And oh yeah, one more thing....buy one of these
http://hobbyking.com/hobbyking/store...dProduct=10080
Turnigy watt meter. You'll need it to know how many AH you have used on your trip so you don't over discharge your batteries. Install it on somewhere on your bike so you can periodically look down and see how much battery you have used. It's only $24. It's a must have if you use lifepo4 battery.
That's about it. The BMS basically just prevents you from over discharging your lithium batteries. Lifepo4 can be used to 90 - 95 % of it's capacity but if you use more than that and the voltage of one single cell goes below about 2.5v then that cell is dead and cannot be used again. That's why I say only use about 10 - 12 AH of the 20AH pack so you make sure that you never over discharge it. Using only 50 - 60 % of the pack prolongs the life of them too.