Your experience of 1S is unusual, sorry to hear that. In four seasons of running 1S in a 12th car with more demanding current requirements than Mardave, I have yet to hear of a cell failure or short life in a 1S used in a 12th Modified car, and we are talking 4.5 motors that draw 5000mAh in a single race! Compared to a Touring Car or Buggy, the current draw in a 1S is not high - a Modified motor in a TC or Buggy will draw more than a 1S cell in a Modified 12th car. 1S cells are just the same as 2S cells - they use the same single cells so the individual cell performance is equivalent from both. Remember that 1S cells are actually 1S2P, just as 2S cells are usually 2S2P, and a GT12 car is only using a 13.5 with no timing boost.
Since the 2S cells most people have are a tight squeeze in a GT12, it seems to me less likely that people will use cells from their TC or Buggy. This cell will screw the weight distribution in the car anyway, so it won't handle as well. James's proposal was illustrated with 2S shorty cells and the 2S cells used by the micro boys. He didn't test any car using a standard 2S cell.
Whichever way you cut this, to use 2S people will be buying a new cell. Arguably the best cell is the Yokomo 2S which is in the same case size as a 1S, since it will drop straight in to a standard car. Agreed most people have 2S equipment, which is what makes me say that the problem is the booster, not the cell. Once someone comes up with a simple booster at a good price, the 2S problem goes away. Now there is more demand, someone will do it eventually.
There are no issues with 1S cells, and no issues using receiver packs or boosters with 1S cells. Over 30 different GT12 racers at the Nationals used 1S cells and either a '1S' compatible speedo, a receiver pack or a booster. We had no failures. Your experience is unusual, and everyone should know that we would not have chosen 1S if there were problems. Over 150 12th racers have been using it for the last four years with no problems. Similarly, you won't find posts on any of the worldwide forums complaining about 1S cell problems. SMC cells are priced very competitively (£35) and are a top cell used by many. I hope people are re-assured that 1S is reliable.
Since the GT12 car draws about 1500mAh in a race, re-charging at 1C can take no more than 15 or 20 minutes, plenty of time between heats even at a club evening. One of our GT12 racers ran five consecutive Nationals, both days, using one 1S cell. It was only five because he forgot his cell at the last National! There is no need to charge above 1C (BRCA and manufacturer's recommendation) to get the car ready again for the next race.
I hope that gives people the information they need to make their decision. I do understand that people will find putting a 2S cell into a GT12 will make their lives simpler. However, no one should pretend that there is any equivalence to 1S, because there isn't. We will see how this pans out over time. If it turns out that 2S thrives and 1S dies, then we have the Rule in place and can change the GT12 National class to 2S. Let the people decide! HTH
