Submitted by axel.brunger on Sat, 2013-05-11 15:01
I noticed that it takes more kWh (according to the electric meter) than is what is actually stored in the battery. Example: I drove ~ 75 miles on a particular day. According to the trip meter this required 24.4 kWh battery power. After charging overnight with the Tesla HPWC connected to a dedicated meter, it required ~ 32 kWh to replenish the battery to the same level as before the 75 mile trip. The charging current was set to the default 60 A setting, and I let it charge to the default 85% level. The temperature in my garage was normal (about 65 degrees). Thus, it required ~ 7 kWh more power to charge the battery than the actual power that was deposited in the battery.
Does anybody have experience if it is more efficient to charge the battery more slowly, i.e., set the current to less than 60 A?