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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #1
I have recently spent some time repairing one of these chargers. I will be posting some of the pictures and my observations

The main issue with the early version is that one of the power supply capacitors (C63) was fitted the wrong way around, which lead to a gradual failure; fortunately, usually still within the 3 year warranty. Also C44 was only rated at 6.3V but was on the 12V supply, this would also lead to early failure. On all pictures of failed chargers that I've seen, both of these capacitors are 'doming' - a sure sign of failure. IMHO, there should have been a recall on these chargers as there was a safety issue, although I have never heard of one actually going bang.

On later circuit boards, both of these errors were corrected. See pictures below:

ChargemasterCaps(old).jpg

Early version (note the incorrect + near the red wire)

ChargemasterCaps(new).jpg

Later version

Apparently, several of the returned chargers have since been sold to the public. If you have bought one, I strongly suggest checking the capacitors.

I'll add more pictures later.
 

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Do the caps take anything else out if they fail?
I am just about to go and take a look inside my ebay derived unit.
 

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The best there is at what I do
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I have two EBay CM 30A tethered chargers so this is really good info, thanks for taking the time to post, any other info would be greatly appreciated.
 

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Just checked mine, C63 is correctly fitted and C44 is rated at 16V
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #5
Here are some more pictures of the charger.

ChargeMaster Tethered med-res.jpg


ChargeMasterMain2.JPG

The 2 black lumps in the top picture are 2 pole contactors (relays) for switching live and neutral mains through to the car. The weird thing is that they are in series and are energised together via the small blue relay between them, so really only one is required.

The tiny 8 pin chip on the lower right of the bottom picture senses the charging current, so the entire 30A+ goes through it! The later version has a thin wire soldered across between the connections either side, effectively shorting out the chip - I don't know how that's supposed to work.

The capacitors used in the power supply are excellent quality (Panasonic FR range for main ones in newer version), so should last well (assuming that they are in the right way around and have sufficient voltage rating).

Later version has the following:

C44 - 3300uF @ 16V - Used on 12V rail
C53 - 3300uF @ 16V (or 10V) - Used on 6V rail
C63 & C60 - 560uF @ 35V - Used on 6V and 12V rails

The early version had 4700uF @ 6.3V for C44 & C53

The main processor is an Atmel AT91SAM7X256, which is a big brother of the Arduino chip ATmega328P. The whole thing seems over complicated for what it needs to do. There are chargers offering the same functions based on an Arduino and a handful of additional components. Thanks to @yoh-there, I (and others) have built a granny cable with the equivalent circuitry built into the Mennekes plug. See Granny charging . The only difference is that the ChargeMaster also has a GSM module to send back data. @yoh-there has also built a wall mounted Arduino home charger.

ChargeMasterGSM.JPG

GSM Adaptor module

There's not much to say about this module. It contains a SIM card and runs on 6.4V via the somewhat confusing brown and blue wires from the main board. The front panel LEDS are mounted upside down, so that they shine through holes in the circuit board. Good quality capacitors again.
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #6 (Edited)
There's a USB connector on the main board, but I've not been brave enough to connect anything to it. I suspect that it is only used for updating the firmware. There is a link LK1 alongside it which may be how it is enabled, but this is just guesswork.

EDIT: Don't put a jumper onto LK1 - see below
 

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Co-author of CanZE. Q210 nov 2013
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4,273 Posts
Thanks for the heads up. I just slammed it together, the real geniuses are the openEVSE developers IMHO. Few techy remarks. Here some info about it (warning: Dunglish ahead) Granny charging

- Those current sensing chips are scary indeed. They are VERY low impedance and sense through a HAL element, so all pretty clever, but those thin pins....... I bet they were shorted out because of some frying and then they simply disabled the "see if the car takes any / more than it is supposed to" logic from the firmware. To be honest, I don' t regard that as big deal and actually good when charging a ZOE as it sometimes uses a little bit over what it is allowed to (so "they" say).

- Not massively impressed by the lack of gaps between the power en low voltage end.

- USB: Oh come on, be brave :sneaky: . Good chance you get a serial prompt if you start a serial-over-usb program, and that could get interesting. If you are using Linux: minicom -D /dev/ttyUSB0 (or whatever tty device it might want to give you).

- If you'd want to control that thing externally, you'd either have to reverse-engineer the USB-Serial (if it is that), sneak into the comms between the GSM and the processor (probably doable as I bet the GSM module is controlled through AT commands), but much easier is a small relay in the CP line, common to the car, NC to the CP of the charger, NO to a 1K resistor to the 12 volt rail of the charger. ZOE understands that perfectly well and does not fall in deep sleep. Lovely trick to do Economy charging the right way.

Arrogant nitpick: The SAM processors are ARM cores. Quite a different beast than the ATmega stuff. It's more like a Due. Seems like a lot of the commercial products are using ARM processors. I know the KEBA's do.
 

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I'm not crazy, the attack has begun.
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Thanks, @andyfras.

Do you have any sort of dates for what constitutes 'early'? Mine was fitted in early 2013. I also have a couple further unused NOS I have acquired.

It beggars belief that this sort of thing goes on, inefficient designs, bad component placements.

I'm amazed an electrolytic can survive being reversed for so long, or even act as a viable capacitor! I'd have thought if it's worked for >4 years it is OK, but I never expected that, so maybe not! The whole point of them is that they have an electrolyte.. which will conduct if reverse-polarised.

Does the whole unit require removal to access the board, and if so then it would be a good idea to junk the GSM board at this point, is that easy to do?
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #9
My 'early' charger was fitted in August '13. It was replaced by the later type early '16, so they'd fixed the problem by then.

I think that the original C63 (560uF @ 35V) was not a particularly low ESR version and only reversed by about 6V, so it very slowly failed. It followed C53 (4700uF @ 6.3V) through a very small, SMD inductor, so C53 was doing the main smoothing.

You can remove the front panel without taking the unit off the wall; you just need a short Philips bit with a spanner (no room for a handle), or one of those cranked screwdrivers. I don't know how to disable the GSM; I doubt that just disconnecting it or pulling the SIM would work. Also, the GSM board has the front panel LEDs.
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #10 (Edited)
I'm currently trying to fix a fault where the charger goes through it's lengthy start-up procedure but ends in a red light. By substitution, I've confirmed that it's the main board, which has had its capacitors replaced. I have compared it to a working main board, but can find no differences apart from some current sensing components, which would only apply once charging had begun.

The main board is at least 4 layers, so it's very tricky to trace connections.
 

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Co-author of CanZE. Q210 nov 2013
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So the equivalent of "an error has occured" :confused:. Time to grab the usb cable and a terminal emulator? One can always try?
 

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Co-author of CanZE. Q210 nov 2013
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Seriously, I don't want to entice you into something you don't want to do, but maybe you'd be lucky and it would display a menu. Of course, chances are not great but not zeo either. I would expect that SAM processor to have native USB serial support (didn't check).

As for how to, it depends on what PC OS you are using and if the USB interface is indeed presenting a terminal (serial) interface. On Windows, it would probably create a new COM port, to which you can connect with something like Hyperterminal. On anything -ix, I would expect a new device showing up under /dev/ttyxxxx (ie /dev/ttyUSB0), to which you can connect using i.e. minicom. Apple I think the same and AFAIK the terminal emulator is called "screen".
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #14
I received a second early version charger board for capacitor replacement today. I have replaced the damaged capacitors and the others. Unfortunately, it's showing the same red light fault as the first one.
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #15 (Edited)
DO NOT PUT A JUMPER ONTO LK1.

It is the program erase link, as I found to my cost while trying to disable GSM.

After effectively bricking the board, I tried the USB. It comes up as a BOSSA program port, but I didn't know where to go after that.
 

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ZOE Q210 Oct'13
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557 Posts
Discussion Starter #16 (Edited)
Latest update:

The second charger board I received had shorted contacts on the contactors. The circuit board around the contactors shows signs of having got very hot at some point. The energising relay had poor contact resistance (different every time), so I suspect that it had caused chattering of the contactors; this would explain the overheating and eventual welding of the contacts. The good news is that with the contactors removed, the board boots to an orange light, so I'm confident it will be OK once the contactor(s) and relay are replaced. I still believe that only one contactor is required.

The original board I received no longer boots following the jumper on LK1 incident, so I am intending to build an Arduino based OpenEVSE inside it, utilising the power supply, contactor, and front panel lights; so it should look just like the original, but will boot much quicker and consume less standby power. It won't use the GSM of course.
 

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Does anyone else think this goes some way to explaining all the BCIs and electric failure problems Renault Zoes have experienced, seeing as we all had this particular home charger unit thrown in with the deal?
 

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Co-author of CanZE. Q210 nov 2013
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4,273 Posts
Does anyone else think this goes some way to explaining all the BCIs and electric failure problems Renault Zoes have experienced, seeing as we all had this particular home charger unit thrown in with the deal?
No, I don't think so. But in the development version of CanZE you can see the earth resistance, and harmonic leak currents in the three monitored frequency bands, the two most common grounds (no pun intended) for a BCI.

The true electric failures should really be left to the dealer IMHO. It's usually serious.
 
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