The high voltage batteries used in the Ranger Pro should be charged on LiHV, rather than LiPo, which is the default setting on the SKYRC dual battery charger that is packaged with WISPR drones. In the event of a power outage in a location where your charger was plugged in, be sure to change your charger back to LiHV- as the charger will reset to LiPo when disconnected from power.
How do I set my battery charger to LiHV for charging high voltage batteries, and what is the process of charging a battery?
Hold the up and down arrows on the charger until the setting is changed to LiHV.
Plug the battery’s XT90 connector into the XT90 port on the charger.
Plug the balance port on the battery into the balance port connected to the battery charger.
Change charging to 20A, if the charger is not already set to this value.
Press and hold the start button until the charger beeps. You should see a warning on the screen about charging high voltage batteries.
Press start one more time to begin charging.
You should see the volts increasing, as the battery is now charging. If you would like to change a setting such as balanced charge to fast charge, simply press the start button once. The selected option will blink, and can be changed using the up or down arrows. Each press of the start button will select the next item on the screen that can be changed. Once you have the settings configured the way you would like, press start again to lock the changes in.
To see an example of how to charge your batteries correctly, and how to configure your charger settings properly, please watch the video below.
Charging Your Batteries with the Ranger Pro
Charging a LiHV battery on LiPo setting will likely not cause a fire but will not allow a full charge, and can damage the battery. Charging a LiPo battery on LiHV settings can cause a fire. Please be aware of this.
What volts should my battery read to ensure it is completely charged?
26.11 volts to confirm it is fully charged. Once the battery voltage hits 26.11 on the LCD screen of the charger, that does not mean it is fully charged. You should wait until the charger sounds to indicate the battery is finished and the LCD screen reads “END: FINISH” to have a fully charged battery.
What is the different between fast charge, balanced charge and storage charge settings on my charger?
Fast Charge - This mode directs the charger to only complete the first charging phase, constant current (CC) charging. The charger applies a high enough voltage to cause current to flow into the battery, up to the max current you've set. This will mostly charge the battery, but there will still be some unused capacity with this mode.
Balanced Charge - For maximum health, you should always balance charge your batteries. This is also why your battery has a second plug. This second plug is called the “balance plug” and is used by your charger to individually monitor and balance charge each cell.
Storage Charge - This option should be used if you are not planning on using your battery for an extended period of time. You should never store a fully-charged LiHV battery. Instead, it should be set to the storage charge setting, and the voltage decreased to “storage voltage”, which is 3.8 to 3.85 volts per cell.
If I plug my battery in and the charger instantly beeps with an error preventing charging , what should I do?
Check that the balancer plug (white plastic plug on the battery) and the XT90 plug are properly plugged in. Wires on both ports (balancer and XT90) should be plugged in tightly.
Verify that you have the correct charging mode set on the charger.
If these options are not the issue, use the charger to make sure all cells are balanced. You can check the cells by pressing the stop button once, the start button once, and then the up arrow once. If you see a damaged cell, replace the battery immediately.
Can I still fly using a damaged battery?
NEVER fly with a damaged battery, even if it is minimal damage. This can cause your drone to fly in an unsafe fashion, and crash. Replace the battery and safely dispose of the damaged battery.
When inserting the battery into the battery tray on the drone, should I have the positive and negative wires facing to the right, or facing to the left?
The positive and negative wires (red and black wires attached to the XT90 battery connector) should be on the right side when inserting into the battery tray.
Additionally, the battery strap should be:
Looped around the left standoff of the entrance to the battery tray. The velcro side should be facing outwards.
Pulled from left to the right, threaded between the positive and negative wires.
Around the right side of the battery, in between the battery and the standoff.
Run back through the battery wires, pulled tight, and pressed firmly against the soft side of the velcro to secure the battery in the tray.
Wedge the remaining connector in between the battery and the strap.
Ensure that the loop around the left standoff is positioned to rest in the center of the standoff, so that the strap stays in place for the duration of the flight. The strap should go evenly across and be firmly pressed against the battery.
Battery Insertion Walkthrough for the Ranger Pro
How to properly use hotswap :
Hotswapping a battery allows you to swap batteries in your drone while the drone is still powered on. This allows you to extend flight time without having to power down the drone. This also allows you to continue your mission from the previowus waypoint without powering down the drone.
To hotswap a battery follow these steps:
Ensure that your drone is equipped with the WISPR hotswap cable.
Fly the drone until the battery's charge level is low enough a low battery RTL is iniated.
Ensure that the RLT is landing where it was launched and is a suitable landing spot that is flat and free of any obstacles. The drone will need to land here in order to have its battery changed.
The drone should RTL (Return To Launch) where it was engaged at.
Let the drone RTL, making sure that the drone is stable and not drifting.
Once landed, on the right of the smart controller screen you will see three options appear : Keep mission, Resume from waypoint X and Delete mission. You will select Resume from waypoint X to resume from the last waypoint you reached in the mission once you hotswap and re-launch.
Plug the new, freshly charged battery into the free XT90 cable and remove the old battery from the drone by unplugging it (only after the fully charged battery is plugged in). Next, slide the new battery into the battery tray after the depleted battery has been removed and unplugged and make sure that the new battery is securely attached and properly secured in the battery tray.
Once the new battery is inserted and plugged into the how swap cable, you will see the percentage at the top of the Fly Vew bar raise to the percentage of the new battery.
Once the drone’s new battery is in use and the percentage is reading, you may re-arm and takeoff to continue your mission. The mission will start from the previous waypoint and continue with a now new fully charged battery without ever powering down the drone.
It's important to note that to use only batteries from WISPR, as this can help reduce the risk of accidents or malfunctions. Be sure to follow all safety guidelines and precautions when hotswapping a battery in a drone.
Hotswap during a LiDAR mission :
Please note that when performing hot-swaps while using any Inertial Labs or RESEPI LiDAR payload (such as the Avia Livox or RESEPI Hesai XT32), the time from when the LiDAR begins recording data to the time the LiDAR stops recording data should never exceed 50 minutes. This is a limitation of the LiDAR’s computer and is not limited by the WISPR Ranger Pro. Typically, this means the Lidar should be rebooted every two flights if the user is to include two 20 minute flights and allow time on the ground for hot-swapping.
Battery Insertion Walkthrough for the Ranger Pro
Further Battery instructional videos can be found here: