I run makita everything and am a commercial glazier. I'll spend all day constantly drilling into concrete either m8/10 with my drz202 hammer drill, cutting down bolts on my grinder and fastening with my impact.
I bought 2x 5ah last year and have already had them replaced by makita, they would say fully charged but once they showed 2 or sometimes even 3 bars my hammer drill would die.
On the hammer drill it would show the battery only has 1 bar but on the battery it would show 2 or 3.
I have just taken my 6ah batteries back that are less than a year old because they are doing the same.
Its winter here and In the cold wind it will take up to 1.5hrs to charge, out of the wind the normal 45mins.
(yes this is a thing, mind you has to be super cold as in the battery itself isn't even slightly warm while charging)
Today I've bit the bullet and bought the new makita BL DHR242 with vacuum attachment which is supposed to give us 30% more battery life than the brushed. Fingers crossed this helps.
At the moment I'm going thru batteries like crazy, I'll get maybe 10 holes drilled and 10 bolts installed before the battery dies (brand new battery) on both my 5ah and 6ah.
Im guessing the cold in general is not helping (im wearing 7 layers and have heated insoles in my shoes!)
Anyway, i hope that gives you some idea on battery life.
Makita batteries all come with a 3yr warranty so don't be afraid to take them back when they play up!