Lithium Polymer (LiPo) batteries are the powerhouse behind electric radio-controlled (RC) aircraft. To maximize performance and safety, users must understand three core specifications: voltage, capacity, and discharge rate (Crates). 

1. Voltage: The Power Behind Each Cell  

Nominal Voltage per Cell: 

       •      LiPo: 3.7V (Fully charged: 4.2V | Cutoff: 3.0V)  

       •      NiCd: 1.2V | Lead Acid: 2.0V  

Series Connection (S): 

       •      3S LiPo = 3 cells × 3.7V = 11.1V (~12.6V when fully charged) 

       •      6S LiPo = 6 cells × 3.7V = 22.2V (~25.2V when fully charged) 

2. Capacity: Runtime in mAh/Ah 

Definition:  Capacity (e.g., 5000mAh) indicates how long a battery can deliver current before reaching cutoff voltage.  

Example: 

A 5000mAh (5Ah) battery can supply:  

       •      5A for 1 hour  

       •      10A for 0.5 hours  

 Key Notes:  

       •      Capacity drops under high load or extreme temperatures.  

       •      For longevity, land at ~3.8V/cell (uses ~55% capacity).  

3. CRates: Charge & Discharge Limits  

A. Charging CRate  

       •      Safe standard: 1C (e.g., 5A for 5000mAh).  

       •      High-performance: Up to 5C (use sparingly).  

B. Discharge CRate  

       •      Continuous (e.g., 25C): Max sustained current (25C = 125A for 5000mAh).  

       •      Burst (e.g., 50C for 30s): Short-term peaks.   

Label Example: "25C–50C" = 25C continuous / 50C burst.  

Best Practices  

   •    Voltage Range: Keep cells between 3.0V–4.2V.  

   •    Storage: Store at 3.8V/cell.  

   •    Charging: Prefer 1C for battery health.