---
publication_id: "OT-2026-000000468"
title: "Power tool including an internal auxiliary power supply"
published_at: "2026-09-15T19:02:55.550737Z"
canonical_url: "https://opentechnical.org/p/OT-2026-000000468"
categories:
  - "tools-tooling/powered-hand-tools"
keywords:
  - "b25f5/02"
  - "h01m2220/30"
  - "h01m50/247"
---

# Power tool including an internal auxiliary power supply

## Abstract

A power tool including a power tool housing, an interface configured to receive a battery pack, an internal energy storage circuit located within the power tool housing, a trigger for user control of power tool operation, a plurality of switches configured to connect the battery pack and the internal energy storage circuit in series or parallel, and a controller. The controller is configured to receive a control signal from the trigger, control the power tool based on the control signal, control the plurality of switches to set a power source configuration of the power tool by selectively connecting the battery pack, the internal energy storage circuit, or both the battery pack and the internal energy storage circuit to a load of the power tool, and provide energy to the load of the power tool according to the power source configuration.