During the development and testing of our product we became aware of what we referred to as an inherent mounting/attachment design issue with the Mavic battery pack.
Additionally, we have noticed many discussions on battery swelling. The attachment issue described below will be further compounded when the battery cells swell. Swelling occurs more when discharging than charging due to the very quick and high current draw that occurs. Swelling occurs at the bottom of the battery pack and more toward the center of the bottom. This bulge may cause the battery to rock slightly forward and/or backward. Such movement may cause intermittent electrical contact at the connector. This issue may contribute to loss of control or triggering a low voltage command to return home or just land or worse complete loss of power.
The following is copied from our application notes and my shed some light this issue.
IF YOU CAN’T FIND REUSABLE, THEN GET SINGLE USE ZIPTIES AND A PAIR OF WIRE CUTTERS .
Hope this helps someone
Additionally, we have noticed many discussions on battery swelling. The attachment issue described below will be further compounded when the battery cells swell. Swelling occurs more when discharging than charging due to the very quick and high current draw that occurs. Swelling occurs at the bottom of the battery pack and more toward the center of the bottom. This bulge may cause the battery to rock slightly forward and/or backward. Such movement may cause intermittent electrical contact at the connector. This issue may contribute to loss of control or triggering a low voltage command to return home or just land or worse complete loss of power.
The following is copied from our application notes and my shed some light this issue.
- DANGER: Battery retention on the MAVIC Pro series of drones has an inherent flaw in the battery mounting clip design.
- This problem occurs if during insertion or removal of the battery, the battery side retention buttons are pushed “in” with excessive force.
- The plastic locking mechanism is designed to be under spring tension.
- The metal used for the spring section of the retention design is NOT made of spring steel but rather is made of plain steel.
- If the battery retention clips are deflected beyond their design point they will not provide adequate tension against the plastic locking mechanism on the drone body which could easily cause the battery to disengage during a violent landing.
- How to check if your battery spring clip has been over extended.
- Look at the section of the latch where it locks into the body of the drone. If you observe the latch to be loose or under very light tension, then the metal retention clip has been over extended.
- How to repair an over extended battery retention spring.
- Option #1
- CAUTION: This process requires high level of skill.
- You need to disassemble the plastic battery housing. Note it is a snap fit design. No glue, no screws.
- Once the plastic housing is opened the battery needs to be removed.
- Each battery housing clip is held in place with 2 philips head screws.
- Remove screws and using a pair of pliers bend the metal clip 2-4 degrees outward.
- Reassemble.
- Option #2 (recommended)
- Use a releasable ziptie every time you fly this battery to keep it from becoming dislodged in the event of a violent impact.
- Do not risk damaging the battery.
- The ziptie should be inserted into the front or back of the Drone Retriever and slid through the plastic housing of the Drone Retriever along the bottom of the enclosure. DO NOT PUT THE ZIPTIE OVER THE TOP OF THE DRONE RETRIEVER AS THIS WILL NOT ALLOW IT TO OPEN WHEN NEEDED.
- The ziptie should be tightened SNUGLY around the body of the drone making sure that it does not interfere with any vision system sensors.
IF YOU CAN’T FIND REUSABLE, THEN GET SINGLE USE ZIPTIES AND A PAIR OF WIRE CUTTERS .
Hope this helps someone
