Energy Capacity of the Hybrid Battery

As an adjunct and update to this, putting it in perspective, the brand new 2023 Yaris Cross, has a battery capacity of just 0.7kWh, which I thought was incredibly low. Low enough so some e-bike projects have more. The above explanations of how lightly-utilised it is, fit this neatly into being half the older NiCad capacity.

It is Lithium-ion of course, and Toyota may have decided to run this a lot closer to its full capacity, than the older NiCad cell versions. I have a gen 3 just bought this year, and it has 1.6kWh but as the policy was to leave a lot of capacity compared to what may be normally used, this is explained.

I suspect based on my own limited experience, the NiCad performance degrades so much in the cold, Toyota had to make it double the size they’d like, partly to account for the loss of performance. And, the battery can never be used to what seems the full extent because that makes it much less efficient…however as I discovered thrashing a Nissan LEAF at 70mph or so, working a small battery hard, diminishes it’s apparent capacity of energy as well as the well-known rule of somebody scientific, that this happens. (FYI using 0.5kWh per mile instead of the official Nissan figures implying just half that or less, and running that 30kWh battery hard must’ve made it’s effective capacity more like 23kWh or so, hence we only got 50 miles on a full charge that day.)

So the Yaris Cross of 2023, really doesn’t move the dial much, Toyota must feel their original capacities of energy were about right, for these sizes of vehicles and to make it non-plugin (‘self-charging’). I remain surprised at how little energy it seems possible to regen-charge into the battery, because all that effort expended to drive up to and at speed, is so huge. They had to compromise I suppose, imagining a typical urban stop-start at slow speeds, and I only have one hill near home where it fills totally while regen-braking down, so it’s about right from this experience.