About ST10+ battery...

[Pier2162]

During the preparations for the last flight I realized that the YP-3 battery of my ST10+ did not charge completely, despite the many hours left connected via the USB cable to a mobile phone charger. Charge indicator stops around 80%.

During use I did not notice any abnormal charge loss, after a couple of flights, for a total of about 30 minutes, the battery level remained almost identical. Once back, I removed the battery from the remote control and connected it to a charger / analyzer, and I realized that the battery did not charge well... the internal resistance was 1Mohm, this value seem to be good, the charge (at 400 ma) starts but after a couple of minutes stops indicating that battery is full.
On discharge, at 200 mA, in few minutes voltage goes to zero.
I don't understand how could I fly for half an hour with a battery in these conditions!

I tried to perform some charge /discharge cycles but without getting improvements, so I decided to buy a new battery: I wanted to know if there are any contraindications in using a LIPO instead of a LI-ION battery, and if the original battery contains some internal protection circuit.

On the market I found batteries that report on the label to be LI-ION but the tension is 3,7V instead of 3,6V as the original.

 

[Vaklin]

Better is to use an original battery. The elements inside are two 18650 and they're balanced and protected with a circuit inside the battery. I'm afraid, if you try to use a battery without this circuit you can damage your ST10+ if you try to charge it via an external USB charger. If you will ever charge it outside of the unit, no reason to not use any Li-Ion battery. LIPO is not a good idea, because you should keep it in storage charged level if you want to have it for a long time. This is not practical for the controller's power sources.

You can replace the elements inside the battery if you want.

 

[Pier2162]

Your last phrase is a good option, is it easy to open the battery?

 

[Vaklin]

Check the forum. I have posted some pictures. Easiest depends on the skills. I can't say for anything that it is easy or not.

 

[Vaklin]

Correction! I have posted pictures from the opened battery for SteadyGrip. I have had an opened battery for ST10+ but I can't find it now. Only the elements are here. In any case, you can open it. Press firmly with fingers on both long sides simultaneously. You should hear some quiet noise. The battery is glued with an ultrasound heating gun, so the opening is almost trivial.