USB outlet for Pino battery

The Hailong battery on the Pino e-bike kit didn’t have a USB outlet and as I use my iPhone for navigating and tracking our rides, an outlet would be useful for keeping the phone charged, as GPS use tends to drain the phone battery pretty quickly.

The battery is a 36V 17.5 Ah Hailong.

There is a compartment towards the back of the battery mount that houses the connectors and wiring, accessible by removing the four cross-head screws, so that seemed to be the logical place to start.

My battery didn’t have a fuse or large connector, so there was more free space available.

The battery produces 36-39V and a USB phone charge lead needs only 5V at about 2-3 amps. A search on Amazon provided me with a suitable ‘step-down converter’. Input from 8V-50V and output at 5V 3A. It had a USB lead too so seemed perfect for the job.

I removed the battery mounting bracket cover and tapped into the positive and negative outlets on the power supply, then ran a USB lead from the socket up to the handlebars.

The box of tricks was too big to fit inside the mounting bracket, so I zip-tied it to the seat tube. It’s sealed with epoxy resin, so is waterproof. With everything in place, it worked…. for about a minute, then the charge died. Disconnecting it and reconnecting, the same thing happened. Faulty unit, so I got a refund and went looking for an alternative.

This one was cheaper but not sealed. However, it was small enough to fit into the compartment in the battery mounting bracket. I slipped a length of MTB inner tube over it to protect it and prevent any solder on the underside coming into contact with the metal base of the compartment. There’s a USB socket and wiring connectors, so it’s more flexible than the first type I tried and being housed within the mounting bracket makes the whole thing a lot tidier. Better still, it works.