Power supply - LukasMert/Birdbox_Owncloud_Python GitHub Wiki

Used components

We use one:

Universal Power 12 Volt 7Ah Rechargable
6V/12V 5A/10A Solar Controller PWM Charge Regulator
DC-DC 5V 3A Power Supply Module Buck Step Down Regulator Module 24V 12V 9V To 5V
18V 5A Solar Panel Monocrystalline

Scheme

Operating time

Raspberry pi 4 = 3,4W 24 hours a day

calculations battery:

3.4w x 24 hour = 81.6 Wh Because power (watts) = voltage (V) times current (A), you need 81.6 / 12 = 6.8 Ah per day with a 12 volt battery. Suppose you want to bridge two days. Then you need a 12 volt battery or at least 2 times 6.8 = 13.6 Ah. Because a lead battery may never be completely discharged, but up to an average of a maximum of 50%, you certainly need a battery of 30Ah.

Solar panel calculations: If after 2 days there is 4 hours of (full light) sun again, the battery must be completely refilled during these 4 hours to be able to bridge the next two sunless days. Per two days we use 2 times 81.6 = 163.2 Wh, so the capacity of the solar panel must be 163.2 Wh / 4 hours = 40.8 Watt. Because the power of panels is always stated on the basis of the theoretically achievable power, we choose solar panels with a little more power.

Universal Power 12 Volt 35Ah rechargable Link

Voltage: 12 Volt
Amperage: 35 AH
Chemistry: SLA, AGM
7.68 in x 5.16 in x 7.13 in
Weight: 23.15 Lbs

6V/12V 5A/10A Solar Controller PWM Charge Regulator Link

Charging mode: PWM
Systemflow: 5A / 10A
Voltage: 6V / 12V
Inputpower: ≤30W / ≤60W
overload, short circuit : 1,5 keer nominale stroom , vijf minuten vrij; vijf minuten om te herstellen
Nominal voltage no-load current: ≤6mA zonnecontroller.

DC-DC 5V 3A Power Supply Module Regulator Module 24V 12V 9V To 5V Link

Input voltage: 7 - 26V
Output voltage: 5V
Output flow: 3A (Max), de stroom moet binnen 1,6A worden geregeld voor lange werkdagen
Conversion efficiency: 96% (Max)
Output ripple: <30mV
Operating temperature: -40 ℃ - 85 ℃
Size: 22,3 x 17 x 4,2 mm (L x B x H)