M5StickC and 18650C endurance

  • @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?

  • @Kees
    The simplest thing is to use a powerbank: The square ones mostly are powered by a18650. Today most powerbanks are designed pass through, so you can charge them and at the same time powering a device as the cellphone, the M5Stack, -stickc or the atom (matrix). I mostly hock up my M5Stack devices to a powerbank instead of an USB wall plug charger when programming them over WiFi with an API Key. My M5Stack runs up to 48 hours on an 3500 mAh power bank. I'm also using a nice square one 100x50x10mm from SKROSS (3 Reload) which fits nicely with the M5Stack.
    0_1587383542626_25097b67-85ca-4701-ad68-a128dcc0f9c4-image.png .
    THat way, you don't have to solder or fiddle around with the M5Stack battery charger.

  • @crami25 the question was not related to the M5Stack but to the M5StickC. And most powerbanks will only work for a few minutes. this because the current is to low and the powerbank will cute off the power.
    The 18650C will provide 3.7V direclty to the LDO regulator. to convert it to 3.3Volt.
    With a powerbank you will loose power. from the step up converter. 3.7V to 5V and later a step down, from 5V to 3.3V

  • @Kees
    My Skross (and other powerbanks) work fine with the M5Stick (and Atom matrix), they don't switch off. Maybe you got an old style one. The newer ones are made that you also can charge earplugs (with batteries smaller than the M5Stick) without shutting off. Never mind the power loss. Modern step up and step down have a power loss < 5% . Maybe you want to use a cheap 18650 from Bangood (I got 4 of them marked 5000mAh !) as a backup power. I will stick to my powerbanks. You probably will loose 4-5 hours of run time (of 48). By the way, the IP5306 used for the power management in the M5Stick according to the data sheet (http://www.datasheetcafe.com/ip5306-datasheet-battery-ic/) supports a 2.1A charging current. So it should be no problem charging a 18650.

  • @crami25 thanks for the advice. I've used branded and unbranded powerbanks. The modern powerbanks require a minimum current consumption. the older don't.

    @Kees I've build a page turner based on BLE. This is for an iPad Mini 2 sheetmusic. so about 4 pushes per minute. with the LCD on.
    In the code I use the front button to set the brightness. (but still on) I also use the screen as battery indicator.
    I'm also running on 2 cores. I'm still figuring out how to get some parts to run on one core and the other part on the second core.

    the other thing I've done is to change the corespeed. to 80Mhz. instead of the 260.

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

  • @Pepsi @Kees
    Here is a tutorial on battery cells for the ESP32 and ESP8266:

    An AA LiFePO4 cell has approximatly the same size as the M5Stick. You can feed the voltage directly into the 3.3V port.

  • @crami25 i have 2 of them.
    Downside is that they need to be removed for charging. Second is, by bypassing the voltage regulator, you will nat be able to use the voltage. So an wxternal battery status indicator is required.

  • @kees said in M5StickC and 18650C endurance:

    @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.

    Today I did an experiment to measure the time and the current needed to charge the battery. In short, it needs around 8 hours, a steady current of 100 mA, and the final reading showed that the battery has a capacity of around 800 mAh. I can't be sure that I discharged completely before charging the battery. But hopefully, this will give you a rough estimation.

  • @kees After 2 hours charging

  • @kees Finished after 8 hours charging

  • @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.

  • I use a USB type watt meter. Please see below.


  • @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.

  • Those usb meters are so useful. I use a kewize one

  • @ajb2k3 said in M5StickC and 18650C endurance:


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

  • @kees I bought with the brand Keweisi from Aliexpress a long time ago (same with the one mentioned by @ajb2k3 ?). But I could not find now. However, I found a very close one in Aliexpress:

    10 in 1 Digital Dispay DC USB Tester Current Voltage Charger Voltmeter power bank wattmeter voltage tester doctor detector (462 Japanese Yen + 12 Yen Shipping to Japan).


  • @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.