Friday, December 7, 2012

The Best Batteries for RC Receivers


RC equipment mounted in a plane, car or boat needs an on-board battery to power the receiver and servos.

While most servos only require 4.8 volts to operate, some can use 6 volts and will deliver more torque at higher speeds with the higher voltage. There are 3 types of rechargeable batteries that are commonly used to power receivers, each has pros and cons.
Nickel Cadmium Batteries

NiCad batteries have been used in RCs for many years. These batteries come in different size just like common alkaline batteries do. The size of the lipo battery effects the amperage of the cell not the voltage. NiCads are rated at 1.2 volts per cell, a pack of 4 or 5 can be used providing either 4.8 or 6 volts.

Not all servos can handle 6 volts, so check their ratings before deciding on the size pack to use. NiCads can be recharged 100s of times and make an excellent choice for RC receiver packs. One downside is that NiCad packs are heavier than other batteries.

Lithium Polymer Batteries

LiPo batteries are used throughout the RC hobby. These batteries are lightweight, powerful and rechargeable. Each LiPo cell is rated at 3.7 volts, so a 2-cell pack would be needed to power a receiver and servos.

The voltage of a fully charged 2 cell LiPo pack is 8.4 volts. This much voltage will damage the receiver and servos. To use a LiPo pack for a RC receiver, you need to put a voltage regulator in line to reduce the voltage to 4.8 or 6 volts.

LiPo cells can be recharged up to 500 times. A special charger is needed for LiPo batteries; using a NiCad or NiMh charger with a LiPo pack will damage the pack and could start a fire.

Nickel Metal Hydride Batteries

NiMh batteries are very similar to NiCads. They are rated at 1.2 volts and are rechargeable 100s of times. NiMh cells tend to be lighter then NiCad cells and deliver the same power. Unlike NiCads however, NiMh cells are a little more delicate and have a higher failure rate then NiCad cells.

The power to weight ratio of these batteries makes them an attractive choice for on-board receiver packs. Don't allow a NiMh pack to get too hot while charging, this will damage cells and reduce the life of the pack. Use a temperature probe while charging, if possible.

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