So - my experience with buying non-brand name batteries for my Milwaukee cordless tools has been very mixed. Mostly the batteries themselves keep working, but they are poorly put together. One 12-volt drill fell off my table and, while the drill itself was fine, the off-brand battery was destroyed. Just last week, another 12-volt one came apart while I was using the impact driver to make some threads. All of my Milwaukee-brand batteries are fine - although after maybe 8 years, some are getting pretty weak.