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Waterproof • Greaseproof

12 Volt Wiring Size Quick Reference

12 Volt Wiring Size Quick Reference

3% and 10% voltage drop tables

Designed to be kept onboard in your tool box

Regular price $9.18 USD
Regular price Sale price $9.18 USD
FREE US Shipping Orders $60+ • $3 US Shipping If Under 1 Pound • 30-Day Free No-Hassle Returns

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At The Boat Galley, we have one mission: to make boat life better.

Everyone on The Boat Galley team is a liveaboard cruiser and understands the challenges that come with life on a boat. When we encounter frustration, we come up with practical and innovative solutions.

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Benefits of Our 12V Wiring Reference

  • Easier and faster to use than leafing through thick electrical manuals
  • No need for an internet connection to Google wire sizes
  • Shaded lines and large print make look-ups easy
  • Clearly labeled sections and no tiny print
  • Printed on durable, heavy-duty, waterproof, and grease-proof paper that can confidently be stored in toolboxes, work benches, and tool lockers


  • When to use 3% or 10% tables
  • Wiring connector sizes/colors
  • Battery state of charge
  • How to calculate watts, amps, and volts
Made in USA

Designed in the USA; printed in the USA on American-made recyclable synthetic paper using environmentally-friendly soy-based inks at a facility that is completely wind-powered. Minimal packaging.

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Customer Reviews

Based on 6 reviews
Ginger C.
Husband likes it but I don’t understand it

My husband explained the charts to me and now I understand it. Neither of us are electricians.

Allen P.

12 Volt Wiring Size Quick Reference

Ron H.

Haven’t had time to use it yet; however, I like the color, layout, and charts.