Are you sure the battery is protected? It usually isn’t. The Quad charger should be and it’s good to see it haven’t blow up already Just switch the wires and try again. Maybe measure the battery voltage before inserting if it’s OK (this should apply for any battery).
I believe the guys at Seeed tested the Quad well but they didn’t check the separately packaged batteries. Looks like some questionable cheap manufacturer who doesn’t care about polarity… This is serious Beta issue and should be good warning for further products and testing before shipping.
After some soldering and heat shrinking I reversed the JST connector on my battery, and it works! Of course now the leads are too short, so I had to flip the battery over, and the door doesn’t quite close right.
I don’t know how Shiguru managed to plug the connector in backwards. On mine, I couldn’t have put the plug in the wrong way without destroying the socket.
Here is a picture of my temporary fix. (I believe that Seeed will send me a replacement battery soon)
I also was given a battery with the reverse polarity. I can now run the DSO Quad off of battery but the status light does not come on when connected to usb with the battery in. If I remove the battery and plug in the usb the status light does come on. Also the battery does not seem to be charging now.
Technically, the battery polarity ok; red=positive, black=negative. I opened my DSO Quad up and the silk-screening on the board appears to be labeled properly, so it looks like it’s the connector socket that’s been soldered in the wrong way around.
Just got my DSO Quad. I was excited and plug the battery in. I then smell some burn and feel some heat near the switch.
It didn’t turn on. I searched Seed forum and found this thread. So I swapped the battery wires and the DSO nano can turn on with the battery, but it has no back light. If I use the USB port, the back light comes up. The battery voltage measured is 3.8v. Anyone seeing the back light after fixing this issue? And what’s your battery voltage please?
By the way, the battery does have a protection circuit on its output. It didn’t suffer any damage when plugged in in reverse with USB cable connected to the DSO quad.
It might be more reasonable and safer to follow Pulsar’s advice in this same thread and just reverse the pins in the battery connector. Then write an indelible felt tip pen warning in the battery compartment.
It seems my battery is still charging normal after I swap the red&black battery wires in the JST plug.
After leaving the quad off with USB cable plugged in for all night, the battery voltage is measured at 4.3v (with a Fluke 179 - should be max at 4.2 only)
However, even with this voltage, the quad still reports that my battery is empty (red empty battery symbol).
Even after all night, the red light is still on.
My only suggestion would be to measure the Vbat signal (between U14 and U15 on the schematic) and see if that is 1/2 the actual battery voltage. If not, then this voltage divider circuit is defective, or more likely, the reverse voltage damaged that input-pin on the STM.
If the STM can’t see the battery voltage, then it will pull down the CHRG output signal and this could possibly force an overcharge condition to the battery and also keep the red LED on.
Does the red LED turn to yel/org when the unit goes to sleep?
The STM chip does see the voltage changes. When plugged into the USB port, the charge indicator goes green.
I measured the voltage at R51&R52 bridge, it’s exactly half of the input voltage. In my case, with battery voltage at 3.9v, I measured only 2.6v on top of the R52, thus it’s only 1.3v at the Vbat point. So the STM thinks battery is low for obvious reason.
The voltage at the on/off switch is only 2.6v. The voltage of the battery is 3.9v. So something is lost in between.
Looking at the schematic, I don’t understand why there is an X betwen pin 3 of U19 and the switch? Does that mean pin 3 is not connected?
If pin 3 is not connected then the voltage is passed from the battery solely through the diode inside U19. Is it a Schottky diode or is it a zener diode? I think it should be a Schottky diode. So maybe U19 is dead in my board. If I make a jumper between the switch and the battery, the quad indicates it’s 50% charged.
Could anyone please measure the voltage at the middle pin of your quad’s switch?