I had a similar issue. I bought a new battery and my computer moved slowly... almost as if it was delayed by something. I put the old battery back in and it worked beautifully again.
So more than likely the battery is incompatible with your laptop. The battery might have been advertised as being compatible with your laptop model name (Example A1369) but some batteries are only compatible certain processors speeds on that Model(example 1.86ghz core duo or 2.13ghz core duo. The battery itself has a model name on it. (Example A1405) Find out what Model Battery should be and buy that one. No reason to waste time trying other things that won't work when the issue occurred after the battery was replaced.