Tom NC 1 speaks truth! And Tom your strategies are valid and effective, in my experience of employing them.
I can add five points as well.
According to Battery University and other reliable sources, the combination of high heat and full charge is most harmful. This implies that starting charge in the middle of the night is better than starting charge as soon as one gets home. (Here I am assuming a typical commuting to work driving pattern.) At 3 AM or so, the HVB has cooled somewhat and also by the time it hits 100% SOC later in the morning, the internal fan and cooler ambient temps will have brought the temp down even more in most circumstances.
Heavy acceleration raises HVB temperature a LOT. When it’s really hot out, I accelerate with like 1.5 bars as much as possible.
Regen also raises HVB temp a lot. When I see my HVB temp hit 105F, I brake harder so that the mechanical brake pads get used more, and less regen occurs. Once, in a moment of pique, I braked in N a few times to avoid any regen at all! But I did manage to keep it at 105F....
Windows wide open or, better yet, using A/C, if it’s just me in the car, I have both back seats folded down and the cargo cover open in hot weather. Just like I’m carrying cargo in the back, even when there is none. And never block those HVB vents on the left and right in the back!! These things all improve air circulation.
Finally, in three years of experimentation in all forms of ambient temperatures, in our garage and out, starting with both high and low HVB temps at the start of charge, I have determined this:
L2 charging leads to lower full-charge temperatures than does L1 charging.
Or, to put it another way, 110V charging with the car’s charging gear consistently leaves us with a higher HVB temperature at the end of the charge.
It’s not a big difference—usually 2 to 4 degrees F—but it is consistent.
It’s funny to be writing about hot batteries in January. I’ve been turning this around and charging on L1 sometimes just to keep the battery as warm as possible!
Edited by P=E/t, 21 January 2018 - 08:41 AM.