I have a Nitecore Intellicharger I2 that came with a vamo-v3 starter kit. My however is in regards to the charger and can't seem to find any information. I'm assuming there was an I2, then a I3, and finally they are out with the I4 chargers. Can anyone explain the differences. Do I need to be concerned that I have an older version charger? Is the I4 safer or does it just support different battery types?