Powering Arduino UNO with 7.4V 1300mAh 20C LiPo Battery: Setup & Runtime for I2C LCD Display

Sabat666 wrote:

the battery gives about 20A

ie, can give the maximum, I guess?
How much electricity will be spent on your arduino is a different matter and depends on what it will supply in total - what and how it will load it.


This battery has a capacity of 1300 mAh, which means that it can spend e.g. 1.3 A in an hour, 130 mA in 10 hours, 650 mA in 2 hours, etc.
Calculate this time beforehand by measuring the total current consumption of the arduino - multimeter in the current range and you will have it all.
The LCD backlight (if available) will consume the most power and when you want to use as little power as possible, disconnect it.
The relay also needs to be taken into account if it will work relatively long / often.

Initially - this rechargeable battery will pass the test and keep the project calmly for over 10 hours.

Added after 9 [minutes]:

Kraniec_Internetów wrote:

Arduino takes about 40mA, the relay only works for a while, so I'm not counting it. The buzzer is about 17mA and the display is 3mA. Together this is 50mA.

Well, with these economical assumptions, 60 mA comes out, provided that the LCD has no backlight. You also need to know how often the relay will be turned on ...

In addition, in arduino there are various stabilizers used and if there is no LDO there, the battery voltage may drop below the threshold of such a stabilizer and it will no longer give +5 V and it will be "dark"