bjr981s
Second Officer
Flight distance : 139698 ft
Australia
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JimDandy Posted at 10-25 01:57
24 hours is a not a maximum time that lipo chemistry should be at a full charge. Maybe a personal preference, and I agree with that. I do personally like to fly a charged pack the same day I charge it. I've been flying FPV for since it's inception. Long before DJI was a player. Battery technology has come a long way since then. Now it is true that lipos don't tolerate a full charge for long periods of time. It breaks down the internal resistance of the the cells, and they loose the ability to discharge properly under load. They end up weakened, and with a shorter service life. However. 24 hours is no maximum measure. 1 week has been the guideline for a long time now, before needing to put the packs in a safe charge mode. None, (zero) of my FPV packs have a feature to discharge them form some sort of internal clock. I keep notes on the 15 packs I have to fly with, and I use the charger I have to bring the cells, Notice I said cells, and not pack, to a storage voltage. That storage voltage is 3.81-3.85 volts per cell. (CELL). NEVER discharge a cell below 3.7 volts! This is how so many early packs puffed and caught fire. Over discharging is as bad, if not worse than over charging. I've puffed a lot of Lipo packs in the past before being educated on what they truly need to serve a long and happy life. This is why DJI has circuity built in to discharge after 5 days. Now why this has changed with the new update is beyond me. But now that I understand It is a problem, I'll "Hover" each pack at the end of my flight, until I see the CELL voltage reach 3.8 under load. Then I'll land. My FPV lipo packs do recover a bit after landing and cooing a bit. Usually shows 4.0 volts per cell with a cell checker. I have FPV packs that are 3 years old with over 100 flights on them. Still working great today. DJI packs will be no different. Do yourself a big favor. Charge, fly (same day if you wish), before landing pull up the battery info screen in the app and land when the cells get to 3.8 volts. Forget about the silly % of battery left. That is just a quick reference. Go by cell voltage. 3.8 while in a hover or slow flight, set her down. Your packs will be happy.
Actually its 0 hours. The LiPo as opposed to Lion is under major stress at full charge. Ideally they should be charged and flown as soon as they cool down then put on storage as soon as they again cool down. 24 hours is what i consider to be an appropriate time I charge overnight, fly and then return to storage when I return from the club. I fly Ducted fan jets and the batteries are expensive and you need many I have over 200 LiPos. They get checked every 6 months in storage. DJI batteries must be checked every 3 months. Don't trust the 4 lights if you check. They will show 2 lights but that was the battery status at the time it self discharged. If you put it on a charge or turn the battery on it will go down to 1 light in 3 months. The monitoring hardware puts a slow drain on the battery.
Yes hold them at full charge fort any length of time will cause swelling and reduce the number of cycles available.
The DJI Battery meter in the Go 4 and Fly app is not accurate and doe not represent the battery charge status. DJI recommend a full drain (Not good for the battery) and a full recharge every 3 months. This is to calibrate the battery sensor with Watt Hours absorbed.
if this is not done the remaining battery level will not be accurate. As some have experienced with the battery going from 50% remaining to zero in a matter of seconds.
LiPos are great but they do require care and feeding.
Cheers
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