OpenEVSE hardware version 5.5 and above supports variable relay power. The relay is closed at full power then after a set time the power is decreases. Differences in hardware and temperature can require slightly more hold power.
To alter the settings login to OpenEVSE WiFi
Click the System tab
Enable Developer Mode
Click the RAPI tab
Enter the command $Z0 xxx yyy
xxx = the number of ms to run 100% power
yyy = the power out of 257\5 (example 90/255 = 0.35 or 35% power)
Recommended setting is $Z0 100 105
100 ms full power then 40% power
Additional Example
200 ms full power then 50% power
$Z0 200 127
Disable the feature
$Z0 255 255
Note the $ is required
Z must be capitalized
after Z is a zero not a capital O
spaces are required