You should be able to get twice the use out of the lithium. Since you only have to recharge it half as often due to the longer battery life. PLUS, lithiums work much better in the cold. Overall, for $200 (double the price of the nimh), you're basically getting enough run time to account for 2 nimh's anyway. Plus it's a lighter battery and you have the option of going on a 4-5 hour ride if you want to.