Mini-lathe DRO Battery Lifetime

It seems 390/389 alkaline button cells can power the mini-lathe’s DROs for about a year:

Mini-lathe DRO battery replacement - 11 months
Mini-lathe DRO battery replacement – 11 months

Given that the replacement cells all come from the same batch, they’re aging on the shelf as well as in the DROs.

Once again, I replaced both of them.