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Battery charging

Timothy Jewell
 

Willi
Great job with the kit, it was easy to put together and worked immediately.

However I am having a problem with the battery charging. I am using a 1000mAh 3.7V battery which appears to register as empty when it gets to approximately 3.55V . When running it shows 70 to 80 mA discharge and when asleep about 15mA. Plugging is a 5V 2.1A adapter when in the off position will light the orange light. Switching over to the on position the light goes out and there is no discharge from the battery. When it goes to sleep there is no current to or from the battery. If I plug the adapter in when asleep the 15mA drops to zero. It does same on the two identical batteries that I have. They both charge normally using an external charger. What is really confusing is that the voltage at the battery goes from 3.5v or so to 4V but there is no current to the battery and the light is not on.

Bit of a pain but just a minor inconvenience as I can charge externally and I do have two batteries.

73 de Tim EI9KH


Timothy Jewell
 

Willi
Update: I left the unit on to discharge the battery and at about 3.1V the microprocessor gives up. . I plugged in the adapter and it started charging (orange light was on). Charging current was about 70mA. After an hour the voltage had climbed to 3.44V but the charging current had decreased to a few milliamps. At 3.54V charging current was a fraction of a milliamp although I don't think my ammeter is all that accurate. Over the next few 4 hours it climbed to 3.67V. On waking the unit the battery symbol was all but empty. So basically it will only start charging if the battery is very low and stops charging at just over 3.5V. No load charging voltage is 3.74V (battery disconnected). So charging does work but is all but unusable.

Best regards
Tim

On Mon, Jan 28, 2019 at 1:32 PM Timothy Jewell <trjewell1@...> wrote:
Willi
Great job with the kit, it was easy to put together and worked immediately.

However I am having a problem with the battery charging. I am using a 1000mAh 3.7V battery which appears to register as empty when it gets to approximately 3.55V . When running it shows 70 to 80 mA discharge and when asleep about 15mA. Plugging is a 5V 2.1A adapter when in the off position will light the orange light. Switching over to the on position the light goes out and there is no discharge from the battery. When it goes to sleep there is no current to or from the battery. If I plug the adapter in when asleep the 15mA drops to zero. It does same on the two identical batteries that I have. They both charge normally using an external charger. What is really confusing is that the voltage at the battery goes from 3.5v or so to 4V but there is no current to the battery and the light is not on.

Bit of a pain but just a minor inconvenience as I can charge externally and I do have two batteries.

73 de Tim EI9KH


Willi, OE1WKL
 

Try to keep it connected to USB for at least 10 hours…. This would be the first time that it cannot charge a battery as far as my experience goes. What kind of LiPo battery are you using? Are you sure your battery is just a single LiPo cell without any electronics like charging regulator in it? A battery with built-in charging electronics probably cannot be charged through the Heltec module, as it requires much higher voltage levels than the Heltec module would provide.

73
Willi
OE1WKL

Howard W6HDG
 
Edited

I have had to charge externally for best results. Wake up screen will then show 50% battery and I get a lot of operating time. Perhaps this is due to the charging protection in the battery? 

I'm glad I listened to Gary W4EEI and purchased these batteries  
https://www.amazon.com/gp/product/B0756WN9JS
They come with a nice USB charger with accurate charging light. Plus, I have a spare battery for the future.

Timothy Jewell
 

Willi
I am not sure at all if these batteries have an internal charger or not. I will try and get hold of the exact model you have recommended. I can not find it in Ireland unless I buy 6 at the same time for about the price of the morserino. It may take me a while to get one but I will report back when I do. Thanks for the advice.
Regards
Tim


On Tue, Jan 29, 2019 at 3:47 PM Willi, OE1WKL <willi@...> wrote:
Try to keep it connected to USB for at least 10 hours…. This would be the first time that it cannot charge a battery as far as my experience goes. What kind of LiPo battery are you using? Are you sure your battery is just a single LiPo cell without any electronics like charging regulator in it? A battery with built-in charging electronics probably cannot be charged through the Heltec module, as it requires much higher voltage levels than the Heltec module would provide.

73
Willi
OE1WKL


DD1TOM
 

Dear Willi,

I charged my Morserino via USB over night, in the morning it were 4,09V at 0,01mA loading current. Nevertheless battery is shown as nearly empty :-O

73
Tommes
DD1TOM

Willi, OE1WKL
 

Very strange behavior. I am not sure what’s going in there, and how (or if) I can do anything via Software to improve the situation. Charging itself cannot be influenced by software, but measuring the voltage is a software feature, but apparently a very unreliable one. I will do further experiments (documentation is hardly available), and if I find something useful, will incorporate it into the next firmware release…

73
Willi

Chuck Broadwell, W5UXH
 

I have a strange situation related to the battery voltage measurement.  I swapped in another Heltec module that I ordered some time ago from Heltec.  I used Arduino to program the firmware.  At power up, the display reports the voltage is 7.9V.   I am not concerned, only curious at this point. 

I have read another thread discussing the fact that the battery voltage readout is not reliable.   I get the impression that the built in charger maintenance of the battery is independent of the measurement.  If this is correct, is the orange LED status software based or is it a function of the charging current?  I ran on the battery for a few minutes, to see if the orange led turns on when I reconnect USB power and it did not.  I think with the original Heltec the charge led indicator would come on after running on the battery for a few minutes.  When I disconnect the battery while USB power is connected, the orange led blinks rapidly.

Later I will switch back to the original Heltec to verify that it works as before, then I will try another new Heltec, I think I have two more.  

 I normally will keep USB power connected, but do want to be able to depend on the battery being maintained properly.

Chuck, W5UXH

Willi, OE1WKL
 

Charging is done in hardware on teh module, and completely independent from teh software. The software just measures the voltage, but under certain circumstances this is far off - not sure why, but this seems to be a bug in the ESP32 firmware.

When the battery is being charged, there is a bright orange light, when it is full the light is off. Running rom USB without a battery lets the LED flicker.


73

Willi




Am 18.10.2019 um 18:45 schrieb Chuck Broadwell, W5UXH <Chuck.Broadwell@...>:

I have a strange situation related to the battery voltage measurement.  I swapped in another Heltec module that I ordered some time ago from Heltec.  I used Arduino to program the firmware.  At power up, the display reports the voltage is 7.9V.   I am not concerned, only curious at this point. 

I have read another thread discussing the fact that the battery voltage readout is not reliable.   I get the impression that the built in charger maintenance of the battery is independent of the measurement.  If this is correct, is the orange LED status software based or is it a function of the charging current?  I ran on the battery for a few minutes, to see if the orange led turns on when I reconnect USB power and it did not.  I think with the original Heltec the charge led indicator would come on after running on the battery for a few minutes.  When I disconnect the battery while USB power is connected, the orange led blinks rapidly.

Later I will switch back to the original Heltec to verify that it works as before, then I will try another new Heltec, I think I have two more.  

 I normally will keep USB power connected, but do want to be able to depend on the battery being maintained properly.

Chuck, W5UXH

Chuck Broadwell, W5UXH
 

I ran it for two hours and then connected USB power again, and it is now charging.  I just had to drain it down a bit before it showed charging again, a couple of minutes was not enough to trigger a short period of charging.  It will be interesting to see how my other two modules behave, the “7.9V” certainly was different from the other reports I read in another thread.

Thanks.

On Oct 18, 2019, at 11:22 AM, Willi, OE1WKL <willi@...> wrote:

When the battery is being charged, there is a bright orange light, when it is full the light is off. Running rom USB without a battery lets the LED flicker.