This article Nissan Leaf: Does A Battery Inspection Give Peace Of Mind? raises the issue of battery degradation in Leafs. Heat appears to be the big danger. Our owner's manual cautions about this but I have not found any specific temperature targets. I recall that what is comfortable for the passenger is comfortable for the traction battery but I don't remember where I got that information. I did read in "Wiki" that the effect of heat goes up in a geometric rate, but there is a "sweet spot" between what is so cold as to affect performance and what is so hot as to be damaging. What is that "sweet spot" expressed in degrees of temperature? I speak of the temperature of the traction battery itself, rather than how warm it is outside (I have a ScanGauge).
The temperature issue regarding the battery does bring up two additional questions regarding temperature in the traction battery. 1: Since the amount of charge current applied does affect the internal temperature of the battery, will the 220 volt charger cause an additional heat load on the battery since it charges at a rate nearly double that of the 110 volt charger and will this additional heat load affect the battery life? 2: Some forum members have recommended using the charge timer to begin the charging at a later time to allow the charge cycle to finish just before the start of the days driving. This is done to avoid leaving the battery at a fully charged state overnight as one might do if the car was plugged in and charged after returning home for the evening. The logic behind this action is because the type of traction battery the PiP has can be damaged if it is stored in a fully charged state for an extended period. Since the traction battery is never fully charged by the cars power systems in order to protect the battery life would this short cycling between discharge and charging be of any benefit or would it be harmful because the battery doesn't have a chance to cool off before going right back on line to a discharge mode which also causes heating of the battery? Could this extended heating exposure affect the battery in a negative manner more than leaving it fully charged for a few hours before the morning commute?
Thank you for your response. My question is "what is the target heat range". With that information, one can assess the affects which you suggest. I note that my measured traction battery temperature is usually within ten degrees of the ambient temperature. If heat is the issue being considered, charging at night makes the most sense because night time temperatures are less. The timer is made to do that. We can't fast charge the PiP, but those who can, experience far more heat from that than the difference between 110v and 220v.
