Newby battery question [Archive]

AlbinoAlligator

05-26-2006, 07:04 PM

I just bought my first rc boat. I know very little about rc stuff. My first question is about batteries. My boat came with a NiCad SC 1800 mAh 7.2 volt battery pack. What I want to know is, what types of battery packs will work with this boat? Does it have to be exactly the same, or can I use one with more volts? Or a higher mAh number? Any and all info on this topic would be very helpful. "RC batteries 101" is kinda what I'm looking for.

Thanks,
AA

CG Bob

05-26-2006, 11:32 PM

What I want to know is, what types of battery packs will work with this boat? Any 6 cell pack will work in the boat. NiCd and NiMh batteries come in packs with different numbers of cells, with the 6 cell 7.2V being the most common.

Does it have to be exactly the same, or can I use one with more volts? That would depend on the speed control. Some speed controls can only handle 7.2 volts, while others are rated for a higher voltage. Check the speed control first before increasing the number of cells.

Or a higher mAh number? You can use battery packs with a higher mAh rating, they will give you a longer run time, but also require more time to charge. Generally speaking, 100 mAh is about one minute of run or charge time. Your actual run time may vary based on the motor, prop size & pitch, and any friction in the drive system.

Increasing the number of cells in a battery pack increases the motors top speed, provided the speed control can handle the load. Increasing the mAh rating increases the run and charge times.

Depending on the motor and drive system, you may have to let the battery pack cool down before charging it. I have a 1/10 scale Crackerbox where the motor and battery get quite warm after a 5-7 minute run with a 7.2V 1700 mAh NiCd pack. I let the batteries cool down at least 15 minutes before recharging them. I also let the motor cool down at least 15 minutes before running the model again. I can run the same battery pack in a different boat for almost 15 minutes before the battery discharges.

If you're using the stock Tamiya connectors on the batteries, they may get very warm during a full speed run. I've seen some of the Tamiya connectors melt togetjher from the current flowing thru them. If they get warm, you may want to consider changing all the battery connectors to Sermos Power Poles or Dean's Ultra Plugs.