I have a small snack bar/kitchen trailer that I need to convert partly to 12 volt. There is a 12 volt dc water pump 5.2amp and an LED strip light 12volt 5.2 amp - both of these devices currently have transformers attached to the 240volt AC supply.

I have a deep cycle battery and a 50w 12 volt solar panel. I have 12ga copper wire. (I will add another panel & battery so I can run another light strip and some small power outlets for charging phones & minirigs etc and one day I hope to cover the whole roof of trailer and vehicle in adjustable solar panel/roof racks, so I can also run a fridge and freezer)

What do I need to do to right now make the current match the 5.2 amps needed for my pump and led lights?

  • 1
    You don't match current. The device does, based on voltage. Feed it the right voltage and it does the rest, assuming adequate available current.
    – isherwood
    Feb 23 '17 at 19:57

You can just remove the transformer and wire the devices direct to the 12V circuit (paying attention to polarity of course).

Current is drawn by devices, and your power supply must be able to support it. There's nothing you need to 'do' other than ensure your supply can provide the current your devices need.

Note that a 50W panel at 12V is 4.16A, so it may not charge the battery fast enough for your situation -- even if you're only using the 5.2A lights (as opposed to the full 10.4A load with the lights and pump running).

This may or may not be a problem depending on what you're doing. If your battery is rated at 100 AH (amp hours), and you're not charging it, it should in theory power the LED lights for about 19 hours (calculator). This isn't exact because battery capacity can be affected by load, charge level, and other factors.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.