Why is battery heater overheating the motors

[fbitz777]

It's pretty cold today at 21F so I set the charger as destination and I immediately noticed that the front motors (conserve mode) were warming up as I was driving.
I was noticeable because if I canceled the trip then they would cool down
Then I arrived at Superchager and after 5 minutes (time it to to fully warm up the battery) I got crazy temperatures on front motors; see attached
After the battery was warm and I started getting full rate of charge the motors temperature came back down

I know tesla M3 in the past used to use the back motors to warm up the battery but I would not expect this in a Rivian.

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[COdogman]

It’s not overheating the motors according to Rivian.

 

[fbitz777]

It’s not overheating the motors according to Rivian.

It got a little bit higher to the red bar but then the heater kicked off as the battery was warm enough. Not sure about you but that orange warning is obviously high temperature.

 

[R.I.P.]

It's pretty cold today at 21F so I set the charger as destination and I immediately noticed that the front motors (conserve mode) were warming up as I was driving.
I was noticeable because if I canceled the trip then they would cool down
Then I arrived at Superchager and after 5 minutes (time it to to fully warm up the battery) I got crazy temperatures on front motors; see attached
After the battery was warm and I started getting full rate of charge the motors temperature came back down

I know tesla M3 in the past used to use the back motors to warm up the battery but I would not expect this in a Rivian.

Normal behavior for a quad. What's interesting, is that I'm not seeing it in the DM units.

There are some theories floating around as to why this is, but still in the watching phase...
?

 

[COdogman]

It got a little bit higher to the red bar but then the heater kicked off as the battery was warm enough. Not sure about you but that orange warning is obviously high temperature.

I understand why you would think that based on the graphic, but others have seen this and Rivian told them there is nothing to worry about. You can ask them yourself if you need to hear it from them. ??‍

 

[fbitz777]

Next time I'll use the normal mode instead of conserve...the back motors started at only 55F and it took energy to warm it up.

 

[Donald Stanfield]

I think the current speculation is that Rivian is using the motor heat to precondition the battery pack for fast charging. It's more efficient than using the resistive heater and the coolant is used to warm the battery.

 

[W1SE]

It's pretty cold today at 21F so I set the charger as destination and I immediately noticed that the front motors (conserve mode) were warming up as I was driving.

For those that don’t know. Rivian (and tesla) use a coolant (which in this case I guess is also a heatant) fluid that runs between the motors and the battery. When it wants to warm the battery faster (ie to charge) then it puts resistance in the motors to heat them up. So the fluid gets warm and moves the warmth to the battery.

This is what the motors have been doing for the last 2 years on all rivians ever manufactured before we had a motor temp gauge.

so my take away, If there is no warning lights on the driver screen don’t make changes to your normal habits. The temp gauge in the infotainment screen is “infotainment”

 

[SeaGeo]

For those that don’t know. Rivian (and tesla) use a coolant (which in this case I guess is also a heatant) fluid that runs between the motors and the battery. When it wants to warm the battery faster (ie to charge) then it puts resistance in the motors to heat them up. So the fluid gets warm and moves the warmth to the battery.

This is what the motors have been doing for the last 2 years on all rivians ever manufactured before we had a motor temp gauge.

so my take away, If there is no warning lights on the driver screen don’t make changes to your normal habits. The temp gauge in the infotainment screen is “infotainment”

This. It's not throwing a warning message, don't worry about it.

 

[VSG]

I agree with all the advice about not paying too much attention to the graphic and not worrying about the heat unless your vehicle tells you there's a problem. And I agree with all the explanation about how the vehicle is using the motors to generate heat for the battery (and also, IIRC, for the cabin heating too!).

HOWEVER.

Your graphic shows only 1 out of 4 motors getting hot. I find that weird. Every other graphic I've seen shows the the motors acting symmetrically. If you have it in Conserve, then I would expect only the two fronts to get hot, but I would expect BOTH of them to get hot. If you have it in AWD, then I would expect all 4 to warm up.

So, I don't think it would hurt to contact service about just this ONE motor heating up - stress that your concern is that's it's just ONE motor. This might be an early sign of a stuck valve on the cooling system that might lead to drive system failure down the road.

 

[emoore]

Next time I'll use the normal mode instead of conserve...the back motors started at only 55F and it took energy to warm it up.

You’ll still see it in AP mode too. It’s fine.

 

[Jared2]

I noticed this on a long drive as well. As soon as I told it I was going to stop at a DC charger, I saw the temp in the front motors spike up to almost 300 degrees. I switch to AP mode to divert some of the heat/power, and I was right, it did raise the back motor temps and lower the fronts.

With temps now dropping in the north east, I saw a snowflake symbol for the first time and a notice saying “acceleration and regen will be limited until battery is warmed up” (something like that). So my question is: is there a way to warm up the battery remotely so it’s ready when you get to the vehicle like you can to the interior?

Thank you all again.

 

[R1Tom]

What I do is calculate time to charge my battery and start the charging that much before my scheduled departure time.

Not only does this maximize range, and the heating energy comes from the external power source, but it also saves energy, as the waste heat of charging isn't lost to the environment prior to departure and then need to be recreated with inefficient motor scheme.

Hopefully Rivian automates this for us in future with scheduled departure time. And the throws in cabin preheat to start that at appropriate time.

 

[vandy1981]

For those that don’t know. Rivian (and tesla) use a coolant (which in this case I guess is also a heatant) fluid that runs between the motors and the battery. When it wants to warm the battery faster (ie to charge) then it puts resistance in the motors to heat them up. So the fluid gets warm and moves the warmth to the battery.

This is what the motors have been doing for the last 2 years on all rivians ever manufactured before we had a motor temp gauge.

so my take away, If there is no warning lights on the driver screen don’t make changes to your normal habits. The temp gauge in the infotainment screen is “infotainment”

I predict that motor temps will disappear in the next update. This is obviously TMI given the number of posts we're seeing about motor temperatures. At the very least they shouldn't have used more soothing colors for the temperature bar.

 

[R1Tom]

I predict that motor temps will disappear in the next update. This is obviously TMI given the number of posts we're seeing about motor temperatures. At the very least they shouldn't have used more soothing colors for the temperature bar.

Or not make stuff turn colors at all?

It's not the information at fault...it's the presentation.

I can't think of another gauge in any vehicle I have owned that had a line not to cross or had something turn color, but driver should ignore in certain instances, with no explanation as to when those instances where.

I hope they don't pull the info. I love info. I want to know the battery temp when warming too.

And I'd love to see a full schematic of powerflow on screen including cabin heater, etc....

So hopefully Rivian recognizes it isn't TMI, but rather just an oversight that the gauges and graphic are turning colors when they shouldn't be.

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