Went on a long trip through the desert. At one point elevation rose from sea level to 4,000 feet after about 10-15 miles of driving distance. Bars on the battery were at the mid point upon starting the ascent, but prior to completing the climb the bars on battery went down to one. This happened on return trip also. Car suffered from noticeable lack of power until I started the downhill phase. Within 5 miles of going downhill all the bars were lit. Has this rapid fluctuation happened to others?
Totally normal, battery was assisting on your climb, that's what it's supposed to do. When it runs low on charge you're pretty much on ICE power only which will be less than ICE + battery.
Long trip + desert + Summer + 4,000 feet . . . was your car packed and the air conditioner on too? :huh: Bet you got outstanding mileage on the way down.
