Dick: Clearly, many RCers are using the A123 cells with excellent results. They certainly appear to be a safer technology and yes, they can be somewhat abused without as much risk as that associated with LiPos. My Partner 2 meter pattern ship, with Thunderpower 5300 cells, weighs 10 lbs 13.5 oz ready to fly. I thought I would compute the weight of my Partner with A123 cells. According to the A123 Systems website, each cell produces a nominal 3.3 volts, weighs 70 grams and is rated at 2.3AH. To put together a pack with sufficient voltage and current capacity to fly a Masters pattern, I would need two strings of 12 cells in parallel or 24 cells. With the resulting 4.6 amps of capacity, I could get through the pattern; however, that pack would weigh 59 ounces (without wiring/connectors) which would add 1 lb 3 ounces to the weight of my ready-to-fly Partner......not an option for me or most other 2 meter pattern ships being used today. Clearly, you are an advocate of the A123 cells.....but I don't see how they can be used in pattern competition due to weight. As a side note, I've been using lithium polymer cells since before most pattern flyers even knew of their existence. I follow the rules for handling, charging, storage, etc. and have had excellent performance without fires or other accidents/incidents. Again, I think the A123 cells clearly have a place in R/C, but I'm not sure, as a result of their weight, they will benefit the pattern community. If I'm missing something, please clarify.

Mike

P.S. I miss your production of outstanding pattern designs....have flown many of them over the years.