2 hours of runtime is pretty good. my Dell inspiron 1520 never game more than one hour of backup even when it was new. this model is a messed up unit from dell. i have read stories from other 1520 owners online. everyone suffered the same problem. the battery died within the first 12 months of operations. dell india is asking 10-15k for a new battery depending upon the number of cells in it. i run it on power 24x7.