Noticed something while charging a battery

[Alien Warrior]

I did a long road trip recently and decided to use a 300W inverter plugged into cigarette lighter socket to provide power to the usual 57W charger.
Worked fine and kept 4 battery packs and the remote controller fully charged throughout the trip.
I did notice some interesting observations after inadvertently disconnecting the inverter prior to the battery being fully charged. I observed the charging routine very closely afterwards and noted the following:
Usual charge times are 1hr & 10mins/20mins always.

• I accidentally powered off after 40 minutes charging. Powered back on straight away. LED's on battery did not illuminate and battery did not charge any further.
• I then used that battery on the next flight. Battery at 100% charge and all cells same voltage.Worked fine and recharged fine.

I stupidly turned the power off again after 20 minutes of charging while inverter fan was still running(doh!) and noted the following:

• Started the inverter and battery continued charging and completed in usual time.

I then started paying more attention to charging and noted the following:

• Begin charging and inverter cooling fan starts - indicates high capacity electrical load.
• After 30'ish minutes inverter cooling fan stops - indicates reduced electrical load.
• LED's continue flashing till the usual recharge time is reached and then stop normally.

My conclusion are:

1. Batteries should not be disconnected for any reason during the charging phase.
2. Top up charging is "iffy".
3. Battery appears fully charged after only 30 minutes.
4. Battery technology is beyond my comprehension!

I don't know if this helps but at least adds to the archive of battery information.

 

[Rocket_Aus]

Thx for the FYI I have found similar even just using the charger at home.

 

[PhantomFun]

Seems once the charger completes on one battery when the next battery is hooked up, I've noted having to unplug the charger to start fresh, or push the test button on the battery before it recognized a needing to be charged battery was in the que.

Mark.

 

[III% Streve]

The "chargers" from DJI are nothing but a power supply. Unplugging them and plugging back in would have ZERO affect. There is nothing in them to reset.

 

[Meta4]

I accidentally powered off after 40 minutes charging. Powered back on straight away. LED's on battery did not illuminate and battery did not charge any further.

1. Top up charging is "iffy".

Whether at home or using an inverter, if you try to charge a battery that is at 90+%, it will not charge.
But if you turn on the battery switch, it will accept a top up charge.

 

[Alien Warrior]

Handy to know that pressing the button will allow additional "top-up/completion" charge.
I didn't try that, thanks for the info.

 

[kirk2579]

Whether at home or using an inverter, if you try to charge a battery that is at 90+%, it will not charge.
But if you turn on the battery switch, it will accept a top up charge.

I use that method fairly often , have 4 batteries and 2 quads, p2v1 and p2v2+.
often fly 5 to 10 minutes and hate to re-fly on battery that low so a top off charge is handy

 

[Alien Warrior]

Does the charge counter increment when topping up?

 

[Cacc]

Does the charge counter increment when topping up?

The indicator will increment when topping up. The number of charges shown in the app is "full" charges, meaning 100% was added to the battery. So if you top up from 90%, 10% will be added to the total charges value. Do that 10 times and it will add 1 to the number of charges. Similarly, bring your battery level down to 30% three times for three charge cycles of adding 70% to the battery, that will count as 2 charge cycles in the app as that is 210% that has been added. A weird way to count charges, but they seem to prefer this method.

 

[4wd]

Does the charge counter increment when topping up?

I've found it doesn't, at least not if it's only 5% or less needed.
Not sure if it's smart enough to add the 5% to an ongoing total.