drilling concrete

I have access to only one side of a concrete gravel board. There is very limited access to the other side (i.e. barely finger reach). Can expanding bolts be used without cracking the concrete? Would a toggle fixing be an option for outdoors? If so, what fixing products might I consider for a...

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...