I have a fox pro game caller, its about 8 years old .I was wondering what battery lasts the longest.I bought duracell rechargable batteries , when I got them I put them in charger , charged them up , and yesterday used it for first time using the rechargable batteries.They lasted only about 2 hours , and not even that long really, before it lost volume drasticly.Is this a issue with rechargable batteries ? What have you found out about batteries for game callers.Thanks for any info. on this subject.