resistors assuming they may not be marked.


The image in this post is your friend:
http://www.diyelectriccar.com/forums/showthread.php?p=1011289#post1011289

See also the TCCH Elcon charger troubleshooting and repair topic and the TCCH Elcon 1.5kw charger schematics thread.



> I'll request a schematic from Elcon as I only received a very basic user's manual at the time of purchase.


 Good luck with that. I don't believe that they'll give it out. That's why Kenny and Paul traced the schematics for you (link above).


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## PaulRekow (May 24, 2017)

I am having similar issues with my Elcon model #TCCH-48-25 charger. This is on a Grasshopper lawnmower I converted to electric four years ago. I have a similar setup with 48V lithium batteries, bms and Elcon charger. Because I don't carry the charger on the mower I am plugging and unplugging the charger from the battery and bms frequently. The connecting cable from the bms to the charger broke a year or two ago and a friend replaced it with one that was friendlier to plugging and unplugging. I am no longer using the bms system and the cable between the bms board and charger seems to not be working again.
Is there a way to not have to have this cable connected and get the charger to charge. From what Coulomb indicated in his post shorting pins 1 and 3. I no longer have that connector. Just short the two wires on the inside?

Thanks, Paul


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## Coulomb (Apr 22, 2009)

PaulRekow said:


> From what Coulomb indicated in his post shorting pins 1 and 3. I no longer have that connector. Just short the two wires on the inside?


Yes, or use a 1 A diode pigtail around 3/4" - 1" long (something around 0.9 mm thick from poor memory) and bend into a rectangular U shape with the spacing to suit the connector. It will shake loose on an actual vehicle or mower, but might work in a stationary application.

That saves you opening the case, which has about 24 screws.


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## jlanman (Dec 23, 2012)

Shorting 1 & 3 pins using started the charger. It flashed red 5 times indicating curve 5 (matching the paper work received at time of purchase). It than settled into a steady red green flash on about a 1 second interval. I'm not sure from the manual what this means. Wrong Battery? Two of my 45 cells are at 1.2 volts or so. Could it be picking this up? 



As an aside the connector sucks. I ended up taking the "shove wire into the female connector" approach as suggested. With almost no pressure the connector failed and ended up inside the charger. It appeared that some silicon goop on the back side was all that was holding it. I can relate to Paul's failing.



Well, on to checking resistors per the earlier suggestion.


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## Coulomb (Apr 22, 2009)

Sorry for the late reply.



jlanman said:


> It than settled into a steady red green flash on about a 1 second interval. I'm not sure from the manual what this means. Wrong Battery?


Yes. But it could also be that pin 1 (enable) isn't seeing the 12 V from pin 3. It sounds like you still have issues with the 7-pin round connector. I've never had trouble with it, but others have reported odd things happening.

The five red flashes before the green will always happen, regardless of what the enable input is doing. So this is no progress as yet.



> Two of my 45 cells are at 1.2 volts or so.


Eek. That's really bad. You should use a current limited power supply on each, starting with 3 A or less, until the open circuit voltage rests (after say 1 minute) above 2.0 V. Don't leave it unattended, as this is the zone where shorts can occur and fires start.



> Could it be picking this up?


It might, but i doubt it. One mechanism might be that the low cells look almost open circuit, and the high dV/dt might make the charger decide that the battery is not present. But I'd say the problem is still the enable input.


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## jlanman (Dec 23, 2012)

Late reply (delayed) is no problem at all. I greatly appreciate the help. 



You have me worried about the low voltage batteries. It appears I need to deal with them before attacking the charger further. 



I need help with the suggested charging. Can you recommend a charger and a source for one. I assume after that the process mainly consists of isolating the bad battery from the pack, connecting the charger and monitoring. I was considering just by passing the two bad cells and using the 43 left once the charger issue is resolved. Based on your comment regarding fire I'm now considering pulling them out.


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## Coulomb (Apr 22, 2009)

jlanman said:


> I need help with the suggested charging. Can you recommend a charger and a source for one.


I just use a lab power supply, because I have one for other uses. Mine is a dual 30 V 3*A model, which seems to be a common size, meaning I can get 6 A when I put the two halves in parallel. (I have to up the voltage limit a lot, so it's not completely hands off).



> I assume after that the process mainly consists of isolating the bad battery from the pack,


Yes, ideally. But if the pack is around 144 V nominal, it could be OK to charge in-situ.



> connecting the charger and monitoring. I was considering just by passing the two bad cells and using the 43 left once the charger issue is resolved.


If you do that, you likely have to change the charger voltage. But yes, possible.



> Based on your comment regarding fire I'm now considering pulling them out.


The risk is low, but non-zero. I've had several LiFePO₄ cells come back from under 2.0 V, but it is the voltage zone where copper dendrites may form when re-charging. It may form a short circuit. Charging at low rates (a few amps) seems to reduce the chances of this happening.


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## jlanman (Dec 23, 2012)

Thanks, once again. I am not familiar with what's available in electronics. The term "lab power supply" was what I needed. I was looking for battery chargers. I am ordering one.


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## jlanman (Dec 23, 2012)

I got my lab power supply and was able to bring one cell back. The other one is completely dead. (no voltage reading at all.) I left the power supply connected for several day to no avail. 



Thanks to the great help here I was able to get the charger going by shorting pins 1 & 3. I now have a fully charged pack of 44 cells vs. my old 45.


Are pins 1 & 3 the same ones that are normally connect the MiniBMS system and charger via the red & green wires to the 7 pin connector. My connector is trashed so I plan a hard wired connection.


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## Coulomb (Apr 22, 2009)

jlanman said:


> Are pins 1 & 3 the same ones that are normally connect the MiniBMS system and charger via the red & green wires to the 7 pin connector.


I'd say so. They don't mention pins 1 and 3, but the colors (for older models) match.

The attached is from the MiniBMS user manual.


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## jlanman (Dec 23, 2012)

Thanks again. I'll find out if my issues are resolved the next time I power up the charger. If it turns on and shuts down like it did in the past I'll be "a happy camper". Right now the pack is at 100%


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## Mike K (Apr 23, 2020)

I feel like a real novice. I have a new PFC 2500 Charger to fit in my car. I cant find a schematic anywhere to understand how to wire it up. If I plug it in there is no sign of life. I ignorantly assumed I just plug it in. Where do I start?


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## Coulomb (Apr 22, 2009)

Mike K said:


> If I plug it in there is no sign of life.


There should be some sign of life just connecting AC-in. For example, the red/yellow/green LED should flash a few times, then settle to an error code if something is wrong (or solid red if it really is charging).

Is it a "CAN" model? If so, it won't charge without communications.

Are the voltages (charger and car HV battery) compatible? If the battery voltage is too high or much too low, the charger won't connect.

Perhaps you could post photos of any labels on the side of the charger, and tell us the chemistry and nominal battery voltage of your car.

I hope this post comes out OK; the forum software is being more weird than usual. I could not post at all from Firefox, for example; it wiped out my post and told me to lengthen it to at least 10 characters. Here with Chrome I can't do bold / italic etc.


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## Mike K (Apr 23, 2020)

My set up is 5 Tesla modules (120v). I am using a TBS Gauge and a ACV2 charger controller so am not using the interlock function on the Charger. I understand the charger is a nonCAN. The only wires out of it are: AC in, DC out, 7 pin plug (red/black/green), a small green/yellow wire coming out with the DC cables.

I wonder whether the issue is simply that I have the wiring on the 7 pin plug wrong. The wiring I have assumed is as follows:

Red Connects to Main Battery +ve
Black Connects to Main Battery -ve 
Green Connects to the red wire (not using the interlock function)

The Green/yellow wire is an earth to the car chassis?

I don't want to connect it up until I know this is right......

I appreciate your help with this, I am new to all this.


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## kennybobby (Aug 10, 2012)

No that is not a ground wire, it is used for a safety interlock. Poor color choice because it has your full pack voltage on the exposed end.

You might wish to go the Elcon website and get a free download of the owner's manual for your charger.


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## pdove (Jan 9, 2012)

kennybobby said:


> No that is not a ground wire, it is used for a safety interlock. Poor color choice because it has your full pack voltage on the exposed end.
> 
> You might wish to go the Elcon website and get a free download of the owner's manual for your charger.


I agree with Kennybobby.

You message is confusing. I have only ever seen 3 wires on the output. Red goes to Battery Pos. Black goes to Battery Neg. and the Green wire is the interlock as you said but it does not get connected to the red. If you are not using the interlock it is connected to nothing.

It may prevent the charger from turning on if you connect it to the red wire.


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## Coulomb (Apr 22, 2009)

Mike K said:


> The only wires out of it are: AC in, DC out, 7 pin plug (red/black/green), a small green/yellow wire coming out with the DC cables.


I'm surprised that the small wire with the output is green/yellow (presumably striped, like earth wires). It's probably the normally closed contact on the output relay: normally connected to pack positive, but goes open circuit when charging. It's supposed to be a "charger in use" signal, but it's useless. If the power goes off (perhaps even if the charging is complete), the output relay goes off, allowing you to drive off with the charger plugged in. I'd carefully insulate it, and ignore it. DO NOT CONNECT IT TO VEHICLE CHASSIS!



> The wiring I have assumed is as follows:
> 
> Red Connects to Main Battery +ve
> Black Connects to Main Battery -ve
> Green Connects to the red wire (not using the interlock function)


No, assuming that those are the thin wires connecting via the 7-pin round plug. Those wires' insulation are far too thin to withstand pack voltage between each other.

Assuming the 7-pin plug:
Green is the common for the control part of the charger; it's basically at pack negative potential. BEWARE!
Red is +12 V with respect to green.
Black is an enable signal. If you're not using the enable protocol, you STILL have to connect black to red to get out of state zero, i.e. for any charging to happen.
I would check for 11-12 V between red and green with a multimeter first to be sure I have this correct. Shorting +12 and common (usually red and green) will blow SMD fuses (possibly "fusible" resistors) on the control board; they are not easy to replace or even to locate.



> The Green/yellow wire is an earth to the car chassis?


As per the above, NO!



> I don't want to connect it up until I know this is right......


An excellent attitude.


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## pdove (Jan 9, 2012)

Coulomb said:


> I'm surprised that the small wire with the output is green/yellow (presumably striped, like earth wires). It's probably the normally closed contact on the output relay: normally connected to pack positive, but goes open circuit when charging. It's supposed to be a "charger in use" signal, but it's useless. If the power goes off (perhaps even if the charging is complete), the output relay goes off, allowing you to drive off with the charger plugged in. I'd carefully insulate it, and ignore it. DO NOT CONNECT IT TO VEHICLE CHASSIS!
> 
> 
> An excellent attitude.


Like I said confusing. See you read that differently than I.
I believe pictures are warranted here. 

The first picture in the bag is the 7 pin round cable. This one has 3 wires. Green Red and black. Seen connected to charger in other photo. Green is enable, Red is 12V, black is ground. The other cable is the battery connections. Black battery Neg, Red Battery Pos, Green not connected to anything. It has battery voltage when the output relay is off not charging to be used as drive off interlock.

The picture inside the dos show where the are connected. The center connection with the green wire is connected to NO on the relay. Black goes to ground and Red goes to NC on the relay.

Correction: Center green wire goes to NC Relay connection and Red goes to Common connection on Relay. Thanks Coulomb!


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## Coulomb (Apr 22, 2009)

pdove said:


> Like I said confusing.


Yes. Two cables with red/black/green wires and very different functions. Sigh.



> The first picture in the bag is the 7 pin round cable. This one has 3 wires. Green Red and black. Seen connected to charger in other photo. Green is enable, Red is 12V, black is ground.


So this is the THIN cable.
My manual shows black and green the other way around. Ick, I can't seem to attach images any more. Sigh. What browser are you using, Paul? Resorting to Imgur:












> The other cable is the battery connections. Black battery Neg, Red Battery Pos, Green not connected to anything. It has battery voltage when the output relay is off not charging to be used as drive off interlock.


Yes. So this is the THICK cable.



> The center connection with the green wire is connected to NO on the relay.


I think you mean the NC (normally closed) contact.



> Black goes to ground and Red goes to NC on the relay.


I think you mean red goes to the common of the relay contacts, via F1.

Sorry to be picky.


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## pdove (Jan 9, 2012)

Coulomb said:


> So this is the THIN cable.
> My manual shows black and green the other way around. Ick, I can't seem to attach images any more. Sigh. What browser are you using, Paul? Resorting to Imgur:
> 
> 
> ...


Yes, I suppose he needs to turn on the charger and measure the voltage on the thin cables wires to determine which is which or open the charger and ohm it out to be sure. I like that you are picky or I would say diligent.


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## pdove (Jan 9, 2012)

pdove said:


> Yes, I suppose he needs to turn on the charger and measure the voltage on the thin cables wires to determine which is which or open the charger and ohm it out to be sure. I like that you are picky or I would say diligent.



Duh!

You could also ohm to the thin cable and see which wire goes to which pin. Pin are as described in above message. 
1. Enable
2. Ground
3. 12V


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