Radio Controlled Boats Battery Secrets

Modern radio controlled boats usually use nickel-cadmium (Ni-Cd) batteries to power the engine. Their advantage lies in their ability to discharge energy rapidly. Older-style batteries could hold more power, but their slower energy release meant lower horsepower and thus lower speeds. Additional advantages to using Ni-Cd batteries include their rapid recharge rate and reasonable price.

How to Choose the Proper Battery Type

Individual batteries are called cells and Ni-Cd cells each produce about 1.2 volts. By joining 6 cells together, your battery pack has 7.2 volts (6 cells x 1.2 volts). You can increase the voltage by adding more cells, but eventually the weight gain will offset the increased power. You have to find the best combination for each boat.

Electrical current is measured in amps and the capacity of a cell is rated in amp hours. Most Ni-Cd batteries used in radio controlled boats have a capacity of 1.4 amp hours, which is usually written as 1400 milliamp hours, or 1400 mAh. The batteries will last longer with a low discharge rate and will run out quicker if the rate is higher. The amount of power delivered to your boat's engine is calculated by multiplying the total voltage (determined by the number of cells) and the current draw in amps. Most ready-to-run (RTR) boats consume between 10 and 20 amps, so the run time is about 4-8 minutes. This is a sweet spot for the beginner because the batteries won't overheat the motor or the speed control.

To increase your boat's speed, you can either increase the voltage or the amperage. Usually, it's a good idea to increase the voltage by adding cells and keep the amperage at a moderate level to prevent overheating.

Three Types of Batteries

Nickel-Cadmium Ni-Cd batteries for radio controlled boats are classified listed as SC, SCR and SCRC. The SCs are what you'll most often get with a basic ready to run boat. For beginners they're a good choice because they last a long time and don't cost very much.

SCR cells discharge their power faster, producing more horsepower and faster quicker boats. They can also be recharged many multiple times a day, so if you have several a few battery packs in rotation you can run your boat for hours.

SCRC cells usually put out 1700 mAh, so they can run longer and produce more energy, but you have to be careful not to overheat them. Also, they will only take 2 or 3 recharges per day, so most radio control boaters only use them for special occasions, if at all.

Re-Charging Your Batteries

There are several types of battery chargers to choose from. A timed charger will automatically turn off when the time you set has expired. So if you charge a flat battery at 5 amps, it will take 17 minutes to fully charge. The problems arise if a cell wasn't completely discharged before recharging. This can lead to overheating, the leading cause of battery failure.

A peak-detector charger, on the other hand, will turn itself off when it detects that the battery has received a full charge. These are very convenient, and unlikely to overcharge a battery. However, some of these chargers may stop the charging cycle before the cells are completely fully charged. If you suspect think this is the case, wait a few minutes and then turn it back on. If it shuts off within a minute or so, the pack was fully charged. If not, this second run will finish the charging.

Since overheating is a cell's worst enemy, always make sure it's cool before charging or being put in your boat.

You'll get the best long-term performance from your battery pack if you make sure it is completely drained before recharging. Some chargers have a discharge function, but if not, you can attach the pack to a small lightbulb until it goes dark. That way you'll always get the maximum charge to your pack.

With all the information you've learned from this brief article, you should be able to maximize your batteries' ability to power your radio controlled boat. Now go out and have fun!