Overall, the battery adds a little bit of extra weight, but the HP Mini 5101 gains from a huge improvement in battery life.
Not surprisingly, the battery life was the one weak spot of the HP mini range, but at least with the 5101, an extended battery will lift its rather measly 3hr and 28mins light-use battery life to a far more satisfying 7hrs 19mins.
While that doesn't scale the lofty heights of battery life set by the impressive Samsung N110, It's enough to provide stiff competition to the likes of the Eee PC 1000HE and Dell Mini 10.
Given everything else it has going for it, the additional battery life is worth the $130 cost, but it still offers less value for money than either of those two systems.