Does Level 2 charging have a curve the way Level 3 does?

[Lawrence-of-Blaine]

Living in Minnesota with a cabin in Wisconsin, I’m dealing with cold weather now, like many others. I have a Rivian wall charger at both locations. When I can, I’ve run some informal tests regarding warming the battery, range vs. battery temp, etc.
Tomorrow, I’ll do a 3-hour charge just before heading home from the cabin. Said charge will warm the battery, to some degree. But since the charger always delivers 10.5-11 KWh, is there any way to influence the charge rate, really? Seems to me there isn’t. Other than maybe: start at a lower s.o.c., set a higher goal, and then pull the plug early.
Could that have an effect, and if so, what?
Does anyone really know for sure?

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[portdirect]

It shouldn't really have much if any of a curve - and for the Gen1 and many Gen2's this is the case - its very flat throughout regardless of SoC, up until around 97% where it does taper off to a bit less. In really cold conditions some power will be diverted to heating the battery - but in general you can expect >=10.5kW to be delivered to the battery throughout its whole SoC range.

In at least some Gen2's (seemly especially newer ones) - currently folks (including myself) are seeing a much reduced rate of charge starting somewhere between 70 and 85%, that's described in more detail over in this thread: https://www.rivianforums.com/forum/...n-to-2-7kwh-at-24f-should-i-be-worried.37845/ - the current thought is that this is a bug, and will hopefully be fixed soon.

 

[hobbyjogger71]

There shouldn't be - in essence. The EVSE will deliver 9.6 (40a) or 11 (48a) steady based on what the car will request. With that said, my G1 R1T does show a behavior where the first part of the charge is used to warm the battery; this is reflected in the "miles per hour" on the dash - it may start at just 2-3 mph before working up to the 20-21. However, the EVSE is delivering 9.6 the entire time, as expected (40a)

The G2 issue is something entirely different. The charge delivered is stepping down from the EVSE side to 6kwh and then 1 and then below one at certain intervals (80% and 90% seem to be popular).

 

[SANZC02]

In extreme temperatures (high or low) I would expect a difference.

On my G1 R1S most of the time my curve is flat but if I’m in the Coachella Valley with temps above 100 degrees I do see my charge rate drop down to around 7 kWh sometimes. Once it drops it seems to stay there for the rest of the session.

 

[Dave Cundiff]

Living in Minnesota with a cabin in Wisconsin, I’m dealing with cold weather now, like many others. I have a Rivian wall charger at both locations. When I can, I’ve run some informal tests regarding warming the battery, range vs. battery temp, etc.
Tomorrow, I’ll do a 3-hour charge just before heading home from the cabin. Said charge will warm the battery, to some degree. But since the charger always delivers 10.5-11 KWh, is there any way to influence the charge rate, really? Seems to me there isn’t. Other than maybe: start at a lower s.o.c., set a higher goal, and then pull the plug early.
Could that have an effect, and if so, what?
Does anyone really know for sure?

@Lawrence-of-Blaine: You can set a location-specific charge rate on the "Energy" (charging) screen in the center display, or in the "Schedule" function of the app. Anything between 8 and 48 amps, depending on what the charger is willing to supply.

Best wishes!

 

[Lawrence-of-Blaine]

Thanks folks. Good info.

 

[bfilippo]

It shouldn't really have much if any of a curve - and for the Gen1 and many Gen2's this is the case - its very flat throughout regardless of SoC, up until around 97% where it does taper off to a bit less. In really cold conditions some power will be diverted to heating the battery - but in general you can expect >=10.5kW to be delivered to the battery throughout its whole SoC range.

In at least some Gen2's (seemly especially newer ones) - currently folks (including myself) are seeing a much reduced rate of charge starting somewhere between 70 and 85%, that's described in more detail over in this thread: https://www.rivianforums.com/forum/...n-to-2-7kwh-at-24f-should-i-be-worried.37845/ - the current thought is that this is a bug, and will hopefully be fixed soon.

Same here, but I think it’s mentioned in the notes for the new update, at least related to cold weather charging issues- since this is the first really cold month Gen2’s have collectively been through for data to populate.

 

[DeafPug]

Even with L2 charging, you will see a drop off, that tends to only happen at the high 90% range (98% or higher) when trying to do a 100% charge.

There is a thread here that seems to be limited to 2025 Rivians and that they charge slow when L2 charging above 80%. Oddly, the same vehicle can charge at a regular speed at L3 stations. L2 charger down to 2.7kwh at 24F.. Should I be worried? has details. This seems to be a recent software bug, which will hopefully be fixed soon. (just saw this was mentioned in the first reply)

The tapering that happens on L3 charging speed is because the battery is getting warm. It limits to a speed that the battery can safely accept at the % state of charge that the battery currently is at. Since 10 kW L2 charging is WAY less than the safe charging speed for the battery, you don't notice it until the battery is almost fully charged (97-98% range).

Safe charging speed is also why when you fully charge an EV battery that you do not have regenerative braking for the first 5-20 miles. There is nowhere for the energy to go (can't be dumped in the battery), so it can't generate 50 kW of electricity from regenerative braking.

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