Hello!
I have a single esp32 Xaio C3 module that is in deep sleep 24 hours a day at 47 micro amps confirmed current draw from a battery. I am using the 3.7V 2000mah lithium ion battery shown below. The question I have is that it should last YEARS (3-5) with the current draw from the esp32 Xaio in deep sleep. It was measured at exactly 4 volts when installed. After 1 month it is at 3.5V. I am not sure why it is dropping so rapidly. Any ideas will greatly help. Link for the Battery:
It will not last 3 to 5 years. Your 1 month performance is not bad. Research self discharge and get the 47 uA lower. No LEDS on I hope. There is a lot of very technical articles on deep sleep, many devices are over/under rated and marketing BS. Get a Current Ranger and measure accuratly. Self discharge is 5% and IIRC the curve is not flat. I would assume it started at 3.7 not 4, the 4 reading is not realistic. So my calc is you started (within a few mins) at 3.7 lost 0.185 due to self discharge and now sit at 3.515 even with NO device draw.
No no leds currently on. Battery shows 4.007V with multimeter. Current draw at exactly 47micro amps drawn currently
I think your meter is reading wrong but you will know better when the battery dies.
If your numbers are correct, you should have lost less than 10% of your battery capacity, mainly self discharge.
So either your battery is bad or your measurements way off.
Where did you get that 47uA number from. Did you measure that, and how.
Did you use the sleep code from Seeed or otherwise.
Leo..
Did you throughly clean all the flux from the battery connections?
What type of solder did you use?
Note that 4.007V is already partially discharged.
The specs of lipoly batteries bought from Amazon (or anyplace that sells the, retail, really) are frequently not very trustworthy 
If it always in deep sleep, then what is the application ?
If it wakes even occasionally to perform some activity, then of course, depending on the wake period and load, the battery discharges accordingly.
It wakes up for 8 seconds a day and uses 100ma otherwise it’s 47micro always
OK. So it looks like the contribution from the wake activity to the load is about only 20%
approx 4,320,000 uAs / day in sleep mode
approx 800,000 uAs / day awake
Measure the actual capacity of the battery.
Have you used something like a Current Ranger to measure the 47uA? A VMM is not a good tool for low draw measurements.
Show us your math that results in 3 to 5 yrs.
BTW, self discharge is 2% to 5% per month, or 40 to 100mAh. Lets' use the lowest 40mAh. If the battery starts out full and self discharges 40mAh then 2000mAh / 40mAh is 50 months, not your stated 60 to 120. If the rate is 70mAh / month (the midpoint of 40-100) then 2000/70 is a bit less than 30 months or 2.5 yrs. Now reduce that by the 23hrs, 59 minutes 52secs at 47uA plus 8 secs at 100ma.
I will let you do the math, but I will make a small bet your battery is working as designed.
Please read and use the sticky post "How to get the best out of this forum" and update Your post.
I have merged your forum topics due to them having too much overlap on the same subject matter @alandinho10.
In the future, please only create one topic for each distinct subject matter and be careful not to cause them to converge into parallel discussions.
The reason is that generating multiple forum topics on the same subject matter can waste the time of the people trying to help. Someone might spend a lot of time investigating and writing a detailed answer on one topic, without knowing that someone else already did the same in the other topic.
Thanks in advance for your cooperation.
Xiao C3 board from Seed Studio? Be aware that it charges the battery when connected to usb, and in this case only compatible with 3.7V li-ion or lipo.
If you don't charge, you could try with another ER14505 type of battery that have higher discharge rate. Or if you charge, some good quality 14500 li-ion battery (self discharge 2-3%/month).
Hello!
I have a esp32 Xaio C3 module that is in deep sleep 24 hours a day at 47 micro amps confirmed current draw from a battery. Tested using a multimeter for 24 hours and plotted the values. The xaio uses 80mA for 20 seconds a day (tested with multimeter confirmed) then goes back to 47 micro amps (deep sleep).
This system is inside of a mailbox. The problem I have is that a lithium ion battery connected dies after 1 month. I tried a Tadiran battery as well, but only lasted 1 month. No other leds or anything in the circuit. Just a xaio module and mercury switch (for tilt). I need it to be in the mailbox for a year or more. Any suggestions anyone? Please Help
“a battery” tells nothing.
