in 2020 (updated)
In 2015 https://pushevs.com/2020/04/04/comparison-of-different-ev-batteries-in-2020/
Tesla was the only automaker using the most energy dense batteries available, which were
NCA battery cells in cylindrical form. Most automakers were using LMO battery cells in their
electric cars, which are far from great…
what is LFMP battery
Lithium Iron Manganese Phosphate (LiFeMnPO4) battery, or simply LFMP. This is a
400Ah, 24 volt – 10.24 kWh – battery. That roughly equates to a 1400Ah lead-
acid battery bank
500AH Battery Package 6.4kWh, Weight 143 pounds
includes the above items and 5 Battery Packs and 5 EMS boards
Dimensions (side by side) 27.5” X 10.25”, 9.25” High
$4,329
High energy density by weight and by volume
– Superior safety performance due to patented new safety valve and pressure cap designs
– Batteries do not explode or catch fire when batteries are shorted or punctuated resulting in
internal shorts
– More robust connection due to new electrode terminal design using four screws per terminal.
Prevents loose connections caused by vibration
– Reduced impedance due to improved electrode terminal design
– Long cycle life, over 5000 Cycles possible
-Cell structure easily facilitates BMS integration and battery pack formation.
When automakers – pushed by stricter emissions regulations – finally started to get a
little more serious about electric cars, battery cell makers began to develop NCM high
energy density cells in prismatic and pouch forms, especially made to use in electric
cars. Until then, the most interested in high energy density battery cells were laptop
manufacturers, that’s why they were made in cylindrical form.
Now in 2020 the scenario is very different from what we had when I started this blog in
2015. Legacy automakers are actually selling electric cars with good batteries. Most of
them are now using NCM 523 or NCM 622 battery cells and prepare to upgrade to even
more energy dense cells such as NCM 712, NCM 811 and even NCMA
Note: the chart above is a bit outdated considering that now NCM 811 battery cells can
easily surpass 1.000 cycles before reaching the EOL (End of Life). However, it still
shows us that NCMA, which combines the best characteristics of NCM and NCA
chemistries represents a solid improvement.
Anyway, right now it seems that two cathode chemistries will dominate the EV battery
world in the near future. The NCMA cathode which offers the best energy density and
the cobalt-free LFMP cathode which offers the best cost. A smart strategy for
automakers would be to offer the same electric car with two different battery packs, one
optimized for range and another for cost.
Now that I gave you a bit of context let’s move to the interesting part and compare some
batteries of popular electric cars.
Nissan LEAF
40 kWh battery
Total battery capacity: 40 kWh
Usable battery capacity: 36 kWh
Battery weight: 303 kg
Battery energy density: 132 Wh/kg
Chemistry: NCM 523
Manufacturer: Envision AESC
TMS: passive air cooling
62 kWh battery
Total battery capacity: 62 kWh
Usable battery capacity: 56 kWh
Battery weight: 443 kg (estimation)
Battery energy density: 140 Wh/kg (estimation)
Chemistry: NCM 523
Manufacturer: Envision AESC
TMS: passive air cooling
Chevrolet Bolt EV
Old generation
Total battery capacity: 60 kWh
Usable battery capacity: 58 kWh (estimation)
Battery weight: 435 kg
Battery energy density: 138 Wh/kg
Chemistry: NCM 622
Manufacturer: LG Chem
TMS: active liquid cooling
Tesla Model 3
Long range version
Total battery capacity: 80,5 kWh
Usable battery capacity: 76 kWh
Battery weight: 478 kg
Battery energy density: 168 Wh/kg
Chemistry: NCA
Manufacturer: Panasonic
TMS: active liquid cooling
Expected incoming upgrades
1. Envision AESC that supplies battery cells to Nissan will upgrade its cells from NCM
523 to NCM 811 during this year. Nissan has the chance to upgrade the LEAF with
more energy dense battery cells and finally give it an active TMS (Temperature
Management System) to properly handle fast charging and prevent excessive
capacity degradation.
2. Hyundai could upgrade their battery cells to NCM 712 already this year, or wait until
next year to get the NCMA cells from LG Chem instead.
3. Next year Samsung SDI will bring its own NCM 811 battery cells and the BMW i3 will
probably be the first electric car to get them. The battery capacity will likely increase
around 10 kWh from the current 42,2 kWh to 52 kWh.
While I think that’s important to keep pushing for more energy dense batteries that give
electric cars the best range possible, I also think that’s important to make them
affordable. This is why we also need cobalt-free batteries like LFMP. Allowing
customers to choose which kind of battery they want (maximized for range or cost) is
the strategy that I think will become norm in the near future.
Bonus: if you want to know what a battery cell maker like Samsung SDI thinks about
this strategy take a look at this internal report (translated from Korean to English).
Making batteries last longer
It’s not surprising that the 30 kWh versions suffer more from charge/discharge cycles,
since they are more often charged to 100 %. Remember that the option to limit
the charge to 80 % was removed when the 2014 model year debuted (to game EPA
range ratings). This means that none Nissan Leaf with the 30 kWh battery has this
option.
If you want to improve your electric car battery lifespan, you should know that it’s better
to charge to 80 % and discharge till 0 % than to charge to 100 % and discharge to 20
%. Nonetheless, if you can use the battery between a SoC (State of Charge) of 80 and
20 % even better… And if you really want to take care of your battery, try to use it only
between 70 and 20 %.
Moreover, having the battery sitting at 100 % SoC is worse with the 30 kWh version
than it’s in the 24 kWh variants. Because in the same conditions the 30 kWh battery will
likely be hotter. In the 24 kWh battery pack, each module has 4 cells, while in the 30
kWh variant there are 8 cells per module. A more dense battery pack will dissipate heat
more slowly.