Question about cooling battery with a/c

Many have, but doubtful if anyone has put more effort or has more practical knowledge and real world data on this subject than @Grit

I've personally noticed an increase in airflow, with or without the A/C on has a positive effect. Have you tried increasing the HV fan speed?

 

did you get 12 years out of the first pack?

 

That's a good point. Moving air transfers heat from what's hotter to what's cooler. If the air blown over the battery is hotter than the battery, it'll make the battery hotter rather than cooler.

 

I do remember a thread on the forum by a member who ran some 4 inch (?) AC silver flex duct from the passenger side dash vent, along the door rests and to the battery intake. Same kind of situation, where he was pretty much the only one to use the car so he wasn't worried about passengers opening the doors.

 

I’m one of those over engineering, take it to the MAX next level kind of guys. If I lived in a climate like the hot part of Arizona where every day is over 100 to 110° And the rising surface air off the blacktop is 125°. I would do just that run a duct from under the passenger air duct outlet to the inlet of my battery fan.
And if you had one of the software interface for your Toyota you could read your battery temperatures. Or if you were like me I have a bunch of wireless temperature sensors and wired for misters that I can actually attach right to battery individual cases and take temperature right off the case of each individual sale at random points that I choose. You can actually set yourself out your own battery monitoring system with a Arduino some simple codes writing high school level little 50 Cent thermistor temperature sensors and some wiring.

 

I was going to suggest a couple of long cardboard tubes from gift wrapping paper, but flex duct is good.

 

The back seat vent is located relatively low though, so convectively the hottest air in the cabin is going to be up near the roof, and as soon as your airflow starts when you get it the car and the A/C is on, it will be relatively cooler air that starts moving through the battery. (The air intake was up above the back seat in Gen 1 and probably picking up the hottest air in the car, but that got changed in later generations.)

 

One of ScanGuage's best features is its always-on (when car is on) nature; no waiting for techstream to boot, no expensive equipment left in car, no phones to get out and turn apps on, etc. It's always there working; no muss no fuss.

Maybe pickup up a wireless cooking thermometer over in the outdoor cooking section.

The AA batteries last a very long time, the wire leads to the wireless transmitter are more than long enough to reach the modules while keeping the transmitter outside the case so you can turn it on/off, change AA's, etc. Most have two probes (for meat and for grill) so you'd have options.

Dang, why didn't I think of this before.

 

That sounds like using a crane to crush a fly to my ears.

Yeah, the fan might blow some hot air over the battery in those first few minutes. But it can't be taking that long to get cool air into the car, can it?

Keep in mind, the seats and plastic may still be scorching hot 10 minutes into your journey but the actual air in the car started getting colder about 5 seconds after you pushed the A/C button, and the air is what the fan & battery care about.

I think I'd want a log of actual, own-car temperature measurements before going all Allie Fox on the thing.

 

I live in the heat (first 100f was back in March) and have found the best long term solution is to find and park in shade+heavy tinting. Downsides: the exterior gets more bird poop so I need to wash it more and I need to get to work early to get one of the few coveted spots. I have not used the new, expensive ceramic tinting but nearly all reports say this is the way to go (including windshield).

Also, liquid cooled packs are the way to go.

 

That would be the one and the same. There are also three (3) additional temperature sensors inside the HV battery case, and Torque can also read those as well. Torque can also override the HV fan, and when used in combination with the A/C will move more cool air through the battery case. Other apps can do this HV fan override, and the curve to implement such would be easier for sure.

 

Not really, some older relatives live across the river who always get an early start and *rarely* run errands past 8am

Best to crack the windows as much as possible if parking outside. On hotter days or after driving for the day, monitor the battery temps, if the battery is warmer than the ambient air then let the battery cool down to match before parking outside, or inside with the windows down.

My routine in a coastal environment that rarely exceeds 85F, is after driving (highway speeds, up and down hills, etc) to cool the battery below 90F before offing the vehicle. This doesn't take that many minutes if the battery is under 110F, and depending on the outside ambient air temps may include using the AC, or just rolling all of the windows down, either way the HV battery fan is set at the highest speed (6) whenever cooling or driving, but not during winter or freezing temps.

I've found that a cabin temp that is comfortable for myself is best for the HV battery, and if I fail to keep the battery on the cooler side it will climb to higher temps and take longer to cool with the AC on. Plumbing the AC would help in those situations no doubt.