FunRCBoats Battery School

Battery School 101

Hi, welcome to Battery School 101.

There are two ways to wire in ADDITIONAL batteries. Both have completely different results. Read carefully to achieve the results you are looking for!

Series (a): will increase the voltage (for more power & speed). By adding more cells + to - This will increase the voltage by the amount of each individual cell (i.e. a 1.2V increase per cell added).

Parallel (b): will increase the mAh or amperage (for more or longer run time). By adding more cells + to + this will not in crease the voltage (as listed above in Series), just the amperage (or Milli Amp Hours: mAh) by the amount of each individual cell (i.e. 2400mAh or 2.4 amps increase per cell added). This means longer run times.

Figure 1: (a) a series connection of four batteries, and (b) a parallel battery network.

Pretty cool hua? Now you can build your battery packs to do exactly what you would like them to do!

Typical configurations:
6 cell pack = 7.2 volts (standard battery pack)
7 cell pack = 8.4 volts (commonly known as a hump pack)
8 cell pack = 9.6 volts (same as two 4 cell packs in Series)
9 cell pack = 10.8 volts (same as one 4 cell and one 5 cell pack in Series)
10 cell pack = 12.0 volts (same as two 5 cell packs in Series)
12 cell pack = 14.4 volts (same as two 6 cell packs in Series)

A few IMPORTANT points to remember:

Batteries can be added by directly "strapping" (like a stock battery pack) the batteries together or by using wires and plugs to connect multiple packs together.
Check your existing charger's capability (some chargers will not charge more than 7 cells at a time) and your boat's hull (where do your existing battery pack(s) fit?) to determine the best battery configuration to properly fit your equipment.
More power (higher voltage) or longer run time will INCREASE the amount of heat produced by the electric motor. To avoid a "melt down" check your motors temperature several times during the first few runs. Then add a water cooling coil as soon as you can.
More power means you can drive a prop with more pitch or bigger diameter. It's time to experiment - that's the fun of model boating!
Do not exceed 10 cells in "series" this is the point of no return. Meaning you are adding too much weight to the boat for the power gained.

More about maintaining my batteries