Initial supercharging results suggest that the new lithium iron phosphate (LFP) battery powered Tesla Model 3 can supercharge even faster than the version with the nickel battery. This looks promising, and is not unexpected.
China-based website 42HOW conducted a side-by-side test of the new LFP battery Tesla Model 3 and the regular nickel battery Tesla Model 3. Photos tweeted via Ray4Tesla (access the tweet below for full sized photos) recorded that the speed of supercharging from ~40% to 99% was significantly faster for the LFP variant:
One good thing about LFP: you can charge it to 100% (recommended) all the time without worrying about excessive degradation. pic.twitter.com/q3sVg0Yfb1
— Ray4Tesla⚡️🚘☀️🔋 (@ray4tesla) October 31, 2020
The supercharging session photos in the above tweet demonstrate that the original nickel-based battery Tesla Model 3 took ~62 minutes to go from 40% to 99% state of charge (SOC), whilst the LFP variant took just ~42 minutes to get from 41% to 99%. Although these SOCs at best represent approximately the “second half” of a typical charging session, the LFP nevertheless would seem to demonstrate a time saving of around 32% or approximately a third.
Useful Early Indications
Let’s be clear that whilst 42HOW and Ray4Tesla have done a great job here, these are very early and somewhat anecdotal (though documented) results and we’ll need more data to draw any strong conclusions.
Likewise there are a number of unrecorded variables influencing these sessions, so there are a few caveats even with these limited results. Both sessions were conducted at a location in central Shanghai (the above photo of the two vehicles suggests the same location). All superchargers in the area currently max out at 120 kW according to Tesla’s supercharger map.
The supercharging station appears to be fairly empty, suggesting that full power was available for the two vehicles. Ambient temperatures show 25 degrees celsius in both cases, though the vehicle clock times are offset (maybe or may not be accurate). The battery pack temperatures at start of each charging session may or may not have been equal between the two vehicles, which can influence charging power.
Both vehicles are SR+ Model 3s, but the age (and odometer) of the nickel battery Model 3 is unknown. Based on these two charging sessions, the usable capacity of the nickel pack appears to be 48 to 49 kWh, and the LFP pack appears to be 55 to 56 kWh usable capacity. This larger size of the LFP pack is in line with documents from the China Ministry of Industry and Information Technology.
It’s obviously too early for any firm conclusions, but it certainly appears likely that the LFP Tesla Model 3 is capable of supercharging significantly faster than the older nickel-based variant, at least over some portion of the charging cycle.
As mentioned above, the clearest conclusion from the session photos is that the LFP variant added 41% to 99% charge (32 kWh) in 42 minutes, and the nickel variant added 40% to 99% charge (29 kWh) in 62 minutes.
We can also see that the LFP pack appears to accept higher charging power at a given state of charge. At 40% SOC, the nickel variant is charging at 64 kW, and at 41% SOC, the LFP variant is charging at 69 kW. Whilst we would expect both to charge at much higher rates at around these SOCs on Tesla’s V3 superchargers, this slightly higher charging rate for the LFP is suggestive. Likewise, at 99% SOC, the newer LFP variant is still accepting 9 kW of power and the nickel variant is accepting 4 kW of power.
We obviously need more evidence to build a full picture, but I would guess that for mid-trip top ups of the typical 10% to 80% SOC, the LFP variant may be able to charge roughly 10% faster (at least) than the nickel variant, saving perhaps 2 or 3 minutes.
We recently saw that Tesla do recommend that the LFP Model 3 can habitually be charged to 100% full. This contrasts with guidance for the nickel pack, which should ideally only be charged to 100% SOC occasionally (e.g. for periodic cell balancing, or immediately before long trips). For the nickel pack, habitual charging to a lower 80% to 90% level is considered better for long term pack life.
So it seems that the LFP variant of the Model 3 is both designed to be regularly charged to close to 100% and is also capable of faster charging to 99% full, compared to the nickel variant. This means that the LFP variant is ideal for those minority of EV owners who may not have access to a regular plug (neither at home nor at work) and want a quick top up to almost a full, around once a week, to cover commuting duties.
LFP Powering The Transition
I’ve written extensively about why I believe LFP batteries are a great fit for powering affordable mass market electric vehicles. This mainly comes down to the sheer abundance (and low cost) of most of the key constituent minerals, relative to the current availability of minerals for nickel based batteries. This is a key strength for tackling the massive task that lies ahead of us – the task of quickly shifting the world over to zero emissions transportation (and energy storage).
We do expect to make heavy use of LFP for medium range cars & stationary storage
— Elon Musk (@elonmusk) October 7, 2020
Tesla is sensibly taking a diversified approach to battery chemistries, with LFP for the most affordable mass market vehicles, medium nickel chemistry for the longer range vehicles, and high-nickel (in the new 4680 form factor) for the longest range, highest performance and weight sensitive vehicles.
Alongside Tesla’s use of this chemistry, LFP cells are also providing a central pillar of the strategy of the world’s #2 EV manufacturer, BYD. Tesla’s LFP supplier, CATL, is also supplying this chemistry to other EV makers.
There is plenty of development potential remaining for LFP cells. We recently saw battery manufacturer Guoxuan say that they are aiming for higher energy density LFP chemistries in the coming years, bringing ever more use cases into the scope of LFP
#Guoxuan to expand capacity to 28 GWh this year, 80 GWh by 2023 as it aims at 100 GWh by 2025, #China #battery maker reveals.
The company targets 260 Wh/kg #LFP and 350 Wh/kg #ternary battery by 2022, company added. pic.twitter.com/V6VFfJ5qTI
— Moneyball (@DKurac) October 26, 2020
Whilst there are many varieties of LFP, each of which can prioritize different characteristics, one of the general strengths of most types of LFP is standing up relatively well to both high cycle life and also to high power (high C-rate) charging.
Now that EVs are available with very decent range (over 500km even with LFP, in some cases) which is already “enough” for many global consumers, having strong DC charging performance is a key priority for EVs. This early data from 42HOW and Ray4Tesla suggests that the LFP Tesla Model 3 appears to be pushing for progress in this area.
We’ll be on the lookout for more data on charging speeds as the LFP Model 3 gets into the hands of more owners in the coming weeks.