With all the new charges spend some time to reasearch and as long as you charge them correctly there is no need for worries. Most chargers you tell them how many cells = voltage most auto cut off and have a set charge rate which is adjustable if you want but to be safe just stick with factory settings if you want to charge fast do your research and buy a lipo bag. No need to worry everyday the cahrgers get safer.
Heres a good artilcle. education is the key take the time to learn what you are doing and you will love the power and the savings of not having to buy Nitro every week with the price of fuel these days...
http://www.rchelicopterfun.com/rc-lipo-batteries.html
Plus no tuning it is a plug and play thing...
Basics
Cells = voltage each cell is 3.7 volts the more cells the more voltage
C rating is discharge rating and also determines how many amps can be used to charge the battery. 3500C for example can be charged at 3.5 amps max. I stick to 3 amps myself but some push it to charge faster I am about being safe. How much puch the battery has . Lets say how fast 0 to top speed is achieved
MAH - How long the battery will run for the higher the MAH the longer you can run your vehicle
I hope this helps I was real hesistant at first as well