Discharge clock

G Lee · Mar 19, 2020

What resets or starts the discharge timer or clock on M2P batts?? Thx

WithTheBirds · Mar 19, 2020

Connecting the charger or fiddling with the power button resets it.

Leaving it along lets it run.

Camino Ken · Mar 19, 2020

WithTheBirds said:
Connecting the charger or fiddling with the power button resets it.

Leaving it along lets it run.

I think it used to reset when you touched the power button but it seems to me that it doesn’t do that anymore since a recent firmware change. I haven't tried to prove this yet though.

WithTheBirds · Mar 19, 2020

Camino Ken said:
I think it used to reset when you touched the power button but it seems to me that it doesn’t do that anymore since a recent firmware change. I haven't tried to prove this yet though.

I’m on very early firmware so couldn’t say. Hopefully it does reset for the occasions where you might like to keep fully charged for an extended period, remote use away from a charging power supply being a very obvious example.

G Lee · Mar 20, 2020

Thx for replies. Just wanted to know when its triggered. I would like to be able to see this in Go4 app but dont think i can.

GadgetGuy · Mar 21, 2020

G Lee said:
What resets or starts the discharge timer or clock on M2P batts?? Thx

Turning the battery on and off again resets the discharge timer, as best I have been able to discern, assuming it hasn't already expired. Simply checking the charge level no longer resets it.

Checki · Mar 21, 2020

GadgetGuy said:
Turning the battery on and off again resets the discharge timer, as best I have been able to discern, assuming it hasn't already expired. Simply checking the charge level no longer resets it.

That's it. I tested it. I'm 90% sure, maybe I was stupid, but I had 2 batteries, on one I just touched it, the other I did long press. The long press Batterie stop discharging.
So I guess it's right ?

G Lee · Mar 21, 2020

Sounds good. Thx for the info

OurAngryBadger · Mar 21, 2020

So I guess the batteries discharge automatically because LiPo batteries arent safe to maintain a full charge for long periods of time. How far does it discharge them down to?

Is it also unsafe for them to be at a 0% charge for a long period of time? Should I periodically charge them back up tp 100% when not in use?

I wonder about Lithium Ion batteries too, like my DSLR camera batteries. I don't think they are "smart" batteries like the DJI batteries, but they seem to discharge on their own too. For example I can put a fully charged camera battery in storage and come back a few months later and it will be down to 60% or so.

Do lithium polymer batteries not lose any charge on their own where lithium ion do?

Checki · Mar 21, 2020

Sorry, but there are soooo many threads in this forum, other forums, and google...its basic knowledge using a drone.

GadgetGuy · Mar 21, 2020

Photogad said:
So I guess the batteries discharge automatically because LiPo batteries arent safe to maintain a full charge for long periods of time. How far does it discharge them down to?

Is it also unsafe for them to be at a 0% charge for a long period of time? Should I periodically charge them back up tp 100% when not in use?

I wonder about Lithium Ion batteries too, like my DSLR camera batteries. I don't think they are "smart" batteries like the DJI batteries, but they seem to discharge on their own too. For example I can put a fully charged camera battery in storage and come back a few months later and it will be down to 60% or so.

Do lithium polymer batteries not lose any charge on their own where lithium ion do?

All batteries lose charge over time. Never leave a battery at 0% after use without charging it. Ideal storage charge is 50-60%. If during storage it drops significantly below that, it should be recharged. Leaving batteries fully charged at all times is not a safety problem per se. It can lead to swelling over time, which can prevent a battery from being inserted or properly latching. If you are using the fully charged batteries weekly, it's not a problem.

WithTheBirds · Mar 21, 2020

GadgetGuy said:
All batteries lose charge over time. Never leave a battery at 0% after use without charging it. Ideal storage charge is 50-60%. If during storage it drops significantly below that, it should be recharged. Leaving batteries fully charged at all times is not a safety problem per se. It can lead to swelling over time, which can prevent a battery from being inserted or properly latching. If you are using the fully charged batteries weekly, it's not a problem.

I wouldn’t be confidently suggesting SOC night not be related to safety. I recall reading FAA commissioned testing and research where the findings suggested higher SOC not only increased risk of cell failure it also increases the ferocity of any associated fire. The difference between 100 and 30% SOC was threefold from memory. That is why the max SOC permissible for air cargo LiION is 30%.

GadgetGuy · Mar 21, 2020

WithTheBirds said:
I wouldn’t be confidently suggesting SOC night not be related to safety. I recall reading FAA commissioned testing and research where the findings suggested higher SOC not only increased risk of cell failure it also increases the ferocity of any associated fire. The difference between 100 and 30% SOC was threefold from memory. That is why the max SOC permissible for air cargo LiION is 30%.

Duly noted. For travel purposes, follow the air cargo guidelines. However DJI batteries are in a different class than the FAA tested batteries, with smart battery chips that help add safety by auto-discharging. As a practical matter, the risk of leaving DJI batteries fully charged is minimal, although I expect you will likely disagree.

WithTheBirds · Mar 22, 2020

GadgetGuy said:
Duly noted. For travel purposes, follow the air cargo guidelines. However DJI batteries are in a different class than the FAA tested batteries, with smart battery chips that help add safety by auto-discharging. As a practical matter, the risk of leaving DJI batteries fully charged is minimal, although I expect you will likely disagree.

Likely disagree about which part? The safety aspects of LiION chemistry aren’t modified by any smart circuitry to the extent the cells are at 100% SOC.

To the extent you believe “the risk of leaving DJI batteries fully charged is minimal” that is probably true. It is the least safe condition for the battery to be in however, that is a fact.

GadgetGuy · Mar 22, 2020

WithTheBirds said:
Likely disagree about which part? The safety aspects of LiION chemistry aren’t modified by any smart circuitry to the extent the cells are at 100% SOC.

To the extent you believe “the risk of leaving DJI batteries fully charged is minimal” that is probably true. It is the least safe condition for the battery to be in however, that is a fact.

I was only referring to my last statement, and, happily, we agree! Thumbswayup