I've used Tadiran on military projects. Good. But very pricey.
They make super high capacity C and D cells that cannot deliver high current so one bridges them with a superCap for the bursts, and the superCap recharges from the Tadiran exotic-chemistry cells.
Burst - like an MCU wakeup, receive, transmit, sleep cycle of say 50mSec.
This message was edited 2 times. Last update was at 22/05/2015 19:47:59