Battery technology is always continuously evolving. The cell phone revolution has certainly spawned large capital investments in this space. In the past decade several varieties of batteries have been tried and tested but Lithium Polymer (LiPo) batteries are currently the choice R/C hobbyists are using to power their FPV multi-rotors.
There are several things you need to understand about LiPo batteries. However, for this post I am focusing on the C Rating; otherwise known as the capacity rating.
A battery that has a 35C rating means it can be discharged safely at a rate 35 times more than the capacity of the pack. The C Rating is effectively a measure of how fast the battery ions flow from the anode (-) to the cathode (+). Simply put, the larger the C Rating the faster the ions can flow.
Here are a few points to consider when selecting a battery:
- LiPo batteries tend to increase in weight as the C Ratings increase
- High C Rating batteries cost more
- V = iR so you want more voltage to reduce the heat
Example:
I am using the Lumenier High Discharge LiPo battery to illustrate the following calculations.
Battery parameters:
- 11.1V
- 3 Cell (3S)
- 2250 mAh
- 35C Discharge
- 70C Burst
- XT-60 Connector Plug
Maximum continuous discharge rate on the LiPo battery pack
(35C) x (2250 mAh) = 78,750 mAh or 78.8 Amp discharge rate
Theoretical maximum current draw per minute
78,750 mAh / 60 = 1,312.5 mAh
Theoretical time to drain battery at maximum continuous discharge rate
(2250 mAh) / (1312.5 mAh) = 1.714 minutes or 1 min 43 sec at a maximum continuous discharge.
Check out our famous Best 5 Recommendations Lists!
Best 5: Flight Controller Recommendations
Best 5: Electronic Speed Controller (ESC) Recommendations
Best 5: Beginner Drones for FPV Flight