L2 charger down to 2.7kwh at 24F.. Should I be worried?

[mkhuffman]

Gen1 max and Gen2 max are the same capacity. Same cells, and same number of cells. Unless they snuck a change in there that nobody has documented.

Do we know for a fact that the Gen2 Max has the same number of cells as the Gen1 Max? Usable capacity is the same, that is true. But I don't recall seeing a teardown of the Gen2 Max to see how many cells are actually there.

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[portdirect]

Do we know for a fact that the Gen2 Max has the same number of cells as the Gen1 Max? Usable capacity is the same, that is true. But I don't recall seeing a teardown of the Gen2 Max to see how many cells are actually there.

At this point, all we really know for sure is that the advertised capacity has changed from 141.5kWh (gen1 max pack) to 140kWh (gen2 max pack). Unfortunately, beyond the details in post #74, I don’t think we currently have any additional data. I apologize for not including further sources; however, aside from the assumed nominal voltage, I am confident in the accuracy of this information (scant as it is):

Gen1 Max Pack

• Nominal Gross Capacity: ~149 kWh at an assumed 392 V
• Cell Composition: Unknown number of Samsung SDI 21700 53G NMC cells (unclear if off-the-shelf or customized)
• Usable Capacity: ~141.5 kWh, meaning “100%” is ~94% of the battery’s true gross capacity
• Data Availability: Limited; no known listings on eBay for teardown info.

Gen2 Max Pack

• Nominal Gross Capacity: Unknown
• Cell Composition: 21700 53G NMC cells (number of total cells and any customization are unclear)
• Usable Capacity: ~140 kWh at “100% charge”
• Data Availability: Virtually none; no known listings on eBay yet.

Note that I don’t think we know for sure that the cells in gen2 come from Samsung SDI, it’s probably fairly safe to assume so - but would be great to get clarification. In addition to that what would probably be the key to answering this question would be getting the configuration of the cells into the battery pack, for example we know that the gen1 large pack is 108s72p - this value for the gen2 max pack would let us determine the max capacity (or someone could just drop the pack from an R1 and read the nominal capacity off the label that’s almost certainly printed on it somewhere ).

 

[MarkNorman]

New theory:

1. At <50F the Gen 2 R1 will stairstep throttle its charge rate at >80% SoC.
2. The latest OTA (2024.51.31) successfully attempts to warm the pack >50F while L2 charging.
3. Once the truck enters a throttled session it cannot recover from it even if the pack warms to >50F during the session.
4. However, if you reset the session (when >50F) it should charge at full speed >80% SoC.

Evidence:
From my own testing, and others, we know the trucks can charge at full speed from 80 to ~100% SoC if you initiate a charge >50F (maybe as high as 55F).

@COMtnEV In your last data gathering you charged from 20% to 100% and even though your battery warmed to 54F you still saw stairstep throttling starting around 80%.

Yesterday, I charged from about 50 to 85% and my pack warmed to 50F, but I still saw throttling >78%.

Last night, I went for a drive and pre-conditioned for a while on my way home. At arrival the pack was at 60F, which I knew from previous experience was warm enough for full speed charging. So I let it cool down to 56F (wanted to go a bit lower but I had to go to bed). Initiated an L2 charge at 56F and charged to 65 to 85% at full speed with no throttling.

 

[COMtnEV]

New theory:

1. At <50F the Gen 2 R1 will stairstep throttle its charge rate at >80% SoC.
2. The latest OTA (2024.51.31) successfully attempts to warm the pack >50F while L2 charging.
3. Once the truck enters a throttled session it cannot recover from it even if the pack warms to >50F during the session.
4. However, if you reset the session (when >50F) it should charge at full speed >80% SoC.

Evidence:
From my own testing, and others, we know the trucks can charge at full speed from 80 to ~100% SoC if you initiate a charge >50F (maybe as high as 55F).

@COMtnEV In your last data gathering you charged from 20% to 100% and even though your battery warmed to 54F you still saw stairstep throttling starting around 80%.

Yesterday, I charged from about 50 to 85% and my pack warmed to 50F, but I still saw throttling >78%.

Last night, I went for a drive and pre-conditioned for a while on my way home. At arrival the pack was at 60F, which I knew from previous experience was warm enough for full speed charging. So I let it cool down to 56F (wanted to go a bit lower but I had to go to bed). Initiated an L2 charge at 56F and charged to 65 to 85% at full speed with no throttling.

Correct. ABRP Battery Temp was 54-55F as the pack stepped down to 3.3kW.
In a previous charging session with starting battery temp 65F, I charged to 90% with no throttling.

New theory:

1. At <50F the Gen 2 R1 will stairstep throttle its charge rate at >80% SoC.
2. The latest OTA (2024.51.31) successfully attempts to warm the pack >50F while L2 charging.
3. Once the truck enters a throttled session it cannot recover from it even if the pack warms to >50F during the session.
4. However, if you reset the session (when >50F) it should charge at full speed >80% SoC.

Evidence:
From my own testing, and others, we know the trucks can charge at full speed from 80 to ~100% SoC if you initiate a charge >50F (maybe as high as 55F).

@COMtnEV In your last data gathering you charged from 20% to 100% and even though your battery warmed to 54F you still saw stairstep throttling starting around 80%.

Yesterday, I charged from about 50 to 85% and my pack warmed to 50F, but I still saw throttling >78%.

Last night, I went for a drive and pre-conditioned for a while on my way home. At arrival the pack was at 60F, which I knew from previous experience was warm enough for full speed charging. So I let it cool down to 56F (wanted to go a bit lower but I had to go to bed). Initiated an L2 charge at 56F and charged to 65 to 85% at full speed with no throttling.

Correct. Battery temp was 54-55F while charging throttled down to 3.3kW.
In a previous charging session, with battery at 65F to start, I was able to charge 65-90% with no throttling.

 

[Chi_Guy]

Hey everyone, I've decided to try and get a bit more organized about this—let's get some solid data so we can push for a resolution or at least closure:

Edit-1: removed extraneous content
Edit-2: Updated table with feedback from @windblowlc & @Glogic

Note: these tables originally came from running OpenAI's o1-pro over this thread, so may well have a load of errors:

Group 1: Users Experiencing the Issue

Username	Vehicle Model & Pack	Motor / Gen	Approx. Delivery/Build Date	Charging Slowdown Pattern	Ambient / Battery Temp Range	Charger (Amps/Type)	Preconditioning Attempts	Service Ticket	Notes on Root-Cause Variables
@Glogic	R1S (Likely Max Pack)	Gen2	~Mid-Dec 2024	Drops sharply above ~80% SoC (from ~11 kW to ~2–3 kW or lower)	~20–30 °F ambient (Massachusetts winter)	Tesla home charger + adapter	Tried battery heat from short drive; still inconsistent	Yes	Never saw this problem with his Tesla in same temps. Finds it “unpredictable.” Does not mention exact battery temperature data. Concern about overnight top-offs.
@portdirect	R1T Tri Motor Max (stated)	Gen2	~Nov 12, 2024 build (mentioned)	“Stair-step” throttle above ~75–80% SoC in cold; reminiscent of BMS limit	Often <50 °F; battery remains cooler	Rivian Wall Charger, Wallbox Pulsar, Clipper Creek tested	No mention of purposeful “DCFC route” trick	Yes	Owns a Gen1 for comparison. Notes Gen2 is significantly worse above ~80%. Hard to sustain higher charge rate if battery never warms enough.
@MarkNorman	R1S (Dual Motor Large)	Gen2	Early Dec 2024	Steps from ~11 kW → 8 kW → 4 kW → ~1–2 kW as SoC rises (80–90%+)	Battery stable around 46 °F during charge	Not specified EVSE	Tried partial DCFC before L2 with varied success	Unclear	Provides extensive logs (via ABRP). Observes battery is not heating enough to avoid throttling. “Thought it was a bug, but remains an issue.”
@COMtnEV	R1T Dual Perf. Max	Gen2	~Sep 2024	Consistent “stair-step” from ~9 kW → 6–7 kW → 3–4 kW as SoC climbs (75–90%)	~40–50 °F (battery often ~45–55 °F)	40 A Eviqo charger; sees mismatch across data tools	Has methodically tried driving first; partial success	Yes (filed)	Very detailed logs show repeated throttling above ~75% in 40–50 °F. Reports it severely impacts daily use. Data conflicts between ABRP & truck’s readouts.
@OYLman	R1S (Likely Max)	Gen2	Dec 6, 2024	Very slow topping from ~80% to 100%; can’t reliably reach 100% overnight	Not specified (car in unheated garage ~50 °F)	Not specified	Possibly attempted partial “drive then charge,” still limited	Possibly	Service center had the vehicle; no resolution. States charging might drop to near trickle after ~80%. Big complication for road trips.
@Chi_Guy	R1S Dual Max	Gen2	Not specified	Confirmed drop above ~80% SoC; even limiting amps from 48 → 40 didn’t help	Typically <50–55 °F battery for the slowdown	Not specified	Has used DCFC preheat route to push battery above ~65 °F, which helps	Not reported	Says it’s consistent “stair-step” at 80% with battery <50–55 °F. If warmed to ~65+ °F (via nav to DCFC), can maintain 11 kW for longer.
@Riouxgrande	R1S Tri‑Max	Gen2	Factory-gated Sep 17, 2024	OTA updates have not solved the severe L2 throttling above 80% SoC	Not specified	Not specified	Has tried each new OTA; still sees no fix	Yes	*Has an internal perspective (employee?), says Gen2 architecture “does something weird” with AC charging. Filed a ticket.
@bfilippo	R1T Standard LFP	Gen2	Not specified	~13–15 hrs to fully charge to 100%; becomes near-impossible for daily use	Not specified	Not specified	Tried 100% charge multiple times, fails or takes >13 hrs	Yes	Indicates LFP BMS also shows big slowdowns approaching 100%. Not purely a Max-pack phenomenon.
@SparkyR1t	Not specified R1T or R1S	Gen2	Not specified	Mentions initial throttling, minimal details provided	Not specified	Not specified	Reached out to Tesla’s charger support, but presumably truck-limited	Unknown	Details are sparse. Possibly overcame a separate home-charger overheat, but acknowledges the Rivian side was also throttling.
@MrMechanic	2025 R1S (Gen2)	Gen2	Not specified	Observes the same stepwise L2 drop at higher SoC, consistent w/ others	Not specified	Not specified	No mention of preheat strategies or partial DCFC	Not specified	Confirms “same behaviors,” presumably in moderate ambient/cold.
@SSFC5	Possibly an R1T/R1S w/ Max	Gen2	Not specified	Says the latest OTA didn’t fix throttling; still slow at high SoC	Not specified	Not specified	Doesn’t mention preconditioning or other attempts	Possibly	Frustration that software updates had no real improvement.
@windblowlc	Tri Max R1T	Gen2	Delivered December 9, 2024	Must start L2 hours earlier than normal to reach 100%; big scheduling issues	Ambient temperature is 20-50F outside	Rivian EVSE - 48A, on 60A Circuit	Not indicated (some manual preheat?)	Yes	Severe slowdowns hamper using the top 15–20% of SoC effectively. Has not experienced throttling issue in 3 years of Gen 1 R1T Quad ownership. Received a service in January, service advisor did nothing accept noting an OTA 2024.51 will fix the problem. Problem remains the same after OTA 2024.51. Would not have gotten Gen 2 if this was disclosed.

Group 2: Users Not Experiencing the Issue

Username	Vehicle Model & Pack	Motor / Gen	Approx. Delivery/Build Date	Any Throttle Observed?	Ambient / Battery Temps	Charger (Amps/Type)	Preconditioning Attempts	Service Ticket	Notes on Root-Cause Variables
@SeaGeo	R1T or R1S (Max Pack)	Gen2	Not specified	No—no major throttling reported	Not specified	Not specified	None needed (didn’t see slowdown)	No	Suggests personal usage may keep battery warmer; never replicates others’ slowdowns

Group 3: Users Commenting / Concerned (No Personal Issue Reported)

Username	Vehicle Model / Pack	Motor / Gen	Has This Issue?	Approx. Delivery	Key Comment / Concern	Ambient / Battery Temps	Charger	Ticket Filed	Additional Observations
@mkhuffman	Not an owner yet; possibly looking at Tri Max	Gen1	N/A	N/A	States the throttling is “unacceptable”	N/A	N/A	Unknown	Worried about low-temperature top-off; says it’s a deal-breaker if not fixed
@tbross319	N/A	N/A	N/A	N/A	Only inquires about software release evidence; no personal charge issues	N/A	N/A	No	Has no reported throttling, just verifying if new OTA is real/fixes anything
@hobbyjogger71	Not specified; a friend’s Gen2 is impacted	Likely Gen2	No (just referencing friend)	N/A	Reports friend’s issues (matching slow L2 speeds); worried about reliability	N/A	N/A	Not reported	Possibly sees same pattern with a friend’s Tesla UWC EVSE. Concerned by cold
@DeafPug	Not specified; offers advice only	Advisory	Does not say if impacted	N/A	Suggests calibrating or topping to 100% as workaround; no personal data	N/A	N/A	N/A	Not personally impacted—giving potential solutions (charging to 100% more often)

Thanks for assembling this data!

To clarify my charging experience:
My Gen 2 Dual Max was delivered November 23, 2024.
In cold temperatures I have seen a consistent stairstep down: ~11kW below 80%, ~7-8kW from 80-90%, 3-4kW from 90-96%, <2kW above 96%.
I charge inside a garage typically 30-40°F in winter.
I’ve tested a Tesla Wall Connector with adapter, a Tesla Universal Wall Connector, and a Clipper Creek.
Preconditioning to 65°F (with nav to DCFC) was successful in maintaining charge rate of 11kW. Preconditioning to 50°F was not successful, but it did maintain 11kW until 96% battery, when it dropped to 7kW.
I have not filed a service ticket yet.

 

[Chi_Guy]

New theory:

1. At <50F the Gen 2 R1 will stairstep throttle its charge rate at >80% SoC.
2. The latest OTA (2024.51.31) successfully attempts to warm the pack >50F while L2 charging.
3. Once the truck enters a throttled session it cannot recover from it even if the pack warms to >50F during the session.
4. However, if you reset the session (when >50F) it should charge at full speed >80% SoC.

Evidence:
From my own testing, and others, we know the trucks can charge at full speed from 80 to ~100% SoC if you initiate a charge >50F (maybe as high as 55F).

@COMtnEV In your last data gathering you charged from 20% to 100% and even though your battery warmed to 54F you still saw stairstep throttling starting around 80%.

Yesterday, I charged from about 50 to 85% and my pack warmed to 50F, but I still saw throttling >78%.

Last night, I went for a drive and pre-conditioned for a while on my way home. At arrival the pack was at 60F, which I knew from previous experience was warm enough for full speed charging. So I let it cool down to 56F (wanted to go a bit lower but I had to go to bed). Initiated an L2 charge at 56F and charged to 65 to 85% at full speed with no throttling.

I like this theory but would make one amendment. In my experience 50°F battery temp is not high enough to avoid throttling above 96%.
65°F battery temp will charge to 100% without throttling.

 

[MarkNorman]

I like this theory but would make one amendment. In my experience 50°F battery temp is not high enough to avoid throttling above 96%.
65°F battery temp will charge to 100% without throttling.

Agreed, we haven’t pinned down an exact temp, but the threshold seems to be somewhere between 50 and 55F. My main point in the last theory is that it doesn’t seem to be able to recover from a throttled session even if the pack warms above 50F.

 

[Chi_Guy]

Agreed, we haven’t pinned down an exact temp, but the threshold seems to be somewhere between 50 and 55F. My main point in the last theory is that it doesn’t seem to be able to recover from a throttled session even if the pack warms above 50F.

The threshold may be higher than 55°F for *unthrottled* charging to 100%.
I just charged from starting battery level 56% and battery temp of 55°F (using DCFC nav workaround). It maintained 11kW until 97% battery, when it dropped to 8kW. I noted the battery temp at that time was 59°F. (The ambient temperature in my garage was 28°F)

 

[mkhuffman]

Today I visited the Richmond SC to test drive a R1T. I had a long discussion with the sales team about this issue. Nobody there seemed to think this is a real problem.

They park their demo vehicles outside, and this winter it has been cold, with temperatures well below freezing. The R1T I drove today had a battery temperature of 35 F. (I asked them if we could do a test charge to see if there is throttling, but they said they cannot do that since the vehicle needs to be available for test drives. Bummer.)

They say they charge all their demo vehicles to 100% every night (I won't be getting a demo vehicle, LOL). They have never had an issue reaching 100% by the next morning. They have not monitored the charging speed, so of course the charge rate could very well be throttled. But regardless, they are always at 100% by 9 AM the next morning.

While this issue is still a problem that should be addressed, maybe I can live with it.

 

[portdirect]

Today I visited the Richmond SC to test drive a R1T. I had a long discussion with the sales team about this issue. Nobody there seemed to think this is a real problem.

They park their demo vehicles outside, and this winter it has been cold, with temperatures well below freezing. The R1T I drove today had a battery temperature of 35 F. (I asked them if we could do a test charge to see if there is throttling, but they said they cannot do that since the vehicle needs to be available for test drives. Bummer.)

They say they charge all their demo vehicles to 100% every night (I won't be getting a demo vehicle, LOL). They have never had an issue reaching 100% by the next morning. They have not monitored the charging speed, so of course the charge rate could very well be throttled. But regardless, they are always at 100% by 9 AM the next morning.

While this issue is still a problem that should be addressed, maybe I can live with it.

If you routinely charge only up to 85%, you’ll likely never notice the added charging time. Even if you charge to 100% overnight, and the temperature isn’t especially cold, the process might take an additional five hours—something many people may not notice or care about.

Where this does matters most, and for some is a major step back:

• Time-of-Use (TOU) Contracts
  If you rely on off-peak electricity rates, not being able to complete a full charge during the off-peak window could force part of your charging into peak hours. In some regions, that can effectively double (or more) your charging costs.
• Partial Top-Offs for Long Outings
  If you want to top off from 70% to 95% before a long day trip, charging time could jump from around three hours to over six. This makes it impossible to charge between, say, 7:00 a.m. and 10:00 a.m. and still have a full day’s range.

Ultimately, this extra charging time will significantly affect some folks while being irrelevant to others. One concern for everyone is that if the slower charge is in-fact tied to reduced overall battery capacity, it may lead to more rapid degradation than in packs with larger “headroom.”


Based on some other reports it's not clear if this behavior as always been the case with gen2 or if earlier gen2 builds behaved like gen1 in colder weather.

 

[OYLman]

Tried the fast charging precondition trick today for the first time. Didn't throttle until 95% but it did still throttle. Battery temp at start was 54F according to the car and 59F in ABRP (first time using that as well -- why different readings?). ABRP battery temp 63F when it started throttling.

 

[portdirect]

Tried the fast charging precondition trick today for the first time. Didn't throttle until 95% but it did still throttle. Battery temp at start was 54F according to the car and 59F in ABRP (first time using that as well -- why different readings?). ABRP battery temp 63F when it started throttling.

Forgive my ignorance of ABRP, but that shows your battery capacity as 111.2kWh?

 

[OYLman]

Forgive my ignorance of ABRP, but that shows your battery capacity as 111.2kWh?

Dial motor, large battery.

 

[mkhuffman]

Dial motor, large battery.

I must have missed it earlier in this thread. (I am following this pretty closely.) I was under the impression that this was a Gen2 Max issue. Are you saying this impacts the Large as well?

IMO throttling at 95% is not really unusual. My Mach-e starts throttling over 95% (I am not sure exactly where, but if needed I can find out,) L2 throttling at 80% is not normal for the BEV industry. My MME has never throttled at a SoC that low, even when the battery was frozen.

Another question I have is: do you have a Large+, or a Large? If you have 80% throttling and have a Large+, that throws out the capacity theory.

 

[OYLman]

I must have missed it earlier in this thread. (I am following this pretty closely.) I was under the impression that this was a Gen2 Max issue. Are you saying this impacts the Large as well?

IMO throttling at 95% is not really unusual. My Mach-e starts throttling over 95% (I am not sure exactly where, but if needed I can find out,) L2 throttling at 80% is not normal for the BEV industry. My MME has never throttled at a SoC that low, even when the battery was frozen.

Another question I have is: do you have a Large+, or a Large? If you have 80% throttling and have a Large+, that throws out the capacity theory.

It's a large, not large+. And throttling has affected me since I got the car in December.

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