Tello in distress SOS

[RMF808]

I received a bad battery that won’t be charged in a multi battery charger so I decided to try to plug the Tello in with the battery in place. As it turns out, the blue light blinks SOS for the bad battery but good batteries are short continuous blinks.

 

[Flydrone]

If the battery arrived faulty or perhaps completely discharged, you should try connecting it to a computerized external lipo charger and see what it does. I did the wiring for this.
in this way it is possible to test and check the batteries during charging and discharging.
Blue light flashes slowly: battery charging
Blue light flashes quickly: charging error.

 

[Flydrone]

I also add this: to quickly check the actual voltage of the batteries, I took this tool for 1S quite accurate and made a tello battery cable.
Surely not everyone does this, but I think it's useful to check our batteries.

 

[RMF808]

I received a bad battery that won’t be charged in a multi battery charger so I decided to try to plug the Tello in with the battery in place. As it turns out, the blue light blinks SOS for the bad battery but good batteries are short continuous blinks.

That’s rad and thank you for the responses. Personally, I prefer to just buy stuff that works so I will be sending this battery back but that is grey info for the future. I do most of my own repairs. I’m just about to change an arm on my inspire.

 

[akward59]

If the battery arrived faulty or perhaps completely discharged, you should try connecting it to a computerized external lipo charger and see what it does. I did the wiring for this.
in this way it is possible to test and check the batteries during charging and discharging.
Blue light flashes slowly: battery charging
Blue light flashes quickly: charging error.

Like your charging arrangement. Where did you get the connector to connect to the battery and how did you connect inside the tello charger?

 

[Flydrone]

Like your charging arrangement. Where did you get the connector to connect to the battery and how did you connect inside the tello charger?

cables and modifications to the tello charger are handcrafted modifications made by me .. for the charger I disassembled everything and put in series the three batteries with balancing cable and charging socket.