Regarding battery life of A13 zinc air batteries, they are expected to last in hearing aids approximately 150 hours. As
@Freddypip said, this means you go for a couple of hours shooting one weekend , the batteries are likely dead the by next weekend.
The A13 Battery will have a life of approximately 300mAh (milli Amps per hour)
If we divide 300mAh by 150 hours, we can reasonably assume our device consumed 2mAh
Therefore, if we used a silver oxide battery, with about 1/4 the energy density (circa 80mAh) of the zinc air battery and a similar and very stable voltage, we would get approximately 40 hours use.
being able to turn off the battery, by switching or removal, our couple of hours shooting of a weekend would theoretically yield 20 weeks use.
the A13 costs about 25p per unit, purchased 60 at a time, whereas the silver oxide bought in similar numbers would cost about 3x that.
Therefore, unless I’ve made a schoolboy error (not unlikely) then the A13 costs £5 for 20 weeks shooting, whereas the SR48 silver oxide battery would, if managed well, would cost less than £1.
Am now wondering if there are possibly issues I’m unaware of, using a SR48 over a A13
To be fair though, If I’m going to quibble over less than what amounts to 20p a week, then I really ought not to be buying £400 ear plugs.
I can only shoot about 30 times a year so a batch of A13 will last me two years!
I only really wanted to go the digital route to hopefully make it easier to hear my coach. If I were in a competition, I’d want to turn them off and a passive would be just as suitable. Come to think of it, a passive module might be a good idea, rather than overly risk the digital ones when not really required.
My son uses industrial foam plugs as he says he couldn’t live with paying £400’s of “idiot tax” if he were to lose a module.
My son