Meh. I like to live life on the wild side, I've never used a lipo bag and don't intend to. Just don't be an idiot and you'll have no problems. It's not like lipos are magical fickle things that will decide it doesn't like you and blow up in
your face randomly.
Also, if you want a seriously good device for checking lipo voltages get a multi meter like the Fluke
ones (granted they're like $300 for a base model so unless you're really hardcore into this stuff or do it for your job there are cheaper alternatives).
Otherwise a cheaper battery analyzer will do the trick for most people.
Simple $2-3 one like this
Or you can go "crazy" and get something like this from Turnigy
Even crazier 7 in 1 Turnigy meter
that does stuff you'll never need like Servos and such for $40
And if you don't want to live life on the wild side like me then might as well get a lipo bag for $2: http://www.hobbyking.com/hobbyking/s...22cm_Sack.html
Although they're designed to be fireproof and contain a fire inside the bag it doesn't always so don't think of it like it's a "safety" and gives you a blank cheque to do whatever the hell you want with it or it will blow up in your face and set your house on fire.