You are okay....that's exactly how it is designed to be handled. I run my 2 with my 15K AC and it acts lust like yours - when the AC kicks in the genns run at full speed.
2014 Jayflight 24FBS Elite
2009 F150 Supercab, 5.4L ,3.73, HD Tow Package, Equal-i-zer 1K,
Progressive EMS-LCHW30, TST 507RV TPMS, Hydro Life HL-200, Maxxis 8008.
Best friend wife and dog Cooper. RETIRED 6/30/16. WOOHOO! Now the "endless summer" begins.