There are many RC’s on the market that are setup in such a way to use 2 LiPo battery packs. Theoretically, you can have any RC Airplane, Car, Boat, Helicopter or Drone setup using 2 battery packs. However, it is fairly common that RC manufactures would setup higher powered vehicles in this way. In this article we break it down using 2 LiPo battery packs in a RTR setup or even your own build!
Why RC’s are setup with 2 LiPo Batteries?
Manufactures of RTR vehicles setup an RC in this way for a few primary reasons. Let’s take a look.
Placement of Batteries
As we have mentioned above, it’s more common to use 2 LiPo batteries in a high powered RC. Higher powered RC vehicles just by inherited nature use larger batteries to be able to pump out higher amounts of power. It is more simple to break down the 1 large battery in to 2 smaller packs. Depending on the vehicle, it may be easier to physically locate 2 smaller packs on a chassis rather than 1 larger pack.
Weight Balance
In addition, placing 2 battery packs on an RC car will allow better balance of weight. Most 2 battery rigs will have the packs placed symmetrically about the length of the vehicle. Since the battery is usually the heaviest component to be placed in to your RC, balance of it is very important.
Availability of Battery Packs
It becomes more apparent as to the availability of LiPo batteries when running an RC car or boat using a cell count of 6 or more. There are not as many 6s LiPo batteries on the market as there would be for 3s LiPo’s for example. Then consider an 8s – 12s setup and purchasing 8s – 12s LiPo’s. I have not seen one in a very long time.
Is Parallel Or Series Better for 2 Packs
There are a few advantages to both a parallel setup and a series setup. However the true answer to this question lies in the Manufactures recommendation and your personal preference. Most manufactures already have the appropriate battery harness selected. This way you can simply take your charged batteries, plug them in and run the RC.
Parallel Advantages
- Parallel setups do not increase the wire length leading to the ESC
- Allows smaller Capacity Batteries to be used
- Boosts maximum continuous current output
- Condition or Health is not as critical
Series Advantages
- Series wiring can be achieved in many different setups (If you are trying to parallel a setup that requires 12s, this may be quite difficult as 12s packs are very rare to be sold in one pack)
- Boosts voltage of the setup
Conclusion to Wiring 2 Battery Packs
In general, if you are using a RTR vehicle, it is best to use the batteries that were intended to run in the vehicle. However, if you are comfortable with wiring and understand wiring, you can make a change to the RTR setup! Just keep in mind that this may void any warranty or support the manufacture may offer.
When I select which wiring I want to use for my specific RC car, boat, or plane, I generally don’t look at it as a parallel vs series. My main focus is trying to match up against the batteries that I own.
Wire 2 LiPo’s Based on What Packs you Own
Batteries are expensive. They have an average life of about 3 years, even if you do not use them. There is no point to purchasing additional batteries just for a new RC vehicle when you have packs that can already work.
Consider requiring a 6s 5000mAh setup for an RC car. The first thing I do is look at what packs I already own and pull out 2 6s 2500mAh. These packs come from an RC airplane but could work very well in the 6s RC car. In this case to get to the 5000mAh that I require, I must parallel the 2 battery packs.
On the other hand if I were to already own 2 3s 5000mAh packs from an offroad 1/10 scale car, wiring would be different. In this case, using a series wire harness would achieve 6s 5000mAh.
It’s a lot more simple to decide which batteries to use when your setup starts to get up to 8s or higher. Here you are forced in to running 4-6s packs placed in to series in order to hit the higher voltage requirement.
Don’t forget to consider how many cells in series your charger can charge. This limitation may determine the path that you must take.
Parallel Wiring Quick Tips
- Only wire packs in parallel that have the same voltage
- It is a good idea to wire packs in parallel that are around the same age and condition (otherwise power will be split based on health of the battery where the healthier pack delivers more)
- The C rating of a battery pack does not double, the battery capacity doubles
Series Wiring Quick Tips
- Wire packs that both have the same capacity (mAh) and C rating
- Packs wired in series must be around the same age and condition (Otherwise the least healthy pack will be pushed harder)