Battery Secrets for Your Radio Controlled Boat

Today's radio controlled boats usually most often use nickel-cadmium (Ni-Cd) batteries to power the engine because of their ability to discharge energy rapidly. Older-style batteries could hold more power, but because it took longer to release their energy, they produced lower horsepower and thus lower slower speeds. In addition, people prefer Ni-Cd batteries because of their rapid quick recharge rate and reasonable inexpensive 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

Ni-Cd batteries are classified as SC, SCR and SCRC. The SCs are what you'll generally get with a basic RTR boat. For beginners they're a good choice because they last a long time and don't cost much.

SCR cells discharge their power faster, producing more horsepower and faster quicker boats. They can also be recharged many several 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

Battery charges come in two main types. 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 completely charge. The problems difficulties arise if a cell hadn't been 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. The main problem with some of these chargers is the possibility of turning off too soon. If you suspect this is the case, wait a few minutes and turn it back on. If it shuts off within a minute or so, the pack was fully charged. If not, this second run will do the trick.

A cell's worst enemy is overheating so always make sure your battery pack is cool before charging or being put back into your boat.

In order to get the best long-term performance from your battery pack you should make sure it is completely totally drained before recharging. Some chargers have a discharge function that will take care of this for you, but if not, you can attach the pack to a small light bulb (like a car's turn bulb) until it goes dark. This will ensure 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!