TB48 - disaster time

[ChrisRL]

Are you seriously telling me you expect DJI to ship individual Lipo cells ? Show me where ANY manufacture supplies cells for their lipo batteries.

I am also an electromechanical engineer who has been fixing and building stuff since I was 5, I have worked in IT, AV and other industry's as well as Radio and TV, yet I don't expect a lipo cell to be available.

Thanks for your reply. And just search on Hobby People or any other hobby shop for individual LiPo cells sold by manufacturers. They all do it, or have equivalents available.

Here's one example: Traxxas Parts 11.1v 8400mah LiPo Battery ID Plug 25C.

And before you go there, on that same page are bare LiPo cells without connectors.

And no, I normally wouldn't bother except that the TB48's costs are pretty darned high, aren't they? So I'd at least like to have the option to be able to DIY rather than being told something that's blatantly untrue by a supposed tech support person of a company that's meant to be in DIY.

I guess people's expectations are just a little different from each other's, right?

Thanks again. No sarcasm intended, I get your point entirely.

 

[ChrisRL]

Long ago I sourced the lipo cells in China. The cells are about 9.00 each and it's a difficult job to replace them

Aha! Now *that's* what I've been talking about. Thank you! Could you please PM me and let me know where you sourced them from?

 

[ChrisRL]

I've seen defective one's on eBay for sale with one bad cell for around 20$ . The simple fact is people don't or just simply don't care to be bothered by putting a couple brain cells together an fixing there own **** . Kinda like having a spare tire in there car an waiting for 5 hours for triple A to come do it for them.

Couldn't have said it better than that.
One doesn't need a degree in anything at all, anybody who can fly one of these and use a soldering iron and a couple of screwdrivers, can re-cell one of these.
Mine were out of warranty when I got them so nothing to lose, and the seller's gone AWOL of course, so I'm going to have to go bang on his door.

BTW I built my first Inspire from parts of other crashed Inspires for around half the price it might have cost me to buy my own at the time. Couldn't afford the money, but I could afford the time, and I'm very old school - I guess. I like to see what's going on inside the machines I fly, if at all possible.

Coming from the DIY hobbyist world means that I'm used to building small aircraft myself and understanding if not exactly how every piece of electronics is constructed, at least what its function should be. So if something isn't working properly, I can tell what's wrong pretty darned quickly and yes, I do have spare parts for at least one complete Inspire 1 in my flight cases so I can effect field repairs on the job should they be required. And yes, I've been known to bug my fave A&P mechanic to look over his shoulder while he's repairing certified aircraft.

And yes, I've replaced the transmissions on my cars myself (not alone, mind you, but with my son mostly) and the ECUs, etc. And I've fixed our washing machines as well.

For me, there's a difference between what we in the UK used to call a mechanic (someone who knows how to diagnose and repair the engine of a car) and a fitter (someone who knows how to replace the engine of a car).
The difference is in degree. For instance, even though a spark plug is technically part of the engine of a car, I think even a fitter can replace a spark plug. One of the cylinder linings, though, might be considered to be an integral part of the engine. However, when you look at it, everything in an engine can be taken apart and put together again with the proper fasteners and tools. So the difference between a spark plug and a cylinder head (and by extension a mechanic and a fitter) is just degree of involvement, of time and energy.

Well for me, this has been a hobby for many decades. It's what I choose to fiddle about with in my spare time, and it gives me pleasure to build something that I'll later fly. Which is why I built, for instance, a flame wheel instead of buying one as an ARF or BNF. Old school, quirky, whatever. I understand that others just want to fly and will indeed call AAA in and wait for someone to come in and replace their flat tire for them. I just prefer to do it myself, or at least to have the choice to do it myself, as in replacing my flat tire myself, or not.

Imagine if Firestone said "your tire warranty is void if you *don't* call Firestone Service to replace the tire"..... and don't forget, they don't actually make the rims....

 

[Ftolino]

Waiting for the roof to blow off this M/F

 

[Ftolino]

Couldn't have said it better than that.
One doesn't need a degree in anything at all, anybody who can fly one of these and use a soldering iron and a couple of screwdrivers, can re-cell one of these.
Mine were out of warranty when I got them so nothing to lose, and the seller's gone AWOL of course, so I'm going to have to go bang on his door.

BTW I built my first Inspire from parts of other crashed Inspires for around half the price it might have cost me to buy my own at the time. Couldn't afford the money, but I could afford the time, and I'm very old school - I guess. I like to see what's going on inside the machines I fly, if at all possible.

Coming from the DIY hobbyist world means that I'm used to building small aircraft myself and understanding if not exactly how every piece of electronics is constructed, at least what its function should be. So if something isn't working properly, I can tell what's wrong pretty darned quickly and yes, I do have spare parts for at least one complete Inspire 1 in my flight cases so I can effect field repairs on the job should they be required. And yes, I've been known to bug my fave A&P mechanic to look over his shoulder while he's repairing certified aircraft.

And yes, I've replaced the transmissions on my cars myself (not alone, mind you, but with my son mostly) and the ECUs, etc. And I've fixed our washing machines as well.

For me, there's a difference between what we in the UK used to call a mechanic (someone who knows how to diagnose and repair the engine of a car) and a fitter (someone who knows how to replace the engine of a car).
The difference is in degree. For instance, even though a spark plug is technically part of the engine of a car, I think even a fitter can replace a spark plug. One of the cylinder linings, though, might be considered to be an integral part of the engine. However, when you look at it, everything in an engine can be taken apart and put together again with the proper fasteners and tools. So the difference between a spark plug and a cylinder head (and by extension a mechanic and a fitter) is just degree of involvement, of time and energy.

Well for me, this has been a hobby for many decades. It's what I choose to fiddle about with in my spare time, and it gives me pleasure to build something that I'll later fly. Which is why I built, for instance, a flame wheel instead of buying one as an ARF or BNF. Old school, quirky, whatever. I understand that others just want to fly and will indeed call AAA in and wait for someone to come in and replace their flat tire for them. I just prefer to do it myself, or at least to have the choice to do it myself, as in replacing my flat tire myself, or not.

Imagine if Firestone said "your tire warranty is void if you *don't* call Firestone Service to replace the tire"..... and don't forget, they don't actually make the rims....

Couldn't have said it better than that.
One doesn't need a degree in anything at all, anybody who can fly one of these and use a soldering iron and a couple of screwdrivers, can re-cell one of these.
Mine were out of warranty when I got them so nothing to lose, and the seller's gone AWOL of course, so I'm going to have to go bang on his door.

BTW I built my first Inspire from parts of other crashed Inspires for around half the price it might have cost me to buy my own at the time. Couldn't afford the money, but I could afford the time, and I'm very old school - I guess. I like to see what's going on inside the machines I fly, if at all possible.

Coming from the DIY hobbyist world means that I'm used to building small aircraft myself and understanding if not exactly how every piece of electronics is constructed, at least what its function should be. So if something isn't working properly, I can tell what's wrong pretty darned quickly and yes, I do have spare parts for at least one complete Inspire 1 in my flight cases so I can effect field repairs on the job should they be required. And yes, I've been known to bug my fave A&P mechanic to look over his shoulder while he's repairing certified aircraft.

And yes, I've replaced the transmissions on my cars myself (not alone, mind you, but with my son mostly) and the ECUs, etc. And I've fixed our washing machines as well.

For me, there's a difference between what we in the UK used to call a mechanic (someone who knows how to diagnose and repair the engine of a car) and a fitter (someone who knows how to replace the engine of a car).
The difference is in degree. For instance, even though a spark plug is technically part of the engine of a car, I think even a fitter can replace a spark plug. One of the cylinder linings, though, might be considered to be an integral part of the engine. However, when you look at it, everything in an engine can be taken apart and put together again with the proper fasteners and tools. So the difference between a spark plug and a cylinder head (and by extension a mechanic and a fitter) is just degree of involvement, of time and energy.

Well for me, this has been a hobby for many decades. It's what I choose to fiddle about with in my spare time, and it gives me pleasure to build something that I'll later fly. Which is why I built, for instance, a flame wheel instead of buying one as an ARF or BNF. Old school, quirky, whatever. I understand that others just want to fly and will indeed call AAA in and wait for someone to come in and replace their flat tire for them. I just prefer to do it myself, or at least to have the choice to do it myself, as in replacing my flat tire myself, or not.

Imagine if Firestone said "your tire warranty is void if you *don't* call Firestone Service to replace the tire"..... and don't forget, they don't actually make the rims....

I love putting a tranny on my chest an trying to line the hub splines up all while not having a hernia. That's the problem today it's to easy to ***** an moan about problems then fixing it themselves. Do some research fix your tb's an even add a extra aftermarket battery an you'll have a longer safer flight

 

[ChrisRL]

Waiting for the roof to blow off this M/F

Woah! Cool! : )

 

[ajohnsonlaird]

I have four TB48's that were killed by the mistake in DJI's firmware that over-discharged them last winter. As it happened, the warranty expired in early 2016, so by the time the weather had improved enough and I went to fly, they had already committed DJI-induced suicide.

As you would expect it was a case "Sorry, yeah, we know about the mistake in our firmware, but your batteries are out of warranty now." Reasoning like "Yes, they are out of warranty now, but when your firmware bug killed them they were not" met with a predictable reaction.

Oh, and when I sent images of the batteries, the response was "they're puffed up too..." Well, of course, they were -- because the DJI firmware mistake had ensured that they would be puffed up because they were over-discharged. (Total charge cycles on these new batteries? 12. $800 worth toasted because of incompetent firmware testing by DJI.

I'm a forensic software analyst/systems programmer/electronics technician and fully understand that DJI *could* have tested the "intelligent" firmware properly if they had wanted to -- I mean what is the point of claiming you have "intelligent" firmware for battery management if you have not tested what it does if you leave the LiPo in storage for six months?

Bottom line: Has anyone actually found LiPo cells that can be use to replace the ones in the LiPo's? I'm not sure it will be cost-effective (or cost-offective ) for me to replace them but I'd like to make an informed decision.

I saw the Editor's link but I'm not sure which product is the right one. (The link is 3.7V, 1,000-5,000mAh Li-polymer battery).

I'd be happy to purchase some cells and replace them and document the procedure I used so that others who know which end of a soldering iron is hot can do so too. I'm with ChrisRL on this. DJI's handling of this is total bollocks, IMO.

Andy.

 

[ChrisRL]

Andy, hello!
Let's see if we can't get a solid source for these cells. I know that there's a transport restriction on them - i.e. unless they're sent from the factory in original and unopened packaging, then the regular shipping carriers won't touch them. Except one, which I found myself by looking through all of their rule books.

A propos of this:
My better half just traveled for the first time in recent years to Mexico, where she is shooting a book on dogs. The security people took all of her (six) Leica LiPo spares and confiscated them as being hazardous to flight, despite the fact that Delta had the packaging specifications clearly listed on their websites, etc (tape terminals down with electrical tape, pack batteries individually in waterproof baggies, etc). Those Leica LiPo's aren't cheap either. You're allowed one in the camera, that's it. Unless the others are in unopened original factory wrapping, game over.

So I just sent (and they said it coudn't be done) some el cheapo China eBay replacement LiPos (came in from China at $6 each, free shipping) via a carrier to Mexico. Cost me $80 to send them 3-day, and of course the Mexican customs will charge her what they want to for them, but at least she'll have two spares there for her job.

Cost effective? Nope, not at all. But she can't buy Leica batteries where she is - she has to go to Mexico City to the Leica dealer only to get them... So screwed, no choice.

If there is some kind of shipping or packaging restriction, I do know the national carrier that will ship. So once we ascertain the correct replacement LiPo part, if you want to do a group ship to split costs, etc., I'm open for that, as are at least two others I know of in the LA area alone.

That's the thing about high-priced monopolies in a free trade economy, isn't it?

 

[ChrisRL]

Oh, and if that tests out successfully, I know of at least one local repair guy (in LA) who will be offering this as a third party repair service.

One year warranty minimum, parts and labor. Core charge, or send in your core. Somehow if the battery is dead, it's not classified as being hazardous any more. Go figure, but last time I looked, them's the rules.

And of course, like all warranties, dji or not, that will only cover the replacement cost of a re-serviced battery, not a new one.

Which will be much less than the cost of a new dji battery.

Which of course only dji or its dealers can supply you with.

 

[Rich Sugden MD]

Greetings!
Chris here, bought a couple used TB48's from someone local and they're both bricks.
Did the dji dance and to sum it up, because shipping of LiPos is restricted (they must not ship with FedEx), if your 47 or 48 is older than 6 months (mine were) then they're out of warranty and the only option is to buy new.
If it's under warranty they will send a replacement for free.
No repair or diagnosis possibilities. No re-cell possibilities. I know I'm preaching to the choir here, but isn't that illegal? I thought any US vendor needed to keep parts for the items it sells available for at least 5 years after that part has been discontinued. Or is that law not applicable here? I'm pretty upset - I thought I'd be spending some money to get the batteries re-celled, but this is ridiculous.
I actually live not too far from the dji tech center and was able to get someone on the line pretty quickly, but it was really like talking to a brick wall. The person was clearly reading a script an didn't know the first thing about what she was talking about. Very frustrating.
Anyway, I'm hanging onto mine until someone figures out a way to get around this problem. I mean, most of us R/C people came from building their own, and a move like this from an older company like dji seems to be what it is - a great big slap on the face, because they know their customer base, and have no excuse for this.
Rant could continue all day long but you get my drift!

Well, I have $600 worth of TB48's where the charge/monitoring electronics in the batteries put a drain on them during storage, and allowed the cells to discharge to the point where they were discharged. All DJI needed to do was have a switch that would cut off all drain during storage .. the batteries would last a year plus w/o any drain ... That's the big advantage of LiPo .. they store for VERY long times if there is no drain ... years even, and DJI destroyed that advantage by having electronics that drain the battery to destruction.

Wonder how many folks own DJI batteries where that has happened ... maybe a class action suit re. a design that was destined to destroy the product?? Wonder about the Phantom batteries ...

 

[Rich Sugden MD]

There is a way to reset your battery by taking the top off, but I don't have the procedure, it is simple and on the internet.
There was a video at one time. One of the new firmware's caused a lot of people's batteries to be bricked whether they were New or old. I had one that was bricked with just a few flights on it luckily they replaced it.

You remove the white top by wedging a screwdrive in each end, dislodging the 'tabs', while pulling out on the sides, as there are clips there too ... Then disconnect the small plug w. wires going to each cell bank ... small black wires .. slide the connector out sideways carefully ... it DOES NOT pull straight up ... pull it out sideways. Leave it unplugged an hour, plug it back in and see if it charges. If there was sufficient charge remaining in the battery it will charge .. but if you discharge LiPo's below a certain threshold they are destroyed.

Tried this on my three bricked batteries due to DJI design that drains them to destruction during storage and no luck.

 

[Rich Sugden MD]

Are you seriously telling me you expect DJI to ship individual Lipo cells ? Show me where ANY manufacture supplies cells for their lipo batteries.

I am also an electromechanical engineer who has been fixing and building stuff since I was 5, I have worked in IT, AV and other industry's as well as Radio and TV, yet I don't expect a lipo cell to be available.

Don't need for DJI to ship cells .. but they could sell them to a repair facility that could replace the cells ... The charge/monitoring electronics in the batteries are fine .. just the cells have been discharged to the point where they are destroyed ... usually due to DJI's charging/monitoring electronics having a continued drain on the batteries during storage. "Designed destruction" by DJI. They should repair the batteries .. and have a switch that would disconnect any drain during storage ... I have $600 worth of battery paper weights.

 

[Rich Sugden MD]

Oh, and if that tests out successfully, I know of at least one local repair guy (in LA) who will be offering this as a third party repair service.

One year warranty minimum, parts and labor. Core charge, or send in your core. Somehow if the battery is dead, it's not classified as being hazardous any more. Go figure, but last time I looked, them's the rules.

And of course, like all warranties, dji or not, that will only cover the replacement cost of a re-serviced battery, not a new one.

Which will be much less than the cost of a new dji battery.

Which of course only dji or its dealers can supply you with.

Who is the 'Repair Guy' in LA who will repair the DJI batteries?? I have 4 to send to him!!

 

[ChrisRL]

Rich and Richard...
Here's a thought. We used to do this many times on the very first Nikon/Kodak DCS power packs back in the day when digital photography first came out.
Okay, so the thinking is this:

Like the TB47/48, the Nikon/Kodak battery cells were in a plastic container which also housed a printed circuit board with logics, LEDs, butttons etc. Same setup, really.
So - what's powering the PCB? Residual power from the cells, right?
So if the cells fall below what I'll call a "critical charge level", then the board doesn't have enough voltage to power up (and sense the cells' voltage level enough to tell a charger to charge or not to).
That's one of the main problems I'm thinking is going on. (The other is the bulged cells that indicate that re-celling is required, which I've researched to death on my Hubsans and LaTrax quads. That's true. If they are bulged at all, don't fly them, But don't throw them away either! .

So... I'm going to try this on a TB48 when I have some time, but it worked really well on the camera batteries.

0) inspect the battery for obvious dirt, bad contacts etc.,

1) check that the sides of the battery aren't bulging or loose. Squeeze the sides of the battery together. They should be flat and feel like one piece. Bulged batteries feel, well, bulged, sure, but also they feel like some wrapping or an inner cover has come loose - you can press the sides and feel like a bubble-wrap kind of give, like something's de-laminated inside (which it has). If bulged, stop, don't fly the battery, store it in a cool and dry place and await further news!

if not bulged:

a) remove the top and disconnect the logic board (as in the above posts and also on YouTube).

b) try the simple reset

c) If a simple 30 minute reset [per YouTube et al] doesn't work and the LEDs are still dead, then chances are the cells are down to zero volts instead of the couple three needed to run the board and light the LEDs.

d) "jump" the battery by connecting a regular battery, battery eliminator, or battery charger to the main power cell terminals. If you have a meter, monitor the voltage and amperage and don't cook the cells.

e) check to see if the cells hold any charge at all. If they do, then you're in business, it's just a matter of finding out what the critical level is to wake up the logic board and LEDs again. Then POST THAT INFO HERE!!! : )

f) all you need to do is to get the LEDs to wake up. If/when they do, the battery is officially "repaired" and can be recharged in the charger and should show up in the Go app.

g) I'd still be running the "repaired" battery through a charge cycle or two (idling on the ground or used for sim mode flying, route planning, mission simulation, crew training, camera and gimbal calibration etc) before trying it on a flight. But that's just me, I guess. YMMV after that.

I'll be going down that route myself, and then if successful I'll be posting it up here. I know that in the case of our 16.8v or something weird like that camera battery packs of yore, I used a regular 9v battery and left it "jumped" overnight. Next morning I popped the "legally dead" battery back into the camera and lo and behold.... : )

 

[Eric Braun]

Kilrah, thanks for your message. I've contacted the seller, let's see what he says!

Hmm... let's see. If BMW said to you "this car is a single part number", would you necessarily believe them? It's obvious to anybody at all who has dealt with RC that the "single part" battery is built of shell, logic board, cells, buttons, LEDs. If an LED went out, then one then has to replace the entire battery, because dji says it's one part? As in "my headlight on the BMW just blew. Have to replace the car, because BMW says it's one part".... Hmmm...

I had a BMW M5. There is a concept called a "service level". The 79 cent fan went out in the climate control system so it no longer could sample the cabin air temp. The entire climate control system had to be replaced for a total of $700 because that was BMW's service level. They do not service to the component level, just the module level. This is not unusual at all.

 

[The Editor]

Rich and Richard...
Here's a thought. We used to do this many times on the very first Nikon/Kodak DCS power packs back in the day when digital photography first came out.
Okay, so the thinking is this:

Like the TB47/48, the Nikon/Kodak battery cells were in a plastic container which also housed a printed circuit board with logics, LEDs, butttons etc. Same setup, really.
So - what's powering the PCB? Residual power from the cells, right?
So if the cells fall below what I'll call a "critical charge level", then the board doesn't have enough voltage to power up (and sense the cells' voltage level enough to tell a charger to charge or not to).
That's one of the main problems I'm thinking is going on. (The other is the bulged cells that indicate that re-celling is required, which I've researched to death on my Hubsans and LaTrax quads. That's true. If they are bulged at all, don't fly them, But don't throw them away either! .

So... I'm going to try this on a TB48 when I have some time, but it worked really well on the camera batteries.

0) inspect the battery for obvious dirt, bad contacts etc.,

1) check that the sides of the battery aren't bulging or loose. Squeeze the sides of the battery together. They should be flat and feel like one piece. Bulged batteries feel, well, bulged, sure, but also they feel like some wrapping or an inner cover has come loose - you can press the sides and feel like a bubble-wrap kind of give, like something's de-laminated inside (which it has). If bulged, stop, don't fly the battery, store it in a cool and dry place and await further news!

if not bulged:

a) remove the top and disconnect the logic board (as in the above posts and also on YouTube).

b) try the simple reset

c) If a simple 30 minute reset [per YouTube et al] doesn't work and the LEDs are still dead, then chances are the cells are down to zero volts instead of the couple three needed to run the board and light the LEDs.

d) "jump" the battery by connecting a regular battery, battery eliminator, or battery charger to the main power cell terminals. If you have a meter, monitor the voltage and amperage and don't cook the cells.

e) check to see if the cells hold any charge at all. If they do, then you're in business, it's just a matter of finding out what the critical level is to wake up the logic board and LEDs again. Then POST THAT INFO HERE!!! : )

f) all you need to do is to get the LEDs to wake up. If/when they do, the battery is officially "repaired" and can be recharged in the charger and should show up in the Go app.

g) I'd still be running the "repaired" battery through a charge cycle or two (idling on the ground or used for sim mode flying, route planning, mission simulation, crew training, camera and gimbal calibration etc) before trying it on a flight. But that's just me, I guess. YMMV after that.

I'll be going down that route myself, and then if successful I'll be posting it up here. I know that in the case of our 16.8v or something weird like that camera battery packs of yore, I used a regular 9v battery and left it "jumped" overnight. Next morning I popped the "legally dead" battery back into the camera and lo and behold.... : )

And you would trust the chemistry in a pack who's cells had been dragged down below LVC plateau to hold up and be reliable in keeping a 3kg machine airborne while drawing 5C in climb-outs?
Don't fly anywhere near me with those batteries installed!

 

[Mad_angler1]

I suspect there may be a price drop in the I1 packs very soon so It may not be worth the risk or cost.

 

[ChrisRL]

Gents, thanks for your comments.
I just need to reiterate that we are not dealing with cars or certified aircraft here, despite what dji would have us believe.
If I test my cells as being good, and i verify that they are OEM, then I'm going to fly them.If for hire,then within the provisions of 14CFR107. There is absolutely nothing to say that a dji battery cannot fail in flight regardless of being within warranty or not, any more than any other part, and as rPIC with it's up to me to satisfy myself that I'm not going to do anything stupid to myself, my craft, or anybody else.
And yes, let's see what the 15th brings!

 

[jaymiejame]

Andy, hello!
Let's see if we can't get a solid source for these cells. I know that there's a transport restriction on them - i.e. unless they're sent from the factory in original and unopened packaging, then the regular shipping carriers won't touch them. Except one, which I found myself by looking through all of their rule books.

A propos of this:
My better half just traveled for the first time in recent years to Mexico, where she is shooting a book on dogs. The security people took all of her (six) Leica LiPo spares and confiscated them as being hazardous to flight, despite the fact that Delta had the packaging specifications clearly listed on their websites, etc (tape terminals down with electrical tape, pack batteries individually in waterproof baggies, etc). Those Leica LiPo's aren't cheap either. You're allowed one in the camera, that's it. Unless the others are in unopened original factory wrapping, game over.

So I just sent (and they said it coudn't be done) some el cheapo China eBay replacement LiPos (came in from China at $6 each, free shipping) via a carrier to Mexico. Cost me $80 to send them 3-day, and of course the Mexican customs will charge her what they want to for them, but at least she'll have two spares there for her job.

Cost effective? Nope, not at all. But she can't buy Leica batteries where she is - she has to go to Mexico City to the Leica dealer only to get them... So screwed, no choice.

If there is some kind of shipping or packaging restriction, I do know the national carrier that will ship. So once we ascertain the correct replacement LiPo part, if you want to do a group ship to split costs, etc., I'm open for that, as are at least two others I know of in the LA area alone.

That's the thing about high-priced monopolies in a free trade economy, isn't it?

high chris i work down to component level as well, repaired 2 batteries of my own another two ive got coming in the post this week, to source the cells i'll take them from a battery that has a faulty circuit board and the cell are fine as you can see from the images i have tb47's and tb 48's cells its no great sweat changing the cells. if you disconnect the cell voltage reading connector the wide white one then charge the battery with a balance charger, start off at a low voltage about 14v and build up to 22v. then reconnect the cell voltage reading connector and charge normally with dji charger. once its full up put it in the inspire and press the battery voltage indicator it'll tell you which cells are faulty i swap the pair out.some people think there's magic involved in mass producing stuff in factories, they use the same cells, soldering irons and pair of hands etc ,that i can provide myself and i'm sure you can also. it can be done i've done it so have others.i'd rather pay £25 quid for a tb48 than £189 and do an hours work, if it fails it fails. the circuit board will test the battery and tell you if the cells are faulty, thats it's job. good luck. and if you can source the new cells please send me a link.

 

[ChrisRL]

Will do, Andy, and thanks!
Yeah, if we can source properly and get maybe the OEM people to supply us, I'll be trying for a group buy if the prices are right and dji doesn't cut the prices to ridiculous levels.
I'm going to do the same thing - i.e. I have a battery with bulged cells and good board, and another with what appear to be good cells and definitely a bad board, so that's the first place I'm going to go, like you.
All the best and let's keep each other in the loop, especially after the 15th. I'm very interested to see what dji comes up with!
Chris