Reconditioning batteries

SnoozeDoggyDog · Jun 18, 2015

Hi
I'm a relative newbie but was thinking. Why don't DJI offer a reduced pricing for a new battery if you send them your old one? There must be parts that they can reuse ...

Phil.

msinger · Jun 18, 2015

But, wouldn't it be dishonest to sell brand new batteries with parts from old batteries?

SnoozeDoggyDog · Jun 18, 2015

msinger said:
But, wouldn't it be dishonest to sell brand new batteries with parts from old batteries?

They could advertise as reconditioned. All I mean is it seems really wasteful to just bin the old ones given the circuitry inside

msinger · Jun 18, 2015

True. They're having enough trouble getting new products out the door though, so I hope they don't attempt an idea like this right now

DrJoe · Jun 18, 2015

I have had my Phantom for 14 months. I don't have an original battery left. I found that they last about 50 flights before they have issues. Less if bumped or dropped, less if stored charged (no longer an issue), less if run down too far too often, less if you fly "hard" (lots of fast maneuvers and throttle changes spike the voltage and can eventually damage the battery).

At current prices, that's $2 per flight in battery expenses. Not awful.

RoyVa · Jun 18, 2015

50 flights your doing good. My best is 45 trying new things to see if I can beat my record.... Love to hear from someone who has made it to the 300 or let's say even to 200 charges.

justin00 · Jun 18, 2015

I have 2 batteries and they each have around 160 recharges
I have a non-v3 and have the upgraded 2312 motors which look like they use more power? than the original 2212.
I'll be honest I am not very comfortable flying with 160 recharges; However only now started to be seriously worried, especially regarding 1 battery in particular...
The one battery had its first major 'incident' the other day. The percentage went from like 40% to 0% in a split second, no error in the stock DJI app, I just saw it flashing red saying 0% and it did the hard auto landing it does normally at like 16-17%. (The auto landing you can't disable). LUCKILY the issue occurred when I was like 2ft above the ground as coincidentally I was coming in to land anyways, can't remember why.. wasn't due to a problem but great timing as I was at like 200ft a min or so earlier.

Anyways rebooted everything at battery was reported at 17%.

Fully discharged both batteries to 0% and charged back up... not to sure how to test if issue is still there... assistant software shows all cells fine/within same range.

I think its time for new batteries though :/ If my maths is correct paying 2 x $130ish now is better than $1800 for new phantom.

kid168 · Jun 19, 2015

Phantom 2 bats are now $99 at amazon

StevenQX · Jun 19, 2015

kid168 said:
Phantom 2 bats are now $99 at amazon

Link please

kid168 · Jun 19, 2015

http://www.amazon.com/DJI-Battery-P...F8&qid=1434708583&sr=8-1&keywords=dji+battery

SnoozeDoggyDog · Jun 19, 2015

kid168 said:
http://www.amazon.com/DJI-Battery-P...F8&qid=1434708583&sr=8-1&keywords=dji+battery

They're not the version 2 battery. My batteries that came with the P2V+ have version 2 printed on them. Does that matter? I'm in the UK anyway so that if of no use to me :-(

kid168 · Jun 19, 2015

They are for Phantom 2. I use this batts on my P2V+v3 and they work perfectly.

UgashikBob · Jun 20, 2015

I had 3 batteries for my P2V+ First went TU at 31 flights and the 2nd at 34 flights. Second failure resulted in falling out of the sky from 20 feet and heavy damage. Neither failing battery had been crashed or heavily discharged but had not followed the latest DJI suggestion to discharge as close to zero % as possible every 20 cycles. Just can't buy into the fact that total discharge on any battery is good for overall life span. Is there an agreement on how to break in and maintain the alleged "smart battery"? Would be interesting to see the actual DJI cost of these batteries to better understand there motivation to fix this problem instead of passing requirements on to the end user.

RoyVa · Jun 20, 2015

Lipo batteries are simular to Laptop batteries. They are smart (they think) and if you charge to 100% and discharge to 20% after a while a memory is set up and they think 20% is the bottom discharge rate. Every 20 cycles by discharging them down to 8% or even 0 re-teaches the battery that it's bottom is not the 20% but an actual lower rate. Hope that makes sense, but it re-established where it's to 0 and back to where it 100 so we get full use of the battery. A lot of laptop user that keep their laptops plugged in to AC all the time find that the battery goes bad real quick as it looses its memory where the discharged point is from being at 100 all the time.

UgashikBob · Jun 21, 2015

RoyVa:
I agree about the established memory but question what discharging a battery to 8 or even 0% does for longevity. I also have a difficult time following the recommendation of flying low and close to quickly discharge to these levels. I've had two units fall out the sky at much higher levels because of a sagging cell. The assumption is the "smart" logic was confused because the user didn't discharge to the 8 to 0 %. May be case but a defective or sagging cell is also a high possibility. Unless analysis of the failing lipo is done we will never know the real cause and its much easier to recommend end user actions than it is to improve the quality of $100 +batteries. I've seen the same type of lipo failures on non DJI high dollar batteries and with the Taranis telemetry function was able to see the actual failing cell. My point is there seems to be an above average amount of people that are getting neither the advertised flight time or battery life with the Phantom batteries . I have several non dji lipos with over 100 uses and no deep discharge every 20 cycles but have 2 out of three DJI batteries tu with less than 40 cycles.

RoyVa · Jun 24, 2015

I fully agree there are issues with the batteries. I can't get to 100 cycles with an original battery. Those that you are getting over 100 cycles would you mind sharing where, what mfg, model and cost with us. Just may have to give em a go. Thanks Bob.

StevenQX · Jun 24, 2015

My 2 batteries has around 30-35 discharge cycles and now a flight from 100% to 30% while recording last around 13 minutes. Not so good, i absolutely don't believe in the 300 cycles like the manufacturer says.

RoyVa · Jun 24, 2015

I fully agree, I've gotten 45 cycles and am straining to try to see if I can get one to go to 100. Have 5 batteries I'm using now and babying them all to see if I can get to 100 on just one of them. 300 is out to lunch and not comming back. I'd like to hear from someone that has over 125 cycles on and original DJI battery. Anyone out there!!!

yorlik · Jun 24, 2015

RoyVa said:
Lipo batteries.....after a while a memory is set up ........Every 20 cycles by discharging them down to 8% or even 0 re-teaches the battery that it's bottom is not the 20% but an actual lower rate.....

I believe the data that 100% states lipos do NOT suffer from memory as nicads did, so I question that first comment.

Consequently I believe the follow up thesis comment above is also incorrect.

I strongly believe dji's attempt to extend battery life by this deep discharge is to try to BALANCE the cells. the control chip they use only allows very superficial cell balancing. I believe they realize this and truly believe if they deep discharge then all 6 cells will go similarly low and thus be more "balanced" when all charged again. Unfortunately I think this erroneous philosophy only serves to further damage the cells by deep discharging them. They do not offer a method to truly balance the cells, so offer this instead.

And, fyi, the smart batt will not allow discharging to 0%: it will discharge to min of about 8% according to them. besides, discharge ANY lipo to 0% and most likely it is gone and will never come back.

Someday, if folks get mad enough, rather than throwing their batts away, some will take me up on my offer to test this theory by sending me their useless batteries. To date, folks like to complain but no one has sent me their old batts to test........

yorlik · Jun 24, 2015

UgashikBob said:
....The assumption is the "smart" logic was confused because the user didn't discharge to the 8 to 0 %. May be case but a defective or sagging cell is also a high possibility. Unless analysis of the failing lipo is done we will never know the real cause and its much easier to recommend end user actions than it is to improve the quality of $100 +batteries......

BINGO!

I totally agree. A sagging cell is not necessarily a bad cell, just not charged all the way. Once undercharged by too much, it probably will never get 'balanced' back to full charge by the dji circuitry, and thus the batt is prematurely called bad.

I saw this in my 100% electric 35kwh lipo battery too....

Agreed too this theory needs testing. I've offered....