aarond12 wrote:My Mitsubishi i-MiEV also had a "B" mode, which I used exclusively (as I do in my LEAF). The difference is, even on a full battery, the i-MiEV would give me full regenerative braking. My theory is that even if I got up to speed slowly and then used maximum regen, I would still have less power returned to the battery than it originally had. I wonder why Nissan has chosen a different route...
Keep in mind that concepts like "full battery" are not absolutes in practice. 100% is an engineering compromise taking into account safety, utility, and longevity. A manufacturer may say its cell is at 100% at, say, 3.7 volts. That doesn't mean the battery can't be charged to 3.8 volts or 4.0 volts, and therefore hold more energy. But the number of recharge cycles may be significantly less. At some point safety also becomes a concern. And battery-charging characteristics change depending on state of charge. This is why fast-chargers dial back the amps as the battery gets full. Heat increases near the top.
Also, the battery manufacturer's opinion of "100%" is not the same as what a car manufacturer presents to the driver as "100%".
So, "full" is an arbitrary construct, not an inherent property. It may be that the i-Miev "hides" more capacity from the user thus allowing a bit more overage from regen. Or Nissan may simply have chosen to be more conservative. I'd suspect though, that if you rode regen on a "full" i-MiEV on a long descent, that regen would eventually be cut back. Otherwise you'd be in great danger.