High charging time on a brand new 2020 Prime

That's exactly what I've been thinking lately. Beside possibly being more accurate, it would be more convenient to me since I don't very often use all my EV range. Since the charge rate tapers off toward the end of charging, it might be most accurate to charge from a low SOC to minimize the impact of any posssible difference in ratio between energy put into the battery an energy put into other loads.

I'm sure it does increase the amount of energy required to charge the battery.

 

The cooler switch is harder to find in the settings than the Traction Pack Heater is, but as you can see it's another option available to those who want to use it.

 

So you actually found it. The manual gave the impression there wasn't one; just the pop up at shut down on hot days.

 

It took a couple years to find it. When I went to switch it off 6 months later it was not easy to find again.
I'm not surprised Toyota didn't list it in the manual in an easy to find way either or, if at all.
So many toys to choose from on the dash.

 

I think the photo you posted on #42 is from the customization section of the setting. It is not ON or OFF for the traction battery cooler, but rather the ON or OFF for the notification for the Traction Battery Cooler that comes on the MID when the hybrid battery is above a certain temperature and the power switch is turned off. See the diagram from the manual at bottom.

There is an explanation of this customization setting in the manual. In essence, selecting NO on this customization will disable the notification and the Traction Battery Cooler implementation, but selecting YES will not automatically turn on the Traction Battery Cooler. It enables MID notification and you still have to pick Yes to enable the Traction Battery Cooler. To this day, I have no idea why Toyota programed the Traction Battery Cooler usage this way. It almost seems to be by default, they don't want us to use the traction battery cooler. Setting the customization menu to Traction Battery Cooler OFF will disable this vital functionality by an operator, but why?



on P. 247 "Meter Customize" settings

 

Plus, if memory serves - that popup setting on the mid is something like 5 seconds, barely enough time to read, understand and push the correct button to accept unless it's already been seen a few times and one is quick enought to get to the button. lol
for me " once every blue moon" ymmv

 

Correct. In my PP2017 the customization setting was set to "OFF" from the dealer, thus I never saw the traction battery cooler notification pup-up on my car for the first two years. When I was reading about this functionality here, I got curious but I dismissed the reason I have never seen the "pop-up" is because I live in such a cool region the car never needed this functionality. But when I checked the setting, I found that was not the case. It was disabled to show the pop-up. After I enabled the pop-up in the setting, I did actually saw the traction battery cooler pop-up a few times during summer. However, in my case the traction battery cooler was never used on my car for I have never charged my car when the traction battery was that hot. By the time I did routine nightly charging, the temperature was well below the threshold of the traction battery cooler needs.

 

I enabled that cooler notification as soon as I spotted it in the manual, which was pretty soon after I got the car. Still, it popped up several times before I got the idea through my skull that I had to just know that's what it said and hit "yes" instantly. As you said, if you take the time to read it, you took too much time. I use that thing every day in the summer and very often the rest of the year. I REALLY wish it could just be left on.

 

Especially in your region. I can't understand the reasoning behind why this feature, "traction battery cooler", is not set to ON all the time by default. I can't think of a single reason why the owner input is needed to decide the use of the traction battery cooler when the temperature of the battery pack is high enough that it needs to be be cooled. Luckily I live in area not needing this feature often, and with my routine charging at night, this feature is not needed, but still, if the battery need to be cooled, it should be cooled regardless...

 

Exactly!! And I charge in the afternoon at work several times a week. It's in the shade, but it's still much hotter than in the morning.

 

Similarly, I don't understand the logic behind allowing the owner to turn off the traction battery heater. I have never tested this, but if the traction battery heater is turned off from the charge setting, and if the traction battery temperature is below freezing (or whatever the temperature that is set to turn on the heater if enabled) when the charging is carried out, I am hoping that the car will know not to start the charging until the temperature is up in the safe range. This is much more relevant situation for me but may not be so much worry for you. In any case, at least for the battery heater, it can be left to be ON all the time unlike the battery cooler feature.

 

A hypothesus put forward here is that it isn't really about cooling for the battery, but to counter the extra heat charging will add to the cabin on a hot day. As it is, it will only be an option to turn on when it is already hot out. No way of operating it if it was cooler when you left the car. In which case, the car will simply delay charging. It does have that ICE back up, in the event it isn't done charging.

I'm starting to think it was an afterthought to the design. Any testing would reveal that the pop up needs to be up longer for most people.

While heat is bad for the pack, it is bad in an extra wear sort of way. Not permanent damage way like if charged while frozen.

I think it is for saving energy if the car wouldn't be used for a period. Like turning off the SKS on older models. It might even run off the 12volt when not plugged in.

The car shouldn't charge at those temperatures, but it might work like the PiP, which didn't have a battery heater. Charge at an extremely slow rate until the internal resistance heats up the pack enough.

 

Your hypothesis for the battery cooler being primarily for the cabin temperature comfort is believable one, but I have no idea how one would test the hypothesis. Needless to say, it can be left to be permanently OFF position like my car was at the delivery, so I assume no big harm is done, I hope, by not using this feature.

My understanding is that, the battery heater operated only if the charge cord is plugged in and if charge is scheduled to carry on. It operate only immediately before or during the charging, but not after the charge has been completed. Toyota recommends not to keep the charge cord left plugged in after the charge, and leaving it plugged in for a long period still should not turn on the battery heater unless the battery is actively being charged. So, I don't understand how not using the safety measurement of battery heater not to damage the traction battery under freezing condition is an energy-saving feature???

 

The battery heater also runs at some ready point after charging to have the battery prepped for use. Haven't seen exact details of what temperatures these are, but think block heater for the engine. In the US, it can be on for three days since charging. In Canada and Alaska, up to a month.

 

Yeah, I've read a very vague explanation of that functionality in the manual, but I have not seen or heard any evidence of the battery heater running after the charge is completed. I also have not seen or heard of a PP from Alaska or Canada behaving any differently from the PP sold in the lower states. What the hell does it mean to "insulate the hybrid battery" beyond 3 days. Toyota explicitly recommends not to keep the charger connected after the charging is completed, and also recommend not to keep the car fully charged for a long time. Connected to a charger cord for 30 days is a sure sign that the car is not being used for a long time. This winter, I may try connecting my PP with the charge cord but not scheduling any charging for 3 days to see if the traction battery temperature changes above ambient temperature by the Traction battery Heater function. But, until I see evidence that the battery heater is doing something other than pre-warming the battery pack before active charging, I am not convinced that it does anything else.

 

Yeah, it is vague. The 3 days bit can be taken to mean the heater will run when needed during that time until the battery charged. It keeps the pack above 0C during that time, and ready to be charged. After 3 days, it turns off, and if charging is required then, it will take longer as the heater has to come back on first.

The risk of battery damage at 0C happens during charging. I have not read of any warning for discharging at that temperature, but there might be such risk at even lower temperatures. Or the performance at such temperatures is so poor as to have an obvious impact on the car's performance. That could be the why of the Canadian function. Sounds like it will start charging regardless of the time setting when temperatures drop that low. perhaps it is to prevent literal freezing of the electrolyte when the battery is in a depleted state.

Temperature has an impact on the state of charge. When heated the battery's effective charge increases some. It's a chemical reaction going on the battery, and those reactions go faster when things are warmer. The opposite happens when it gets cold; the effective charge drops. Early Leafs had problems in hot climates because the fully charged batteries were going into an overcharged state in addition to the other issues heat brings.

Toyota's warning against keeping the pack charged is to avoid the Leaf issue on those hot days. While it isn't the best thing to sit fully charged at any time for longevity, in an area with freezing temps, the battery is being chilled in storage, which helps with longevity.

 

Well, you are correct that the manual does say the following (highlighted).

This winter when we have a stretch of 3 days or longer cold days with the temperature well below 32F of the day high, I am going to try connecting the charging cable for 3 days or longer without driving the car and see if the traction battery does indeed get heated when not being charged after the battery charge is completed. I should be able to monitor both the wall draw of electricity and the temperature of the traction battery compared to the ambient temperature for the duration.

This experiment should be enough to demonstrate the Traction Battery Heater functionality.