Charging a Car Battery with a Solar Panel and Charge Controller

Charging a Car Battery with a Solar Panel and Charge Controller

If you connect a solar panel directly to a car battery, it will eventually overcharge the battery and damage it. That’s why you need to use a solar charge controller. This is my own design using the latest microcontroller and MOSFET circuitry. It consumes less than 1mA (that’s very little) and has a neat little blue LED that tells you the battery voltage. It can also be connected in various different configurations so you can do clever things like charge two batteries from one solar panel.

17 Comments on “Charging a Car Battery with a Solar Panel and Charge Controller”

  1. Can anyone help with this question please. In my off grid workshop I have a 100w solar panel going through a 20A controller and into a 12v 130ah battery, that’s working great. On the controller I also have a LOAD output that I have going to my lights, what I would like to know is if I can split that output and feed it into my motorbike battery to keep it topped up. When I look at my charger that I have used that plugs into the house power socket, it states Output 12v / 800mA. If I can feed a cable to the LOAD on the controller and to the bike battery, will it act as a trickle charge or what will happen once the bike battery has fully charged? Or will I need one of these PWM5 type of extra controllers? Thanks

  2. LOL, haters gonna hate. So many people making comments have made assumptions. Only a very simple point was meant to be demonstrated and it very adequately was. Connecting a battery direct to a "12 Volt" (nominally) solar panel with even a moderate amount of current capability can damage a battery. Adding a charge controller will reduce that risk. Nuff said.

  3. wheres the sealed box for the controller am ya sure its charging lol 13.5v get a digital solar charger lol better with fake lipro b6 charger lol

  4. what are the specifications of your solar panel? would you recommend a different one? I'd like to use this for both motorcycle and car battery maintenance. also, is it possible to connect 2 car batteries in parallel to keep them charged? thanks in advance.

  5. I'm building a climate controlled pet camper for my dog. I can sleep in my van but I want him to have a yard on wheels while i'm in the gym and at work. Indoor, outdoor carpet, and a fan or heater. So I need to be charging an extra car battery.

  6. Hi, Mr. Julian!
    First, thank You for the video!
    Well, my wife and I live in Israel and we have a Kalnoit, it's an electric car of four wheels. It runs by a machine of 24volts. I decided to put a polycristaline panel of 180watts 36volts to charge the batteries. But I don't understand much of it so I need your help. How do I know if the panel is really charging the batteries? How can I test?
    The solar panel is connected to an mppt charge controller 12/24volts 10amps which is hooked to the batteries that are 12volts 70amps each connected in series.
    Thank You for your help!
    My Whatsap: 09720586004419
    Emmanuel Távora Freire.

  7. Be careful here…this video is potentially misleading. If you consistently charge at anything less than 13.8V your battery will suffer slow death by sulfation and lose capacity. Nor is charging to 13.8v ideal. Make sure your charge controller takes the battery to around 14.2 V and then reverts to a float charge of 13.8V thereafter.

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