DIY Doctor

Main navigation

12V fused and switched distribution panel

Postby cliver » Fri Jul 08, 2022 7:27 pm

Hi all, New here. I am about to start installing a small, 100w off grid solar system in/on my shed. To start it will be just 12vdc to run a water feature plus internal and external led lights. In the future I may well expand it, add more panels, bigger charge controller and batteries plus an inverter to run some of my tools.
For now though, I just want advice on the best way to distribute the 12v. I want to be able to switch each item on/off and fuse each feed independently. Something like a caravan or RV control panel without the mains charger would be ideal.
Any suggestions or links to what you have used would be greatly appreciated.
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Fri Jul 08, 2022 7:15 pm


Simply Build It

Postby ericmark » Thu Jul 14, 2022 3:07 pm

You can get DIN rail mounted fuse holders, I used them a lot so I could easy disconnect a section to test it, but an old consumer unit would do nicely.

As to the solar panel likely need a mppt controller, when I did it they did not exist, but the idea is it varies the voltage from the solar panel / wind charger to extract the maximum power. It also sets the charge rate for the battery.

Charging a lead acid battery is easy, but charging and using a lead acid battery is more of a problem, the standard way to charge a lead acid battery is using a stage charger, what it does is to bang in as much as it can until 80% charged then reduce the charge rate, it works out when 80% charged by the current the battery draws at a fixed voltage, if you use power, at same time as charging, it can fox the system and over charge the battery.

So the MPPT controller uses the voltage decay time when it stops charging to work out battery state, so less likely to over charge the battery.

As a DIY project, consider centre tapped battery, I used this with a hub dynamo off a push bike, output is 6 volt DC, so two half wave rectifiers, so positive half into one battery, and negative into the other.

The wheel was mounted to face up/down the valley, as wind never blows across the valley, and made the wind vanes by wrapping insulation tape around the spokes, latter version used a drum section to increase spacing. Not my idea, saw it at The Centre for Alternative Technology Machynlleth.
Rank: Project Manager
Posts: 2694
Joined: Fri Oct 02, 2009 8:49 pm
Location: Llanfair Caereinion, Mid Wales.

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics