Is this a dodgy battery life?

Joined
Aug 15, 2016
Messages
3,582
Reaction score
1,527
Age
38
I have had 49 charges in 2 months and it's down to 89% overall battery life. Is this normal as it seems pretty fast to me but I guess if it is 10% a month of dying (give or take) then that means the battery will last around a year. Or should I dispose of it when it's at 30% or less?


Sent from my Power using PhantomPilots mobile app
 
Joined
Jan 4, 2016
Messages
7,723
Reaction score
3,017
Location
Australia
DJI says you can continue using the battery until the lifetime percentage is zero.

89% isn't a bad number for your recorded charge cycles.

More important numbers are the lowest recorded capacity (having regard to original) and the frequency and magnitude of cell voltage imbalances.

Observed flight times in use are also a good indication of health.

You can post it to me if you feel like taking out of service at 70% life.
 
Joined
Oct 6, 2016
Messages
151
Reaction score
50
Age
44
Are you taking it down to 8% every 20 charges? From what I understand this can really help the health of the battery.
 
Joined
Jan 4, 2016
Messages
7,723
Reaction score
3,017
Location
Australia
Are you taking it down to 8% every 20 charges? From what I understand this can really help the health of the battery.
This is no longer a consistent recommendation if DJI. It may provide for s more accurate depiction on the life indicator or reported capacity by allowing the smart circuitry to see how many Ah is put into the battery. Other than that you are just using part of a charge cycle unnecessarily without improving actual cell condition.
 
Joined
Jan 1, 2016
Messages
841
Reaction score
216
Age
65
Location
Ontario, Canada
I have been doing the deep cycle and have more charges than OP. Still showing 100% on both of my 2 batterys. Maybe just luck. Maybe not.
 
Joined
Jan 4, 2016
Messages
7,723
Reaction score
3,017
Location
Australia
I have been doing the deep cycle and have more charges than OP. Still showing 100% on both of my 2 batterys. Maybe just luck. Maybe not.
What I'm suggesting is the life % isn't a great indicator. Taking a battery right down will allow the smart board to log higher Ah put in during charge cycle. I'm very confident if I went out now and flew all my packs down to critical cut off and recharged recorded life % would increase. Cell condition won't be any better though.

Think about this, after 40+ charges no way your cells are as strong as they were at charge 5. The % indicator doesn't mean much.
 
Joined
Jan 1, 2016
Messages
841
Reaction score
216
Age
65
Location
Ontario, Canada
I have 4411mah at 54 charges. So some loss as these are 4480mah batterys. Same battery at 34 charges was 4422mah.
There are other variables than deep cycling.
 
Joined
Aug 26, 2015
Messages
5,312
Reaction score
1,736
I had a battery a couple weeks ago that showed 37 cycles, 86% useful life, great mAh, and with perfectly balanced cells.

It auto landed at 27% and is now permanently retired.
 
Joined
Aug 15, 2016
Messages
3,582
Reaction score
1,527
Age
38
I had a battery a couple weeks ago that showed 37 cycles, 86% useful life, great mAh, and with perfectly balanced cells.

It auto landed at 27% and is now permanently retired.
Wow. Out of curiosity did you mention it to DJI for a replacement? For the price of the batteries I would be expecting a lot more

Sent from my Power using PhantomPilots mobile app
 
Joined
Aug 26, 2015
Messages
5,312
Reaction score
1,736
I had the battery for close to a year - I have (had) five of them. But this one was aftermarket. The problem with it - it was a bit swollen - not horribly but obviously swollen. This happened because I had left it charged last winter for three weeks thinking it would auto discharge, and it didn't, because apparently Venom aftermarkets don't auto discharge! Had I known that, I'd have discharged it manually.

So not wanting to retire it, I watched it closely and continued using it. What I noticed is it would heat up quickly - even in chilly weather. I think that's a side effect of being swollen. Also, the voltage would drop below 11 volts very quickly during flight, but then hang there in the 10.5 to 11 v range for a long time.

Here's its last flight (this is the most boring video I've ever made so just skip ahead to the 14:00 mark). I was just getting myself in position to land it and it was kinda windy up there - I needed another ten secs or so - when it started to drop. Watch the voltage drop like a stone while the battery temp rises...

 

New Threads

Forum statistics

Threads
133,519
Messages
1,382,794
Members
97,446
Latest member
Sinnmaz