Initial results give us a hint behind Toyota's battery capacity retention target.
The 2022 Toyota bZ4X is the first global all-electric model from Toyota, which soon will be launched in Japan, Europe, and the US. It’s also the first model based on the e-TNGA platform.
There are two powertrain versions of the car – single motor, front-wheel drive (FWD) and dual motor, all-wheel drive (AWD) – which in the US differs also by the battery pack (71.4 kWh FWD or 72.8 kWh AWD). In Japan and Europe, both versions are equipped with a 71.4 kWh battery.
As it turns out, the two battery packs have a similar battery capacity, but the maximum charging rate is significantly different. The Panasonic (Prime Planet Energy & Solutions) 71.4 kWh battery can charge at up to 150 kW, while CATL’s 72.8 kWh battery charges at up to 100 kW.
- FWD: 71.4 kWh battery (total capacity), charging at up to 150 kW
- AWD: 72.8 kWh battery (total capacity), charging at up to 100 kW
This difference might significantly affect the charging speed of the AWD version. According to the manufacturer, the 71.4 kWh version is expected to recharge from a low state-of-charge (SOC) up to 80% SOC in about 30 minutes, but there is no such info for the AWD version (see specs: Japan, US, Europe).
Out of Spec Reviews recently had an opportunity to conduct a fast-charging test, of the Limited trim all-wheel-drive version, equipped with a 72.8 kWh battery. So now we can take a look and see what to expect.
Toyota bZ4X fast charging test
According to the video, charging from basically 0% SOC immediately starts at over 80 kW, and is mostly flat in the first part – at around 86-87 kW, with a peak of 88 kW at 16% SOC. That’s not even 100 kW listed in the specs (see at 14:26).
*power, energy and SOC values according to the Electrify America’s charger.
Then, charging power decreases mostly linearly up to just several kW at 95% SOC. Unfortunately, after 25 minutes the charging level was 50%, and to reach 80% SOC, the car needed 62 minutes. The overall charging speed is disappointing.
It’s also very disappointing at the end – after 87% SOC power drops below 10 kW, and from 94% SOC it’s just 1 kW. Those are levels comparable with slow AC charging (the on-board charger is 6.6 kW).
Results:
- start: 0/1% SOC – right away at 86 kW
- 6-8% SOC: 87 kW
- 16% SOC: 88 kW (peak); after about 7 minutes
- 50% SOC: 51 kW after 25 minutes
- 80% SOC: 18 kW after 62 minutes
- 90% SOC: 7 kW after 93 minutes
- 94% SOC or more: 1 kW
- end (99%): 264 minutes (4.4 hours)
Total energy delivered: 61 kWh
Usable battery capacity and warranty
An interesting thing is that the charger reports 61 kWh delivered over the full charging session. Considering that the total battery capacity is 72.8 kWh, the difference is 11.8 kWh and that does not even include charging losses and other auxiliary loads.
That brings us to a conclusion that the Toyota bZ4X must have some quite significant buffer and very limited available battery capacity.
There might be a reason for that. We can only guess that Toyota has a very conservative approach and thus limited the available battery capacity and charging power for safety reasons and longevity.
Toyota’s battery capacity retention target is 90% after 10 years or 240,000 km (150,000 miles).
Well, if there is a significant battery capacity buffer, power limits, and a decent thermal management system, we have no doubts that the battery can meet the target.
FWD vs AWD
We need to wait for more charging tests of various versions of the Toyota bZ4X, but if there is a big difference between the charging time of the AWD and FWD version, customers might not be as interested in the AWD (which gets only slightly more drive power – 160 kW vs 150 kW).
Keyword: Watch Toyota bZ4X AWD Fast Charging Test: 0-80% SOC Took One Hour