Rc twin electric setup

How do you find out the amp draw of a battery? This means that this battery pack will not work for an 80A setup. The only problem with this pack combination is if the motors pull more than 80 amps, you run the risk of heating up the pack from drawing too much current and puffing it, thus ruining the battery pack.

I like to pick my battery power combination with a little extra breathing room so if my power system pulls more amps than expected I have some reserve amps in the pack. In this example I would use a LiPo pack or combination of packs that would equal mAh at 20C allowing me to pull up to amps from the pack at any time.

The advantage here is if the system does pull more then 80 amps the batteries can handle it, and because the batteries are not performing at their maximum peak they run a lot cooler. The beauty of using LiPo batteries for power is that they are lightweight, give longer running times and can be wired in any combination. This is very advantageous for us when we are running more than one motor.

When connecting your batteries in series you are doubling the voltage while maintaining the same capacity rating amp hours. This is done by connecting between the negative of the first battery and the positive of the second battery. Then run the negative wire off the open connector of the first battery to the negative of the motor, and then run the positive off the open connector of the second battery to the positive of the motor.

You would use this type of connection if your motor needs Simply connect two But in most cases, you will be wiring up the packs in parallel, which would double the capacity amp hours of the battery while maintaining the voltage of one individual pack. This can be accomplished by using a Y-connector between two or more batteries that connects the positives of both batteries and the negatives of both batteries together. Then have a positive and negative wire go from one of the batteries to the motor.

This is how we can use two batteries together to meet the current draw required by our multi-motors. In our example above we could connect two mAh 5-cell That would be more than enough to power the needs of our two motors. Most twins, such as this OVD Bronco, have a roomy fuselage in the center of the wing that is a perfect place for a battery compartment.

You do have a couple of options on how you can connect the battery packs to the motors. This first option is to connect a proper-size battery to each motor. The advantage here is that each motor has its own power source and a simple wiring setup. The disadvantage is that as the battery packs get older they may discharge at different rates, causing one motor to be weaker than the other.

This creates more torque on one side of the aircraft, and in some cases this could roll the plane over in a death spin, especially if one battery quits at slower speeds. The other connection option is to use a Y-connector to join both motors to one larger pack of the required size to feed both motors. The advantage here is that when the battery is running low or is weaker, both motors will reflect that in their performance, maintaining equal torque on both sides of the aircraft at all times.

The disadvantage is a little more complicated wiring setup. On a four-motor plane, such as a B, use a Y-connector to join the inboard motors to one battery pack and the outboard motors to another battery pack.

That way even if one battery totally fails, you will still have motors on both sides of the plane working. This Lancaster from ASM Models, has both the inboard motors attached by Y-harness to two batteries while the outboard ones are attached to two different batteries. All four battery packs are stored in the fuselage in the nose right in front of the CG point to balance out this large plane.

Each motor on your multi-motor plane will need its own ESC. But, you can use a Y-connector to attach all of the ESCs to the throttle channel or connect each one to its own channel on the receiver and mix them, through the radio programming, to the throttle channel. On my B 4-motor plane , I used a Y-connector to attach the inboard motors to the throttle channel and connected the out-board motors to an open channel and mixed that one to the throttle channel.

That way they would all operate as one in the air, but on the ground I could flip a toggle on the transmitter and only have the inboard motors operate while taxiing.

As you can see, wiring for multi-motor planes is not all that hard. Several videos on You-tube show that the twin drive does have performance potential. I just put a Rescue Boat together that has two electric motors dressed up in plastic outboard housings.

There is no rudder, it adjusts the prop speeds to effect turns. I posted that earlier and someone replied that there are sophisticated transmitters with mixing capabilities. Helicopter or drone units have to have this. So it would have to be a 3-channel setup, one for rudder and separate channels for each ESC.

I would think having this type of control would be a big advantage for the twin.. Many thanks gentlemen. Join Date Mar Location ny Posts A mono will tilt to one side in a corner, one prop will get deeper Many thanks. I built a twin drive Wasabi Mono. It cornered ok. Even for a hull with no strakes under the hull. You can hear one motor revving a bit more in the corner, in the first video, as the outboard prop lifts a bit higher than the inboard prop.

But it certainly doesn't lift out of the water. The lean angle is not that great. I made the boat purely because I wanted to try twin drives in a mono. Is it more efficient or faster than a single setup in the same hull? Isolation means no electrical connection whatsoever. This scheme has additional noise advantages and is also a bit more expensive than Method 2.

The Rub. The fundamental application issue for a dual battery setup is that with two power sources, the potential exists that one can affect the other. The challenge is to prevent one domain from affecting the other. Several methods exist to accomplish this end and are described below.

Method 1, Power Domain Segregation, Disconnect red wire in throttle connection. One method is to pull the red wire out of the housing of the ESC throttle connection as shown below.

Then the housing is used to plug into the receiver without the red wire. Be sure to cover the exposed metal with tape. This works for the needed domain segregation, but there is a down side. Not the most convenient for programming. Power Domain Segregation, Method 1. How do I do this? If you look at the back of the connector, each of the wires has sort of barb on the connector and the housing has a flexible retention tab, the two of which mate so that once inserted, the wire cannot pull out of the housing.

To remove the wire as shown above, use a hobby knife and raise the plastic tab slightly while holding and releasing extraction tension on the wire.

When you pull the plastic tab up enough, the wire with connector will release and slide out as shown above. If using this method make sure to use some electrical tape to insulate the bare metal to prevent it from shorting to something inappropriately.

Method 2, Power Domain Segregation, Modified servo extension with cut red wire. A modified extension is shown in the picture below. Power Domain Segregation, Method 2. All I did here was to clip the red lead. I actually cut a piece of the wire out note arrow position so it could not inadvertently get reconnected. As you might imagine trying to tape this small stuff is tough so I left a gap.

Still another method is to use an opto isolator shown below. A West Mountain Radio version is pictured below but there are other vendors. The opto method has an additional advantage of conducted noise isolation so that the ESC electronic switching noise is not conducted into the RX due to removal of all the electrical connnections.

More details in the Electrical Details section below. Power Domain Segregation, Method 3. Opto Isolator from West Mountain Radio. You can test the isolation if you have and know how to use an ohm meter. Measure between the gnd on one end to the gnd on the other end and you will read an open, which is indicative of the isolation. Actually you would get the same reading on any connection on one end to the other.

The information traverses one end to the other via an optical path instead of a conducted path. In addition to the ground wire isolation, the other conductors are also not connected between the two ends.

See Electrical Details section for further insights. Electrical Details Viewpoint. Why is this important? The connectors seem to fit so it should be ok. Be Careful. With two separate power sources domains in a single system, care must be taken to make sure that the downstream circuits do not affect each other.

That is, each source should only power the intended circuits and not circuits of the other power domain. If the proper power segregation is not observed, and one source feeds the other or across different power domains without precautions, unintended currents can flow which fully defeat the intended reliability enhancement.