I have purchased two Li-ion 3.7 batteries, each with a current rating of 2000maH. A picture of one of these batteries is below.
Initial tests with the radio modules at 24 dbi (not the max of 30dbi we will use) saw a running time of 5 hrs and 24 minutes. Well beyond my expectations. I increased the radio TX power to 30dbi and I got running time of 4hrs and 40minutes. I performed another test (After making sure the batteries were complete charged….waiting for the charge light to go out). The batteries connected in series to with a total of 8.17 volts. The run time was 5hrs and 40 minutes. Extremely satisfying.
The battery’s are very small and will fit inside the main Electronics box. This is important because these are Li-ion (not to be confused with Lithium) and their operating voltage is best above -20 degrees
..though better at zero or above. These batteries will be next to the internal electronics the radio transmitter which should could it sufficiently warm – hopefully. There is a temperature sensor in the radio and near the radio module that will give us a pretty good idea of how the batteries will be copping.
These batteries will be tapped together and stuck to the top of the box and wires will lead to the power board internally.
These batteries are charged with a USB charger. They required approximately 2.5hrs to charge completely.