PreHeat the battery during the winter?

[Craigins]

Sadly, the R1 doesn't appear to use wall power when doing cabin preconditioning. That's a huge miss for me since that was most of the benefit of cabin preconditioning with my previous EVs. Why hit the battery while plugged it!? As for battery preconditioning, it probably doesn't make much sense for short trips where you don't need a ton of range, but it would be really nice to get this done before heading out on a longer / road trip where that first charge your efficiency will suck until the battery warms up sufficiently.

Yes and no. If your vehicle is at the charge limit it will not kick on wall power to heat the cabin.

While charging it will. Go to your charge summary and it breaks out power usage by battery/climate controls/accessory.

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[RivianNowPlz]

The harsh reality and truth is - for people saying preconditioning isn’t worth it, doesn’t affect the car in noticeable ways, etc all just have no idea at all what cold temperatures do to electric vehicles. And by cold, I don’t mean 50 degrees like some here seem to think is cold.

If you left your EV outside in MN in the dead of winter you would wake up being unable to drive. Period. Manual Preconditioning should be a standard EV option for adoption in northern climates. I would believe it to be fairly safe to assume 50%-65% loss of useable range leaving on a cold battery in winter.

Now there is a difference here between a cold battery and one that just needs a touch up. If you’re charging every night and overnight in a garaged area even if not heated you’re gonna be fine but still going to be looking at a 20%+ loss to useable range. By preconditioning in a garage you take any loss of range almost completely out of the equation, my Tesla sees almost no loss of range when fully preconditioned prior to leaving on a trip in the dead of winter. While I haven’t had the Rivian in a lot of super cold mornings, I have been able to test it now in the overnight single digits and I can tell anecdotally that the Rivian will need to be preconditioned in our climates to be usable for anything more than daily trips.

 

[Lawrence-of-Blaine]

The harsh reality and truth is - for people saying preconditioning isn’t worth it, doesn’t affect the car in noticeable ways, etc all just have no idea at all what cold temperatures do to electric vehicles. And by cold, I don’t mean 50 degrees like some here seem to think is cold.

If you left your EV outside in MN in the dead of winter you would wake up being unable to drive. Period. Manual Preconditioning should be a standard EV option for adoption in northern climates. I would believe it to be fairly safe to assume 50%-65% loss of useable range leaving on a cold battery in winter.

Now there is a difference here between a cold battery and one that just needs a touch up. If you’re charging every night and overnight in a garaged area even if not heated you’re gonna be fine but still going to be looking at a 20%+ loss to useable range. By preconditioning in a garage you take any loss of range almost completely out of the equation, my Tesla sees almost no loss of range when fully preconditioned prior to leaving on a trip in the dead of winter. While I haven’t had the Rivian in a lot of super cold mornings, I have been able to test it now in the overnight single digits and I can tell anecdotally that the Rivian will need to be preconditioned in our climates to be usable for anything more than daily trips.

I’m in the Cities as well. I appreciate your comment here. Is your garage heated?

 

[LL75]

The harsh reality and truth is - for people saying preconditioning isn’t worth it, doesn’t affect the car in noticeable ways, etc all just have no idea at all what cold temperatures do to electric vehicles. And by cold, I don’t mean 50 degrees like some here seem to think is cold.

If you left your EV outside in MN in the dead of winter you would wake up being unable to drive. Period. Manual Preconditioning should be a standard EV option for adoption in northern climates. I would believe it to be fairly safe to assume 50%-65% loss of useable range leaving on a cold battery in winter.

Now there is a difference here between a cold battery and one that just needs a touch up. If you’re charging every night and overnight in a garaged area even if not heated you’re gonna be fine but still going to be looking at a 20%+ loss to useable range. By preconditioning in a garage you take any loss of range almost completely out of the equation, my Tesla sees almost no loss of range when fully preconditioned prior to leaving on a trip in the dead of winter. While I haven’t had the Rivian in a lot of super cold mornings, I have been able to test it now in the overnight single digits and I can tell anecdotally that the Rivian will need to be preconditioned in our climates to be usable for anything more than daily trips.

Do you think Rivian heating system and battery capable of doing this? Is this a software update ?

 

[zefram47]

If this is the case, then I don't see any future update for battery preheat like Tesla.

Why would you say that? It's almost entirely a software problem...they just need to have desire to get it done.

Actually the opposite. On long trips it takes about 10 min to warm up then you're good.

If all you take is short trips in the winter, and never prewarm the system, your efficiency will suffer.

The point is you don't need the range, so why bother wasting the energy. Unless you can prove that the energy required whether from the wall or battery to warm the battery is offset by the efficiency lost while driving then it still doesn't make sense. For many short trips, it's almost certainly not worth the energy burn to do it.

Yes and no. If your vehicle is at the charge limit it will not kick on wall power to heat the cabin.

While charging it will. Go to your charge summary and it breaks out power usage by battery/climate controls/accessory.

Meaning it's doing what I said and not using wall power to precondition. If it's already charging that doesn't count. What Rivian really needs is a charge for departure like my MINI had where it aims to complete charging about 30 min before your departure time. That would help ensure the battery is warmer for departure time as well in the winter since charging inherently warms the battery.

 

[LL75]

Meaning it's doing what I said and not using wall power to precondition. If it's already charging that doesn't count. What Rivian really needs is a charge for departure like my MINI had where it aims to complete charging about 30 min before your departure time. That would help ensure the battery is warmer for departure time as well in the winter since charging inherently warms the battery.

Interesting. Is this what Tesla is doing on their software? Charge the car maybe 30 mins before the departure time set?

 

[Electrified Outdoors]

The net energy gained by preconditioning is negative. If your not taking it from the battery your taking it from shore power. As posted earlier if there is a drivability issue, then it may be worth it to precondition the battery. Its also worth it to precondition on the way to a fast charger in the cold weather (your using more energy to spend less time at the charger).

If your trying to avoid the range loss associated with cold weather pre conditioning isn't going to solve this either. You can heat the battery but once you start driving down the road it will cool down again.

The primary benefit to preconditioning is on long trips where you can use shore power to pre heat the cabin and preserve battery/range for the road trip.

If you have the vehicle plugged in, the BMS should prevent the battery from becoming critically cold or hot. This should also happen, less aggressively, when the vehicle is unplugged. I am only speaking by experience owning EVs over the years....only Rivian knows exactly how their BMS manages this.

Lastly some folks may not care about the extra energy use they may just want to be comfortable when they get in. This is why I asked about reasoning for wanting to do it. It does allow the truck to be more efficient but it isn't saving any energy if that makes sense.

 

[RivianRunner]

Right so for most regular driving pointless but for longer trips helpful.

On longer trips the BMS should route waste heat from the motors, inverters and computers to gently warm the battery as you drive. Any range that was not available due to a cold battery should return as the waste heat warms the battery.

 

[Craigins]

The point is you don't need the range, so why bother wasting the energy. Unless you can prove that the energy required whether from the wall or battery to warm the battery is offset by the efficiency lost while driving then it still doesn't make sense. For many short trips, it's almost certainly not worth the energy burn to do it.
....
Meaning it's doing what I said and not using wall power to precondition. If it's already charging that doesn't count.

I'm not quite sure how charging your battery is "wasting energy". You are simply storing energy in the battery. Actually this is LESS wasteful than letting vehicle warm itself up while driving since it ramps up the motors to heat and wastes energy. The act of charging produces the heat needed to warm the system up, so it is a win/win. Worst case, warming the battery while charging will use the same exact amount of energy as warming the battery while driving. Best case, if you charge slowly, you will use 0 additional energy to warm the battery.

I'm not sure why the "if it's already charging that doesn't count" is applicable. I'm sure Rivian's short term solution will be to kick on the charger for a short period of time to condition the cabin/battery, because it is less wasteful than feeding power to the motors to generate heat to warm the system.

 

[RivianRunner]

If your trying to avoid the range loss associated with cold weather pre conditioning isn't going to solve this either. You can heat the battery but once you start driving down the road it will cool down again.

It would have to be pretty frigid for the battery to get cooler as you drive. Simply drawing energy from the battery has a slight warming effect, and, as the inverters and motors warm up this energy is routed to the battery to continue warming it.

 

[Dark-Fx]

Yes and no. If your vehicle is at the charge limit it will not kick on wall power to heat the cabin.

While charging it will. Go to your charge summary and it breaks out power usage by battery/climate controls/accessory.

My observation as well this morning. Requires a pretty long amount of preconditioning time to dip the battery charge enough for the charger to kick back on. Still wish it would try to match the charge level with consumption the moment preconditioning kicks on. Current method causes cycling on the battery.

 

[defcon888]

Preconditioning probably not worth the energy spent doing so. The only way i can think of without wasting energy is to either use scheduled charging or set your charge limit 5% lower then go into the app shortly before you leave to top it off.

Otherwise if you have the truck plugged in, it should keep the battery from getting too cold. Are you concerned about something specific or do you just not want it to use energy while your driving?

I leave for work at 3 a.m. on Mondays. We start charging it at 12:00am so that is good information to know this winter. I am in Northern California and while we don't get snow that often where we live, we do get inthe high 20's and low 30's.

 

[Electrified Outdoors]

It would have to be pretty frigid for the battery to get cooler as you drive. Simply drawing energy from the battery has a slight warming effect, and, as the inverters and motors warm up this energy is routed to the battery to continue warming it.

True and more so if your driving aggressively. I found in my Tesla's performance was still significantly affected even if keeping it in a heated garage. Under normal driving you may not notice it as much but you couldn't get as much power out of the pack and regen was significantly limited. Even if storing in heated garage overnight and only charging to 70-80%, once I was out driving for 10 or 15 min in freezing temps the regen would be significantly limited and available power output would significantly decrease. It was the one big complaint I had about the Tesla in cold temps. My Bolt EV didn't limit regen but the range really suffered.

I don't have any cold weather datapoints on the Rivian yet but I expect it will behave similar to my other EVs. Once cooler or hotter temps are sustained for a period of time the vehicle behaves differently even though the battery is being thermally managed. Its hard to explain.

I plan to do quite a bit of cold weather testing this winter. We had snow flurries this morning in Mount Airy ?

 

[R1Tom]

Maybe not proven yet with the Rivian (not sure if anyone has tested), but preconditioning the battery does increase the usable range in other vehicles once you’re actually driving. No reason to believe Rivian would be different. If you absolutely need the maximum range, then yeah, it helps. If you don’t, you’re just wasting energy for no reason.

Delaying charging until a calculated amount of time prior to departure, would actually save energy vs earlier heating of the lack during charging....losing that heat to environment, and then having to heat back up at time of departure, right?

 

[Dark-Fx]

It would have to be pretty frigid for the battery to get cooler as you drive. Simply drawing energy from the battery has a slight warming effect, and, as the inverters and motors warm up this energy is routed to the battery to continue warming it.

My Bolt EV would have this problem and they didn't have battery preconditioning for the winter months while driving. Travel in sub zero weather was completely miserable in it. Every DC charging stop would be limited due to the battery temp. No heat exchange between the electronics and the battery, cabin and battery heaters were separate circuits. I had considered trying to engineer a fix, but it was easier to just not travel far in it.

It would heat the battery while L2 charging though, and up to a pretty decent level. The heat just didn't last long enough to make much of a difference.

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