[Dallas Kelly]

When I brought my car back out in 2012 it was equipped with two 16V "lightweight" XS Power batteries. When I returned to the trailer following each and every run my Racepak dash was flashing a warning for low voltage. The batteries were thoroughly charged prior to the first pass and on charge continually between each successive pass. After four passes over 3.5 hours the engine shut off before I got completely back to the trailer. I called XS Power the next business day to learn what they had to say about the situation. I was connected to an engineer who told me that the Lightweight batteries were designed primarily for cars that were towed back from the end of the track, i.e. ProStock. He suggested that I purchase the 47lb "heavy" batteries (white top/lt. gray case) for S/S type racing. I followed his suggestion and have experienced zero voltage issues, in fact my Racepak indicates less than 0.1V decline for an entire pass. I realize that, based solely on the published specs, none of this scenario seems rational but the results speak for themselves.