---
product_id: 294117676
title: "WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA"
brand: "wirthco"
price: "¥10810"
currency: JPY
in_stock: true
reviews_count: 6
category: "Wirth Co"
url: https://www.desertcart.jp/products/294117676-wirthco-battery-doctor-20108-battery-disconnect-knife-switch-for-top
store_origin: JP
region: Japan
---

# Stops parasitic battery drain 250A continuous, 750A surge power Prevents theft & electrical fires WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA

**Brand:** wirthco
**Price:** ¥10810
**Availability:** ✅ In Stock

## Summary

> 🔋 Take charge of your battery life with a flick!

## Quick Answers

- **What is this?** WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA by wirthco
- **How much does it cost?** ¥10810 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/294117676-wirthco-battery-doctor-20108-battery-disconnect-knife-switch-for-top)

## Best For

- wirthco enthusiasts

## Why This Product

- Trusted wirthco brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Instant Power Control:** Lift the knife switch to disconnect power in seconds
- • **Proudly Made in the USA:** Top-quality craftsmanship you can trust
- • **Universal Compatibility:** Fits 5/8" top post terminals on cars, RVs, boats & more
- • **Built for Heavy-Duty Use:** Handles 250 amps continuous and 750 amps surge at 12V
- • **Extend Your Battery’s Lifespan:** Cut parasitic drain and save on costly replacements

## Overview

The WirthCo Battery Doctor 20108 is a robust 12V battery disconnect knife switch designed to prevent parasitic drain, enhance safety by reducing theft risk and electrical fires, and extend battery life. Compatible with a wide range of vehicles and power applications, it supports 250 amps continuous and 750 amps surge current, featuring easy installation on standard 5/8" top post terminals. Made in the USA for reliable, heavy-duty performance.

## Description

Stop unwanted parasitic power draw with our patented Battery Disconnect Knife Switches. It is perfect for mounting on a negative battery post to disconnect the ground and battery. Easy to install and use. A fast and effective way to extend the life of your batteries. Great for cars, RV, ATV, UTV, trucks, boats, campers, and other power disconnect purposes.

Review: good - good
Review: A nice switch. I installed it on my yard truck that never goes out on the road and does plenty of sitting during the year especially the summer. This should save the battery. Seems to be made well. I coated the whole thing with dielectric grease to prevent any corrosion. Was a breeze to install. Plenty of hood clearance with this model as it opens horizontally. Installed on a 1972 Ford F-250 4x4.

## Features

- PROLONG BATTERY LIFE: Stop parasitic drain to save money on battery replacement
- INCREASED SAFETY: Prevent vehicle theft. Shut down power during maintenance and avoid electrical fires
- EASY TO USE: Lift the knife and cut-off power. Works on standard 5/8" top terminal
- COMPATIBLE: Use on cars, RV, ATV, UTV, trucks, boats, campers, and other power disconnect purposes
- TOP QUALITY: Made in the USA. 250 amps continuous and 750 amps surge at 12 volts. 3-1/2"W x 3-3/4"L x 1-1/2"H

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B002OWFLC4 |
| Best Sellers Rank | #187,417 in Automotive ( See Top 100 in Automotive ) #250 in Car Battery Switches |
| Item model number | 20108 |
| Manufacturer | WirthCo |
| Product Dimensions | 17.27 x 11.43 x 5.84 cm; 45.36 g |

## Product Details

- **Connector type:** Crimp
- **Contact type:** Normally Closed
- **Current rating:** 250 Amps
- **Operating voltage:** 12 Volts
- **Operation mode:** manual

## Images

![WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA - Image 1](https://m.media-amazon.com/images/I/41GmHBLEsvL.jpg)
![WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA - Image 2](https://m.media-amazon.com/images/I/511k5zR4RBL.jpg)
![WirthCo Battery Doctor 20108 Battery Disconnect Knife Switch for Top Post Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery - Made In USA - Image 3](https://m.media-amazon.com/images/I/81cZQqamkVL.jpg)

## Questions & Answers

**Q: The wirthco switch i ordered does not say worthco anywhere on it . can i be sure it is made by wirthco and is it made in the usa ?**
A: Same happened to me but i paid extra for the Wirthco!!

**Q: Is the wirthco  switch manufactured in the usa ?**
A: Don't know but high quality product. Used successfully eliminated battery drain easy install

**Q: The stud with wing nut and the bolt and nut, are they stainless?**
A: Jonathan...Just used it the other day...I've had it mounted a couple  years now.  I'm not sure if it is Stainless to be honest.  I live 1 mile from the Pacific Ocean on the NW Oregon Coast.  If it's going to rust, it will rust here and I have the rusty metal in my vehicles and other metal "things" around the house that weren't rusty before moving here to prove it.  The wing nut and bolt appear clean and rust free to date.  I'm taking my motor home out in a week so I'm getting it ready to go!  All that being said, my guess is that it is Stainless as there is no rust on it at all.  Yet, a few parts around it (not any of the switch itself) have gained some tinges of rust while the "Knife Switch" has not.  I would recommend this product to you and others...The other style switches don't seem to work as well...Feel safe in our buying decision!  Ken ~ Pacific Northwest Oregon Coast

**Q: I've been using this daily for 3 months now. Recently the lever became very hard to push. Are there any lubricants that are safe to use on this?**
A: WD40 would do.. or put some grease in the lever connecting part... should do the trick, good luck.

## Customer Reviews

### ⭐⭐⭐⭐⭐ good
*by H***N on 26 May 2024*

good

### ⭐⭐⭐⭐ Review
*by R***. on 10 August 2016*

A nice switch. I installed it on my yard truck that never goes out on the road and does plenty of sitting during the year especially the summer. This should save the battery. Seems to be made well. I coated the whole thing with dielectric grease to prevent any corrosion. Was a breeze to install. Plenty of hood clearance with this model as it opens horizontally. Installed on a 1972 Ford F-250 4x4.

### ⭐⭐⭐⭐⭐ Review
*by A***R on 16 October 2021*

Great price, easy YouTube videos on how to install and works as advertised.

## Frequently Bought Together

- WirthCo Battery Doctor 20108 Disconnect Knife Switch for Top Post Terminal - 12v Kill Switch for Negative Post - Perfect for Saving Car Battery - Made in USA, black
- Battery Doctor 20128 Battery Disconnect Knife Switch for Side Terminal – 12v Battery Kill Switch for Negative Post – Perfect for Saving Car Battery and GM-Type Batteries - Made in USA

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.jp/products/294117676-wirthco-battery-doctor-20108-battery-disconnect-knife-switch-for-top](https://www.desertcart.jp/products/294117676-wirthco-battery-doctor-20108-battery-disconnect-knife-switch-for-top)

---

*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-05*