[Taniwha]

Yeah - I design this sort of thing and I can't understand how the power management of this thing works - battery life has to be a month or so (or it's a cm thick).

Remember that when you're talking at GHz (ie BT) you have to keep your receive PLLs powered up to receive data, that's ~1/2 the power requirements of short distance transmitting

[teruakohatu]

Some media here have claimed a 6 months to a year of battery life. I am very skeptical.

[Taniwha]

Exactly - I'm not saying it can't be done, just that I'm highly highly skeptical

[teruakohatu]

Just noticed the username. Feel free to shoot me an email, would be keen to hear what kind of work you do in nz.

[amelius]

You don't need to transmit or receive continuously.

[Taniwha]

If you have two cards that are going to talk to each other one needs to be listening when the other is transmitting, if they're off 95% of the time (like the stuff I design) then 95% of the time someone transmits no one will be listening.

You can try and do something smart around synchonising wakeup times nationwide, but that is genuinely hard (and requires a xtal clock to be awake at all times, also burning power)