Requirements

• Fully reversible
  • No hacking into the wiring harness.
  • Permanent mods degrade the resale value.
  • In case I find a cleaner, better solution.
• Mistake Proof
  • Turn off when ignition is off.
    • No draining battery because you forgot to unplug the charger.
• Failure Proof
  • Fused in case the charger malfunctions.
• Low visual impact
  • Show as little as possible.

Ignition Only

The lazy solution is to simply wire a 12V socket to the battery. That carries the risk of forgetting to unplug the inserted USB charger and flattening the battery. Like on my other bikes, all of my accessories are only powered when Ignition is ON.

The Z125 Monkey does not have many cubbies and running lights which would allow leeching off to find a suitable light source. Luckily, the main relay is just under the seat.

Relay Needed

The Monkey has some fairly modern wiring which is more sensitive to over-current than what you find on some older motorcycles. The main relay is located under the seat. I considered running a leech wire off the main relay’s output, to power the relatively small USB charger. But, I decided against it. Why?

• Amperage and Future proofing:
  • Some phone chargers exceed 30W of power draw which could overload the wire and cause fuses to blow.
  • Allow use of other items in an emergency, like 12V compressors that can draw >70W.
• Isolation of problems.

To make this modification reversible. You can remove the output pin from the main relay’s connector using something long and thin (a needle or small electronics screw-driver) to push in the “hook” that’s holding the female spade connector in the plug.

I then made up a Y cable with 1 male and 2 female space connectors. The male end going into the output pin that I had pulled out from the plug. One female bit into the plug and the other going into the trigger coil of the aux relay.

Spade Connector Crimping and Jackets

You can watch this YouTube video to see how it’s done properly. Note how the creator mentions, using correct, quality tools. I even had a ratchet style crimper. Unfortunately, it was also a cheap one, making really weak crimps that would slide off easily. That’s also why I stopped using it.

If you don’t have the “correct” tool either. I’ve had reliable results doing the following. Removing the jackets entirely. Then crimping with needle nose pliers and securing the wire using solder. You can get quick results using a small pencil tip lighter, by carefully heating up the terminal (you can glance over it to regulate the temperature) since the solder wants to flow to where metal is hot. Finally secure it with heat-shrink tubing (a couple layers if needed). That looks much cleaner than floppy jackets that might come off because the crimp tool didn’t apply the right pressure. Make sure to leave a bit of overhang with heat-shrink to act as a strain relief.

Outlet Holder

The outlet holder was made using a bits I had lying around. Mainly an aluminium angle piece. I drilled the outlet hole, using a hole-saw bit. I then cut out the round shape around to make it smaller and finished that using a belt sander (also smoothing the edges a bit).

The bracket was a simple steel bracket from an Aldi sale that. I cut on one side and also rounded off. That all mounted nicely onto the frame just under the left access panel (where the tool-roll and manual live).

Why no fully built in Charger?

I could have used “fixed” charger rather than the 12V outlet. The reason is simple: flexibility. I have 12V compressors that I can then easily plug in to re-inflate a low or flat tyre.

Wiring and Phone Holder

I used a long USB cable that I routed under the tank, following the clutch cable up to the phone older.

The phone holder is a RAM Quick Grip. Its claim to fame is that it holds phones super secure and is quick to operate (one handed) unlike the QuadLock or X-Grip.