some esc hv lipo cut off function ( but not 100% accurate)
the best way is to check the voltage every 3-5 mins, and u can find out how long u can play.
1/8 scale system uses a lot more current than 1/10 system. if you want to use 14.8v, try getting 2 packs of 7.4v instead of 1 pack of 14.8v. (try to get brand names ones, like IP or SE etc...)
With Lipo, dont over play the car is the only way to prevent inflating.
As mentioned before, you can try 2 x LiFe (2 x 6.6v=13.2v). You do not have to worry too much about over-discharging LiFe packs as they are safer and has less maintenance than Lipo. I find LiFe is a very good choice for offroad applications.
1. 6.6v LiFe packs varies from $200 to $300 depending on capacity.
2. If inflated just a little, its ok to use, but at your own risk. however, it is better to throw it away.