Does Oticon Dynamo use Power One batteries? Such as p312, p13, p10, etc?
I would think so. As a power aid, it is likely the 13. Brand isn’t that important – assuming a good/known manufacturer. Some might last marginally more than others.
Quick check of the Oticon website says yes, Size 13 (orange tab) batteries. Power One batteries are good. If you have access, Costco batteries are just as good and half the cost.