Hi,
Last week, as the weather was good I decided to fly my bird.  Firstly I  have to precise it was 20°C outside and I really take care to my  batteries and drone, never drained less than 8%.  Then, when I started  up, both of batteries were 50% charged though I charged them up to 100%  few weeks ago.  I flew my bird for a couple of minutes and I saw a  message "critical low voltage landing" I was top of a castle,  fortunately I can get it back but I'm so worry to fly it again, have an  idea of what happened ?

http://healthydrones.com/main?share=zJGrCI&page_id=GENERALNotifications

Thank you so much.

At 44%, your battery was nearly depleted when you took off. Your Phantom had to auto land to prevent the battery from shutting off mid-flight. You should always fully charge your batteries before flying.

Always fully charge your batteries on the day you use them or the night before, they would have self discharged to 50% (being above 70% or below 30% in storage is not good for them).
The amount removed during self discharge is not accurate, they normally claim 50% but there may be a lot less actually left in them.

The explanation as to why your battery was low after charging them a few weeks ago is the auto-discharge feature of the intelligent batteries.  They are programmed to discharge themselves to keep them from becoming damaged.  

Just like the other, this sounds all normal. The batteries auto discharged at some point because you charged them to far in advance of flying. Next, once you noticed that out in the field as hard as it might have been, the best option was to go back home and charge the batteries before flying. NEVER fly on partially charged batteries. You will have people post that they have flown on a partially charged battery and everything was fine. But in my opinion it's a flip of a coin if you might or might not have an issue, so why chance it.

WilliamM Posted at 2017-2-25 10:43
Just like the other, this sounds all normal. The batteries auto discharged at some point because you charged them to far in advance of flying. Next, once you noticed that out in the field as hard as it might have been, the best option was to go back home and charge the batteries before flying. NEVER fly on partially charged batteries. You will have people post that they have flown on a partially charged battery and everything was fine. But in my opinion it's a flip of a coin if you might or might not have an issue, so why chance it.

" You will have people post that they have flown on a partially charged battery and everything was fine. But in my opinion it's a flip of a coin if you might or might not have an issue, so why chance it."
Flying on partial charge is fine as long as it has had a full charge since the last auto discharge.  Eg, If you start off the day with a full charge, then use it down to 20%, then recharge using the car charger to 50%, then use it again down to 10% it will work fine.  You must start off by charging to full before your first use after it being in storage though.

I had the same with one of my batteries last week. Took off from my house and after a minute the same warning and the drone came down.

I had the same with one of my batteries last week. Took off from my house and after a minute the same warning and the drone came down without being able to increase altitude to get back safely.  Then again yesterday with the other battery, same problem: critical low voltage warning. The batteries were 100% !!! How is this possible?

RonAruba Posted at 2017-3-2 09:04
I had the same with one of my batteries last week. Took off from my house and after a minute the same warning and the drone came down without being able to increase altitude to get back safely.  Then again yesterday with the other battery, same problem: critical low voltage warning. The batteries were 100% !!! How is this possible?

Are you sure it was full (95% or higher) when taking off? Also what was the outside temp?

Nigel_ Posted at 2017-2-25 11:59
" You will have people post that they have flown on a partially charged battery and everything was fine. But in my opinion it's a flip of a coin if you might or might not have an issue, so why chance it."
Flying on partial charge is fine as long as it has had a full charge since the last auto discharge.  Eg, If you start off the day with a full charge, then use it down to 20%, then recharge using the car charger to 50%, then use it again down to 10% it will work fine.  You must start off by charging to full before your first use after it being in storage though.

Can you explain why you need to do charge after self discharge as you post ? There is no reason that any charge after self-discharge has any benefit at all.

Partial charge is partial charge whatever you do. And after storage ?

The simple answer is full charge and forget partial charging.

Nigel

The same thing happened to me yesterday whilst capturing a work site. Thanks for o

Before every flight on a battery I click on my battery icon on my app it will show you your voltage and power levels in each cell.

Think its just about covered when you add all the posts together ............

a) DJI battery self discharges initially to 65% over approximately 2 days (manual states clearly 65%)  ... starting from the point set in DJi GO ... Default time before discharge is 10 days, but many people change this to 2 or 3 days to avoid having batterys full charged too long.
b) Continued discharge from about 65% is slow but can bring battery down to 50% or so after the designed 2 days to 65%.
c) Flying part charged batterys is generally advised against unless you are 1. only doing a test hop, 2. sure you will not be flying more than a very short and close in flight. It is always advised to check battery level bu looking at screen and the 'green' line at the top ... which tells you how much % battery is there.
d) Storage state of batterys is best at 30 - 50% for long life. It is not advised to keep leaving batterys fully charged repeatedly. Damage is accumulative and not recoverable.

Its a pain I know to have to charge a battery to go flying - but better that than have to pay out for new batterys by leaving full charged too often.

Its also a wise investment of a few $ to get one of these :

http://www.ebay.co.uk/itm/Batter ... :g:aZAAAOSwHsRYECkR



Not only can you control discharge yourself - but the energy from the discharge can be used to charge your phone, controller, tablet etc.
So if you are at field and want to fly again but tablet is down on battery and you have a spare flight battery ... connect up and charge the tablet ...

Word of advise - Don't do deep discharges on these batterys ... they are basically unbalanced uncontrolled. You may do more damage to the battery.

Nigel