How to test battery with multimeter?

Hi all,

I have late 2013 MBP Retina 13" which had some water spill on the keyboard. it still runs fine and everything works fine however it shows an x in the battery indicator, it no longer registers a battery at all.

I tried resetting SMC and have taken the laptop apart to check the extent of the damage. both the battery circuit board and the logic board showed early signs of corrosion which i cleaned up with contact cleaner and a toothbrush. this didn't fix the battery problem.

Basically i want to narrow the problem down to either a logic board fault or the battery. if it is just the battery i will happily pay a service centre to replace. however i want to be fairly certain the logic board is fine before doing so.

Being the latest model its hard finding replacement parts or friends who are willing to lend me their laptop/battery. so i was wondering if there is a way i can use a multimeter to test the logic board/battery? if so how do i do this?

Any other ideas or tips welcomed and appreciated! have looked through other threads however they all relate to earlier MacBooks with easily available/changeable batteries!