LiPo batteries (henceforth referred to as “LiPo” batteries) are a type of battery now used in many consumer electronics devices.
They have been gaining in popularity in the radio control industry over the last few years.
Now the most popular choice for anyone looking for long run times and high power.
LiPo batteries offer a wide array of benefits, but each user must decide if the benefits outweigh the drawbacks.
A LiPo cell has a nominal voltage of 3.7V. For the 7.4V battery above, that means that there are two cells in series.
(which means the voltage gets adds together).
This is sometimes why you will hear people talk about a “2S” battery pack – it means that there are 2 cells in Series.
So a two-cell (2S) pack is 7.4V, a three-cell (3S) pack is 11.1V, and so on.
Most multi-cell LiPo batteries feature two power connectors.
The primary connector provides the full series voltage of the battery to whatever device it is intended to run.
You will also find a balance plug that enables you to tap into individual cells within the battery.
The voltages of the cells in a battery pack may not stay in synch as they are cycles.
The balance plug allows the charger to ensure that each cell within the pack are charges to the 4.2-volt maximum and no more.
Most other battery chemistries don’t require this level of precision when charging. It matters with LiPos, so don’t overlook it.
The voltage of a battery pack is essentially going to determine how fast your vehicle is going to go.
Voltage directly influences the RPM of the electric motor (brushless motors are rate by kV, which means ‘RPM per Volt’).
So if you have a brushless motor with a rating of 3,500kV, that motor will spin 3,500 RPM for every volt you apply to it.
On a 2S LiPo battery, that motor will spin around 25,900 RPM.
On a 3S, it will spin a whopping 38,850 RPM. So the more voltage you have, the faster you’re going to go.