Inspire 1 TB48 Battery Concerns

[Kevin Cabral]

Is this battery done? It has 61 charges on it I believe. I can't remember if I was full throttling the Inspire to trigger the deviations in cell 1... Regardless if I was full throttling it or not... the deviations in cell 1 seem pretty bad. What you all think? Time to retire the pack?

 

[AlanP]

Cycle it down then back up to full - see how it goes.
If the pattern continues then retire it.

 

[AeroMirage]

How old is it? Warranty is 6 months or 200 charges.

 

[The Editor]

Is this battery done? It has 61 charges on it I believe. I can't remember if I was full throttling the Inspire to trigger the deviations in cell 1... Regardless if I was full throttling it or not... the deviations in cell 1 seem pretty bad. What you all think? Time to retire the pack?

The problem with all these daft apps is that they can give too much info and incite a paranoia.
Calling cell deviations of 70mV 'Major' is just rediculous.
Anything under 200mV difference under load is perfectly acceptable/normal and should not be a cause of concern.

 

[Kevin Cabral]

The problem with all these daft apps is that they can give too much info and incite a paranoia.
Calling cell deviations of 70mV 'Major' is just rediculous.
Anything under 200mV difference under load is perfectly acceptable/normal and should not be a cause of concern.

What's your thoughts in the deviations in cell 1 to my battery? Should I keep using it and just be easy on the throttle while using the battery?

 

[Kevin Cabral]

How old is it? Warranty is 6 months or 200 charges.

It's past the 6 month warranty period

 

[The Editor]

What's your thoughts in the deviations in cell 1 to my battery? Should I keep using it and just be easy on the throttle while using the battery?

Your maximum deviation on cell one appears to be in the order of 170mV so as I mentioned above, nothing to worry about.
Keep an eye on whether the pack balances OK after charging and if the deviation only shows during stressing the pack it is likely just a slightly weaker cell than the rest.
Again, no reason for concern - I would continue flying the pack and simply monitor the voltage (not percentage which is a meaningless figure) during flight as I normally would.

 

[Kevin Cabral]

Your maximum deviation on cell one appears to be in the order of 170mV so as I mentioned above, nothing to worry about.
Keep an eye on whether the pack balances OK after charging and if the deviation only shows during stressing the pack it is likely just a slightly weaker cell than the rest.
Again, no reason for concern - I would continue flying the pack and simply monitor the voltage (not percentage which is a meaningless figure) during flight as I normally would.

Yeah the only time the cells become unbalanced is when there is stress on the packs. While idle, all cells sit balanced. I would expect the cells to be unbalanced while they're being stressed. Question is how much of unbalanced cells is a concern? 170mV mean that's how much of a voltage difference cell 1 from the other cells? What mV deviation is unsafe you think? I see cell 1 reached under 3.3v... Silly question but how come the battery didn't cut out? Unless the DJI Go app detects this and slows down the motor's for battery safety?

Thanks for your help

 

[Jbundy63]

On my 2 Inspire 1 batteries I have the same amount 60 to 65 cycles. I do sometimes get that amount of devastations, so I run the pack down to 8% when I see this or every 20 cycles, let the pack cool down and recharge. This usually helps but if your hitting 3.3 volts I would be a little concerned and careful, mind has got to 3.4 under heavy load. Are you getting the notifications saying Limited motor output to ensure safe flight?

 

[Jbundy63]

Here's my last flight on my TB48 at 75 flights. I would just keep a close eye on it after you cycle it and see how it does?


May 13th, 2018 12:02AM | General / Overview | Drone Flight Log from DJI GO app, version 3.1.34 on iOS | Total Mileage: 12,623 ft | United States | Airdata UAV

 

[Kevin Cabral]

On my 2 Inspire 1 batteries I have the same amount 60 to 65 cycles. I do sometimes get that amount of devastations, so I run the pack down to 8% when I see this or every 20 cycles, let the pack cool down and recharge. This usually helps but if your hitting 3.3 volts I would be a little concerned and careful, mind has got to 3.4 under heavy load. Are you getting the notifications saying Limited motor output to ensure safe flight?

I noticed 'limited motor output', not sure if it was with that battery though. I see the msg when I'm full throttling the Inspire. Hopefully the software detects a voltage being too low on a cell and slowing down the motors for battery safety.

 

[Jbundy63]

I noticed 'limited motor output', not sure if it was with that battery though. I see the msg when I'm full throttling the Inspire. Hopefully the software detects a voltage being too low on a cell and slowing down the motors for battery safety.

Yeah if I remember right that was in a firmware update quit awhile back and I believe it was designed to lower output to the motors due to battery voltages and heavy load. I myself see this when you throttle heavy, I usually let off the throttle a little as well when this happens.

 

[Advexure]

Yeah if I remember right that was in a firmware update quit awhile back and I believe it was designed to lower output to the motors due to battery voltages and heavy load. I myself see this when you throttle heavy, I usually let off the throttle a little as well when this happens.

Yes, I believe on the I1 there is a peak output threshold that triggers the motor output limit reached message when you're pushing too low of a voltage on a cell in heavy draw flight where most voltage is pulling from a single cell. Don't have any figures on maximum deviations under heavy draw but definitely be mindful of this message and don't push it beyond the threshold where the message is triggered. Every so often we see this the motor output limit message on other aircraft but it's definitely most common on the I1.

 

[Kevin Cabral]

Yes, I believe on the I1 there is a peak output threshold that triggers the motor output limit reached message when you're pushing too low of a voltage on a cell in heavy draw flight where most voltage is pulling from a single cell. Don't have any figures on maximum deviations under heavy draw but definitely be mindful of this message and don't push it beyond the threshold where the message is triggered. Every so often we see this the motor output limit message on other aircraft but it's definitely most common on the I1.

Whenever I do see the message pop up, I ease up on the throttle. Sort of sucks if you're flying pretty far and trying to get back fast. The message scares the hell out of me if it pops up when I'm far out.