18V to 12V Tool Battery Converter – Adjustable 5-13V, 10A

18V to 12V · Adjustable 5 to 13V · 10A max

Turn your 18V tool battery into 12V power

This converter turns your 18V tool battery into 12V power to run a car fridge, lights, pumps and fans. It slides straight onto the 18 to 20V power tool batteries you already own, and you dial the output anywhere from 5 to 13V while a live LED readout shows the exact voltage. Plug in through a 12V cigarette socket, an Anderson plug or both, and run your 12V gear at camp, on the ute or in the 4WD without a separate battery box.

Couple relaxing at camp with a 12V fan running off an 18V tool battery through the converter

Key specs: 5 to 13V adjustable output, 10A max draw, 4 safety protections, 12 battery brands supported

Key features

Small box, serious 12V power

5 to 13V adjustable: set the output with the dial and read it on the LED display.
10A max: continuous draw for fridges, fans, lights and pumps.
4 safety protections: low-voltage cut-off, over-current, short-circuit and thermal.
Many battery mounts: choose the mount that fits the tool batteries you own.
Over 95% efficiency: more of your battery goes into your gear.

Where to use it

See it in action

Got an 18V battery lying around? Clip it on and you have portable 12V power. Run a 12V fridge in the 4WD drawer, a fan at camp, LED camp lights, a water pump or a Starlink Mini, all from the batteries you already use on the job.

No dual battery setup to wire in, no cuts to the car. When one battery runs low, swap in another one from the toolbox.

18V to 12V converter on an 18V battery held beside a 12V fridge in a 4WD drawer setup

How to use

Up and running in seconds

Adjusting the converter's voltage display on an 18V tool battery, 12V lead connected

1. Clip in a battery

Slide on your 18 to 20V tool battery.

2. Dial your voltage

Set anywhere from 5 to 13V and watch the LED readout.

3. Power your gear

Plug in and run your 12V kit.

18V to 12V converter on a Milwaukee M18 12Ah battery with Anderson lead on an outdoor table

Built-in battery protection

Your expensive battery stays safe

It has 4-way protection built in, so it will not drain your tool battery down to zero and shorten its life.

Low-voltage cut-off: cuts output at about 15V input, so your battery never drains below a safe level.
Over-current shutdown: trips if your load goes over 10A, protecting the unit and your battery.
Short-circuit protection: shuts down at once on a wiring short and is safe to reconnect.
Thermal protection: if the unit gets too warm, it throttles or shuts down before any damage occurs.

What happens if I run it flat? The low-voltage cut-off trips before your battery reaches a damaging level. Put the battery back on your normal charger. The converter resets when you remove and reattach the battery.

Output plug

Cigarette socket, Anderson plug or both

The cigarette socket suits most fridges and accessories out of the box. The Anderson plug is the more secure, higher-current connector common on 4WD and camping setups. "Both" gives you the two outputs on one unit.

Converter with a 12V cigarette socket output

Converter with both an Anderson plug and a 12V socket output

Did you know?

Tips to extend your fridge runtime

As a guide, one healthy 5Ah battery runs a 40L 12V fridge for around 5 to 7 hours. Real runtime depends on your gear, battery health and the weather.

Keep the lid closed: decide what you're grabbing before you open it.
Keep it in the shade and off hot metal trays.
Give the compressor vents airflow: don't bury it under swags and bags.
Pre-cool it on 240V at home and load it with already-cold food and drinks.
An insulating cover helps on hot days.

18V to 12V converter on a DeWalt 18V 5Ah battery sitting on a ute tray at a work site

Questions people ask

Which battery should I pick?

Choose the brand of the 18 to 20V batteries you already own. The converter mounts straight onto them.

DeWalt FlexVolt, Bosch GBA or PBA: which one am I?

DeWalt FlexVolt batteries automatically switch to 18/20V on this style of mount, so they work fine: pick DeWalt. Bosch (GBA) is the blue professional range and Bosch (PBA) is the green DIY range. Check the label on your battery.

Will it flatten my tool battery?

Built-in over-discharge protection cuts output before the battery is drained too low, so your battery is protected.

Good to know

Maximum continuous draw is 10A. Gear that draws more will trip the over-current shutdown.
Runtime figures are a guide only and depend on your gear, battery size, battery health and the weather.
Use batteries in decent condition. The unit resets when you remove and reattach the battery.

Specifications

Input: 18 to 20V power tool battery (slide-on mount, brand-specific)
Output voltage: 5 to 13V DC, adjustable via dial with live digital LED readout
Max output: 10A continuous
Output plug: 12V cigarette socket, Anderson plug, or both
Battery mounts: Makita, Milwaukee, DeWalt, Ryobi, Ozito, HiKOKI/Hitachi, Bosch (GBA and PBA), AEG, Stanley, Black & Decker
Protection: over-current, over-discharge, short-circuit and thermal
Typical runtime: around 5 to 7 hours running a 40L 12V fridge from one healthy 5Ah battery