On-board charger overheating

Hi,
I am aware of another thread called "Burning smell after charging", I am starting a new thread as I concluded that my issue is not the charger.
Leaf 2011, sold on 07/2011. From the part number of the charger it is the first half of 2011 model. It was sitting in rental agency and I purchased it with 2k miles on it in Nov 2012. As a side note, battery was crap from the gat-go, usual blind eye by Nissan, last Turkey Day (2015) i got new propulsion battery. Now it has 51k miles on it. I love the car.

The symptom: After a couple of hours of 110V or 220V (home and commercial)charging the plastic hump gets hot and there is an electrical burning smell. Doesn't happen with DC charger. I removed plastics covering the charger, the charger and EMI filter get hot to the point that I wouldn't keep mu hand for a long time on them.

Diagnostics I did: 1) Checked the charging currents. they are the same as before. I ran water from the hose through the charger, while charging, charger never got even warm for almost empty to full charge. Did it several times. JFYI, I got another hose and ran used water to my back yard. Pumpkins are almost ready and lawn is getting green and lush, again. I opened the faucet 1/4 turn, what made sense for me to be moderate to low flow.
2) Coolant pump (on passenger side) turns on when the L1/L2 voltage is plugged in. I was able to see coolant moving, but couldn't say if it was good enough. I tested the pump: The pump can pump water to more then 7 feet of height. Probably even higher, but my hose was that long.
3) I bypassed the metal pipes that bring and return coolant to the on-board charger. With the clear hose. Pump takes some time to get all the air out, so I was able to observe the flow, and it seems pretty significant. As I would expect it.
4) I put the system back together, filled it with coolant, got all the air out (same amount of coolant went in by volume) as I drained out. System was probably never opened or flushed before. I doubt they had to touch it during propulsion battery replacement.
Still the same issue. Didn't expect much,a as I didn't do anything to address any issues.

Without service manual, diagrams and schematic i couldn't do much more, but I observed what is car doing during charging and monitored the temp increase. As I mentioned when it is plugged in, the coolant pump starts. When the charger starts to get hot, after about an hour, the coolant hose, return from radiator to pump is warm. However, I noticed that radiator fans will never turn on! So I "started the car" while charging, and turned on AC. Both radiator fans turned on. And, the charger cooled down to almost ambient temperature within 5-10 minutes. As long as I have radiator fans running the charger doesn't warm up. When I turn off the car, fans work for another, give or take, 5-10 min. When they turn off, the charger starts to heat up again.

Can someone more knowledgeable then me suggest what next to look at? I searched the web and just couldn't find any related topic, or diagrams or schematics or service manuals. Maybe my keywords were not good enough, but that is where I stand now.

My next thought is some thermostat or temperature sensor that is faulty. There is a black thing sitting on the metal cover on the side of the charger (originally under plastic hump cover) - I keep it on top of the charger assuming that is a temp sensor. If indeed it is, how do I test it? What should be the readings of off it when it is cool, hot, or at certain temperature?

I have OBDII wifi reader that I use with Leaf Spy Pro. Is there any software that can read all the relevant parameters that can help me diagnose the culprit of the problem?

Thank you for reading this, and thanks in advance for your help!

Scan for fault codes using LeafSpy Pro. Are there any?

What about the second coolant pump? Is this working while charging??

Radiator fans are not used normally until temperature sensor reaches 57C 135F.
Metal surfaces that are above 50C are too hot to keep hand on.

http://imageshack.com/a/img923/965/B46IPF.png

Attached is a screenshot of the DTC codes. If it explains any code, I have unplugged the coolant pump when ruining the water through the charger. Also, 4 months ago my 12V battery died, measured 6.3V, and I replaced it.

Second pump turns only when I turn on the car (equivalent of turning on the ignition on ICE)

Thanks!

According to technical literature both pumps should be running while charging.

I would clear all fault codes using LeafSpy and repeat the charging process.

Tell me about temperatures. You observed that if you pump water manually everything works fine but if you
put all back together coolant does not circulate correctly? Charger in the trunk is hot to touch, coolant lines are cold?

You can try to disconnect that pumps that works. Failsafe should use the second pump at higher speed.
Coolant pumps should have 4 pins. Nr1 and Nr4 are for power, 2 and 3 are control/speed data.
Both pumps should be energized while charging.

I don't know water pump internal design. I hope that waterflow is not obstructed if driver side pump is not operational.
It is even possible that flow is obstructed if passenger side pump is pumping at low RPM and NOT obstructed @high RPM.

After disconnecting driver side pump you should receive another fault code. Report with observations.
Report any other fault code that reappears after charging.

PS! coolant temperature sensor is located on the radiator. It doesn't usually fail.
Coolant pumps speed up if temperature in the radiator goes up. But it has to get hot at the radiator in the first place

Only passenger side pump is on when I plug in. When I turn on the contact both pumps are on.
When I drained the coolant at the rear of the car, bellow the charger, only the tank for passenger pump got emptied. other one staid filled to the top through whole process (yes they share overflow tank, that one got empty - should've disconnect it ahead of time)

With hose it is fine. When I looked at the flow, it seemed right. When I put everything back together, again the same overheating problem. I thought of a low flow, but based on the coolant movement/disturbance/coming back that is visible in the small tank where the return hose is attached, the flow seems normal.
Charger gets hot, even where the coolant flows - back of it-towards trunk space. But it is the hottest just to the back right, top and thin front cover also gets pretty close.

The hoses get warm, maybe 40C when the charger is hot.

I disconnected the passenger side pump while I was using water hose. No other pump was running during charging. I assumed that driver side pump is for drive train inverter... They look like two different cooling systems. Is my assumption wrong?

This sounds like there is a bypass somewhere? is that true? Or cross-connection between two systems? Does this make any sense?

Will do as suggested, erase codes, tr it again. observe codes. Disconenct passenger side pump, check codes. disconnect driver side pump. check codes. Will post findings here.

Do you know where can I find diagrams for my leaf? or some kind of service documentation / manual?

Thanks,
Ivan

imaric said:

Do you know where can I find diagrams for my leaf? or some kind of service documentation / manual?

Click to expand...

The official source is https://www.nissan-techinfo.com/home.aspx.

Does the return hose also get near 40C?(hose that brings cold coolant to charger). It should NOT be possible.
Except if there is a short circuit in the charger and most of the power is wasted on heat
generation and NOT charging. Does LeafSpy report nominal charging speed?

Second pump SHOULD work. This is so weird. It should be one long coolant loop.
It is possible that there is an obstruction in the loop. For example cooling pump with
blades that are stuck or working against direction of flow (reversed).

imaric said:

I assumed that driver side pump is for drive train inverter... They look like two different cooling systems. Is my assumption wrong?

Click to expand...

That is for the heater system which is a 3rd pump. The 2 cooling pumps are connected
in series to provide a higher pressure. there is no T on this connection, the outlet of
pump 1 is connected directly to input of pump 2. Pump 2 is under the headlight and
much harder to hear, still if you hear nothing with pump 1 disconnected, then pump 2
may not be operating, should trigger a DTC.

To answer Arnis questions: When charger is getting hot the charging time is the same as usual, and current into the car is same as usual.


A few hours ago, I have erased all error codes. Connected the car on 220V charge and both pumps are now running and charger doesn't get even warm. I started with 2 bars, now it is at 8 bars and still charging, charger is cold.
Now I am puzzled. :? I guess I will use the car and charge it under watchful eye and periodically read to see if there are any error codes.
Any ideas?

Is it even possible that ECU doesn't turn on the pump or something due to some error code? That would be a bug in the control software, I guess.
Thanks,
Ivan

It happens. The Vextrix electric motorcycle has a bug in the control code that will sometimes, rarely, cause the bike to rapidly reboot on the road while riding, but leaves the cooling fans off, possibly resulting in overheating of the pack or controller board. Just stopping the bike and rebooting it with the power switch will turn the fans back on. This sounds a bit similar.

Most likely you have a shorting water pump. Does anybody have information about electric water pump internal construction?
Does it have brushes or is it brushless?
Motors with brushes might get stuck randomly if carbon from worn brushes shorts few contacts.
It can be remedied (sometimes) by hitting the motor with a blunt object like a wrench while it tries to spin.


It is possible that controller went crazy because of error code but that would be really stupid.
Most controllers try again after restart.
Also possible a bad contact. And you touching the plug might have cured that for short period.
Keep LeafSpy close by and check for codes often.
Most likely problem is not solved.

What appears to have happened is that on 2011/12 Leaf there are two water pumps in series for redundancy. If one fails it appears another pump is unable to push water through standing second pump (that means high-quality pumping mechanism). At least new Leaf does have only one water pump instead of three

If you are out of warranty and replacement pump is not available (most likely new is too expensive) you could just make a bypass with regular pipe and few clamps.

If pumps are identical it is possible to switch them to see will the problem repeat with the same location or with the same pump.

A few days ago i had this horrific smell inside the car after a few hours of charging. It all seemed to be working normal outside of the smell.. and the area in the back hump was hot and the smell was super bad back there. I am thinking my pump/s are not working correctly too. The dealership said "PERFORMED INSPECTION AND FOUND AFTERMARKET CHARGER BEING THE CONCERN WITH THE SYSTEM. CHARGED VEHICLE USING OUR CHARGER AND NO CONCERNS FOUND." I hope that its just my ebusbar charger ( i will try to return to amazon) in the meantime i will trickle charge and hope to possibly get a chargepoint evse... any more info on your situation with this? Did you confirm the pumps? Please let me know.. thanks for your time all!

trytohelpyou said:

A few days ago i had this horrific smell inside the car after a few hours of charging. It all seemed to be working normal outside of the smell.. and the area in the back hump was hot and the smell was super bad back there. I am thinking my pump/s are not working correctly too. The dealership said "PERFORMED INSPECTION AND FOUND AFTERMARKET CHARGER BEING THE CONCERN WITH THE SYSTEM. CHARGED VEHICLE USING OUR CHARGER AND NO CONCERNS FOUND." I hope that its just my ebusbar charger ( i will try to return to amazon) in the meantime i will trickle charge and hope to possibly get a chargepoint evse... any more info on your situation with this? Did you confirm the pumps? Please let me know.. thanks for your time all!

Click to expand...

I've been using my Ebusbar for going on 6 months, almost daily with no such issues. I don't see how a EVSE could cause the charger to get hot and it sounds like it may have just been a cop-out to me. Funny thing is though Amazon no longer sells the Ebusbar, not just out of stock but it's no longer listed :? so I'm not to sure on getting Amazon to take it back.....but I don't know.

Regardless of the cause, if your OBC overheated to the point of "letting its smoke out" (strong bad smell) and was obviously hot to the touch besides, it's been damaged (or at the very least, degraded). Since it is in position to damage your battery, I don't think it's OK for the servicing tech to say "well, it cooled back down so it's all fine now".

Thanks for the feedback guys so I sent an email to the service manager at my local dealership after speaking with the Eevee phone number for Nissan. Basically the person I spoke with from Nissan said the evse should not cause this issue just because it's not the aerovironment brand. He also went to talk further about how when there is a smell with every customer he has interacted with the charger it was always bad in those cases. I did get a reply today from the service manager saying that the technician would be in tomorrow so I hope that they reengage with some other positive forward motion. I'm stuck searching online right now for the entirety of all of those charging gadgets that are under the back hump to see how much just getting a replacement would cost and it's not that successful right now. And of course please be advised I am aware that there is nearly 400 volts at a very high amperage at the battery. Any updates I get I will share on this thread because it will be great to find a solution to this problem.

Sent an email but no word from the dealer. I'm about to go about this myself with the EMI bypass suggestion if it appears burnt/broken

I finally simply went to another dealer, got the proper diagnosis. I communicated with Nissan and they initiated a ticket a while before and then executed a out of warranty assistance esentially supplying the part at no cost. I paid 365 dollars to the dealership and they replaced the charger. They did not quite fill up the cooling system per the requirements in the service manual, but that is a minor thing i hope. The videos about this are up on my channel on youtube. The name is trytohelpyou, if anyone is interested in seeing me talk about the whole situation. ooohhh it says i can embed a video up top here,,, i will try. [youtube]<iframe width="560" height="315" src="https://www.youtube.com/embed/6py7wt4_2Rw" frameborder="0" allowfullscreen></iframe>[/youtube]