# dead Elcon charger, or just the plug?



## dtbaker (Jan 5, 2008)

last night my Swift failed to charge.... looks like outlet cord has power, but charger never comes on. No error light/blinking on charger, so I can't tell if this is just a faulty plug, or dead charger. ideas?

The Swift has had over 30k electric miles over 6 years.... lots of charge cycles on the charger. The plug ends look physically worn, and the molded plug end looks slightly melted over the years. How many charge cycles should I expect to get out of an Elcon?

Any way I can tell if is the plug, or internal? should I just chop off the factory plug and install a new one to eliminate that possibility?


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## Coulomb (Apr 22, 2009)

dtbaker said:


> last night my Swift failed to charge.... ideas?


You could listen for the faint click of the input relay coming on. That tells you if it's the power supply or more serious processor/other.
Check out the TCCH Elcon charger troubleshooting and repair thread.



> How many charge cycles should I expect to get out of an Elcon?


That's a great question, and I wish I knew the answer. I think that they have been around long enough now that we may start to be able to answer that question. They seem to be decent, but not brilliant, quality.



> Any way I can tell if is the plug, or internal? should I just chop off the factory plug and install a new one to eliminate that possibility?


The best way would be to open it up, and measure mains voltage at the terminals inside.

But much easier would be to measure from line to line with a multimeter, on a very high ohms range. On the 20 Mohm range, mine shows a reading for some 5 seconds, then OL (overload, open circuit). Reversing the multimeter leads lets me do it again for about twice as long. If it's pure open circuit all the time, then it's likely the cord. You will be measuring a 2 uF capacitor (quite small, typical of PFC stages) through two diode drops.

There is a very small chance that it's just the input fuse. They have quite strong fuses in there, and I rarely find the fuse blown unless the charger has a catastrophic short circuit after the fuse.

As always, be very careful after opening the charger; there are lethal voltages in there, including around 340 V DC, even from 120 V mains. With the cover off, you can either listen for the input relay to come off (if it ever cones on of course) to know that it's safe, or watch the contacts inside the clear plastic case of the input relay. Off is when the movable part (middle of the three vanes of copper) is towards the coil. When the input relay comes off (having been on), it meas the main DC capacitors have discharged to below about 35 V, which is safe.


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## dtbaker (Jan 5, 2008)

more messing around.... I found a spare end of the power cord, swapped them out, plugged in, and heard a faint 'click'... but charge cycle never started.

unplugged, and a while later heard a faint click.

switched back to old power cord, same results, so its not the cord.

....from post above it sound like the next step is to remove charger and pull the cover off. I am presuming that the input fuse will be obvious...


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## dimitri (May 16, 2008)

dtbaker said:


> ....from post above it sound like the next step is to remove charger and pull the cover off. I am presuming that the input fuse will be obvious...


welcome to the "dead Elcon" club  

if relay clicks then fuse is OK, I wish it was that simple...


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## dtbaker (Jan 5, 2008)

dimitri said:


> welcome to the "dead Elcon" club
> 
> if relay clicks then fuse is OK, I wish it was that simple...



just confirmed.... got the charger removed, pulled the cover off.... semi-weird burnt smell not encouraging.

saw fuse on input side, checked, no resistance, so appears fine.

first found crunchyyellowed dry cracked zip ties falling off a big fat coil (inductor?).... and on closer exam, near the output side in the corner under the 'clicker' adjuster thing.... the whole corner of the board is kinda toasty brown like a campfire marshmallow.

I'll take a picture, but it appears to be literally 'toast' ?!

so.... my data point for Elcons is 30k-ish miles over 6 years, probably 1800-2000 charge cycles. some of which were unplugged while still charging I'm sure when I was grabbing quick charges mid-day.


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## mizlplix (May 1, 2011)

DT: That really sucks. For me too as I have one also... : ) Question: Was yours the model with the built in fan or not? Miz


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## dimitri (May 16, 2008)

dtbaker said:


> I'll take a picture, but it appears to be literally 'toast' ?!


You described my charger when I opened it exactly. I posted picture in my "dead Elcon" thread, I bet you will recognize it as your own 

To everyone claiming Elcons are of "good design" , maybe when you run them inside the freezer, but in a car they literally cook themselves over time. Not a good design for automotive use.


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## kennybobby (Aug 10, 2012)

The electrical circuit design is better than any DIY or kit, but the thermal design definitely has much room for improvement, especially as they have pushed the output power above the original lead-acid ratings. Those fans on the outside are nearly useless.


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## z_power (Dec 17, 2011)

Hijacking a bit...
Are there any more thermal couplings between components and radiator than central "rib" for semiconductors and "isle" for HF transformer? (I'm thinking on liquid cooling for gang of 6 + 1,5 +1,5 kW units; original radiator/enclosure would have to be swapped to custom chill plates and sheetmetal)


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## dtbaker (Jan 5, 2008)

mizlplix said:


> DT: That really sucks. For me too as I have one also... : ) Question: Was yours the model with the built in fan or not? Miz


no fan.... mine was a regular 'sealed' pfc-1500 with the fins mounted vertical for best possible natural convective cooling. It IS mounted above the motor, but I figured that when I was charging the motor would be cooling off when the charger was in use, so not a problem.

Running on regular 110vAC outlet. outputting to 'regular' 120vDC nominal LiFePO4 pack. end of charge voltage 139.0v.

as far as air cooling goes..... The fins were probably designed/sized to be 'ok' if the charger was in open air. Jammed into a motor bay, near the top in fact, I suspect the hot air couldn't escape fast enough to provide best possible convective cooling. I didn't want to put the charger BELOW anything because I didn't want to cook any other components! So, I guess the better design would be to add a hood scoop/vent to allow better cooling, or add a lot of expense to remove the fins and go with fluid cooling and circulate to a better radiator core with fans.

hhhmmmmm, perhaps a controller cooling system could share the loop with the charger? having ONE little radiator with fan serving both the controller and charger chill plates would be pretty slick, but obviously add cost and complexity.

This all might be an argument for retaining stock radiators when converting, and using it for cooling both controller and charger. My Miata uses a small heater core for cooling the Zilla, which I have mounted in the front grill, without any fan... maybe that would be enough, but require adding a fan for the charger since the car would not be moving.

probably simpler just to add a 110vAC fan that would assist circulation over the fins when you plug in for charging....


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## dtbaker (Jan 5, 2008)

thought I'd post the pix....

Is there anything of value in here? should I just toss it?


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## kennybobby (Aug 10, 2012)

Don't toss it, pdove has been fixing the heck out of those things and we learn something new with every repair.

Notice in the first picture that the Line and Neutral wires are reversed for typical US wiring--in your breaker box black will be the Line (hot) and white is Neutral (return). The AC input circuit and input relay don't appear to have any of the signs of overtemp that we have seen in other failures.

In picture two with the number '2' written on the small yellow transformer--the U1 chip is the ViPer chip that regulates the 12 volt power supply for the digital board and for supplying power for the input and output relays.

In the third picture with the arc flash debris and scorching--can't tell if it was around the chassis mounting screw in the corner or from the output relay. The chassis is connected to earth ground (green wire in AC plug) and there are small de-coupling capacitors at most of the chassis screws between the charger ground and earth ground. That goes back to #1 where the line and neutral are reversed, and neutral is referenced back to earth ground in your breaker box. Sometimes outlets get miswired by the electricians helpers so then you could have a hot neutral wire and that could have made the mess you found.

Check the output fuse, maybe that's what blew chunks in the corner. After looking at the pictures it should be repairable.


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## dtbaker (Jan 5, 2008)

kennybobby said:


> Don't toss it, pdove has been fixing the heck out of those things and we learn something new with every repair.
> 
> Notice in the first picture that the Line and Neutral wires are reversed for typical US wiring--in your breaker box black will be the Line (hot) and white is Neutral (return). The AC input circuit and input relay don't appear to have any of the signs of overtemp that we have seen in other failures.
> 
> ...



I have contacted PDove, and await his reply. I'd be willing to send it for parts, or repair if it's reasonable compared to a new charger (like maybe half)...


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## mizlplix (May 1, 2011)

I have had both with and without a fan. The fan-less model would shut down here in Arizona. SO, I got an $8 fan from Walmart and mounted it to blow into the fins. It only came on when charging. Worked great. My present one has a small fan built on it. It seems to do the job fine. I use 220VAC to the Elcon....... I am thinking about mounting an extra fan to maybe extend it's service life. Miz


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## Coulomb (Apr 22, 2009)

dtbaker said:


> thought I'd post the pix....


Thanks. Someone always learns something.

Your ground zero point seems to be either the relay marked K3 or the resistor I've marked as R* in this photo:










1) Do you have a relay installed in the K3 position? Or is it empty like the above?
2) Is the 10K resistor marked R* above all white with silvery bands, or is it pale green with brown, black, orange (then gap) and gold stripes (and looks whitish due to some sort of artefact of the camera)?

I note that you have the green wire installed between the black and red. I've not come across a charger with that yet; I suspect it may be connected to K3. Also, D12 (does it look OK or crispy fried?) and R* are in series across the output relay (the one beside the green and black output wires). Dimitri's charger has an output relay with welded (short circuit) contacts. This might all be fitting into a pattern here; your answers could be very helpful for this.


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## dtbaker (Jan 5, 2008)

Coulomb said:


> Thanks. Someone always learns something.
> 
> Your ground zero point seems to be either the relay marked K3 or the resistor I've marked as R* in this photo:
> 
> ...


looks empty, but toasted...



Coulomb said:


> 2) Is the 10K resistor marked R* above all white with silvery bands, or is it pale green with brown, black, orange (then gap) and gold stripes (and looks whitish due to some sort of artefact of the camera)?


its greenish, I rubbed off some soot, and took another picture...



Coulomb said:


> I note that you have the green wire installed between the black and red. I've not come across a charger with that yet; I suspect it may be connected to K3. Also, D12 (does it look OK or crispy fried?) and R* are in series across the output relay (the one beside the green and black output wires). Dimitri's charger has an output relay with welded (short circuit) contacts. This might all be fitting into a pattern here; your answers could be very helpful for this.


the green wire is a 'charger interlock' output on my version of Elcon charger. It carries pack voltage when charger is not charging, and goes to 0v while charging. The intent was to use as an interlock to controller KSI to prevent drive-away while charging; but it is ineffective, because pack voltage is returned when charge completes, NOT when input is unplugged. In this vehicle I DO have this output wired back thru my pot-box KSI and thence to controller KSI; I was not aware of the exact nature of the interlock until after I installed.... typical lack of decent documentation. 

At this point I am suspecting that some part of that output relay may be sensitive to unplugging while mid-charge? perhaps when there is a momentary arc unplugging the input, it does something bad to output? Unfortunate because there is no 'soft' off switch for unplugging mid-charge.


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## Coulomb (Apr 22, 2009)

dtbaker said:


> looks empty, but toasted...


Ok, thanks. So it looks like that green wire may just connect to the normally closed contact of the relay, so the pack is either connected to the charger, or to the green wire. Not that useful, as you say.



> .... typical lack of decent documentation.


Yes. Maybe we can compensate for that in some way, eventually.



> At this point I am suspecting that some part of that output relay may be sensitive to unplugging while mid-charge? perhaps when there is a momentary arc unplugging the input, it does something bad to output?


It's starting to look that way. It seems that the charger just keeps putting in charge until the 12 V power supply collapses. But at that point, the DC bus voltage (before the transformer) should be down to around 35 V, and that should be way too little to push anything into the pack. So that's a mystery to me. It sure looks like something in the output circuitry got really badly zapped. I'm suspecting some sort of track breakdown over time, but it seems so unlikely. It will be interesting to see whether the relay contacts are welded, whether that diode/zener is shorted, and so on. (It's marked D12 on most chargers; in your photo it looks like it's marked Z10). [ Edit: Now I see that it's actually "D12" upside down. Duh. ]



> Unfortunate because there is no 'soft' off switch for unplugging mid-charge.


Clearly, the manufacturer thinks it's not needed. And according to my logic above, it should not be needed (just switch off the AC, and it sounds like that's what you did). In at least a few cases, perhaps when one or more components has failed due to hear or other causes, it seems like something *is* needed. But maybe once whatever component has failed, a burn-up like you have had is inevitable.

It seems like something could be done to prevent the worst of this in future.


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## dtbaker (Jan 5, 2008)

Coulomb said:


> Ok, thanks. So it looks like that green wire may just connect to the normally closed contact of the relay, so the pack is either connected to the charger, or to the green wire. Not that useful, as you say.



I am really NOT an electrical guy.... but am going to hazard a guess at one possible issue with unplugging mid charge. If the charger is chugging along at it's CA mode when the AC input is unplugged.... would there be a moment when the capacitor might still be kicking out a fairly high voltage when that relay tries to switch, arcs, and maybe weld internal contacts? Then perhaps NEXT charge the max amps run thru something not intended to carry the load?

I guess this would be better than having the charger 'stuck on' and fry a whole battery pack! Perhaps there is a self-destruct if the normal relay gets stuck when the charger *should* turn off?

second small area of damage I see that may or may not be anything is on that 7-pin outlet. It looks like one got hot enough to pop off the sealant? really odd since I wasn't using the 7-pin for anything. I did notice that the plastic thing going thru the casing was broken , but that might have happened during de-installation.


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## pdove (Jan 9, 2012)

dtbaker said:


> I am really NOT an electrical guy.... but am going to hazard a guess at one possible issue with unplugging mid charge. If the charger is chugging along at it's CA mode when the AC input is unplugged.... would there be a moment when the capacitor might still be kicking out a fairly high voltage when that relay tries to switch, arcs, and maybe weld internal contacts? Then perhaps NEXT charge the max amps run thru something not intended to carry the load?
> 
> I guess this would be better than having the charger 'stuck on' and fry a whole battery pack! Perhaps there is a self-destruct if the normal relay gets stuck when the charger *should* turn off?
> 
> second small area of damage I see that may or may not be anything is on that 7-pin outlet. It looks like one got hot enough to pop off the sealant? really odd since I wasn't using the 7-pin for anything. I did notice that the plastic thing going thru the casing was broken , but that might have happened during de-installation.


Looks like similar damage to the one I am working on presently. The output relay welded shut and the transistor that drives the relay coil shorted this caused the processor to draw too much current. fried the voltage regulator that makes 3.3 v which then caused the inductor suppling 12v to the voltage regulator to open.


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## Coulomb (Apr 22, 2009)

dtbaker said:


> second small area of damage I see that may or may not be anything is on that 7-pin outlet. It looks like one got hot enough to pop off the sealant? really odd since I wasn't using the 7-pin for anything.


It's hard to tell with that yellow goop. When they apply it, it seems to string out and ooze, and it's hard to tell if it went on like that or was melted.

Is there a blob of the goop under the small PCB attached to the back of the 7-pin socket, that looks like it melted and pooled? It's hard to tell from the photo. There is also shiny solder showing through, as if that area of yellow goop got blown off, but it seems more likely that they just missed that area when applying the it.



> I did notice that the plastic thing going thru the casing was broken, but that might have happened during de-installation.


Hmmm. I've had another owner say that the 7-pin connector broke. I hope that you decide to send the charger to Paul, so he can do a forensic analysis for us.


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## pdove (Jan 9, 2012)

dtbaker said:


> second small area of damage I see that may or may not be anything is on that 7-pin outlet. It looks like one got hot enough to pop off the sealant? really odd since I wasn't using the 7-pin for anything. I did notice that the plastic thing going thru the casing was broken , but that might have happened during de-installation.



Looks like that was caused by the 12v supply being shorted. Or maybe the enable pin. It's black around those pins. It's possible that is just smoke residue from the traces getting hot below it.


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## Coulomb (Apr 22, 2009)

pdove said:


> Looks like that was caused by the 12v supply being shorted.


That's something that could cause a lot of these symptoms. If the 12 V supply gets shorted, then the relays drop out and the processor stops controlling the current. When the input (AC) relay drops out, the charger can continue charging for many seconds. That's plenty of time for the output relay to disconnect under load, which will cause severe arcing.


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## dtbaker (Jan 5, 2008)

pdove said:


> Looks like that was caused by the 12v supply being shorted. Or maybe the enable pin. It's black around those pins. It's possible that is just smoke residue from the traces getting hot below it.



begs the question as to what shorted the 12v supply?! I had nothing connected to those pins....


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## pdove (Jan 9, 2012)

dtbaker said:


> begs the question as to what shorted the 12v supply?! I had nothing connected to those pins....



My guess is still the other way round. The spark that welded the output relay is what shorted the 12 volts.


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## dtbaker (Jan 5, 2008)

pdove said:


> My guess is still the other way round. The spark that welded the output relay is what shorted the 12 volts.


There have been lots of times I unplugged the input mid-charge, is this good/bad practice?

many times if I was home for more than an hour or so I would plug in to get a little charge over lunch, but it would be chugging along at full steam when I had to leave.... I usually try to unplug it 'fast', but there have been times when there was a pretty good spark at the plug when I unplugged.... Could that be a factor?


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## pdove (Jan 9, 2012)

dtbaker said:


> There have been lots of times I unplugged the input mid-charge, is this good/bad practice?
> 
> many times if I was home for more than an hour or so I would plug in to get a little charge over lunch, but it would be chugging along at full steam when I had to leave.... I usually try to unplug it 'fast', but there have been times when there was a pretty good spark at the plug when I unplugged.... Could that be a factor?


Maybe others will have a different opinion but I believe is is designed to withstand unplugging.

The processor remains active for several minutes after unplugging. The output relay should not shut until the processor commands it and the input relay does not make the 12v bus go down immediately. 

Since there is not off switch or other way to shut it down I believe they accounted for this in the design.


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## kennybobby (Aug 10, 2012)

There is no on/off switch, so no way around just pulling the plug, but that is definitelly not a good practice when charging at full current--in my opinion that is likely a big factor in the failure.

The PFC chip is doing cycle-by-cycle correction and the processor would likely get notified, but have we seen in the code what it does in this event?

If the PWM is on it will drain the bus caps into the HV bus, which shuts off the viper and the 12v shuts off--so the output relay opens with high current flowing, and it's not going to survive the plasma arc (burnt or welded contacts). 

Also there is magnetic fields in the HV inductors that will be looking for a circuit path--if one is not available the collapsing currents will create one.


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## pdove (Jan 9, 2012)

kennybobby said:


> There is no on/off switch, so no way around just pulling the plug, but that is definitelly not a good practice when charging at full current--in my opinion that is likely a big factor in the failure.
> 
> The PFC chip is doing cycle-by-cycle correction and the processor would likely get notified, but have we seen in the code what it does in this event?
> 
> ...


I guess what I am saying and I could be wrong. The processor will immediately see loss of AC voltage and proceed to shutdown the DC output by turning off PVC_OUT and then opening the output relay.

There should be no current after the output is shutdown.


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## Coulomb (Apr 22, 2009)

dtbaker said:


> I usually try to unplug it 'fast', but there have been times when there was a pretty good spark at the plug when I unplugged.... Could that be a factor?


I assume you're talking about the AC plug, not the DC plug. The latter should never be disconnected under load.

When you disconnect the AC plug when charging, there is often an impressive arc. The people at Tritium (who manufacture AC motor controllers and DC fast chargers) remarked about it when we had the MX-5 there for checking of the motor controller.

As Paul has mentioned, the processor should notice the lack of AC. There is a port that reads 2 for 240 V, 1 for 110-120 V, and 0 for less than some threshold, I think about 85 VAC. When it sees the zero, it sets the current set point to zero, which effectively does a soft shut-down of the back end. I think (disassembled firmware is not to hand) it will also put the charger into state zero, which will disconnect the output relay. So the back end should be fine.

However, at the instant of line disconnection, the line current will be flowing through an inductor, into either the load or into the AC side IGBT (depending on the phase of the AC side PWM cycle). If the current happens to be near peak value (it could be around 15 A for a 2.5 kW charger), the inductor is going to want to keep the current going. It is happy to let the voltage increase dramatically to do that, easily into the kilovolt range. That's why the AC plug will arc; the voltage across the gap will increase to try to keep the current flowing. I'm no expert on this, but surely this will send some sort of surge over the DC bus, and this could disturb the 12 V supply, possibly causing damage to any of the control electronics.

Now that I type this, it doesn't seem to explain the typical faults we've been seeing. But yes, I agree it would be really useful to have a way of telling the charger to do a soft shut-down when you just need to use the vehicle, charge complete or not. Maybe we can figure out a way to do this, and incorporate it into the canonical firmware.

I suppose there is already a mechanism for this, the pin-1 (of the 7-pin round connector), sometimes called "external temperature". This could be used to command the charger to zero current before the plug is disconnected. You'd need to get the BMS or whatever else is connected to pin 1 (if the pin 1 control is enabled at all) to cooperate.


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