Battery life and Charging rate (20A vs 40A)

Battery life and Charging rate (20A vs 40A)

Is there any reason to think that charging at a lower amperage is better for the long term battery life than charging at a higher amperage? For example, I can usually 'top off' my battery in 2 hours at 240v 40A with a NEMA 14-50 outlet. So, I could manually dial down my charging rate to 20A or 10A and still have a full charge in the morning. Would this lower charging rate be better for the battery? It seems to me that it would, if you have the luxury of time for slow charging. Does anyone have any hard data on this?

nwdiver93 | 14 januari 2013

I am also very interested in the answer to this question. I know the lower currents are more efficient but what would the effect be on battery life?...

jat | 14 januari 2013

I don't believe that Tesla would not tell us to charge slower if that made a measurable impact on battery longevity. They do say not to charge completely full all the time, but also say the most important thing you can do is keep the car plugged in all the time you aren't driving.

Nissan also says not to charge to 100% if you don't need it, and the battery report indicates particularly it is leaving it sitting at 100% charge that is the thing they are concerned about. They don't even show charging rate on the report.

So, I don't think it makes enough difference to worry about.

Brian H | 15 januari 2013

One big benefit of having the battery still "loading up" when you tell it to stop is that it is warm, and you get full power and regen.

Brian H | 15 januari 2013

For full regen, there needs to be some "room" at the top. You can do this by telling the car to Max charge without really going much into that 'extra'.