Additional cable for easy 12V Battery charging/testing

Continuing the discussion from Twizy shut down when headlamps turned on:

As promised, here is a new thread about adding a cable in the glovebox that runs to the 12V battery to allow easy access for charging, testing or topping up with a solar panel.

I did this over 4 years ago so I can’t remember all the details. I’ll let the pictures do most of the talking but ask away if you need more info.

I bought a set of cables from Halfords in the Motorbike section which used a fairly common type of connector. There were versions with croc-clips, ring connectors, fuses and DC jacks as options on the other end as well as rugged extensions. Most came with a waterproof connector sheath too.

I followed the Twizy wiring loom that runs from near the 12V battery and up into the cabin to the fuse box, which is below the LHS glove box. I had already removed the CANbus connector from the glove box for other reasons so I used the hole to run the new cable through. I may have cut and re-terminated the long “extension” lead to suit my needs. The lead in the glovebox is long but the slack usually stays below the glove box, out of the way.

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The cable splits to battery -ve terminal and +ve terminal (on other side) via a waterproof fuse holder.
It follows the existing battery leads.

Here is a join with waterproof (probably more like splashproof!) connector.

Follow the corrugated cable loom up and it will emerge just above the plastic “firewall” of the footwell / under-dash. (trust me, it does if you reach far enough!)

From here I navigated the way to just behind the fuse “box”. (The OVMS unit seen here can be covered in a future topic)

Passing over the top of the fusebox the cable comes out directly below the Left Hand glovebox, alongside the 3-cable audio system wires which also go into the glove box. Here the extra cable length usually loops round and round and then up into the glove box through the hole where the ODB-II (CANbus) plug usually sits. I 3D-printed a crude block to cover this hole while letting the cable through.

The small lead going through the round hole at the top of the image is for my LED daytime running lights (again, another topic).

Ending like this with a safe cap.

I can connect this to:

  • a small solar panel (with 12V Pb battery charge controller) using a pre-made cable
  • an external 12V charger with jack plugs (pre-made cable)
  • another 12V battery or another car to jump-start via a pre-made cable
  • voltmeter
  • future-planned Lithium Ion batteries from drones / Ryobi tools with appropriate voltage and current limiting circuits; watch this space.