Behind Tesla LFP Model 3: Sales Up, Range Down

Author: HUA Zijian/ Sina
Translation/edit: MoneyballR
Original article:

MIC LFP Model 3 received a new round of scrutiny as its range started to act abnormal. Several owners found issues with LFP battery after receiving the car. In winter conditions, the range is significantly reduced and the battery cannot be charged 100%, while company’s instruction on charging once a week still need to be done.

A Beijinger who owns LFP Model 3 uses his car for short distance travels. In the night he parks it in an underground garage and during the day on a parking lot. The owner said after it fully charges the car, display shows 420 km, but after driving it for 214 km, there is 5% left. After charging 52 kWh for 1h, the display shows 420 km again.

Although it meets my needs, the difference with officially declared 468 km is not small. In reality, you might say that range over 200 km is my bottom line, the owner says. There is not a small number of people that had similar issues like this owner.

On one hand, people who waited for LFP brought price cuts got their delayed gratification, but on the other, LFP made MIC Model 3 more like an old car, also charging anxiety increased too.

LFP Battery R&D Cycle Cut in Half
In winter conditions, LFP battery does lose a lot of capacity. After one of my clients bought it, he got angry really fast, an experienced Tesla dealer told Sina. Now, a lot of people are asking the dealer for ternary MIC Model 3, but there is less and less of them in stock.

He told Sina about a customer that asked him to help him find MIC SR Model 3 with ternary battery. The next day he got one as a favor, but the car was in another city store.

It was a leftover car or display car. But then again, in future you will not get a chance to spend RMB 240 K to get a Model 3 with LG Chem ternary battery, the dealer said.

Buyers started to fight for a handful of LG ternary Model 3s. There were many of them who wanted to buy SR, but have pulled strings to get ternary LR used vehicles, which were either the cars that were driven under 7-day free of charge return scheme or were display or test drive cars with RMB 10–20K discounts, he told our reporter.

This shows that LFP Model 3 range decrease started to affect consumer confidence.

Tesla’s LFP project was rushed. 21700 battery development cycle was 23 months, LFP’s was under 12 months, former Tesla employee that recently resigned from the company says.

A source inside CATL revealed that 9 months passed from the moment Tesla said it wanted LFP battery to the moment mass production started. Vehicle tests, component DV/PV tests were omitted, the inside source said while another source revealed that Tesla does not have vehicle test team in China.

21700 battery was result of Tesla and Panasonic joint R&D with an aim to replace rather unstable 18650. The latter is a cylindrical lithium ion battery that Tesla used in early stages. Compared to 18650, 21700 was safer, had higher density and more cycles.

In the beginning, Model 3s imported in China used Panasonic 21700 ternary battery. In the early stages, MIC Model 3 used Panasonic ternary batteries, but later, due to supply shortages, switched to LG Chem 21700 ternary batteries produced in Nanjing.

21700 is a type of battery packaging technology that uses cylindrical batteries. Panasonic and LG batteries all use this technology, while CATL on the other hand uses prismatic batteries. Since ternary batteries contain precious metals like cobalt, nickel, manganese, its cost is high and is affected by precious metal prices. LFP cost is low and hence stable.

On Oct 1st this year, Tesla announced price cut for MIC Model 3, SR was cut to RMB 249.9, LR to RMB 309.9K. At the same time, SR version battery was changed from ternary to LFP with CATL as supplier.

Already in May, Tesla reported LFP Model 3 to MIIT for sales. Afterwards, it entered MIIT’s 337th batch of road vehicle OEM and products. In May, during 2019 CATL shareholder meeting, CATL confirmed it will start supplying Tesla with LFP batteries.

Naturally, price cuts stimulate sales, but current battery issues are related to shortened battery development cycle, former Tesla employee says. This not only affects user experience, but it also affects charger operating efficiency, which brings us to Tesla’s official suggestion to the owners of LFP Model 3.

Following price cut, on Oct 16, official Tesla customer support microblog published a post suggesting that LFP Model 3 SR battery should be charged 100%. Tesla also suggested that owners charge their batteries at least once a week, saying that in this manner they will help balance the voltage between battery modules as well as preserve precision of left battery power display.

One owner shared his recent experience with superchargers saying that there are more owners now than before, because a lot of owners now wait for their car to be 100% charged and these are all LFP owners doing what company suggested them to do.

Price cuts do not equate to comfort
This suggestion is different from previous Tesla suggestions when Tesla suggested not fully charging ternary batteries, unless on long distance routes.

An insider said that Tesla suggestion is more about helping the company accumulate and improve data on LFP BMS. Also, this is about North and other low temperature regions, where frequent calibration gives more precise understanding of the battery and prevents from imprecise measurements causing range to suddenly become shorter.

In other words, LFP battery measurement of left power is not stable at low temperatures and easily occurs with sudden drop in power. On the other hand, because Tesla shortened R&D cycle, it does not have enough testing data, so it needs users to do data testing, so it can acquire more stable data eventually.

A battery engineer told Sina that MIC Model 3 feature is that high voltage does not power off, so there is always deviation between battery SOC and correction — values are not correct. As for LFP being fully charged, the engineer said fully charged battery affects its life cycle.

A Shanghai owner got his LFP Model 3 end of October. The car was produced on National Day. On the day when he received the car, range was at 413 km. After a week, with a full battery on, range was at 400 km.

After another week passed, he could only charge to 94% and would receive notice that charging was completed, he could not continue charging. Display was showing 387 km. The next day, when he was charging again, he could not fully charge again, while display was showing 353 km. After having a series of issues, he went to Tesla sales center and requested SOC checkup. It showed 46.2 kWh, 80% of declared 55 kWh.

Tesla reduced price to boost sales and made customers help the company measure the data. Tesla can’t have it both ways, can it?

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