Introduction: Cable Terminals - High Current - for Off Grid Solar Batteries

I'm building an off-grid solar power system and wanted a cheap solution to connect my batteries. High powered terminal ends are expensive, so I came up with this!

Because these terminals are so cheap and easy to make, it won't be a long Instructable.

I'm a teacher, so I like to give the 5 second summary upfront for the quicker students...

Summary: Copper tube for plumbing is highly conductive and cheap. Flatten a short section of 17mm copper tube over the end of a cable. Drill a hole for a bolt, and insulate with heatshrink or electric tape. The cross section of the terminal will be around 50 square mm.

Step 1: Tools and Materials


Angle grinder or pipe cutter

Drill press with an 8mm bit (approx)

Two offcuts of timber to protect the copper when flattened

An axe, mallet or vice

Hot gun (heatshrink)



17mm copper pipe

Electrical tape or heatshrink

Cable (I used 2 gauge)

Step 2: Assembly

1. Cut a section of tube about 70 mm long

2. Flatten half of the tube. Squash it with a mallet or something. Use the wooden blocks to keep it pretty. (I 'axxed mine a question.' It couldn't answer back)

3. Drill a hole for the bolt through the flattened part

4. Strip back the cable about 40 mm

5. Feed the exposed cable into the round half of the tube

6. Squash it flat with your mallet setup. (Axe it another question.)

7. Insulate with a few layers of tape, or heatshrink

8. Repeat as necessary, for the end of each cable

Step 3: Finished Product - in Situ

Here they are, all finished and bolted into my system.

I ran the 2 gauge cable between the positive terminals (24V in parallel).

Do you see those straight links? How did I make them?

I'm so glad you asked...

Step 4: Bonus -- Rigid Battery Links

The cable ends in this Instructable were actually an afterthought. The main deal was the rigid battery links.

I came up with this solution when wandering around my local hardware shop. I saw the copper plumbing tube. Pure copper, I thought to myself. That's meant to conduct water, but it also conducts electricity.

So I bought a straight length for about $17 bucks (Australia) and some heatshrink to make it all look neat.

1. Cut to length, with about 12 mm either end.

2. Drill the holes for terminals all the way through

3. Flatten the ends with the axe and blocks

4. Insulate with tape all over, especially the ends, so they're rounded, not sharp

5. Fit heatshrink tube

6. Cut holes in the heatshrink for the bolts with a sharp blade

7. Done!

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