Close call this weekend, while comparing different props, I had a TB48 with 12 previous charge cycles, no mistreatment suddenly fail producing a full electrical failure causing the Inspire 1 to fall dead to the ground.
This occurred on a Inspire 1v2 but could be any LiPO HV battery pack on any model.
Several batteries were charged up to full capacity per the 6 pack M600 battery charger. Started the 4th battery flight. When starting up the Inspire, after about 45-60 seconds a warning popup appeared indicating a battery failure and to land immediately. Since I hadn't taken off yet, it was showing 97% with 1 cell noticeably lower (.4 volt est). I powered off, removed and reseated battery; powered up and no error messages. At this time, I assumed I had a battery pack out of cell balance and my intentions were to fly it till 20%, bring it down and hover it to exhaust battery until forced to land and then let it's fan slowly take it further down to 5% before recharging and maybe correcting the cell balance.
Took off, flew for 6 minutes when a message popped up regarding battery but then cleared and I continued for another 10 minutes for a 16 minute flight, brought it down for 5 foot hover and to visually watch blade's dish for uneven blades and for any vibration... purpose of flights were to test different props. The battery was showing 18%, and suddenly cut off and dropped dead to ground. It hit the concert driveway, stayed on all 4 feet. Quick inspection of Z3 camera (left X5 or X5Raw off for prop tests) showed no impact on camera's underside. Only damage was Rt Motor Arm had slightly tilted inward and required realignment. Inspected AC, inserted 5th battery and proceeded to fly 2 more batteries with normal operations. Very fortunate it wasn't at 200 feet when failure! Also very impressed the I1 could take a 5 foot straight drop and have it's shock absorber legs absorb the impact.
Question of ponder: Is the sudden electrical cut-off due to the uneven cells or battery electronics board?
IF so, how far out of balance will trigger this undesired action and secondly, should it just force a land like a normally exhausted battery?
To see if battery balance & condition can be restored, I've removed the I1 battery top and installed a balance lead. Using a standard LiHV charger, performed a 1.5a (very low) balance operation. I left this morning before complete, but it appeared to be slowing bringing all cells back into balance. I'll later perform a few Charge/Discharge operations on the LiHV Charger to verify condition.
One thing I have noticed on the TB48 & 47's is that they quickly drop on their rated capacity when examining through the DJIGo App. After cycling on a LiHV Charger they capacity returns to a much higher mAH and cells are restored to a balanced voltage.
I'm wondering if the larger cell difference was cause of error message and electrical cut off. When the 1 cell dropped below flight voltage it cut off. ?? My guess, I'll see if I get an error message after balancing the cells.
This occurred on a Inspire 1v2 but could be any LiPO HV battery pack on any model.
Several batteries were charged up to full capacity per the 6 pack M600 battery charger. Started the 4th battery flight. When starting up the Inspire, after about 45-60 seconds a warning popup appeared indicating a battery failure and to land immediately. Since I hadn't taken off yet, it was showing 97% with 1 cell noticeably lower (.4 volt est). I powered off, removed and reseated battery; powered up and no error messages. At this time, I assumed I had a battery pack out of cell balance and my intentions were to fly it till 20%, bring it down and hover it to exhaust battery until forced to land and then let it's fan slowly take it further down to 5% before recharging and maybe correcting the cell balance.
Took off, flew for 6 minutes when a message popped up regarding battery but then cleared and I continued for another 10 minutes for a 16 minute flight, brought it down for 5 foot hover and to visually watch blade's dish for uneven blades and for any vibration... purpose of flights were to test different props. The battery was showing 18%, and suddenly cut off and dropped dead to ground. It hit the concert driveway, stayed on all 4 feet. Quick inspection of Z3 camera (left X5 or X5Raw off for prop tests) showed no impact on camera's underside. Only damage was Rt Motor Arm had slightly tilted inward and required realignment. Inspected AC, inserted 5th battery and proceeded to fly 2 more batteries with normal operations. Very fortunate it wasn't at 200 feet when failure! Also very impressed the I1 could take a 5 foot straight drop and have it's shock absorber legs absorb the impact.
Question of ponder: Is the sudden electrical cut-off due to the uneven cells or battery electronics board?
IF so, how far out of balance will trigger this undesired action and secondly, should it just force a land like a normally exhausted battery?
To see if battery balance & condition can be restored, I've removed the I1 battery top and installed a balance lead. Using a standard LiHV charger, performed a 1.5a (very low) balance operation. I left this morning before complete, but it appeared to be slowing bringing all cells back into balance. I'll later perform a few Charge/Discharge operations on the LiHV Charger to verify condition.
One thing I have noticed on the TB48 & 47's is that they quickly drop on their rated capacity when examining through the DJIGo App. After cycling on a LiHV Charger they capacity returns to a much higher mAH and cells are restored to a balanced voltage.
I'm wondering if the larger cell difference was cause of error message and electrical cut off. When the 1 cell dropped below flight voltage it cut off. ?? My guess, I'll see if I get an error message after balancing the cells.
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