As I am using my farmbot completely off grid, I don’t want (110/)230V to waste energy during transformation.
The solar cell, the battery and the electronics of farmbot work with 12V.
Can I just plug the farmbot into the solar cell controller or do I need to stabilise the voltage with a voltage stabiliser?
Is there one included in the farmduino or do I need to add one to the system?
You usually can directly use the 12V that’s provided by your solar charger controller. The controller keeps the voltage and current in a safe zone for 12V electronics.
1 Like
One problem you may have is the battery won’t last long. The charge controller does provide power but only during the day. If you set this to water at night or during the early morning or right before sunset you will be pulling from the battery. In running my 3D printers off grid from battery’s I have found the battery’s won’t last more than a few months because I will regularly pull my battery’s to low. And when the battery gets lower than 11v my printer begins to miss steps. You may want to put a 12v -35v voltage booster. Set it for 12v. It will keep your battery putting out the steady 12v you need until the battery either drop below what the boost module can handle or your farmbot is done running. Find a voltage booster that has a cut out voltage of 10v or higher or you will risk damaging your battery.
2 Likes
It’s strongly recommeded to use a deep-cycle marine battery for these applications. A normal car battery is designed to provide a huge, yet short, burst of power, rather than sustained low power draw over an extended period of time. Deep-cycle batteries are designed to provide such stable, low-draw power without dropping voltage (leaving you quite literally “dead in the water”).
I would recommend buying a slightly oversized deep-cycle battery for longer life. The closer batteries are cycled to empty, the shorter their life span. The “sweet spot” is to discharge the battery no more than about 60% of its total capacity. So, if you need 500 watt-hours to power your 'Bot for 2-3 days, it would be best to look for something in the 800-900 watt-hour range. Divided by 12 volts, this is a 65-75 amp-hour battery. Yes, it’s more expensive initially, but in the long run, it’s cheaper than buying multiple new batteries as they fail.
Also, it is always possible to add more batteries, wired in PARALLEL (NOT SERIES, as 12v + 12v in series = fried electronics) if you find that your capacity is dipping too low. However, an initial investment in a properly-sized deep-cycle battery should be more than sufficient.
More info is available here: https://en.wikipedia.org/wiki/Deep-cycle_battery. Happy farming!