Finally a sub, shudda done that 2 weeks ago, maybe they did?
Still the pinger's are near end of life, why?
Sure batteries only last for a limited time, 30-45 days we are told. Again, why?
I can understand the expense aspect along with testing but I wonder why the first thought is just about the batteries.
Regardless of what batteries are used in any generation of device why
not install a timer circuit as a quick, perhaps easier to test and prove alternative?
IE Set a timer to offer different ping rates as battery life declines.
7 day's normal rate, 8-20 days 50% rate, 20-40 days 25% rate,
40- end of life 10% just to put a number there.
How long could the current gen. of batteries operate using this ping regime?
Perhaps that is how the current boxes are wired, I don't know but if not
why not? Would this be an easier fix to accomplish than trying to rebuild
the device with newer better and perhaps physically larger batteries?