Bitcraze Forums

Hi, I just got my CF nano a week ago and finally went to get it soldered today.

After the initial...troublesome...flight and battery depletion (pretty sure it started at ~3700mV) it's now having trouble climbing above ~3560mV on USB (The PC client shows it as about 1/3 full).
- Tried plugging the USB into PC and now it's in an adapter directly into socket.
- Tried unplugging and plugging the battery back in

As a side note and a possibly related issue, the blue power LED doesn't seem to come on at all now, and I'm pretty sure it was on when flying it before.

The red blue LEDs are behaving as if they were on battery power regardless if connected to USB or not: plugging in USB gets a 1Hz from red till CF stays still then switches to 2Hz. Green seems to be faintly blinking at 1Hz. (EDIT: this was when I had wireless connection to the CF, disabling that results in 2Hz red, constant green... with a 1Hz red that would mean it's full...what's the meaning of 2Hz red + full green?)

Thanks for any input!

UPDATE: after 2h it climbed to ~3570mV, Could it be that the battery I got was just that bad??

Emptied the CF once more, here's the charging chart: NO clue what the drops are, the CF was untouched on plugged throughout the time observed on the chart.

Tested the blue diode with multimeter and there is voltage on the pins.

Still no clue what to make of the red/green pattern while on USB...

I think it can be either the battery, the USB connector or the power management chip. Does the battery seam to take any charge at all? I can just be that the battery is "recovering".

If you have a multi-meter you can check that there is 5V on the two holes just behind the USB connector when power is connected.

Another thing you can check with the multi-meter is if the PM-chip is trying to charge. Disconnect the battery and measure on the battery connector pins when USB power is connected. The voltage should ping-pong between 0V and 4.2V (it's when it is searching for a battery).

It does seem to take some charge, the graph is not the short period after the motors stop when it jumps back up, it seems to actually be charging. Especially since I tried to deplete the battery for the test (CF was tied down, was trying to calibrate it).

The holes behind it show 4.94V, which I would guess is close enough.

I tried the battery pins when the battery was disconnected and CF plugged in. They indeed were jumping, but the highest I caught on the multimeter was ~3.7V. It is a digital one tho so it might be just refreshing at unfortunate times.

Is the diode/led an unrelated issue and should as such have its own thread?

Well with that information my best guess it that it is the battery. However damaged batteries tend to charge very quickly because they lost most of its capacity. Not slowly as in your case.

The green led displays the charge status. It should be blinking when it is charging so there is something strange here as well. I have sent you a PM.