DaveinOlyWA
Well-known member
Not sure I would label it severe. Yesterday, I did a bit under 300 miles leaving home at LBW. To make a relatively valid comparison, I planned the charges (other than the first one) to be at about the same SOC and added the same amount of charge ~ 17.5 Kwh. All stations were Webasto that run 120-124 amps.
First charge batt temps mid 70's. 23 min charge speed before knee; 43-47 KW
2nd charge batts mid 110's 27 mins charge speed, etc. 40 KW
3rd charge batt temps 123 37 mins charge speed 29 KW
4th charge batt temps 129 40 mins charge speed 26 KW
Notice the small difference between first and 2nd charge? This is because 2nd charge was "temperature restricted" so charge started at 116 amps and slowly dropped to 108 amps as SOC rose to maintain the 40 KW charging speed to 66.1% SOC. The first charge with cool batteries charged between 123.219 to 124.108 amps the rate of power rose as normal but knee happened at 58.6%
Note; previous tests confirmed knee is controlled by "starting" batt temps. the colder the pack, the earlier the knee with starting SOC being unaffected as long as it was below the knee.
In a nutshell; Normal charging is current regulated.
Rapidgate charging is power limited.
FYI; since Rapidgate testing was the secondary purpose (I actually did have a reason to go south) of the trip and not "getting there" so key things to remember.
Leaving home with a "fuller" battery would likely have meant I would have had first charge with batt temps at near ideal conditions (mid 80's) which would have pushed knee to max ideal or about 63%. But since I left home with a low SOC, the first charge naturally had to be relatively early in the trip.
First charge batt temps mid 70's. 23 min charge speed before knee; 43-47 KW
2nd charge batts mid 110's 27 mins charge speed, etc. 40 KW
3rd charge batt temps 123 37 mins charge speed 29 KW
4th charge batt temps 129 40 mins charge speed 26 KW
Notice the small difference between first and 2nd charge? This is because 2nd charge was "temperature restricted" so charge started at 116 amps and slowly dropped to 108 amps as SOC rose to maintain the 40 KW charging speed to 66.1% SOC. The first charge with cool batteries charged between 123.219 to 124.108 amps the rate of power rose as normal but knee happened at 58.6%
Note; previous tests confirmed knee is controlled by "starting" batt temps. the colder the pack, the earlier the knee with starting SOC being unaffected as long as it was below the knee.
In a nutshell; Normal charging is current regulated.
Rapidgate charging is power limited.
FYI; since Rapidgate testing was the secondary purpose (I actually did have a reason to go south) of the trip and not "getting there" so key things to remember.
Leaving home with a "fuller" battery would likely have meant I would have had first charge with batt temps at near ideal conditions (mid 80's) which would have pushed knee to max ideal or about 63%. But since I left home with a low SOC, the first charge naturally had to be relatively early in the trip.
