RTC Standby mode & battery charging

[LIM PHANG MOH]

You can send us the image. Please keep a decent size.

You can even try to test this with a USB port.

Did you try this also?

[Christophe Labouisse]

Images sent by email:

On the second image, the battery pack is connected to the bottom ramp and my multimeter is plugged on row 18. Regarding the battery pack it’s made of 6 EBL 2800mAh AA batteries. I didn’t find any specification regarding the max current of those battery but from what I measured, the pack current is between 0.7 mA when the led is on to something under 0.1 mA when the led is off.

I made a test last night using the USB port instead of the battery pack and I found that the battery was not charged overnight as I measure 3.44V yesterday and 3.36 this morning.

Last the code:

void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(13, OUTPUT);
  SerialUSB.begin(9600);
}

// the loop function runs over and over again forever
void loop() {
  unsigned char counter;
  float batteryVoltage;
  int adcReading;
  adcReading = analogRead(A5);
  // Discard inaccurate 1st reading
  adcReading = 0;
  // Perform averaging
  for (counter = 10; counter > 0; counter--)
  {
    adcReading += analogRead(A5);
  }
  adcReading = adcReading / 10;
  // Convert to volts
  batteryVoltage = adcReading * (4.3 / 1023.0);

  SerialUSB.print(F("Battery: "));
  SerialUSB.print(batteryVoltage);
  SerialUSB.println(F(" V"));
  
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(500);
  digitalWrite(13, LOW);   // turn the LED on (HIGH is the voltage level)
  delay(500);
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  long blink = random(250, 5000);
  SerialUSB.println(blink);
  delay(blink);                       // wait for a second
  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  blink = random(250, 5000);
  delay(blink);                       // wait for a second
}

[LIM PHANG MOH]

You have put the battery polarity wrongly from your photo! Red should be + and black -. There’s possibility that you have already damage the battery management IC.

[Christophe Labouisse]

Yeah I should mentionned this the polarity is good I used a prewrited JST plugs which have the + and – wired at the opposite of the Utlra 3

[LIM PHANG MOH]

Can you load this sleep code and try charging the board?

Please add analogRead(A5); in the setup() as the code is for V2 board without battery monitoring.

Also, is your battery still in good condition? Have they been tested to charge properly on other charger?

[Christophe Labouisse]

I upload the sample code added a single analogRead(A5) in setup. No changes from my side, the battery is definitely not getting charged. The battery is in good condition as it charges with other charger.

[LIM PHANG MOH]

Hi Christophe,
You bought 2 units, are both behaving the same? We did test battery charging too from both VUSB and VIN on all boards.
I would suggest sending us back the faulty units for us to check and I will send a replacement.

[Christophe Labouisse]

Hi,

Yes I brought 2 units indeed and I can tell you they both have been working at some point. I was thinking on send you back the dev one so you can have a look at it. I’m still using the other unit in my sensor and I just have to change the battery with a charged one every couple of weeks. Please mail me your address and I send you back the first one, for the second one, I’ll wait until mid/october when I’m going to remove the sensor for the winter.

Cheers

Christophe

[LIM PHANG MOH]

I’ll reply to your email after this. It might end up in your spam.
Thanks.

[LIM PHANG MOH]

Hi Christophe,
Did you receive my mail? I ask because I received rejected email error from server.

[Christophe Labouisse]

Hi Lim,

No I didn’t get your email i was going to tell you but you were faster than me. I just send you an email with additional addres.

[LIM PHANG MOH]

I just only resend, together with the CC address. Please check.
The server complained on the delay of the delivery to your server.
And this warning repeats every 24 hours until it get delivered or after 3 times of tries.

[Author]

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