Charging and Console behaviors - thoughts?

[spkobay]

Hello all. I'd like to impose and ask for your comments. I have a few items that seem "off" from what I expect and have been bothering me for a while. Since I haven't a second RAV sitting in the driveway, I figured I'd float them to you.

1) During charging, the coolant pump cycles on/off (good); however, NEVER has the radiator fan cycled while charging - even on a hot SoCal day (100 today). How is it supposed to dump the heat from the coolant without the fan? The fan will cycle during AC use while the car is running. So... is this something that needs to be investigated or is this normal behavior on your RAV too?

2) On the driver console/multi-info display, select AUX Power. For me, this rarely moves and is more or less useless. The consumption indicator rarely bounce up more than a quarter inch - even with heavy heat or AC use. Similar for you too?

3) Does item #2 play into this calculation or is it just one of those bothersome GOM things? Assuming I start with a standard charge and turn on AC in eco-lo. The multi-info "Driving Range" will show a hit of ~3 miles. Assume I drive 90 miles during the next 2 hours. After 2 hours of use, and during a follow-on trip, I turn on the AC in eco-lo and I will indicate the same ~3 mile hit. Dont focus on the GOM portion of the equation, but look at the time relation. The calculation is assuming that I'll use the equivilent of 3 miles of energy during a 2 hour drive and will also advise that I will use the equivilent of 3 miles of energy during that remaining ~15 minutes of usage time. So... is this a bad algorithm that can be ignored (and results in another useless screen) or... Is the above #2 issue not seeing AC/Heat consumption and accounting for that in the displays?

Thanks... and I appreciate your thoughts.
Sean

 

[eplantz]

2) On the driver console/multi-info display, select AUX Power. For me, this rarely moves and is more or less useless. The consumption indicator rarely bounce up more than a quarter inch - even with heavy heat or AC use. Similar for you too?

3) Does item #2 play into this calculation or is it just one of those bothersome GOM things? Assuming I start with a standard charge and turn on AC in eco-lo. The multi-info "Driving Range" will show a hit of ~3 miles. Assume I drive 90 miles during the next 2 hours. After 2 hours of use, and during a follow-on trip, I turn on the AC in eco-lo and I will indicate the same ~3 mile hit. Dont focus on the GOM portion of the equation, but look at the time relation. The calculation is assuming that I'll use the equivilent of 3 miles of energy during a 2 hour drive and will also advise that I will use the equivilent of 3 miles of energy during that remaining ~15 minutes of usage time. So... is this a bad algorithm that can be ignored (and results in another useless screen) or... Is the above #2 issue not seeing AC/Heat consumption and accounting for that in the displays?

#2 the manual says AUX is usage of the 12V battery. Mine rarely shows anything and I assume the AC does not run off 12V.

#3 my difference with AC on is usually 5 miles. I think it "learns" from recent trips and therefore will "assume" you will get the same next trip.

Gene

 

[TonyWilliams]

#2 the manual says AUX is usage of the 12V battery. Mine rarely shows anything and I assume the AC does not run off 12V.

The AC is powered by high voltage DC directly from the main traction battery.

 

[Ampster]

.........
1) During charging, the coolant pump cycles on/off (good); however, NEVER has the radiator fan cycled while charging - even on a hot SoCal day (100 today). How is it supposed to dump the heat from the coolant without the fan? The fan will cycle during AC use while the car is running. So... is this something that needs to be investigated or is this normal behavior on your RAV too?
.......
Sean

My only guess is that the batteries don't generate as much heat when charging as the AC does when cooling the cabin. Also I think the onboard chargers can modulate amps based on battery temps, although I have not witnessed it happening. I have confidence in Tesla's temperature management system so I don't worry about it . Somewhere on this forum someone did comment the the car can get pretty hot under the hood when charging.

 

[ToddR]

#2 the manual says AUX is usage of the 12V battery. Mine rarely shows anything and I assume the AC does not run off 12V

So WHY do they need full size and weight car battery? You would think one of those power outage / emergency light batteries would do.

 

[miimura]

#2 the manual says AUX is usage of the 12V battery. Mine rarely shows anything and I assume the AC does not run off 12V

So WHY do they need full size and weight car battery? You would think one of those power outage / emergency light batteries would do.

When the car is off the 12V battery is used for all standby operations. SmartKey, 3G connectivity for remote apps, etc. all use standby power. If you leave the car parked for an extended period, the 12V battery will be drained. I don't know the amount of time it will take, but it's probably between 2 weeks and a month. After that, you will need a "jump" to start the car. So, making the battery smaller would just reduce this time to an unacceptable level.

 

[EVBill]

Regarding #1: I installed a temperature gauge a few weeks back and observed that the radiator fan comes on at 137 degrees F coolant temperature. This occurred whenever I charged my car at home. During charging the temperature rises to 137, fan comes on and stays on until 117 degrees at which point it turns off. Depending on my garage temperature the fan would stay on roughly 5 minutes or less, and it would take another roughly 30 minutes to get back up to 137. Every time I charged the car it would always go thru this cycle with the fan going on and off, garage temperatures have been in the 80s-90s.

However, today I was charging at a Chargepoint station in the afternoon. When I got back to my car it was still charging and the temperature was 145 degrees F, and the fan was not on! This is definitely an anomaly from what the standard has been. I'll charge it at home this weekend where I can monitor it more closely to see if the fan comes on. If it doesn't I'll take it to the dealer to check out the thermal management system, perhaps a sensor went out.

 

[spkobay]

Thanks for the comments... Ampster - I do have confidence in the general Tesla design; however, as EVBill eludes, a sensor could always go bad or provide false readings. I don't have a temp gauge installed, but I'll use my infrared thermometer to keep a closer eye this weekend when I do some daytime charging. It'll be over 100 outside here in LA.

 

[EVBill]

Charged at home yesterday and the fan came on normally, with the coolant temperature not exceeding 135 degrees, so not sure what happened last week at the Chargepoint station when it went higher without the fan coming on.

Here's what I observed: temperature outside was 92, coolant temperature was 106 when I started charging (was driving for about 30 minutes prior to charging). Took 45-50 minutes for temperature to go from 106 to 137 at beginning of charging, garage temperature was high 80s. The fan came on at 135 and it took 2.5 minutes to go to 117, at which point the fan turned off. After that it took 10.5 minutes to go back to 135 and the fan came on again. It continued like this for the 3 hours I charged it, very consistent with the temperature going from 117 to 135 and the fan turning on every 10-11 minutes.

 

[spkobay]

So I was finally able to witness/verify that the fan is indeed cycling during charging. Unlike EVBill (and like most in this forum), I have not installed an inline temp gauge so I had to resort to using an infrared/laser thermometer to get the temp from the coolant line. Since I'm measuring the exterior of the line and not the coolant itself, it's not quite as accurate but passable enough.

We had a nice a toasty day here in the LA area yesterday (going to be like this all week too - ugh). It was just a little under 100 when I got home so decided to take advantage of the temp and charge. Set an immediate charge and popped the hood so that I could get temps. For a little over an hour I witnessed the pumps cycling on and off but no fan. The highest temp that I could find on the coolant line was topping at about 139... with no fan. I'm thinking this is not right, I probably have a bad temp probe and need to make a service call. Then realizing the time and that we needed to head out for dinner plans, I dropped the hood to get ready to go. At this point the variable speed fan comes on low/slow and quiet and then quickly ramps up to full tilt.

Lessons... The fan will cycle with the car turned on and AC on - even if the hood is up. So as to not unexpectedly surprise someone under the hood, there appears to be a safety switch to disable the fan with the hood open and the "ready" off (I popped the hood a couple times to verify and the fan cut out as soon as the hood opened). It would appear the fan has been cycling all along for me, but has been able to maintain the necessary temps running at low speed. As such, I wasn't hearing the fan run and wasn't seeing it run when I popped the hood.

Final lesson... A watch pot doesn't boil and apparently a watched fan doesn't spin. Anyway, thanks everyone for the feedback/comments.

sk

 

[TonyWilliams]

... The fan will cycle with the car turned on and AC on - even if the hood is up. So as to not unexpectedly surprise someone under the hood, there appears to be a safety switch to disable the fan with the hood open and the "ready" off (I popped the hood a couple times to verify and the fan cut out as soon as the hood opened). It would appear the fan has been cycling all along for me...

I guess we need to find that switch!

 

[EVBill]

The hood latch goes into an assembly when closing the hood, in that assembly there is a "switch" that is visible and appears to open and close with the closing and opening of the hood. I experimented with putting a small piece of plastic between the contacts with the hood open to simulate the hood being closed, however this did not do the trick. The only other possibility is a switch in connection with the cable that goes from the handle you pull to open the hood, tight/slack cable possibly changes the state of a switch.