Explaining the LiPo battery (attempt)

Battery Technologies Overview

Types of Battery Technologies

- Li-Ion
- Lithium Iron Phosphate (LiFePo4)
- Lithium Polymer (LiPo)
- Alkaline
- Lithium Rechargeable
- Mercury Cell
- Zinc Air
- Nickel Cadmium (NiCd)
- Nickel Metal Hydride (Ni-MH)

LiPo Battery Technology

Advantages

- High voltage
- High energy density
- Long cycle life
- Light weight
- Smaller size
- No memory effect
- Environmentally friendly
- Good high current discharge performance
- Flexible shapes
- Great high and low temperature endurance

Usage in Drones

- Long run times and high power
- Voltage ratings:
- 2s = 7.4 volts
- 3s = 11.1 volts
- 4s = 14.8 volts
- 6s = 22 volts
- Nominal voltage of a LiPo cell is 3.7v, fully charged voltage is 4.2v
- Example: 4s LiPo nominal voltage is 14.8v, fully charged voltage is 16.8v

Disadvantages

- Supports less recharge life (300 to 400 cycles)
- Chemistry leads to fire when punctured
- Requires special care during charging, discharging, and storage
- Expensive, almost double the cost of Li-Ion battery

Maintenance

- Fully charged at 4.2v/cell
- Minimum safe charge is 3.0v/cell
- Use a LiPo compatible charger
- Voltage is the primary measure of battery charge level

LiFePo4 Batteries

- Twice the power, half the weight, and lasts 4 times longer than a sealed lead acid battery
- Common in fishing electronics and outdoor use
- Single cell is 3.7 volts
- Stacked together to achieve desired voltage levels
- Example: 20v Dewalt tool likely has 6 cells

Optimal Maintenance

- Light use, shallow discharge and shallow charge
- Avoid deep discharge
- Avoid frequent full charge and discharge

NiMH Battery Technology

Advantages

- High capacity compared to other rechargeable batteries
- Resists over-charging and over-discharging
- Lightweight
- Environmentally friendly (no hazardous chemicals)

Drawbacks

- More expensive than other rechargeable models
- Self-discharge rapidly while in storage
- Cut power suddenly rather than a slow trickle down
- Some only work with manufacturer’s charger

NiCd Battery Technology

Advantages

- Relatively inexpensive
- Charge very quickly, simple to charge
- Easy to store and ship
- Take a high number of charges
- Functional in low temperatures

Drawbacks

- Not as powerful as some other rechargeable batteries
- Self-discharge while in storage
- Contain toxic metals that are harmful to the environment