Motorcycle USB phone charger with a voltmeter, fused at the battery
🧰 Starter build: made to be remixed. Open your own copy, change it (another battery, a brighter LED, your own idea), and publish your version: it links back here, and it’s yours.
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Charge your phone on the road. A 12 V to 5 V USB step-down module runs from the motorcycle battery through a 5 A fuse placed right at the battery (the fuse protects the wire, so it goes where the wire starts), and a switch so it does not drain the battery while the bike is parked. A small voltmeter shows the battery: about 12.6–12.8 V resting, 13.8–14.4 V with the engine running and the charging system working; under 12.2 V resting means the battery wants charging. The module draws about 1 A from the battery while a phone charges at 2 A, so it is safe for any bike. Use a waterproof module and housing, and route the wires away from the exhaust.
What is on the bench
6 parts, 7 wires.
| Lead-acid battery | 1 |
|---|---|
| Fuse | 1 |
| Toggle switch | 1 |
| USB step-down module | 1 |
| Smartphone | 1 |
| Battery capacity indicator | 1 |
Built for real
Nobody has posted a real build of this one yet. Be the first!
Comments
⚠️ Mains wiring, big batteries and solar arrays can hurt you. Comments are other makers’ experience, not checked by the lab: check advice against the datasheets and your local electrical code, and report advice that looks dangerous. Be kind: community rules.
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Put it on your page
The project runs live inside the frame: readers can press buttons, turn knobs and read the meters.
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Link
https://zencircuitlab.com/p/zclmotousb
Published by its author under the lab's community terms: it may be opened, copied and changed by anyone. Simulation results are for learning; check a real build against the parts' datasheets.