However, I haven't been able to make it work. Am I doing something wrong?
Guess the battery is a lead battery ? Look for "lead battery 6v datasheet discharge voltage" diagrams: during discharge, the voltage on such a battery drops below 5V quickly. So you should use a buck-boost converter.
Also provide some sort of battery management, when batt voltage drops below a threshold then disconnect the RPi. Battery could be damaged when fully discharged. Of course the RPi needs to be properly shutdown before the disconnect.
Do you have tools to monitor the voltages, which helps to validate your design ? You could setup a raspberry pico with a voltage divider on ADC input to measure battery voltage and on a second channel measure the regulator output.
If doing such experiments, replace the RPi with a appropriate sized resistor in first checks and add a overvoltage protection diode. Overvoltage on RPi would be an expensive problem...
pololu has a wide choice of regulator boards, https://www.pololu.com/category/133/ste ... regulators
They provide good documentation, see the "Maximum continuous output current" charts. Example https://www.pololu.com/product/4082#maxcurrent
Statistics: Posted by ghp — Thu Jan 18, 2024 6:38 am