The short answer is it's not designed to bring the voltage high enough. For more details, I suggest Red's battery site: www.rcbatteryclinic.com. In particular, read through the topic titled "All about Wall Wart Chargers". If you're adventurous, you could probably cobble something together. My solution was to just buy the already recommended Accucycle Elite. I'm glad I did, it's proven to be useful for the variety of different packs I have.