I'm working on a project where I want to supply a magnetic valve powered by two parallel connected Li-ion batteries. Each battery has a voltage of 3.7 V (max. 4.2 V) with a capacity of 3.5 A (in total 7 A).
The magnetic valve need 12 VDC to operate and consumes 3.8 W (approx. 320 mA).
I'm using a step up converter to boost the voltage from 3.7 V to 12 V.
My research includes the following points:
- the magnetic valve isn't working when I only use one battery.
- the magnetic valve is working fine if I use two batteries in parallel (capacity 7 A, 3.7 V). I assume that the maximum capacity has an impact on the consumer. Why?
- In my final circuit I use more components than just the magnetic valve (ESP32, 5 V relay, sensors, etc.). If I connect the other consumers the step-up converter is unable to supply the load for the magnetic valve anymore. Before the step up converter I measured 350 mA (which is fine), after the step up converter 100 mA. 100 mA is not enough to supply the magnetic valve and make it work.
Is the range of the step-up converter to boost from 3.7 V to 12 V simply too large to supply 3.8 W (320 mA)?
In different videos I learned that this step up converter should be used from 5 V up.
Is there any way to solve the issue with this step-up converter?