Traction battery Cooler

I did an experiment today. When I left work the battery was toasty from charging in the sun, and on the way home I could hear the battery fans. When I parked it asked if the traction battery cooler could be used. I said yes, but I didn't plug in until two hours later. Now, five minutes after plugging in I can hear the AC running, so that shows the traction battery cooler can work even if charging starts a while after you park. I'm not sure if it will work with scheduled charging.

I ordered an OBD reader, so hopefully I can figure out at what temperature the battery cooler comes on and by how many degrees it cools the battery.

 

It took me a while to realize that the "Charge Now" thing is simply a poor translation that should read "Ready to charge", "Charge at will", or something along that line. What I believe it's saying is that there is no charge schedule set, so you can charge it "now" -- as in, "whenever you want". The clue is, it's the same even if the battery is 99% full. A friend was in the car and saw it come on after we'd driven around the block, and asked, "Why is it telling you to charge it right now? Is it empty?" No, it was pretty much full. I figured it was saying "there's nothing scheduled, so just charge it whenever you want". They translated it as "charge now".

I've never set a charge schedule because I have flat-rate power. I imagine that if I had a power plan with peak vs. off-peak rates, it would make sense to schedule it for off-peak charging times. Since I don't, I just plug it in whenever I get home.

 

Charge now will immediately start a charge if the battery is not full. You should only see this message if there are schedules set. If there are none, the car will charge immediately on plugin.

 

My experiment #2 worked as planned. I will verify experiment #3 when I have a chance but you could be right.. all my experiments with the keyfob should work.

It looks like that 5 seconds pop up display should be the one that we all should be using.. if we acted fast enough.

I found this thread and stated about insulated garage Prime doesn't give me opportunity to select traction cooling | PriusChat

I think it is a catch 22. To cool the traction battery will heat up my garage+house if attached potentially fire hazards. I think the cooling part is better if it was parked outdoor.

 

Did anyone else catch that it won't cool the battery if there is less than a certain amount of charge in the hybrid battery? I usually only charge when the battery is empty. So basically this setting doesn't apply to me? It's only for top-up charges?

 

I've definitely seen it work when I plug in with the battery empty, at least on a level 2 charger. I pulled up to a chargepoint station in HV mode. I sat there for 30 minutes. It charged for 5 minutes then ran the traction battery cooler for 25 minutes (until I got bored and stopped it so I could go home). In that time it consumed 1 KWh, and I ended up with about 2% charge. Oddly enough the charger wasn't supplying power to the car the whole time.

Pressing the button on the key fob won't work if the battery is empty, but that isn't intended to cool the battery.

 

The traction battery cooler function only when the car is plugged in. It should work even when the EV range is zero. That said, I have to admit that I have never used the traction battery cooler on my car. It never gets that hot where I live and I do charging overnights when it's even cooler.

 

It's just what it says in the manual: Traction battery Cooler

 

It sounds like there are some conditions when it won't run, but in practice it will usually work if you plug in after driving in HV mode. Maybe if you're really low in the usable HV mode capacity it won't run.

 

If you have the Advanced Prime, with the Entunes Charge management, you could also select preconditioning as part of the charge. I’ve used it but this relies on the last setting on the HVAC.


iPhone ? Pro

 

That isn't to cool the battery (though it might help some). It's only intended to make the cabin comfortable when you get in.

 

Your first two experiments are standard procedure for me. I love that I can precool the car before I get in, while it's still plugged in. Really makes a difference in the EV range when I don't have to blast the A/C to cool down the cabin while starting my drive. As to the warm garage, I never run the A/C long enough to make any appreciable difference in the garage temperature (which is typically about 95F in the afternoons this time of year), but it does seem to make it a little warmer.

 

That’s not entirely accurate. Check pages 91 and 562+ of the owner’s manual. There are no separate cooling/heating systems that interact directly with the battery. It is strictly from the cabin air. The fans on the battery housing directly draw air from the cabin to the battery. Toyota has always assumed if you are comfortable then so is the battery.

Also checkout all the Weber University videos on disassembly of the Prime battery. You’ll note there are no cooling/heating subsystems to disconnect when taking the battery out. If you have any further doubts, consult with @john1701a and/or his site. I’ve forgot if he shows a separate animation on the cooling/heating system for the battery.


iPhone ? Pro

 

I know that. The traction battery cooler cycle is specifically designed to cool the battery as effectively as possible. It runs the AC as cold as it goes for 30 minutes and runs the battery fans much faster than normal. Pre-conditoning with the fob or the app runs the AC for 10 minutes to whatever temperature you have it set to, and it doesn't change the speed of the battery fans. If it's not plugged in, I don't think the battery fans will run at all during pre conditioning.

Cooling the battery with the AC from the cabin is a pretty weak way to cool it, so it probably takes the whole 30 minutes to make a difference. Yesterday I parked at a free charger for 15 minutes while I ran an errand. When I got back I could hear the AC running for the traction battery cooler cycle. But when I got in I turned the car on and back off 15 seconds later. The traction battery cooler message still popped up, meaning the battery was still hot.

It's the same reason why the battery gets hot if you're driving and have the AC set to a comfortable temperature. It doesn't prioritize cooling the battery unless it's running the traction battery cooler cycle.

 

Any time I’ve ever charged it, I’ve heard the battery fans run, even in winter.

Takes quite a bit to cool off a self heating 265 lb mass. Toyota designed the battery to be heat tolerant but it is pretty aggressive about using the cooling fans. It will tell you when it’s time to clean the filters in the seat vents because it’s reliant on those for cooling.


iPhone ? Pro

 

I think with AC on and windows down is the best circulation to the traction battery while driving and fast inhale to it too

The seat vents fan will not turn on if not charging so AC on, windows up.. very little air to the traction battery.

Toyota seriously need to fix the pop up display to allow AC while charging. I will mention that next time I take it in for service. I doubt they will know as this is not new and not done anything about it for 2017/2018 Prime. Unless this is fixed in 2020 version?

Japan is hotter in the summer compare to NA, why they didn't implement it? Why just have heat selection option in the menu only

 

Recently Anchorage, Alaska was warmer at 90F than Sacramento at 80F, in the normally hot central valley of California .

 

Actually japan's all time record is 106F, we have lots of places that get that hot and hotter in the U.S....

 

late to the party here. I slogged my way through four pages of this thread trying to figure out how to respond to the Traction Battery Cooler message (yes I read pages 127 and 128). What is the "safe" default mode? What do I press before the message disappears seemingly 2 seconds later, if I had to change for one time?

One of the messages mentioned an 8 amp or 12 amp charge rate. As car is always charged at night I would like to find the screen(s) to lower charge to "gentle" 8A if available. I am using L1 120V 20A dedicated outlet if that enters equation. (what page would I find this information?)

As an aside, the owners manual index really needs improvement and more topic entries.

 

You should say yes every time you see the message (unless you need it to charge in the next 30 minutes for some reason). If you ignore it, it seems to default to no, which is stupid. If you need to get it to come back, turn the car back on, put it in drive, and roll forward a foot or two.

The 8A screen is buried in one of the many settings menus. But the default 12A is pretty gentle already. I don't see much increase in battery temperature while charging, especially at night or if the cabin is cool.