On the A12 the battery will die after 2 days even with about 73% left

[SouthEastman]

Battery will die after about 2 days even with about 73% left 

[BandOfBrothers]

That shouldn't be happening @SouthEastman 

Here are a few things to try.

• Clear your System File Cache vai the instructions in the Samsung Link. You may need to hook upto a computer or insert your headphones to get to the recovery menu. https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ 
• https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/  This will help determine if an app or something you've downloaded is causing an issue.
• Back up and factory reset as a very last resort.
• In your Samsung Members App is a good diagnostic tool that looks at many things including the battery.

A Samsung Experience Store  / Samsung Service Centre will be able to look at your phone.

I wish you all the best with this situation. 

[SouthEastman]

Thanks for that will try