The cold weather conditions some of us were referring to simply prevent braking regen from occurring at ALL times during a commute- not just the typical warmer weather cold start.
During these times the cabin temperature often does rise to an viable range where the batteries can accept regen again. However, this regen starts by coming forcefully from engine load and many times there's very little we can do to manage that. However, as soon as the batteries begin to accept regen they also begin to provide modest amounts of assist as well. Since braking regen is out and engine load regen is the only main means to replenish the battery charge this leaves you you pretty bad fuel economy. (Auto-stop does not work either for an entire commute)

The occasional downshifting can help in this particular scenario especially when the computer no longer prevents charge delivery to the battery pack. In fact, there's no danger of overcharging or delivering improper charge, the system will ensure that.
In other words, downshifting does not shorten the battery life in any way since the system decides whether it is operationally safe for the battery to accept the charge or not.
As drivers, all we're doing is offering the system a charge opportunity that would otherwise be wasted. And when these opportunities are very few they also tend to be very valuable.


Cheers;

MSantos

 

I didn't mean to suggest that there is a danger of overcharging. I meant that Honda programmed the car not to perform regen when the batteries are too cold, probably for a good reason. So forcing regen may be doing so when conditions are not healthy for the battery pack.

As for no auto-stop, Honda probably had good reason for doing that in cold weather. Even in the mild California weather, if I drive for about 10 minutes down a moderate slope where the engine valves are shut, I find that auto-stop is no longer activated. I think this is a result of the engine cooling down too much. A cold engine is very fuel-inefficient, so it's better to keep it idling a bit to keep it warm, which will get you better FE when you start moving again.