12V DC Accessories

I have a collection of DC accessories, largely from when I had first started my solar system and thought I would stick with 12V for the entire thing.

Most are lighting, as shown above. During a winter power outage I quickly realized that good lighting was probably more important to me than heat! Fortunately, it is now pretty easy to light a room without a lot of power.

I have several small AGM batteries for portable use in addition to the ham bench AGM. These are mostly salvaged from "dead" UPSes, they might not be full capacity but they work well enough.

LED Lighting

The LED lights were originally battery powered units. I removed the batteries and installed a voltage regulator. Ideally I could use a constant-current regulator, but most of these have other components built in to the LED PCB which I didn't want to try cutting out so simply emulate a battery supply.

The unit at the front of the picture is from Harbor Freight and has three LEDs in each aimable head. They aren't very bright, but work great for lighting a passageway or similar location where lots of light isn't needed. Uses only 60-70mA, so could run for over two days nonstop before bringing a 7AH battery to 50% charge.

The upright LED drop-lights were found at Westlake Hardware for $25. They had a very weak NiCd battery pack in the handle (600mAh cells) and couldn't be operated on 12V while the battery charged. I removed the battery pack and installed a voltage regulator circuit.

Regulator with heatsink in handleThese LEDs draw enough current to require a heat sink, so I found some DIN rail that fits nicely inside the handle and used it.

The only drawback to the way these are wired is that the switch is after the regulator - I wanted the hi/lo switching, so left it wired as-is. This means with the switch off the regulator still draws a very small idle current. On the other hand I don't intend these to be left powered all the time and it takes weeks before even a small battery is noticeably drained. (Yeah, I left one plugged in once!)

These draw 100mA on low, 300mA on high. Most of the light is produced in a very bright spot straight ahead, but do emit a decent amount of sidelighting (especially on high) that lets you see around the room easily. Very cold monochromatic color, but still tolerable for short term use. Excellent for use as a drop-light when working in a dark area! The hooks let you hang it from the top or horizontally, and the base has a fairly powerful magnet that also doubles as a weight to let it stand upright.

Fluorescent Lighting

While the LED lights are great for long battery life, I just don't like the harsh monchromatic light for long-term use. They also can't really "light up a room" very well. For this I have a few fluorescent fixtures.

The one in the center is from the Harbor Freight 45W kit. I doubt I'll ever use it - these things are ony 5W, and are "daylight" color temp which I hate. Still, it's available and does work. There was a second one in the kit, but it died fairly quickly in spite of little use.

To the right is an RV two-tube 16W fixutre. The only issue I have with it is that I can't turn on just one tube. With both going it draws less than 1.5A and can light a small room nicely. This is a ThinLite model, and it came with "cool white" tubes. I replaced them with "warm white" (available at Home Depot) and like the light a lot better.

The four-foot strip on the far right was a standard 120V two-tube fixture. I replaced the 120V ballast with two 12V versions. Each Iota ballast will only run one F32T8 tube, so I wired separate pigtails to let me run a single tube if I want. Each tube draws 2.2A, a bit much for my smaller batteries but sure can light a room well!

Incandescent Lighting

Yep, incandescent! Doubt I'll ever use it, but the yellow drop-light has a 12V 50W incandescent RV bulb! Bought it back when I was 16 for use in the car and it still works after all those years bouncing around in the trunk. Way too much power draw to be feasible except in a real pinch, but great for load-testing!


Not shown are my inverters. I have an old mod-sine 220W Radio Shack, a 300W Samlex pure-sine, and a 600W Morningstar pure-sine. The first two are portable, so they get used everywhere, including in cars. The Morningstar is intended to be hardwired, and was purchased before converting to 48V. Still haven't done much with it, but it is wired to an outlet strip and is ready to go.