Battery Problem

[nmelectronics]

I had two charged batteries from yesterday. When I went up the first time within about a minute I got a low battery warning and it returned for landing. I put the second battery in and it did the exact same thing. I did notice that on the ST 16 controller that the batteries levels fluctuated between 16% then I would jump around to as high is 86%. Any ideas?

I brought them both home place them on the charger and within 10 minutes they were back to fully charged. The red light on the charger was flashing that it was charging correctly. Is there a way to make the batteries go into a balance/charge mode?

 

[BobW55]

First thing I would do is buy a third party charger. Most will display the actual voltage of each cell, and will usually charge faster.
Use the forum search function (magnifying glass at the top right of each page)
Do a search on battery charger, and you will have lots of reading to do.
I see were several pilots have commented on battery voltage display issues, could you be more specific as to the voltages you were seeing vs flight times?