Battery Terminal Covers for M8 LiFePO4 Batteries

Battery terminal covers for LiFePO4 batteries that typically use an M8 bolt on the battery terminals.

I recently built a battery bank for my RV consisting of (3) 100ah LiFePO4 batteries I purchased on Amazon. They are great batteries, however they did not come with battery terminal covers for the M8 bolts that hold the wires on.

I designed these covers to press-fit on, and they should be a nice snug fit (depending on your printing settings), however I also designed a slot in them to insert a 25x5x3mm bar magnet (common magnet size) that once inserted, will also help hold the covers on. This magnet slot also includes a small hole on the other side in case you want to push the magnet back out. The magnet will be hard to insert, as it's designed to be a tight fit.

These are not made to completely enclose the battery terminal and bolt, and are not made to prevent rust or corrosion of the terminals. I made these to prevent any metal objects from making contact with the battery terminals (my battery box is built out of metal and has metal bolts, screws, etc. that could become loose as my RV travels down bumpy roads.)

Features

• Positive and Negative design versions for easier identification, in case you don't want to print them in two different colored (red/black).
• 25x5x3mm bar magnet slot to help hold them to the battery terminal.
• Magnet slot has a pin hole to push the magnet back out if you need to.
• Press-fit on, should be snug fit as long as your print calibrations are correct and the M8 bolt has a standard head size.
• Should accommodate most wire sizes up to about 1 AWG. May fit bigger, but I am using 1 AWG wire and it has a little bit of wiggle room.
• Open-source design, feel free to remix this and make a better version, but please do not sell commercially.

Print Settings

• Print in same orientation it loads, no supports needed.
• Designed for PETG.
• Due to plastic shrinkage/warping, this may not be an exact fit for other materials such as PLA/ABS/ASA/POLY/etc. and may need scaling adjustments in slicer.
• 0.20mm layer height is good.
• 3-4 walls for strength.

Assembly Instructions

1. After printing, press 25x5x3mm bar magnet into slot (if desired; recommended).
2. Push magnet all the way in (push in with small hex wrench).
3. Magnet slot should be very snug and magnet should not fall out, but if it seems loose on your printer due to printer calibration, you could add a little superglue.
4. Push battery terminal cover onto battery terminal. It should be a snug fit and may require a little bit of force.
5. If it doesn't seem to fit, you may need to scale up or down the print 2 to 3 percent in slicing software.
6. You can remove magnet by inserting a small nail or mini screwdriver into the hole in the front to push out the magnet.

Other notes

The magnet may not do anything if your battery terminal bolt is not steel. Please test with any magnet to the bolt before ordering a box of bar magnets for this.