@Pepsi Thanks, I could not find the call to decrease the speed. Not very much, but it helps.

@liemph and @ajb2k3 Thanks. I ordered a few. It will take several weeks, but they will be useful. Also for other projects I am working on.

@ajb2k3 said in M5StickC and 18650C endurance:

kewize

Can you be a bit more specific? I can not find any information with that name.

@liemph Ah, nice device. Been searching the internet and found one brand with interesting devices (even with blue tooth data gathering) but the shipping costs are ridiculous. Could you tell me what brand you have. Makes searching less difficult.

@crami25 . Thanks for the video. Could be useful for another project I am working on. But for this I can not let an elderly person remove the battery for charging as Pepsi wrote.

@Pepsi I can not find anything on corespeed. How did you lower this? Maybe this will give just enough endurance.

@liemph Thanks. I did a number of simple tests and got rather varying results. Ranging from 8 to 22 hours (only once), but mostly around 12 hours, but with large charging times indeed. I also used two different charging devices. How ever I would like to measure these values (charging and discharging) for better tests, but not on the screen. I want to send them using the BLE I already use. Could you share with me how you read these values.

@Pepsi BTW, how much time does it take to fully charge the battery? Does probably depend on the charger, but just to have an idea.

@crami25 thanks for the information. If I understand the discussion between you and Pepsi correctly I could use an older type power bank!? Nice to know but I wanted to use the supplied battery because combined it is still easy enough to carry around. I am making a simple device for my mother to carry around and use as alarm device in case of emergency for the spare days no one else is around. The device passes the emergency to a local smartphone/tablet which passes the messages to a select group of people who can assist using Google Firebase. One of them responds and this action will be reported back to the local server and then to the device and shown on the LCD. A separate power bank is possible, but less easy to carry around.

@Pepsi Nice project! So you send more messages per time interval and you use the LCD all the time and you also use both cores. The only difference is the speed of the core(s). The battery indicator (what do you use for measurement?) was at first part of my plan, but I skipped that for saving the battery. How do I change the speed? I could test with that. However it feels like there is something I am missing. It seems I should at least get the same results. Thanks anyway.

@Pepsi Thanks for the information. Please confirm you use BLE and you have the LCD on on and you measure/estimate 24+ hours of battery lifetime. Is this correct?

Did you specifically exclude anything else instead of just not using it?

I use BLE as a client that sends one simple characteristic every 5 minutes. Once in 6 seconds I flash the LED for 100 msec. That is all. The LCD is set off (using some informattion I found in the forum). I do use both cores (one for BLE and one for buttons and screen (only exceptional states)). I tested a few times without further optimizing and did not get much more than 11 hours. I hope to get something like the 24+ you mention. Is there a major diiference with your setup that could explain this?

Does anyone has experimented with the 18650C battery? Can it be charged without the M5StickC. How long will charging take? How to measure battery level reliably? How long did it last on 1 charge and in what setting. I did a few simple tests with BLE (shutting down the LCD as much as possible), but the results where bit disappointing. So I am would like to here from others.

Thanks lukasmaximus and m5stack. Combining the two answers solved my problem. Split the work over two cores and added a suggested delay between calling M5.BtnA.wasPressed() and it seems to work as hoped for. Did not use the interrupt solution though interesting.