cordless drill

Hi all, I've got a pair of Erbauer drill drivers with 4x 14v 4Ah Ni-MH batteries which works fairly well for me but the battery chargers are now giving me grief. I'd like to step up to 18v and get a drill & impact combo with 2 x 4 or 5 Ah Li-ion batteries. I've been looking at...

Dear all, I'm drilling concrete fence post with a cordless combi drill in hammer mode and a new fully charged 1300mA battery gets flat after 10-15 mins of drilling. The drill is Dewalt dcd776 Battery is 18V, 1300mAh dcb185 dewalt battery. Both drill and battery are new (bought a few days ago...