can I replace my 45Wh battery with a new and larger capacity 60Wh one?  I believe you can. Dell's specs say that the 60Wh battery is the same length, 1.3 mm narrower and 1 mm higher than the 45Wh battery. Nothing in the Owner's Manual indicates any issues to changing battery type from one to the other.  You can buy the genuine Dell 60Wh battery direct from Dell or from Parts-People. Follow the disassembly and reassembly steps in Dell's Owner's Manual. Whenever touching components or working inside a computer, wear a grounded wrist strap, also called anti-static wrist strap, ESD wrist strap, or ground bracelet. It's a cheap and sensible precaution. Rest the laptop on an anti-static mat or at least a reasonable alternative such as corrugated cardboard.
I just bought myself a second-hand 5289 2-in-1 Latitude laptop and found that the battery life was not great.Running a battery check using powercfg /batteryreport revealed that the original battery capacity is 45Wh but the actual capacity reported is 12,141 mWh, which strikes me as a message that I need a new battery!Looking for a replacement I noticed that there are 60 Wh batteries available - my question is can I replace my 45Wh battery with a new and larger capacity 60Wh one? Didn't want to buy on and find out it is physically bigger and doesn't fit or the battery electronics can't cope with the extra capacity !
5289 2 in 1 Battery Upgrade 45 -> 60 Wh