Inspire 1 Battery- Unbalanced cells

was suggested to create a new thread for this issue but on my advice for a new flyer to an inspire 1 v2 thread after taking the drone up for a test run I had 2 errors within a minute or 2 of taking off. they are below.

@PingSpike said that it looks like unbalanced cells. for reference the battery used is a TB48 with 25 Cycles on it from end 2016. Is this likely to mean the battery is dead or damaged or could it be repaired or is there something else wrong.

If the cells are unbalanced it is possible to correct them by bypassing the ‘smart’ circuit board and using a balance charger.

Unless you really understand what you are doing I would refrain from opening the battery to have a prod around. If you accidentally short the output there’s nothing to stop all the cells discharging everything they’ve got. I once demonstrated this to a member of our club by momentarily shorting a humble 2200mAh pack with a small crocodile clip. A large percentage of the clip was vaporised.

There is nothing within a LiPo cell that can be repaired once it starts to fail. It works by an electrochemical reaction causing electron flow through the electrolyte from one terminal to the other terminal. Recharging reverses this process but in doing so it is inevitable that crystals will form as dendrites (whisker like structures). This buildup restricts current flow causing an increased internal resistance and thus reducing the ability to hold charge and supply current. It is the natural ageing process of LiPo batteries. Unfortunately in a multi-cell battery not all cells degrade at the same rate, especially if the battery has had a hard life or has been abused, and it’s this that leads to the imbalance.

There are techniques for breaking down the formation of dendrites on the conductive plates but none are suitable (read that as wholly catastrophic) for LiPo batteries.

In the end it is a sad fact that Lipo’s die, some apparently before their time, which could be attributed to the previously mentioned abuse or possibly an impurity / contamination of the electrolyte during the manufacturing process.

Like Nidge says, lipos die, shit happens, get over it. There’s two things you can do, (three if you watch all the YouTube videos on how to fix it, then find out that you really can’t), 1. buy another battery (they don’t make them anymore so it’ll be secondhand and therefore probably well used, and 2. do as we’ve said in your other post and send it back and have a refund.
If you really want an Inspire, MPB are doing them for £749 for a Pro, £614 for a V2 and £539 for a V1. At least if you have one off them, you know you’re dealing with a reputable company and they check everything that they sell.
For the same(ish) sort of money, go and buy a Mavic Air 2, it hasn’t got retracts and the gimbal doesn’t go all the way round, but the batteries are available (and cheaper than Inspire’s) and it won’t put your back out every time you want to carry it about anywhere. And it does nearly everything that the Inspire does and some it doesn’t.

John

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Hi everybody,
I´m interested in buying obsolete TB48 batteries, that can no longer be used … for example that they cannot hold the charge, or swollen, etc… the important thing is that the electronics are still efficient.
I am willing to pay 30 euros each.
Thanks for your feedback
Cesare

@cesare we’d rather you shared your plans for refurbishment / repair / modification / resale?

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Posting an update here

Had an idea to drain the battery to 1% (in the DJI Go app) and do a full charge on the battery and seems to of fixed it. (not as many cell imbalance now but still some on cell 4). so going to close this now as it’s run its purpose in my eyes.

method

charge battery to 100% in charge hub.
turn on drone and leave for 5 hours.
set low battery alarm to the lowest it can go (5% i set mine to)
wait till battery level prevents motors starting.
waited 1 Hour to cool down
charge fully
(?profit?)

Flight Test

Time in air:8m 56s Take off battery: 100% Landing Battery: 54% battery heath:

AirData free has its uses but cant justify $6.99 p/m in the current climate for battery monitoring features.

This is the same method I used with three new P2 batteries, as per a DJI document I think I read somewhere.

All three batteries though new may have been sat on a shelf for quite sometime. With the first use flight times were about 5mins before the second stage warning kicked in. Once the batteries had chance to cool down I connected to the P2 Assistant software and left the drone until the battery could no longer power it. I then recharged the battery to 100% flew the P2 again, where it produced a flight time of just over 20mins before the first stage warning kicked in.

I didn’t mention this procedure in an earlier post as you’d said that there was an imbalance, which usually suggests that one or more cells are either damaged or on there way out the door.

I had assumed an imbalance only due to the limited data from AirData UAV. but considering the worst case was the battery was dyeing worth a shot in my book. going to get another TB47 soon as a backup in case.

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