Powering an Arduino Nano and a sim800l from the same battery

Projects General Guidance
1

I have a project with a Arduino Nano and a sim800l module. The sim800l uses 3.7-4.4v at max 2Amps bursts and the Nano uses 7-12v. Do I use one 9v battery with a buck converter? Or a long lasting 3.7v lipo battery with two buck/boost converters?

2

use 3.3V 8MHz pro mini instead and get rid those current-draining converters

with a 3.7V lipo batt going straight to your pro mini's Raw pin as

well as sim800L's Vcc pin

check this out

3

Thanks for the recommendation. Unfortunately the sim800l module doesn't work as a phone at 3.7v it actually needs something closer to 4.2v. I would need a transistor or something anyway. Even if I convert my project over to the pro mini I would still have an issue.

4

johnscott:
Thanks for the recommendation. Unfortunately the sim800l module doesn't work as a phone at 3.7v it actually needs something closer to 4.2v. I would need a transistor or something anyway. Even if I convert my project over to the pro mini I would still have an issue.

can you post link to the sim800L you are using ?

some have on board anti reverse polarity diode(which drops incoming volts by 0.7V) that you will have to scrape off