Thanks for all the great input so far everyone! As Michelangelo has pointed out, the red LED on the front of the AxiomAir will illuminate when you have approximately 15-30 minutes of charge remaining (15 if you have one battery pack, 30 if you have two). This is your indication to plug in your unit for a re-charge. If you ignore the warning LED the AxiomAir will go through a proper shutdown routine and turn itself off. A re-charge from fully discharged takes about 2 hours, regardless if you have one battery pack or two. One thing to keep in mind is that the available power output from the amplifier is reduced during charging, so you should avoid playing the system at full blast.
We decided not to include a battery monitor as it's not practical to create something that would be meaningful for the type and charge life of the batteries we are using. By this I mean the battery output remains nearly constant for over 90% of it's discharge cycle and then falls off a cliff. An indicator would only be accurate at the same time as the battery charge warning LED lights up!
Mojo, the modern battery chemistry used means that you don't have to worry about deep cycling or trickle charging the battery packs. Just use them as you need them. As with any batteries, extreme operating or charging temperatures should be avoided, if possible.
Thanks,
Andrew
