Battery life

[gargreen7]

Few questions about the batteries for my mad rat

this is what im using





Pretty standard from what i gather but my questions are

1. Should i always fast charge the battery or slow charge, (does either effect life and charge holding?)

2.How long should i expect one full battery to run for, 20 mins 30mins ect?

3.are there better batteries out there that give you more power or do they just last longer.