[2022] U-190 reserve battery consumable doesn't work during or soon after emergency surface

Yes, the consumable freezes your Depth Timer for the duration of use. It can be disadvantageous to use if you are at 0:00 Depth Timer remaining.

The consumable is best used while you have Depth Timer but recognize that you will be held underwater for longer than expected (ie: you can't surface for a significant period because of enemies nearby).