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How to power IoT devices with a 12v DC source (Like a Solar Power Kit without the Inverter)? Answered

Hello,

Iam a novice in electronics but have a passion for tinkering with IoT (Internet of Things) devices and other electronics projects, I have a system setup in my farm that uses the following devices,

  1. Raspberry pi 2 (5 Volts 2 amps)
  2. Wifi Modem (12 Volts 1.5 amps)
  3. 3.5inch 250GB Hard disk for data logging (12 Volts 1.5 amps)

I plan to use the system to monitor and control the water flow to some of the crops in our farm using soil moisture sensors, solenoid valves and flow sensors.

The issue is that the system needs to run 24/7 and is located in a remote rural area where power cuts are frequent. I need to run these devices on a solar power solution so that they can stay off-grid (for power).

My question is whether it is possible to power the devices off the DC power that is generated from a Solar power system (Solar panels, some batteries and a charge controller) without the need for an inverter.

My reasoning is that the inverter converts the 12v power from a solar panel and batteries into 240v AC power and the DC wall-warts (DC power plugs for devices) convert the 240v AC power back into 12v or 5v for the respective devices. This conversion causes inefficiencies in the solar power system thus losing energy that can be better utilised.

Note: We use 240v AC standard in India (in the US they use 120v AC standard), I plan to use a DC-DC Step down regulator to power the raspberry pi 2 off the 12v power provided by the solar power system and other similar regulators boards to power the wifi modem and the hard disk.

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user
steveastrouk (author)2018-02-14

With the right power supply you could do it all off the battery volts, but the battery voltage is going to vary up to 14V and down to slightly below 12, which is why you need to find a supply that will work with the ability to buck/boost the input voltage, like this: https://www.amazon.com/DROK-Converter-Efficiency-Regulator-Stabilizers/dp/B00GZHEPW6

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user
steveastrouk (author)2018-02-12

Your battery bank voltage is 12V ?

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user

Yes, the battery is 12v and the solar panel is 18v and the solar charge controller converts the 18v from the solar panel to 12v as output to charge the battery. The charge controller has a second 12v output which I can use to power other devices.

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