Simply put, vendor CYA.. I use Batteries Plus battery in my RV-4, and I had to do a warranty replacement of one that didn't take initial charge..guy kept asking what vehicle I had it in trying to troubleshoot..after a few minutes of rolling my eyes, I finally confessed and I thought he was going to stroke out..WE DONT SELL batteries for aircraft. Hmm, yes you do by the way! 30 minutes of explaining Experimental aircraft regs, he finally honored my warranty claim. From now on, I will buy batteries for my Bobcat lawn mower.