This looks promising for broken battery cell

[Photo Elevate]

I wish that I knew this before disposing of broken cell battery

DJI Inspire One Battery Revival... - PaulJC

 

[Paul Cartwright]

I wish that I knew this before disposing of broken cell battery

DJI Inspire One Battery Revival... - PaulJC

Hi, I wrote that article... If anyone is in the UK, and not a million miles away (i'm on the Herts/Essex border or if you can find a courier), i'll happily plug your pack up to my setup and see what state it is in...

It'll have to be a "leave it with me and wait" kind of offer but i'll get round to it eventually and most packs in this state are due for the bin anyway so if you have to wait a week or two it shouldn't be the end of the world...

 

[Photo Elevate]

Well done Paul.
I'm sure your assistance will benefit a lot of people on here.

 

[phil baldwin]

Hi, I wrote that article... If anyone is in the UK, and not a million miles away (i'm on the Herts/Essex border or if you can find a courier), i'll happily plug your pack up to my setup and see what state it is in...

It'll have to be a "leave it with me and wait" kind of offer but i'll get round to it eventually and most packs in this state are due for the bin anyway so if you have to wait a week or two it shouldn't be the end of the world...

Hi, Where did you get the plug that goes into the battery ?

 

[Paul Cartwright]

Hi, Where did you get the plug that goes into the battery ?

It was custom made... Parts available from DigiKey and RS Components

 

[dv8ed]

Hi, I wrote that article... If anyone is in the UK, and not a million miles away (i'm on the Herts/Essex border or if you can find a courier), i'll happily plug your pack up to my setup and see what state it is in...

Paul thank you for writing up that revival guide lots of useful information.

I have a TB48 fully charged cells shows 4.34V, cell 2 which needs a boost shows 4.22V
I did verify each with a multimeter.

I hooked up cell 2 only to a charger 0.5amp charge 1S won't charge since charger think cell is full at 4.2V

How to go about this? I have a USB adapter I can drain battery cells to 4.2V then cell 2 the one that needs a boost will probably be lower just charge cell 2 back up to 4.2V?

 

[Paul Cartwright]

Most good chargers will allow you to adjust the finishing voltage to some degree...

Failing that, if that battery is still operational? Then fly it to flatten it, then leave it a while to stabilise, then bring up the cell voltage of the individual cell when all the cells are discharged, it wont take long at all to bring one cell up but .12 volts, you can then reassemble the pack and put it on the DJI charger to see if it manages to keep it balanced when fully charged.

 

[dv8ed]

Failing that, if that battery is still operational? Then fly it to flatten it, then leave it a while to stabilise, then bring up the cell voltage of the individual cell when all the cells are discharged, it wont take long at all to bring one cell up but .12 volts, you can then reassemble the pack and put it on the DJI charger to see if it manages to keep it balanced when fully charged.

I have an iMAX B6 AC V2 I'll check the manual.

Yes battery is operational never reported a dead cell. I believe I hovered one time really low to the ground to drain battery hoping DJI charger would balance cell again and it turned off hence reason to fix it.

Good idea to discharge/flatten battery to 3.3V then bring that one cell .12 volts. In your guide you brought your battery cell up a little and it reported it was discharged/flat this way it's already reporting it's flat.

I got all cells showing 4.2V and low one showing 4.08V but I like your idea of flattening battery I'll hover it tomorrow outside.

 

[Paul Cartwright]

From what i can recall i don't think you can change the finishing voltage on the B6, but charging that cell from flat will be fine, you need the complete pack fully discharged before reconnecting the DJI circuit and fully charging on the DJI charger or the voltages, may and LED's will read wrong and that is what the DJI GO app and the Inspire gets it's data from

 

[dv8ed]

Complete flat as in:

cell1: 3.42
cell2: 3.3 (use charger bring this up .12 volts to 3.42 to match other cells set at 0.5amps/1S)?
cell3: 3.42
cell4: 3.42
cell5: 3.42
cell6: 3.42

after they're all equal use DJI charger to charge to 100%?

 

[Paul Cartwright]

Yes

The pack MUST be flat when reconnecting the DJI circuit, it measures the mah put in to the pack, i wrongly connected the circuit to a fully charged pack (it doesn't do any damage), the DJI GO app shows full voltage, but 0 mah available for flight so it wont light the led's or allow flight unless charged from flat through the battery circuit

 

[diablo2112]

I use the Inspire Angel discharger to flatten my packs when needed. I just restored a TB48 that wouldn't accept a charge and that the app reported as a bad cell. Cell 1 was very low (3.2V, others at 3.85V) after an extended period in storage.

As Paul Cartwright did (in his excellent blog post on the topic), I opened the pack, rigged up a single-cell charge cable (bashed from other DJI cables I had for my S1000/S900 rigs, that tiny plug is shared by other equipment such as the A2 and Lightbridge), and brought the low cell up to voltage (at 500 mA). I then drained the whole pack on the Inspire Angel discharger, and finally hooked it up to the DJI charger which now worked fine. I cycled the pack a few times, and it now takes about 5300 mAh and has worked fine ever since.

Moral of this story: DJI batteries are actually pretty robust. When a cell gets low, you can often revive the pack be individually charging that cell (via the balance connector). Drain the pack (either via a discharger on a separate LiPo charger or the Inspire Angel), and you should be good to go.

 

[Paul Cartwright]

Absolutely, essentially the packs when the 'smart' circuit is taken out of the equation is just the same as any other lipo and can be balanced and cycled as such, it's only the 'smart' circuitry that isn't actually that smart and causes the bulk or Inspire pack problems, having had other multi's, helicopters and planes that run on normal lipos, these battery management techniques are all part of the learning process to get the most out of the packs, it's just DJI's smart circuitry which is an attempt to make them maintenance free and foolproof that causes the problems.

 

[diablo2112]

One last tip: you can use the NiCd settings on your charger to bring a very-low cell up to 3V +/-. Many smart chargers won't charge a single-cell LiPo if the voltage is below some set value (in the range of 2.5-3V). You can often revive these cells by first sending 500 mA via the NiCd (or lead acid) setting.

Each NiCd cell is 1.2V, so you can set the number of cells to match the low voltage of your LiPo. For example, if you cell is reading 2V or so, set your charger for 2 NiCd cells (2.4V) and it should bring it up to ~2.5V. Then, set your charger for 3 cells, and that will bring it up to a range that your LiPo setting should now work. FYI, YMMV.

 

[Paul Cartwright]

Something i didn't even think of covering when i wrote the original, but a technique i have also used several times and works exactly as diablo2112 has said

 

[Nasscar][]

I wish someone make an after market balancer cable that will work with the top brand lipo chargers. I would be willing to pay a premium for this type of cable.


Sent from my iPhone using InspirePilots

 

[Paul Cartwright]

I wish someone make an after market balancer cable that will work with the top brand lipo chargers. I would be willing to pay a premium for this type of cable.


Sent from my iPhone using InspirePilots

I made my own... Cost very little really... I'll order the bits to make another one and document it along the way...

 

[diablo2112]

Here's a few pics of the cables I put together to balance and charge the DJI Inspire batteries. The small plugs were taken from spare DJI cables I had from the A2 and Lightbridge systems. They were in my spare cable box, so I'm unsure which specific part number they are. DJI cable packs are quite cheap, check the pictures from one of the online retailers and you should figure out which is which cable is correct.

The small, 2-prong plug is the individual cell charge cable. I made it from the cable shown in the lower pic. The balance cable comes from an 8-pin cable. I used a hobby knife to trim off the connector to 7 pins, and it easily fits the balance plug socket on the DJI batteries.

While not a complete DIY writeup, the pics and description here may help others looking to bash a few cables to restore TB47/48 packs.

Good luck.

 

[Paul Cartwright]

Nicey done Mine are pretty much identical, i do have the part numbers somewhere though, i'll try and find them tomorrow

 

[dv8ed]

Yes

The pack MUST be flat when reconnecting the DJI circuit, it measures the mah put in to the pack, i wrongly connected the circuit to a fully charged pack (it doesn't do any damage), the DJI GO app shows full voltage, but 0 mah available for flight so it wont light the led's or allow flight unless charged from flat through the battery circuit

I drained my TB48 cell2 down to 3.3V, used iMAX charger to bring cell2 up to 3.49 all other cells 3.45 verified it w/ meter and tester then used DJI charger charge to 100% same results all cells 4.34/4.35 cell2 4.22

Should I get an iCharger like yours so I can change finishing voltage to 4.34 on cell2 or you think after what I've already done is best I can do? You're right this charger for LiPo max 4.2 there's LiHV max 4.35

Appears Inspire battery cells charge to 4.34V is there a charger that supports charging a cell up to 4.34V?
Someone in P3 forum set to LiHV in order to charge cell to 4.34/4.35

cell1: 3.45V
cell2: 3.3V
cell3: 3.45V
cell4: 3.45V
cell5: 3.45V
cell6: 3.45V