Yeah, I say this with a grain of salt and can't really recommend because I haven't purchased one. A couple of months back, I was shopping around, and all things considered, convenience (lots of stores), cost ($180), and warranty (no questions asked 4-year free replacement), Walmart rose to the top.
I was getting the sleep mode notification frequently, almost daily, over a 3-month period with no other issues and was thinking it was time as the battery is just now 3 years old. That said, I reset the battery monitor (BMS) and haven't seen the notification in the past 8 weeks. No doubt, it probably is still time for a new battery.
I feel funny throwing Walmart out there.