Onboard charger capacitors failed

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^^ Well done !

If you feel up to it, a tutorial how to swap the OBC would be a wonderful gift to the community since failed OBC stories are relatively common.
 
I figured I would update everyone on the progress…

Last week I got the new onboard charger installed and it is charging the car, but unfortunately it is leaking coolant. I have spent the last few days trying to make sure that it wasn’t just “user error“ on my installation and I have finally come to the conclusion that I think the charger is the cause. I can’t say that I am shocked, because when I got the “new“ used unit out of the box, the bleeder valve was bent about 30° and there were a couple of little dents on both the input and output coolant pipes. I took some pictures immediately so I had timestamped pictures, just in case. I went ahead and installed it anyway, because it’s not like there are a ton of used 2011/2012 chargers running around.

The leak is not gushing, but more like a trickle, and it’s not continuous . Basically, it’s just enough to make me question whether or not I’ve fixed it, or blead things correctly... but after five days now, I’ve reached the ultimate conclusion that it is an issue with the part. During that time frame, it’s probably leaked about a quart of the blue Nissan coolant… Which isn’t cheap.

I’m left at an odd crossroads: the part came with a warranty (in theory) of 6 months... but that warranty is invalid if I open the part up. Yet, I’m half tempted to take the electronic guts from this “new” charger and marry them to the cooling/mechanical guts of the original one from my LEAF.
 
The problem with salvage yard parts: They have no way to test it before sending.

The problem with this salvage yard: they obviously didn't take proper care to pull or ship the parts to avoid damage.

How likely is it that they will have another salvage laef available to pull parts (another OBC) to replace it? How likely is it that they will be careful not to bang and bend up the coolant line?

Your plan to swap the electronics avoids anymore risk of getting damaged goods. You know it works plus you have already done half the job by pulling the electronics boards out of your original unit, and you know that it wasn't a leaker.
 
nlspace said:
Your plan to swap the electronics avoids anymore risk of getting damaged goods. You know it works plus you have already done half the job by pulling the electronics boards out of your original unit, and you know that it wasn't a leaker.

Update: my Friday night plan to Frankenstein a charger has hit a smelly snag.

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Looks like we had a failure in progress as we already had at least one explosion. I immediately noticed the discoloring and the smell when I opened it up and I’m frankly shocked that it was still charging the car in the state it was in. Before proceeding, I did get the OK from the salvage yard person that opening it would not void the warranty. Looks like this will be going back. The exploded part did not fail on my original charger, so in theory I could replace it, but I don’t know how confident I feel in that.

Sidenote… The more I look, the more difference I see between this charger with a model number 296A0-3NA0A, and my original 3NA5A. It makes me believe that there is reasonable enough value in buying the final revision 3NA8A part that is around $1400-$1600 dollars new from an online dealership.


ElEZby2WMAACZKs

3NA0A on top 3NA5A on bottom


ElEZbzIW0AA3j4a

ElEZbzHWAAAmhXn

3NA0A on top 3NA5A on bottom


ElEed7vX0AAnFgk

ElEed7qXYAETw2g

3NA0A on top 3NA5A on bottom

I am sure that there are more differences, but at this point I’m probably not going to take this apart any more in the hopes of sending it back. I always ask God to make it obvious what my next step should be… He made this one VERY obvious!
 
I woke up this morning more positive than last night. I decided that if they tell me to keep the 2x broken OBC, that I’ll try to fix it. Considering it’s expensive to ship back a 2x broken part that they are unlikely or unable to fix, I feel like the odds are relatively good.

That means I’m on the hunt to find the right capacitor.

I did find the specs on that blown capacitor: 450v, 2.2uf Okaya: https://datasheet.octopart.com/AFC450V225K-Okaya-datasheet-11487076.pdf

I know capacitors have different compositions for different activities, so as a novice, I put low confidence in this being the right solution, but I did find this that might work?? https://www.newark.com/panasonic/ecw-fe2w225k/capacitor-film-pp-2-2uf-450v-radial/dp/83X9334
 
That one is close, but the lead spacing is too short, try this one

https://www.newark.com/panasonic/ecw-fe2j225k/capacitor-film-pp-2-2uf-630v-rad/dp/83Y7543?st=ecwfe2j225

it has a higher voltage rating with the same capacitance and correct spacing. If you can't find one i can pull one off of my board to send you.

The difference between the two versions. Your original has 2 empty fenced doghouse areas, these are populated by the AC EMI filter inductors on the salvage unit. Yours are likely external to the enclosure in the biege colored plastic box where the AC from the EVVSE comes in. That is the same style as my unit.

The potted transformers look different but do the same function, so no problem there.
 
Maybe it's just a coincidence, but i'm leary that your EVVSE may be faulty. You have had 2 failures in the same functional section of the OBC, namely the PFC boost stage immediately after the AC rectification.

Do you still have the OEM level 1 version?

When you pull the board there are some diode voltage checks that you can do to make sure the waffle plate is not damaged.

[edit]
My impression is that the Juecebox started back in 2013 as an "open source" kickstarter project on the diy forum,
https://www.diyelectriccar.com/threads/10kw-60a-diy-charger-open-source-design.59210/

but quickly went away from that when real money got involved. i doubt and would be surprised if anyone could ever obtain an open source schematic to diy build their own. i'm not impressed by someone using free open support to design and develop a product and then not making it freely available although touted as such.

The original "bad-boy" charrger design was seriously flawed, as would be all bad-boy concepts. So my personal opinion of them is very low, i would not use or recommend anyone to use it. i have never taken one apart to actually see how it is implemented, so i am ignorant in this respect.
 
I’m still awaiting word from the seller so I haven’t proceeded any farther yet buying capacitors or further dismantling the OBC.

nlspace said:
The difference between the two versions. Your original has 2 empty fenced doghouse areas, these are populated by the AC EMI filter inductors on the salvage unit. Yours are likely external to the enclosure in the biege colored plastic box where the AC from the EVVSE comes in. That is the same style as my unit.

When the time comes, do I need to swap out the beige colored boxes between the two units as well?

I can easily open up my EVSE. I will take some pictures and send those. I intend to check the continuity along the cord because I believe that there is a short in it. I don’t know if the wrong wire shorting would cause this problem, but while I have access to both ends I intend to check that out.
 
Pictures would be great; i'll take a look inside the beige unit if it can be opened to see what's in there.
 
After talking with the seller, and much debate, I’m going to send the used charger back. I am leaning toward buying a new one (at twice the cost unfortunately). While it’s possible that I am only a few minor repairs from fixed with the used unit, it’s also possible I go down a winding road that leads to even more issues. To this point, my wife has been extremely understanding, considering the car has essentially been out of rotation for 2 full months.

But... before I throw down the $1500 that a new on board charger would cost, I’m going to do more testing in the EVSE.


nlspace said:
Do you still have the OEM level 1 version?
Yes. It’s still in great shape as the L2 has been the workhorse.



nlspace said:
Maybe it's just a coincidence, but i'm leary that your EVVSE may be faulty. You have had 2 failures in the same functional section of the OBC, namely the PFC boost stage immediately after the AC rectification.

This is my concern too. I still believe that there may be a short in my cord and I plan to test continuity from both sides (as best I can) to check it out. I feel fairly confident that I know where the short is located, because it is where the garage would have sat on it prior to my purchase of a 3D printed pass through block. I’ve watched some videos about cord repair and plan on using “lineman’s splice(s),” staggered repairs, liquid electrical tape, and an adhesive lined heat shrink. I feel above-average confidence that I can execute the repair, but if not, I’ll replace the cord as long as the internals of the EVSE look decent.


nlspace said:
The original "bad-boy" charrger design was seriously flawed, as would be all bad-boy concepts. So my personal opinion of them is very low, i would not use or recommend anyone to use it. i have never taken one apart to actually see how it is implemented, so i am ignorant in this respect.

So, I don’t know if I have the “bad boy” tor do I fully understand what that means, but here is what I do have:

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ElTy-b0XgAYauyN

I didn’t see anything obvious on first sight... nor smell anything particularly strong.



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ElTy-dSX0AsdjUX

I did see these two pieces of plastic, but upon further review, I think they likely chipped off when the unit was originally assembled and the bolt in the last picture was installed.

Again, I cannot say thank you enough for all of your help, and I hope this thread proves useful for others in the future. I’m still holding out a slim hope that I can find another used OBC, but my EVSE is going to need to be vetted first.
 
A "bad boy" is a bare bones chargger cheap hack that some EV folks used to avoid buying a proper EV chargging device, an example schematic from 2006,

badboy.gif


The juicce box falls into that class in my opinion: notice the lack of fuses or other protection, notice the useless current sensor on both output lines to the car (reads zero current, so what's the purpose) ; notice the tiny screws holding the large crimp terminals on the AC input to the contactor (the red one looks to be cocked) can you imagine 60A running thru that junction?; notice the missing components on the circuit board (what was the design for those parts and why are they missing?); do you see any controller chips? This is what happens when someone copies bits and pieces of stuff from other designs without really knowing what they are doing or how stuff works. Take stuff off to lower the cost--"hey it still works, don't need it."

For example if you were to look inside your OEM EVVSE you will find a zero current sensor such as this, but on the AC input lines in order to check for a ground and detect ground faults--it doesn't do any good on the output leads. Also you would find fuses on both AC inputs.
 
nlspace said:
notice the useless current sensor on both output lines to the car (reads zero current, so what's the purpose) ...

For example if you were to look inside your OEM EVVSE you will find a zero current sensor such as this, but on the AC input lines in order to check for a ground and detect ground faults--it doesn't do any good on the output leads.
? Won't it still detect residual current faults caused by leakage outside the unit?

Perhaps there are small leakages to ground in the unit (perhaps small Y capacitors), which might cause nuisance tripping if it was on the AC input leads?
 
Upon further review, I don't think the seller is going to make me send the unit back, and I feel like I have to do ALL of my due diligence before spending $1,400 on a new OBC, so I'm getting my multimeter back out!

nlspace said:
When you pull the board there are some diode voltage checks that you can do to make sure the waffle plate is not damaged.
I'll likely pull the board tonight or tomorrow depending on time.


nlspace said:
A "bad boy" is a bare bones chargger cheap hack that some EV folks used to avoid buying a proper EV chargging device
I'm planning on purchasing a new EVSE, because I don't believe it can be a coincidence that I have two blown on board chargers AND an EVSE that was an early JuiceBox without some of the protective components you mentioned. If you have a prefered brand/model, I'd appreciate it. I'm still doing some research, but I don't want to bog the thread down too much with that tangent, yet.
 
Update on the Frankin-charger:

I got all of the components removed that need to be transplanted from the used charger chassi with the blown capacitor and coolant leak to the chassis from my original charger Without the coolant leak. I have figured out that the white box on the side is extremely difficult to open, even with the screws removed, so I plan to transfer that portion from the used charger to my original charger chassis as well. That way, I will keep the bottom board (and differences related to it) and the white box together from one chassis to the other.

As discussed, I have ordered a pair of replacement capacitors one necessary, one spare:
https://www.digikey.com/en/products/detail/panasonic-electronic-components/ECW-FE2J225K/5881170

I’m also on the prowl for the right type of RTV (staking compound). To the best of my guesstimation, I’ve determined it’s possibly RTV167. I haven’t been able to find a tube of that for under like 30 bucks. If that’s what it takes, it’s what it takes, but I was wondering if something like this would work: https://www.amazon.com/dp/B00065U8CY/ref=cm_sw_r_cp_api_i_i.wNFbXA4B6PW .



nlspace said:
When you pull the board there are some diode voltage checks that you can do to make sure the waffle plate is not damaged.

I have done some basic comparisons between the two boards, and in particular attempting to do the checks we had previously discussed to verify that those components work. To this point, the only component that I have been able to prove failed is the exploded capacitor on the “new“ salvage board. I have not been able to detect any other trauma, and certainly not the level of what happened to my original waffle plate.

Thank you very much for all of your help.
 
The electrical or electronic grade of RTV on a pcb is called "neutral cure" that doesn't release acetic acid during the curing process. This is to prevent etching and corrosion that could damage metal traces or component leads or solder joints. This is similar to why rosin core flux is used in electrical solder versus the acid core flux of plumbing solder. Don't want no acid on your board.

Most home and automotive type RTVs are acid cure. The neutral cure products do cost more but work great and are worth it compared to the time and cost of repairing acid damage.

It looks like your Loctite product is neutral cure, it releases MEK. Here's the MSDS link

http://industrialbolt.com/msds/loctite/byNumber/18718.pdf
 
I know it’s been a few days so I wanted to give an update…

Yesterday I got the old component desoldered from the board and replaced the capacitor on the bottom board with a new one. It’s not a process I’ve ever done before, so it took me a while to get it done and I ultimately had to break/force the pins off of the solder in the hole that I was not able to suck out. I put in the new component, I soldered it on pretty quickly and then used the “ultra gray” RTV along the sides to secure it.

I took the “new” bottom board and put it in the original charger chassis (N0A -> N5A). After reconnecting all of the internal components, I took the white box from the side and moved it as well (N0A -> N5A). After reinstalling it in the car, it works, and the car shows no errors!!

Thank you for your help in helping me resolving this. I took some videos and I would like to put together a video walking through what I did, but that’s gonna take some time.
 
That's great news i'm glad to hear it, good job on replacing the parts and getting it working.

It can be difficult to get enough heat into parts on such a large board with lots of thick copper traces. i use a 150W solder gun for such applications with copper wick to remove the excess solder.

The RTV helps hold the bigger parts in place and damp out road vibration that could crack the solder joints.
 
goldbrick said:
Since we're on the subject of substandard EVSE, does anyone here have a strong opinion about the OpenEVSE unit?

I've used mine for several years now. I've also modified it to facilitate usage as a solar energy controlled charge controller - using the included RAPI tools. I've not kept up with recent designs - have there been any significant changes? - don't really know. It's a great unit. Maybe not the most "professional" look, but really robust.
 
Thanks Marktm. That is what I thought and I'm glad to hear it since I already bought mine. I haven't hooked it up yet since I want to put a sub-panel in the garage first. Plus, charging at work is free.....

I don't know of any very recent updates but the hardware certainly looks well designed and it is certainly looks well engineered but I haven't worked on analog circuits for about 35 years.
 
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