the bit chris talks about is the trakpower balancer
www.trakpower.co.uk same as flightpower but gold in colour
a balancer is good BUT not a necessity, if you find some one with one ask them to balance your cells ( will take 5 mins max) every few months would be enough (though as allways if you can afford one get one as its a good investment)
the trakpower balancer does have some saftey features which makes them good for new users as its an added saftey feature
just topping them up does actuatlly increase thier life, as two half top up's is equivalent to one full discharge and charge
so a 5000 pack having 1500 taken out is using less that a 1/4 of one cycle
trakpower were amazed at how long car pacjks were lasting as they were comparing them to planes, where the plane do a full dis/charge cycle we do 5 mins and top up