Heat generated from under hood while charging

[doug401]

While walking past the front of my garaged Rav, 2 hours into a charge using my newly installed CS-60, I was surprised to feel heat coming from the front of the vehicle. I popped the hood and took a temperature check, 105 degrees. Ambient in my garage was 70 degrees. The circulation pump was running and the coolant stream could be seen flowing at the top of the reservoir... I very nice design feature for a quick visual of pump operation. I then removed the reservoir cap, the "don't remove while hot" warning really translates to "remove me and take my temperature"... 130 degree fluid temp.

All appears as normal operation, but I had never noticed it before. The CS-60 must be making the system work harder. It's to bad that much electricity is wasted as heat.

 

[TonyWilliams]

I'm sure it will get better, but compared to an oil burner??? It's super efficient.

 

[miimura]

If the charger is 85% efficient, there is still 15% of the 40A current draw burned off in heat somewhere. It's like running a hair dryer full blast. That heat's gotta go somewhere.

 

[Ampster]

If the charger is 85% efficient, there is still 15% of the 40A current draw burned off in heat somewhere. It's like running a hair dryer full blast. That heat's gotta go somewhere.

And that same coolant must also pull heat out of the battery pack when it is being charged.

 

[EVBill]

I noticed the same thing. Also noticed that on hotter days the electric fans will come on during charging. I decided to leave the hood open when charging to help the heat escape. Figure batteries don't like heat and whatever I can do to help the heat get out during charging the better.

 

[cjp767]

I thought EVBill's idea to leave the hood open during charging was a good one-- until I saw this in the owners manual-- Section 1-3 charging, page 54. Or page 114/576 of the PDF version from this site...

Under the bullet "Important things to check before charging"
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● The motor compartment hood is securely closed

If the hood is open the electric cooling fans will not operate, raising the temperature of the charger and traction battery. This may increase charging time or cause charging to be aborted.

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It looks like there is a micro switch telling the charging system whether or not the hood is closed.

 

[EVBill]

Thanks for pointing out the owners manual statement. I'll have to reconsider leaving the hood open. Would be nice if coolant temperature was an option to display on the dash.

 

[miimura]

Thanks for pointing out the owners manual statement. I'll have to reconsider leaving the hood open. Would be nice if coolant temperature was an option to display on the dash.

There are 4 coolant reservoirs and separate loops. Which one(s) do you want to see?

 

[EVBill]

The motor coolant reservoir (identified as 2 on page 355 of the owners manual) is the one that really heats up when charging the battery. This reservoir has a hose that goes straight to the radiator. Upon start of charging you can notice coolant flowing thru it.