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Re: Supplemental cooling for the charger.

Posted: Fri Aug 03, 2018 2:24 pm
by PV1
Has anyone done temperature measurements on a reduced current level 2 charge? Does charging at 12 or 10 amps reduce the generated heat in the charger?

Re: Supplemental cooling for the charger.

Posted: Sat Aug 04, 2018 11:12 am
by Aerowhatt
PV1 wrote:Has anyone done temperature measurements on a reduced current level 2 charge? Does charging at 12 or 10 amps reduce the generated heat in the charger?



As designed the OEM cooling system delivered the following results.

Under L-2 the case temperature peaked at 56F above ambient temp.
Under L-1 (12 amp) the case temperature peaked at 48F above ambient temp.
So charging L-1 only delivered a ~15% decrease in charger temperature rise.

I didn't check the temps at 8 amps L1 since I don't consider it a useful charge rate for our needs. Plus the high percentage of power going to overhead "vampire loads" rubs me the wrong way. Presumably 8 amp L-1 would run some cooler than 12 amp. I wonder though if that matters much though since most components are rated in "Mean TIME between failures". And L-1 runs the unit much longer than L-2 for each recharge?? I'm not sure that most people have the ability to do a lowered amperage L-2 charge but it seems as though the results would be similar to L-1.

Aerowhatt

Re: Supplemental cooling for the charger.

Posted: Sat Aug 04, 2018 2:37 pm
by JoeS
Aerowhatt wrote:...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.
Aerowhatt, looks like a nice clean install. Speaking of clean, is that compartment merely the result of vacuuming?

Re: Supplemental cooling for the charger.

Posted: Sat Aug 04, 2018 5:17 pm
by kiev
The 2014 OBC looks different than the 2012--is there a small EMI filter box bolted to the lid toward the rear of the car?

If you get a chance to open the cover and snap a picture it would be interesting to compare the interior.

Re: Supplemental cooling for the charger.

Posted: Sat Aug 04, 2018 6:41 pm
by Aerowhatt
JoeS wrote:Aerowhatt, looks like a nice clean install. Speaking of clean, is that compartment merely the result of vacuuming?


Thanks JoeS, I think the brackets still look handmade . . . likely because they are handmade. It's a nice sturdy fit though.

As for the cleanliness under the hood. I've always done all of my own mechanic work on vehicles. They are just a lot easier and more pleasant to work on if kept reasonably clean. I use a low pressure compressed air stream to blow out of the bottom everything that that a vacuum with a soft brush can't reach. Then finish off with a slightly damp cloth or paper towel to wipe the obvious culprits. It only takes about 15 minutes per car and once every 6 months is plenty often enough in this climate.

Aerowhatt

Re: Supplemental cooling for the charger.

Posted: Thu Aug 09, 2018 3:38 pm
by jray3
Hey Aerowhatt, could you post a materials list and perhaps a drawing of your fan bracket? I'd like to get that cooling mod made while the weather is still so hot.

Re: Supplemental cooling for the charger.

Posted: Fri Aug 10, 2018 5:01 pm
by Gorfllub
Here is a thought to improve cooling performance.

Use an additive such as water wetter.

It definitely increases heat transfer both into and out of the coolant.

It's inexpensive and requires no setting up of any fans or anything.

Its not going to a be a life changing improvement, but it will indeed be an improvement.

I am definitely going to do it now that I think of it.

Re: Supplemental cooling for the charger.

Posted: Fri Aug 10, 2018 5:31 pm
by Don
Great idea!!

They claim an improvement of as much as 20 degrees, which in our case is a pretty significant improvement. One bottle should do 2 or 3 cars. I think I'll be doing it also. Every little bit helps!

https://www.redlineoil.com/waterwetter

Don

Re: Supplemental cooling for the charger.

Posted: Fri Aug 10, 2018 7:55 pm
by Aerowhatt
Don wrote:Great idea!!

They claim an improvement of as much as 20 degrees, which in our case is a pretty significant improvement. One bottle should do 2 or 3 cars. I think I'll be doing it also. Every little bit helps!

https://www.redlineoil.com/waterwetter

Don


"Reduces or eliminates bubbles or vapor barrier that form on hot metal surfaces to reduce coolant temperatures by up to 20°"


Yeah pretty unlikely that this will make a difference at the coolant temps on the iMiev. More geared toward the near vaporization temps found in ICE engine cylinder heads.

Aerowhatt

Re: Supplemental cooling for the charger.

Posted: Fri Aug 10, 2018 8:02 pm
by Aerowhatt
jray3 wrote:Hey Aerowhatt, could you post a materials list and perhaps a drawing of your fan bracket? I'd like to get that cooling mod made while the weather is still so hot.


Sure I will do that as soon as I can. Some life complications at present unfortunately. What would be best perhaps a template for the bracket? The blower used is critical a lesser one will not make the cut. I just got those temp switches in yesterdays mail. They came all the way from China which explains why they took so long. How the heck do you sell something shipped for $11. Ship it half way around the world and make any money?? Hope they aren't crap! Testing tomorrow or Sunday hopefully.

Aerowhatt