danrjones wrote:I'm not a battery expert but it seems to me resistance by itself would not determine battery capacity, but might impact available power at any given time or maximum charge speed.
A higher internal resistance causes more heat production, especially at higher current. In particular, I noticed that when I replaced the battery pack on my 2011, the car had significantly more power than before. In addition, accelerating rapidly had a massive impact on the "fuel economy" with my old battery, but much less so with the new battery.
Also, you'd want to avoid rapid charging at high internal resistances as well, due to heat production and possibly other factors. Nissan resolves this issue by basically disabling regen braking (limited to <10 kW & only below 20 mph) as the battery begins to degrade. My old pack had 0 regen braking at speeds above 35 mph.
The effect of this is that you're burning up the friction brakes below 8 bars or so, and your range is significantly less as a result of all the above.
To answer SageBrush's original question:
SageBrush wrote:Is it correct to say that battery (A) with the same capacity as battery (B) but 25% higher R would have 25% lower range if we presume identical driving ?
No, it is not. The vast majority of energy discharged by the battery goes into the motor and wires, not into resistance in the battery. So yes, you would have 25% higher resistive losses in the battery, but these account for a small fraction of the total energy used. However, at higher power outputs, the battery internal resistance losses are amplified.
Practically speaking, with a Leaf, your range may still decline significantly from all factors, but primarily due to the loss of regen braking. My new battery took me from SOH 55%->87%, but more than doubled the range.