@gowbow
Did you calibrate the new battery as shown in the ifixit [product|IF356-290] parts description?
If you did, can you try using the old battery again?
I realize that it wasn't that good but I assume that it didn't discharge as quickly as the new one. If it still behaves the same way as before then it's looking like the replacement is the problem.
Who did you purchase the replacement battery from? Looking at the battery I linked above, ifixit gives a 1 year guarantee on their battery so if you go to purchase a new one, check the seller's guarantee or warranty first before purchasing it. That way if the battery is the problem you shouldn't lose out, money wise