In the RC hobby today, modelers typically use Ni-Cd or NiMH cells. Both are rechargeable batteries. Under normal operation they can be recharged hundreds of times and have been known to last an average of three to five years and more.
From a beginner’s perspective Ni-Cd rechargeable batteries and NiMH cells provide roughly the same kind of service, so you need not worry at the start about what kind of cells were supplied with your particular RC system.
The NiMH can offer more capacity than the Ni-Cd cell of the same physical size. More capacity means that it can operate your system longer or fly your airplane longer. have a slightly lower characteristic voltage under load than Ni-Cd cells. From an RC-system standpoint, that difference is of little concern because the load is relatively low.
However, when using NiMH batteries for electric-powered flight, the difference can be important. If you fly a model with a seven-cell Ni-Cd pack, then substitute a pack with NiMH cells, you might have to go up one more cell to a total of eight to achieve comparable performance. With every passing day, advancements in NiMH battery technology are removing this deficiency.
Some inexpensive RC systems are sold with no batteries included. If that is the case, you will have to purchase 12 AA-size alkaline batteries. Although these cells will last a long time, they must eventually be replaced since they can’t be recharged.
There is a new type of battery technology called Polymer Lithium ion Battery, which has emerged thanks to the cellular-telephone industry. There isn’t much application for this type of battery cell for RC systems at this time, but you will be hearing and reading more about the great advantages of low weight and high capacity for electric-powered flight. There will be more about that in another installment.