Page 1 of 5

Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 3:43 pm
by Danl
I Have a 2013. I am doing some experimenting with battery temperature and I think the cabin air exhausts down into the Battery area.

If this is true, I am amazed that someone has not found it before in order to cool the battery and therefore prolong its life.

What I did was to turn on the AC set at 73degF with the fan running full. It is set to outside air input and then I rolled all the windows up. I did this with an L2 charge happening at the same time.

First I checked Leafspy. 4kw going into the charger. 2.5kw going into the battery. so we have 1.5kw going into the AC. After 15 minutes or so, the AC power drops to about 0.75kw. Also I see T1 is the lowest temp. Without AC T1 is normally the highest.

Then look for warm and cool airflow around the car.
The radiator fans are running. Hot air is blowing out over the front tires.
The cabin blower is running. it is sucking air in at the bottom of the windshield.
The cool air exhausting from the cabin appears to be coming out around the battery shield.

I have data logging going on LeafSpy so later I will chart the temps and see if the battery is being cooled.

This is important Because this gives us a tool to cool the battery during charging and therefore increase the life of the battery.

Has anyone else seen this?
Am I crazy, or has this been available but Nissan has not given us instructions on how to improve the battery life?

Thanks,
Dan

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 5:28 pm
by knightmb
I take it this would only work with the "fresh air" setting and not "recirculate" setting? You can get right into the battery from the safety disconnect fuse in the center, I've often though about running a tub down into it to force cool air into the battery compartment. :)

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 6:25 pm
by Danl
knightmb wrote:I take it this would only work with the "fresh air" setting and not "recirculate" setting? You can get right into the battery from the safety disconnect fuse in the center, I've often though about running a tub down into it to force cool air into the battery compartment. :)
Hello Knightmb,
Yes, you are correct. Run in Fresh air mode all the time. Then turn on the cabin fan while charging.

No, you do not need to run a tube, the Leaf is already plumbed for the cabin air to exhaust into the battery area.

Thanks,
Dan

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 7:05 pm
by LeftieBiker
It might explain why some cars do much better than others in similar situations and locations. I *always* use the A/C if it's Hot, and while it's often on Recirculate, when I switch to Fresh (which do regularly while driving) that would blow extra chilly air down around the battery cases...

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 7:13 pm
by Danl
Image

Here is todays data.
You see that during the last charge T3 stayed level and did not climb as it had done in the first charge of the day when the AC had not been on.

Thanks,
Dan

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 7:18 pm
by Danl
LeftieBiker wrote:It might explain why some cars do much better than others in similar situations and locations. I *always* use the A/C if it's Hot, and while it's often on Recirculate, when I switch to Fresh (which do regularly while driving) that would blow extra chilly air down around the battery cases...
Yes, I would advise never run in Recirculate. The cool exhausted cabin air is of more value to cool the battery than the cost to cool down new air coming into the cabin.

In addition I would advise running the cabin fan with the windows up even when the AC is not needed.

Thanks,
Dan

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 7:36 pm
by LeftieBiker
Yes, I would advise never run in Recirculate. The cool exhausted cabin air is of more value to cool the battery than the cost to cool down new air coming into the cabin.

In addition I would advise running the cabin fan with the windows up even when the AC is not needed.

I use Recirculate to block exhaust fumes more than as an energy saver. I still have 12 bars and 89% SOH, and my lease is ending in the next 12 months, so I'll keep up what I'm doing. If this info proves true, it will help those who regularly avoid A/C use to extend range, to reconsider.

Re: Cabin Air Cooling the Battery

Posted: Wed Jul 20, 2016 8:23 pm
by Danl
LeftieBiker wrote: I use Recirculate to block exhaust fumes more than as an energy saver. I still have 12 bars and 89% SOH, and my lease is ending in the next 12 months, so I'll keep up what I'm doing. If this info proves true, it will help those who regularly avoid A/C use to extend range, to reconsider.
Yes, I use Recirculate when I get on a gravel road and then turn it off when the dust clears.

Re: Cabin Air Cooling the Battery

Posted: Thu Jul 21, 2016 9:36 am
by knightmb
Danl wrote:Image

Here is todays data.
You see that during the last charge T3 stayed level and did not climb as it had done in the first charge of the day when the AC had not been on.

Thanks,
Dan
Now that is fascinating for sure! I can actually run some data logging on LeafSpy because my Charger Connection and Office Window are right next to each other. So I can run LeafSpy from my Phone inside the office (bluetooth link can reach just far enough for LeafSpy). I'll see if I can get the same result. :mrgreen:

Re: Cabin Air Cooling the Battery

Posted: Thu Jul 21, 2016 10:44 am
by Stanton
You are full of surprises @Danl! I don't remember this phenomena being discussed much way back, but there's one thing I would like to see (with all of your data actually): hotter ambient temps (like 100 degrees). If this method can drive a 7TB event to a 6TB event (or even lower), that would be a big benefit to the battery pack.