The Troubleshooting and Repair for On-board Charger (OBC) Thread

[Barbagris]

Well, I finally have some time. I have disconnected the traction battery (under the driver's seat) and I have accessed the charger, from the trunk, without removing it from the car.

Above the charger there is a small box (doghouse?) and everything seems normal. There is a fuse, but it is OK.

Accessing the interior of the magazine has been difficult, the cover seemed sealed / glued. When I finally lifted the cover I got a familiar smell of burned electronics.

The cover seemed somewhat toasted by the area on the wiring / coils.

Again, there is a fuse, it seems to be OK.

The large condenser on the left has a color that is a bit more toasted than the other two.

I remove the small top board, and I find visible damage, there is something melted.

Detail:

The top board, below:

¿Ideas? What has been burned? Next step?

Let's put this little ball on the road again! Thank you all!

Barbagris (Greybeard)

 

[coulomb]

The cover seemed somewhat toasted by the area on the wiring / coils.

Yeah, the charrgers run really hot. That's unfortunately normal, or at least usual.

The large condenser on the left has a color that is a bit more toasted than the other two.

It will probably survive, but would be good to replace if it's not a whole lot of trouble.

I remove the small top board, and I find visible damage, there is something melted.

There's your problem :shock: It will be the 2.2 μF capacitor, shown in this schematic (available from the index on the first page).

Problem is, it might be melted due to heat from the pre-charge resistors, which are looking a bit toasty. It seems to be melted from the -re-charge resistor side. So you may well have high resistance or otherwise bad pre-charge resistors, and that might be because of a short circuit on the other side of the pre-charge resistors.

The other possible problem is this:

There are two small blue capacitors, one outlined in red. The other one is unfortunately hidden by a connector. These often blow, and are a major cause of iMiev charger failures. So please check the other blue capacitor, and if possible check that they aren't shorted. (Usually they'll blow to smithereens if they do short, however).

Please follow the instructions in the first few pages of this topic, and see where that gets you. Kiev has summarised a lot of good information there.

 

[kiev]

[edit: Looks like Coulomb beat me to the keyboard...]
Howdy Greybeard, those are some great photos you have posted--such high resolution that we could trace the circuits if needed.

That black charred device is an AC filter capacitor also known as a Class X2 safety capacitor, which designates the rating for surge and overvoltage protection. Evidently it did it's job and hopefully saved the rest of your box from damage. i think that's the first one of those that we have seen fail. Usually they fail shorted and the result is fire and burnage such as you found.

That exact same part is found in your first picture above of the little external filter box. Any big surge would have to travel thru the AC line filter of the top box before it enters the main OBC box, so i think Coulomb's idea about heating from the big white precharge resistor standing next to the capacitor is a likely culprit. That could occur if power to the coil of the input AC relay were to be interrupted, which could occur if the 12V Aux battery were old, weak or worn out. So what is the condition of your 12V Aux battery? Is it the original that came with the car, is it old or fresh, etc.?

Open the access cover of the MCU located next to the OBC, and see if your 20A fuse is blown? That supplies power to the DCDC converter which recharges the 12V aux battery.

here is a link to the LE255-FE datasheet: https://www.okaya.com/noise-products/capacitors/ac-capacitors/le-fx/le-fx.pdf

and the LE225 datasheet: https://www.okaya.com/noise-products/capacitors/ac-capacitors/le/le.pdf

My device is only marked LE225 but has the 310 voltage marking, so it's not clear which sheet applies.

That entire bottom board and the waffle plate soldered underneath it can be removed from the housing by unscrewing the black standoffs and screws holding it down. Then from the bottom side you can access at least one of the solder terminals for the capacitor. Maybe the leads stick up on the top side such that you could solder to those after removing all the black char material. You could try that approach first, then remove the board if top-soldering won't work. Hopefully you could get solder on the capacitor terminal that lies above the aluminum waffle plate that is soldered to the bottom side of the big bottom board. The waffle plate is covered in white gooey thermal compound that you don't want to touch if possible, and don't get it in your eyes.

 

[Barbagris]

Thanks, guys!

...So what is the condition of your 12V Aux battery? Is it the original that came with the car, is it old or fresh, etc.?.

The original 12V battery ('2011) was changed only two months ago, after some strange behavior.

Open the access cover of the MCU located next to the OBC, and see if your 20A fuse is blown? That supplies power to the DCDC converter which recharges the 12V aux battery.

Hey, slowly, please!

I think "OBC" is the On Board Charger, the big box that I have open, but ¿what is (and where is) the MCU?

Thanks in advance,

Barbagris (Greybeard)

 

[coulomb]

I think "OBC" is the On Board Charger, the big box that I have open,

Correct.

but ¿what is (and where is) the MCU?

It's the next big box to the right, the Motor Control Unit.

See this post.

[ Edit: that's the fuse at the bottom right of the area under the access cover. ]

 

[Barbagris]

It's the next big box to the right, the Motor Control Unit.

Thanks!

That fuse is OK.

 

[kiev]

The original 12V battery ('2011) was changed only two months ago, after some strange behavior.

i suspect the OEM battery may have been involved in this failure.

Good news about the fuse, your damage may be contained to components within the potted doghouse area with the plastic fence: AC relay, precharge resistors, filter coil, filter capacitor, snubber caps.

The black rubber potting material in the doghouse can be removed using a wooden spudger tool--like a bamboo chopstick whittled to a flat screwdriver blade, and use it like a scraper.

 

[Barbagris]

Well, finally I have been able to put in some time and I have removed the board off the OBC.

I do not see any more visible damage. The fuse is OK.

(Sorry if the photos are too big)

Detail of the damage:

The small capacitors seem OK, I don't see explosions or similar.

The bigs capacitors are... how could I say it? It seems that the plastic cover had slipped on the metal, forming ¿wrinkles? at the bottom (no idea if it is a symptom of something or purely accidental)

White thermal compound on the bottom was cleaned/retired.

To be continue...

 

[kiev]

No worry on the pictures, sometimes it helps to see the details.

If you wanted to clean up the board for inspection, the solder and smoky residue on the board and big caps, etc can be wiped off and cleaned with alcohol on a rag or small stiff brush.

The plastic sleeve on the large caps is a PVC tubing that shrinks when heated during manufacturing, but they have obviously had some heat exposure in your box that has caused additional shrinkage.

The question to answer is whether the safety cap failed on its own, or was the AC relay circuit involved in over-heating the big white ceramic resistor?

Do you have any electronics repair shops around that have de-soldering equipment? It may be necessary to remove the waffle plate for troubleshooting and repair of your board.

 

[Barbagris]

I'm having big trouble desoldering the waffle plate, it gives the impression that it dissipates so much heat that it can't melt the tin.


Edited:
Finally, trying to remove the waffle plate I damaged the main board.

I start the search for another charger from a wrecked car.




(Was: In an electronics store they have not been able either, they say they need special equipment (???)

I'm tempted to re-weld the waffle plate and try to change the burst capacitor from above. Although I can not find the "OKAYA LE 225 FX", but find in stock "LE 225", "LE 225 ROHS" and "LE 225 MX"

https://www.onlinecomponents.com/keywordsearch.aspx?text=okaya+le225

On the manufacturer's page I can´t see big diferences, I don't know which is the better option

https://www.okayaelec.co.jp/dcms_media/other/eg1704_all.pdf

If I can not remove the plate and access it below, and I do not see other faults, it might be interesting to try changing the capacitor from above.

If everything goes wrong, I think I can find a OBC from a wrecked Mitsubishi i-MiEV, but my car is a clone (Peugeot iOn); I do not know if changing the OBCs would be easy (plug&play) or I will have any other problems.)

Working... thanks to everyone!

 

[jray3]

I replaced another OBC today, transplanted a 11k mile 2011 manufacture date charger from Texas into a 2012 Premium Edition with 44k miles. 90 minutes from start to finish, including a lot of BS time with the crew of EV club members. I could probably do the next one by myself within 45 minutes (IMHO) :roll: .

The failed unit had the same burnt blue capacitor as most others, on the 2nd board down. Interestingly, the failed charger showed much less heat damage than mine that failed at twice the mileage, as it is a daily driver, but with far fewer miles per day, so few long-duration recharges, though most were at L2, outdoors in Seattle. However, the capacitor itself was completely brown and blown apart, where mine had just quietly cracked open. This failure occurred during a deep freeze.
It makes one wonder if calendar age plus thermal extremes (warming up an ice-cold component) made the difference.

Delivered cost was $475 from a wrecking yard found on car-part.com

 

[phb10186]

^

It is extremely surprising to me that such a clear single point of failure is not protected properly by a) thermal protection, b) resistance protection, c) secondary circuit breaking or d) a replaceable sub-component.

What's that fuse on the board there for?

This is the sort of evolution that ICE cars benefit from over the relatively limited amount of post marketing R&D the IMIEV has benefited from/ had available.

I wonder if the global IMIEV iterations have different componentry - though I would guess it would be the same.

Don't forget that far more of the world likely runs on 220-240v than 110v, so the most common global charging scenario would be a L2 charge.

I would think that a certain amount of thermal shock would occur at extreme temperatures, and that full charging from near empty on a very hot/ cold day would place additional stress on the component, but it should have been designed with the relevant safety mechanisms.

5-8 years of age (depending on charge cycles of course) isn't that old for the high quality components available today - so I am drawn to premature failure by either quality control issues (less likely) or sub-optimal design (more likely).

Quite simply, at such extremes of temperature; it should either not charge at all, charge partially, or charge incrementally in a way that prevents unduly high loads on the charger, battery or anything else.

To make matters worse, the failure of that single component not only takes the whole board out, it takes the entire charger out.

 

[mikedufty]

At least 2 of the failures in Australia were chargers that had already been replaced under a recall and were only about 18 months old.

 

[kiev]

I replaced another OBC today, transplanted a 11k mile 2011 manufacture date charger from Texas into a 2012 Premium Edition with 44k miles.

Thanks for posting the information about this. Would you happen to know, or could you ask them, about the recent history and status of the 12V aux battery before the OBC failure--had it been replaced, were they having any starting issues, was it an old original OEM, etc? Just looking for clues to help identify the root cause.

@phb
i think that the little blue snubber cap (failure) is acting somewhat like a "fuse" to protect the more expensive and inaccessible switching transistors in the waffle plate.

There are at least 4 little fuses in the OBC/DC Conv., and it seems that none have ever been reported as having blown.

But in many failures it seems that the big MCU 20A fuse blows, in the HV(+) line between the OBC/DCDC and the MCU.

i don't think these are component failures, but rather the damage that results from some system-level glitch. Do all the failures have a common root cause, or are there a couple of separate mechanisms or paths to the damage?

 

[jray3]

Yes, this victim had an original 12V battery, and it's weakness was not apparent until the owner tried to drive in 'total loss mode'- overnight 12V recharging and DCFC traction battery recharging.
He replaced the 12V battery before we replaced the OBC.

This car had been subjected to 'hard shutdowns' by yanking the plug before disconnecting via J1772 when opportunity charging on 120V a number of times.

 

[Barbagris]

Finally I was able to return my little car (problem described on the previous page) to the road, thanks to the change of the complete converter.

New was more modern and I had to modify wiring / connectors, but everything seems to be fine.

Thank you all!

 

[phb10186]

Yes, this victim had an original 12V battery, and it's weakness was not apparent until the owner tried to drive in 'total loss mode'- overnight 12V recharging and DCFC traction battery recharging.
He replaced the 12V battery before we replaced the OBC.

This car had been subjected to 'hard shutdowns' by yanking the plug before disconnecting via J1772 when opportunity charging on 120V a number of times.

The obvious two culprits.

I think, especially now that these cars are ageing a bit, I will charge control more closely in the very hot/ very cold weather via the remote... though luckily that is quite rare here in the UK (and the climate is somewhat similar to Japan) (can't remember any charger failures here). If I lived in a hot dry climate, a well placed CPU fan cut into the charger case could also help with heat dispersion, as could (possibly) modification with an improved heatsink in the vulnerable places.

 

[DBMandrake]

The obvious two culprits.

I think, especially now that these cars are ageing a bit, I will charge control more closely in the very hot/ very cold weather via the remote... though luckily that is quite rare here in the UK (and the climate is somewhat similar to Japan) (can't remember any charger failures here). If I lived in a hot dry climate, a well placed CPU fan cut into the charger case could also help with heat dispersion, as could (possibly) modification with an improved heatsink in the vulnerable places.

Don't get too comfy, there have been multiple on board charger failures in the UK recently.

Kes who posted this thread is located in Scotland not far from me and has had the charger go on both his cars...

He also posted over on speakev.com about his problems, (with more up to date information) and there have been other reports on speakev.com of UK charger failures recently as well.

Makes me a bit nervous about mine which is a 2011 model with over 50k miles now. On the plus side I recently replaced the very weak 12v battery so it has a good healthy 12v battery now. If that is the underlying cause of many of the failures I should be alright for a few years, touch wood.

I also use a Rolec wall charger and always end charging either by letting it finish charging itself (most days) or squeezing the trigger on the J-1772 connector - I never turn the power off at the wall first even if I was using the granny EVSE. So if that's another cause of failures I should be OK there too, especially now I'm aware not to do that.

 

[phb10186]

The obvious two culprits.

I think, especially now that these cars are ageing a bit, I will charge control more closely in the very hot/ very cold weather via the remote... though luckily that is quite rare here in the UK (and the climate is somewhat similar to Japan) (can't remember any charger failures here). If I lived in a hot dry climate, a well placed CPU fan cut into the charger case could also help with heat dispersion, as could (possibly) modification with an improved heatsink in the vulnerable places.

Don't get too comfy, there have been multiple on board charger failures in the UK recently.

Kes who posted this thread is located in Scotland not far from me and has had the charger go on both his cars...

He also posted over on speakev.com about his problems, (with more up to date information) and there have been other reports on speakev.com of UK charger failures recently as well.

Makes me a bit nervous about mine which is a 2011 model with over 50k miles now. On the plus side I recently replaced the very weak 12v battery so it has a good healthy 12v battery now. If that is the underlying cause of many of the failures I should be alright for a few years, touch wood.

I also use a Rolec wall charger and always end charging either by letting it finish charging itself (most days) or squeezing the trigger on the J-1772 connector - I never turn the power off at the wall first even if I was using the granny EVSE. So if that's another cause of failures I should be OK there too, especially now I'm aware not to do that.

I use a Rolec as well - but I doubt the wall charger has anything to do with it - saying that I find my Rolec can be a bit jumpy on occasion which may be a hard stop in effect. I too never hard unplug, and let the car end the charging cycle. My parents also have an IMIEV, and they use the standard 3 pin wall outlet charger - but charge the same way I do. No problems yet, though mileages are lower than yours.

To have two failures on two cars in the same household is either the worst luck imaginable, or due to some charging practice or domestic electricity issue... but I wouldn't speculate.

Unfortunately, I'll probably have to sell the IMIEV as its very restricted with two kids seats in it - even though I am trying not to.

 

[Kes]

Thanks for the mention DBMandrake, Yes both my ION's failed. I sent them to a local EV specialist, he has managed to get one up and running by cleaning off corrosion and dry solders on inverter. The other he couldn't repair unfortunately. He says there is a hole in the box for cooling and due to the car having no undertray water and salt are getting in causing the damage?
I sent the inverter box to a PCB repair place and they can't/won't repair.
I know quite a few of you have managed to repair these boxes, would anyone be interested in taking on the repair. I am sure I could ship the package worldwide and am at a wits end, my electric van has just given up on me too! Happy to pay.