DkubusEV
Posts: 5
Joined: Sat Jul 21, 2018 9:03 pm

Re: nichicon Charger and DC/DC Converter

Tue Jul 24, 2018 12:37 am

kiev wrote:The box has a nichicon part number, and looking thru their website i found they take credit for the miev OBC. In fact they claim that it worked so well for Mitsubishi that Nissan converted over to using their design in the Leaf.

Here is a page from a product brochure:

Image

So i would say that nichicon is to blame if there are any thermal issues. Wonder if we could buy them direct without getting middle-manned by Mits?



Very cool info :D

anyone ever get any information on removing the top speed limiter or the torque limiting that seems to occur? "re map" the MCU??
the Pikes Peak ImiEv Evolution apparently ran 3 imiev motors and they were all boosted up to 80kW and higher RPM...

my project isn't "normal" so more power for temporary bursts would be great.

kiev
Posts: 711
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Supplemental cooling for the charger.

Tue Jul 24, 2018 6:24 am

A web search came back with a story that nichicon agreed to pay $42M to settle a USA Dept of Justice case that accused them of price fixing electrolytic capacitors. Later reports indicated that many more companies were included in this lawsuit. So it may be that there is not much e-cap support in the USA anymore...
kiev = kenny's innovative electric vehicle

kiev
Posts: 711
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

OBC Thermals

Tue Jul 24, 2018 6:32 am

Curiousity killed the cat.

Here is before charging started. The residual heat from driving several hours earlier still shows up in the coolant tube near the top of the picture.

Image


About 30 minutes after start of charging with the cover in place:
Image

and with the cover open:
Image


About an hour after start:
Image

under the cover:
Image

Coolant line to the MCU:
Image

Left the cover open for the evening charge session:
Image

Be Thirsty (and Careful) My Friends,
kiev = kenny's innovative electric vehicle

coulomb
Posts: 53
Joined: Sun Jun 10, 2018 8:32 pm

Re: OBC Thermals

Tue Jul 24, 2018 6:03 pm

kiev wrote:Curiousity killed the cat.

Nah, fascinating stuff.

I'm curious (am I in danger? :D ) about the hot rectangles here:

Image

Are these merely because the cover is thinner at those points? I can't see any internal structures that would correspond to the hot rectangles. Unless the blue rectangle is the waffle plate™ showing through, but it seems unlikely to remain that sharp.

The mains cables really have fire in them, huh? At least from these shots with the cover on. It certainly seems that it's the magnetics that get the hottest. Of course, they can stand it, but they transfer a lot of their heat to the capacitors and semiconductors, which will age. Edit: however, the capacitors, at least the tops of them, seem quite cool compared to the furnace elsewhere.

kiev
Posts: 711
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Supplemental cooling for the charger.

Tue Jul 24, 2018 6:37 pm

Those rectangles are silver/aluminum labels on the cover which can reflect and give false readings. i probably should have covered them with black tape.

i did put black electrical tape on the caps which is supposed to allow a temperature measurement rather than a false reflection of the aluminum tops. Compare the before and after with cover off to see the caps and tape.

The big blue rectangle on the top is the external EMI filter bolted to the lid. It too has an aluminum label, as does the MCU located to the right of the OBC.


There is already a small ~1/2" vent hole in the front left side of the charger--it has a plastic (filter?) plug. So maybe another hole could be added near the right rear corner by the inductor to blow air in, and remove the plug to let it flow out.
kiev = kenny's innovative electric vehicle

jray3
Posts: 1515
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: Supplemental cooling for the charger.

Thu Jul 26, 2018 1:25 pm

Aerowhatt wrote:Jay if I'm understanding your description of the motor bay hatch insulation on your 2012 it actually touches the top of the charger unit? The 2014 hatch definitely has some air space between the hatch sound insulation and the top of the charger. I would guess somewhere around 3/4 of an inch. The insulation is molded on the bottom side to provide this space.
Aerowhatt


Aero, I mistook the molded relief space to be in contact, but there's no rub marks or a dust shadow to confirm this, so yes- no contact.

How about some teaser photos of your blower prototyping? Wife's getting tired of me opening the motor bay hatch and cracking all windows during a recharge.. :roll:
2012 i-SE "MR BEAN" 90,000 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

JoeS
Site Moderator
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Location: Los Altos Hills, California

Re: Supplemental cooling for the charger.

Thu Jul 26, 2018 2:00 pm

jray3 wrote:.. Wife's getting tired of me opening the motor bay hatch and cracking all windows during a recharge.. :roll:
Good to know there's more than one paranoid person worried about this issue ... need a quick-release for that motor bay cover and it's a PIA to move my carpet and spare tires out of the way... :roll: For now, at home I just have the fan blasting upwards and have abandoned the fan in front of the radiator after running over it (one of the drawbacks of backing into the garage) :oops:
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
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Location: Biloxi MS

Re: Supplemental cooling for the charger.

Thu Jul 26, 2018 6:37 pm

Yup - Paranoid!

I've been recharging only overnight now when it's cooler and since time is no longer of the essence at all I'm only using the OE 8 amp L1 EVSE. I think the big 435 cfm blower I have does a good job of moving air around and probably will make L2 charging safe, but it's a pain to stuff that under the back of the car every time I want to charge

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

Aerowhatt
Gold Member
Posts: 425
Joined: Wed Jan 28, 2015 1:52 pm

Re: Supplemental cooling for the charger.

Fri Jul 27, 2018 8:59 am

I don't think it's paranoia. Given the internal temps that Kiev has posted it's a valid concern.

I've gotten the blower airflow optimized and my wife is out of town this weekend. so I should get the bracket jig together and a few brackets made (she calls things like this "goofing off" so perfect timing ;) ). Kiev has been generous enough to agree to taking new readings with this kit in place on his iMiev. I'm waiting to get delivery on the thermal switches to make them automatic. Currently, I have turned a switch up in the shop (wrong type for the environment, but right temperature rating) and wired the prototype on my car up with it. Really, really like hearing it kick in and do it's valuable work throughout the whole charge cycle. I haven't caught the end of the charge cycle yet so I don't know how long after the charge ends that the unit continues to run. I'm not worried about that though, only pulling 0.7 amps it doesn't put a dent in the 12V battery while getting cooled down enough to turn itself off.

Aerowhatt
2014 cool silver ES, acquired new 4/2015 (42.7ah at ~26K miles)
2014 Labrador Black Pearl ES, acquired new 3/2016 (41.5ah at ~15k miles)

Aerowhatt
Gold Member
Posts: 425
Joined: Wed Jan 28, 2015 1:52 pm

Re: Supplemental cooling for the charger.

Fri Aug 03, 2018 11:58 am

So a bit of an update. I have had the updated bracket in the car most of the week and working in "automatic" mode. The thermal switches that I ordered for this project are set to arrive in tomorrows mail. :)

So far I'm pretty happy with the function (these are all L2 charges). With the temporary thermal switch, it comes on in the first 30 minutes of charging starting. Only about 5 minutes if it has just been driven with the AC cranking. Then at the other end of the charge it lingers, running anywhere from 20 minutes to 70 minutes after the charge ends before turning off. Definitely making a significant difference in the overall temperature of the unit during charging. Really looking forward to Kiev's imaging comparison for a more quantitative read on internal component temperatures.

VGV7iKdbSc+6z561KUrobA_thumb_178b.jpg
VGV7iKdbSc+6z561KUrobA_thumb_178b.jpg (176.48 KiB) Viewed 135 times


You can just see the blower under the bracket. It is held in place by the channel over the lip of the "hood" opening. And a single bolt in the existing threaded hole on the charger case.
2014 cool silver ES, acquired new 4/2015 (42.7ah at ~26K miles)
2014 Labrador Black Pearl ES, acquired new 3/2016 (41.5ah at ~15k miles)

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