I have used a few different battery models: Oregon 40V and Redback 120 V (discontinued).Spent a couple hours running the Stihl....weedeater that is. Wife wants a battery one because she can't start the gas one. Anybody have one of those? And if so, how do you like it?
String trimming is one of the easiest tasks for battery powered outdoor equipment. So you may be happy with most any major brand, if that is all you do.
The key thing I keep repeating is that you may want another battery tool soon (leaf blower, hedge trimmer, lawn mower, chainsaw, pole saw, etc. ), and the batteries are brand specific. So take a look at the whole ‘family’ of tools supported by the battery platform (STIHL HAS 3 different ones!) so that you can share / swap the batteries between tools.
Or look at outdoor tools that work with the batteries from your cordless drill, etc.
Philbert