It I read the article correctly, these guys took off with two dead batteries in violation to the recommendations from the manufacturer. Obviously the batteries did not have time to recharge in the short time after the engines were up and running.
Reminds me of a friend that said it is very difficult to make something idiot proof, as idiots are so ingenious.
Maybe they should have charged the batteries overnight and therefore have two fresh batteries for flight (I assume they have two batteries as my plane does). Or even better replace the batteries when they go completely dead.
RV 7A H-6
Almost finished Finishing
Lafayette La.