Intelligent battery help

[Blacksails]

I've carried out a quick search but couldn't find a thread that directly answered my question.

I have 11 TB48's in storage. I occasionally check on them, like once every two weeks. I generally like to see two lights on them, sitting around 50% charge for storage. However, sometimes when I check on them it has dropped down to one light, or one single flashing light. Is this normal (I'm guessing so as all of them do it!) and is it ok for them to stay like this?

So, I guess my main question is: When ever I have seen them drop below two lights, I have plugged them in and topped them back up to 50%. Advisable and correct to do so?
This is what I would do with standard lipos but I'm not sure if this denotes the slow decent into hibernation mode and is actually nothing to worry about...

Sometimes I wish these batteries were just like regular good old fashioned lipos! I found them way easier to care for. I understand the self discharge thing is for people who don't come from a lipo background, but I do and this just confuses me..

The aircraft firmware is 1.8

Thanks,

Alex

 

[SanCap]

I've carried out a quick search but couldn't find a thread that directly answered my question.

I have 11 TB48's in storage. I occasionally check on them, like once every two weeks. I generally like to see two lights on them, sitting around 50% charge for storage. However, sometimes when I check on them it has dropped down to one light, or one single flashing light. Is this normal (I'm guessing so as all of them do it!) and is it ok for them to stay like this?

So, I guess my main question is: When ever I have seen them drop below two lights, I have plugged them in and topped them back up to 50%. Advisable and correct to do so?
This is what I would do with standard lipos but I'm not sure if this denotes the slow decent into hibernation mode and is actually nothing to worry about...

Sometimes I wish these batteries were just like regular good old fashioned lipos! I found them way easier to care for. I understand the self discharge thing is for people who don't come from a lipo background, but I do and this just confuses me..

The aircraft firmware is 1.8

Thanks,

Alex

It appears you are doing the most appropriate steps to preserve your batteries. How many days do you have your batteries set to discharg at?

 

[Blacksails]

It appears you are doing the most appropriate steps to preserve your batteries. How many days do you have your batteries set to discharg at?

I have them set to 10 days, but this is never used really. I charge before flight, usually land when they're between 30-50% and charge any that need it back up to 50% for storage when home.

 

[The Editor]

I've carried out a quick search but couldn't find a thread that directly answered my question.

I have 11 TB48's in storage. I occasionally check on them, like once every two weeks. I generally like to see two lights on them, sitting around 50% charge for storage. However, sometimes when I check on them it has dropped down to one light, or one single flashing light. Is this normal (I'm guessing so as all of them do it!) and is it ok for them to stay like this?

So, I guess my main question is: When ever I have seen them drop below two lights, I have plugged them in and topped them back up to 50%. Advisable and correct to do so?
This is what I would do with standard lipos but I'm not sure if this denotes the slow decent into hibernation mode and is actually nothing to worry about...

Sometimes I wish these batteries were just like regular good old fashioned lipos! I found them way easier to care for. I understand the self discharge thing is for people who don't come from a lipo background, but I do and this just confuses me..

The aircraft firmware is 1.8

Thanks,

Alex

That's pretty much exactly what I do.
It's a pain in the backside but as we know DJI's 'intelligent' flight batteries are anything but.
Unfortunately there is always a slight current drain even quiescent current and this will cause a draw and depletion of the battery over time.
It is extremely rare that I go three weeks without flying but that's as long as I like to leave it before checking the charge level.
I top them up until the third LED has been flashing for around 1:30 then if you check the packs on the app they are pretty much sitting at bang on 3.86v per cell which is ideal.
Then I just rinse and repeat as necessary
Not much else you can do with the DJI packs unless you pop the lid and totally disconnect them - that's even more of a faff.

 

[rilot]

I completely disconnect mine by popping the lid. Yes, it's a hassle but I fly very infrequently these days and after having a TB47 kill itself (which I recovered by charging the cells directly) it saves me the possibility of having to replace the stupidly expensive (not at all) intelligent batteries.

 

[Blacksails]

Thanks guys, just wanted to confirm I was doing the correct thing. I'm not flying much recently and having any number of TB48's die is an expensive occurrence!
They really are a faff! How they aren't all DOA I don't know. When I put in my first order of 10 48's when buying the Inspire, I had to send 7 back straight away as they wouldn't light up or take a charge. Intelligent.

 

[Håkan22]

I completely disconnect mine by popping the lid. Yes, it's a hassle but I fly very infrequently these days and after having a TB47 kill itself (which I recovered by charging the cells directly) it saves me the possibility of having to replace the stupidly expensive (not at all) intelligent batteries.

I haven't yet checked. But you say it's possible to remove the upper part and then get access to each individual cell? I'm used to use unintelligent batts and charging the cells individually when required to get them in balance and this might be an option as i have a TB47 with cells that don't want to get matched by the "intelligent" balancing.

 

[rilot]

You can indeed. Pop the white lid using a small screwdriver to release the little clips. There's 4 of them.
Once it's open, disconnect the balance port and move the top piece away to get some room. You will see tape covering all of the cells. Peel the tape back to get access to the massive solder pads.

They are connected like this:

Each cell is as follows:

Pads 1 to 2 = Cell 1
Pads 2 to 3 = Cell 2
Pads 3 to 4 = Cell 3
Pads 4 to 5 = Cell 4
Pads 5 to 6 = Cell 5
Pads 6 to 7 = Cell 6

With Pads 1 to 7 as the full battery voltage.

Get a multimeter and measure the voltage of each cell individually and write it down.
Rather than charge the cells, the best way to do it is to discharge all of the high cells down to the voltage of the lowest one. To make them all the same, it's best to set a discharge program on a basic LiPo charger to a specific voltage and do them all. Then you know they are all the same.

For example, my TB47 I just rescued had 1 cell that was at 4.01V while the rest were at 4.3V. I set a discharge program to 3.8V and discharged each cell individually to that voltage. I then stuck it back together and on the DJI dumb charger and violla! Working battery again. I've flown that battery at least 5 times since then and it's absolutely fine.

The DJI Intelligent Batteries don't really have a balance charger built in to them like DJI wants you to believe. The balance leads are only for voltage monitoring from what I can tell. If a cell is more that 0.1V out then the circuitry just refuses to charge it and you end up giving DJI $200.

 

[Håkan22]

Grand, thanks! I'm on it as I write.

 

[Blacksails]

Very useful information! A battery that I have flown maybe twice, so basically brand new, after charging this morning has cell 1 and cell 2 around .3v lower than the rest when fully charged.

I'll be balancing them on my cellpro later this evening!

 

[Håkan22]

Ok.. Soldered a more compatible connector and hooked up to a balancer. Let's see what the outcome is tomorrow. I have the last flight with that batt logged at healthy drones and it will be an easy comparison of a before and after operation.

 

[rilot]

Looks good. I didn't actually solder a balance port on. I just used croc clips to access each cell individually. It took a long time to do it my way.