Longer battery life equals better protection
RAM device is designed to last up to 20 years in the field assuming a use-case specified in Configuration and power consumption. Such lifetime is provided only by LiSOCl2 primary lithium battery chemistry and as such this is chosen for this device. Device supports the following configuration:
- 2x Primary lithium battery in size 17500 or 18505,
- 1x Supporting super-capacitor to smooth out the current peaks (before or after boost configurable),
- Boost converter to decrease the minimal battery voltage.
Saft is the leading manufacturer of primary lithium cells and the LM product series is suitable for RAM, cell LM17500 is selected for use in low-temperature conditions. The drawback of this LiMnO2 chemistry is lower nominal cell voltage and smaller capacity, however capable of high discharge currents, making it suitable for use without a supercapacitor. Lower voltage however requires the use of Boost for the majority of operation.
Table below represents expected life duration of the battery for various places on the planet, some with extreme cold weather conditions, according to simulations analysis with consumption input according to RAM-1 most frequent measuring in communication setting.