You can buy various AA batteries in bulk at good prices, such that rechargables become more trouble than they are worth. I use Duracell industrial ones which wholesale are much cheaper than shop prices, or bulk ones from CPC for Radio Microphones. Sometimes I use 30 or 40 a day for productions, and the capacity is little different from the more expensive D* ones. I have tried rechargables and they take a lot of effort and time to charge and the life of the kit power ends up the same as a normal AA, although the advertised capacity may be more. This is as Mike says the voltage monitors don't like rechargable 1.2 nominal voltage. Equipment designed for rechargable batteries has a switch mode, wide input range converter from the batteries so that they may be fully discharged properly, which may not be there in older equipment.

You can buy various AA batteries in bulk at good prices, such that rechargables become more trouble than they are worth. I use Duracell industrial ones which wholesale are much cheaper than shop prices, or bulk ones from CPC for Radio Microphones. Sometimes I use 30 or 40 a day for productions, and the capacity is little different from the more expensive D* ones. I have tried rechargables and they take a lot of effort and time to charge and the life of the kit power ends up the same as a normal AA, although the advertised capacity may be more. This is as Mike says the voltage monitors don't like rechargable 1.2 nominal voltage. Equipment designed for rechargable batteries has a switch mode, wide input range converter from the batteries so that they may be fully discharged properly, which may not be there in older equipment.