Written By Noelle Talmon
Published Oct. 14, 2021

If you leave a vehicle sitting for a prolonged period of time, have a racecar, boat, or RV, it’s a good idea to invest in a battery disconnect switch. Why? It can be a pain to try and start your vehicle after it’s been sitting for a while only to discover that the battery is dead. A battery disconnect switch prevents the battery from draining when it’s not in use because it cuts off the connection between the battery and your vehicle’s accessories. These switches are also a theft deterrent, can prevent electrical issues from occurring, and offer safety in the event of an on-track accident. Check out our list of the best battery switch disconnect devices in the buying guide below.

Best Battery Disconnect Switches Reviews & Recommendations

Our top pick is this disconnect switch from Gama Electronics as it features an easy twist/untwist design, is easy to install, and it efficiently does the job of preventing battery drain. The plastic top is specially designed to be easy on your fingers if you have to fully unscrew it and you can use this item on your car, RV, truck, ATV, or boat batteries.

To disconnect it from the battery, simply untwist it. The switch also acts as a deterrent for car theft as by simply unscrewing its cap, you keep your car safe from thieves. However, the cap is small and easy to lose if you’re not careful. The battery cut-off switch is also made from zinc alloy and not brass, so it’s less durable than some other options. Also, the male post may be too small for the negative battery cable. Since some batteries have larger posts, you may need to use a shim for proper operation.

Specs
  • Measures 4.1 x 3.1 x 1.2 inches
  • Easy-to-follow prompts on the switch
  • Plastic knob prevents accidental shock
  • Continuous amp load of 200A
PROS

Deep grooves

Small enough to fit in your pocket

Solidly built and sturdy

CONS

Disconnect switch is made from zinc alloy and not brass

Male post may be too small for negative battery cable

The Ampper disconnect switch features brass construction, which makes it rust- and corrosion-resistant, and the grooves on the side provide a good grip, so it’s easy to operate even in wet conditions. The switch works by connecting to the negative terminal and giving it a small turn to isolate the battery from a power source. It is easy to fit and install. The prompts on the black knob are easy to follow and make the task easy—even for a first-time user.

This battery cut-off switch also functions as an anti-theft device as you can remove the knob without removing the whole unit. It also has one big drawback: It is only suitable for side post installation. Additionally, the knob and bolt that hold the switch together are a little flimsy.

Specs
  • Measures 3.9 x 1.5 x 1.5 inches
  • Rated current of 125A
  • Plastic knob makes it safe for handling electricity
PROS

Easy no-tool installation

Corrosion- and rust-resistant

Can be used for car, RV, ATV, and boat batteries as well as electrical equipment

Made of heavy-duty, solid brass

CONS

125 amperage is limiting

Limited to side post installation

Knob and bolt are a little flimsy

This disconnect switch from QuickCar Racing Products is a great option if you have a bigger budget and need something for your racecar. It features a quick-turn handle that immediately cuts off the electrical supply to your vehicle’s battery and also features a mounting plate, which sets it apart from some other brands. This switch is ideal for racing cars and setups where a quick disconnect is required.

However, it also works in RVs and regular vehicles. The handle is long and makes it easy for you to switch off power and its red color makes it highly visible. Despite its ease of use, it does not come with an instruction manual and people who don’t know how battery disconnect systems work may find it difficult to use. It is also not waterproof and won’t serve you for a long time.

Specs
  • Measures 5.8 x 5.6 x 5.3 inches
  • Mounting plate with prompts
  • 125A rating
  • Epoxy coat on handle enhances durability
PROS

Red and black color scheme is good for visibility

Quick-turn handle makes it easy to use

Design adheres to rules set by racing organizations and sanctioning bodies

CONS

No instruction manual

Not waterproof

Not very durable

This disconnect switch from Orion Motor Tech features corrosion-resistant, copper-plated steel construction and can tolerate 12-24 volts of 125A continuous and 300A momentary current. It’s compatible with most vehicles, boats, RVs, and jet skis, and the switch is coated in plastic and quickly disconnects and reconnects the battery. The plastic base and finger guard provide insulation to prevent shocks, short-circuiting, and potential fires.

To use the device, simply raise the level to disconnect power to the electrical supply, and lower the level to reconnect it. It fits all negative battery terminals with 15–17 mm widths. It also comes with a one-year warranty should you experience any issues. Overall, it’s a good quality product for the price. However, if you have a battery with a large post, it may not fit properly. The switch also requires 3.1 inches of vertical height to permit full range of motion.

Specs
  • Measures 3.94 x 3.15 x 2.17 inches
  • Handles 12–24V of 125A continuous and 300A momentary current
  • Fits around cathode terminals 15-17 mm in diameter
PROS

Easy to install

Easy to use

Sturdy and well-built

CONS

Large

You need a certain amount of space to operate the lever

May be too small for some battery posts

Best Weather-Resistant

This battery cut-off switch includes a mounting plate, which makes installation easy. While it can be used in many types of vehicles and electrical systems, it’s specifically designed for panel-mount applications, such as RVs and travel trailers. One great feature is the rear insulation cover, which mitigates the risk of short-circuiting. It’s also waterproof and rated for marine use, so you can install it on boats.

The control knob acts as a security feature, so if you want to use it as a security device, simply turn it counterclockwise to disengage the knob. It’s also designed to prevent accidental adjustments. Overall, the switch operates smoothly, it’s solidly built, and the knob is large and easy to grip. ​However, the switch doesn’t come with an instruction manual or mounting parts. In addition, its on/off prompts are difficult to read, as they are written in small letters.

Specs
  • Measures 7 x 4 x 3 inches
  • 275A rating
  • Removable knob
  • Rear insulation cover
PROS

Universal wiring

Water-resistant

Minimal risk of short-circuiting

CONS

Hard to read the on/off labels

No instruction manual

No mounting parts included

The Zoostliss Kill Switch is a simple, well-designed device and it features a quick-turn key that’s easy to operate because its two knobs move smoothly without resistance. Built to last, it features brass nuts and washers that are rust- and corrosion-resistant. We like the protective cover that safeguards the keyhole because it prevents water from getting inside, extending the switch’s lifespan.

It’s also easy to install and comes with an additional key should you misplace the original. Overall, it’s sturdy, well made, and an inexpensive way to disconnect your battery while your vehicle is in storage. However, it can only withstand a maximum current of 500A for five seconds. You may need to coat the brass parts to prolong their lifespan. Also, you can’t remove the key when it’s engaged.

Specs
  • Measures 3.1 x 2.6 x 2.6 inches
  • Handles up to 500 Amperes
  • Two keys included
  • Brass lug nuts and washers
PROS

No-tool installation

Protective waterproof cover

Rust- and corrosion-resistant

CONS

Can’t last for more than five seconds at maximum current (500A)

May need to coat the brass parts to extend their lifespan

Key can’t be removed when engaged

How We Selected The Products 

We took several features into consideration when choosing the best battery disconnect switches. First, we made sure the products were easy to install and use. We also chose switches with safety features, so they won’t cause shocks, short-circuiting, and other issues. Our list features different types of switches, so you are sure to find the right one for your car, truck, RV, racecar, or boat. We also selected products in a range of prices to meet every budget. We avoided items with poor user feedback and cheaply made materials. 

Our product selections, rankings, and awards for this story are based on research. While we haven’t conducted real-world testing on all of these products yet, we’ve looked at consumer testimonials and data, tutorials, and general discussions on social media and in forums. We also consider price and specification in the context of the segment. And, of course, we rely on our institutional knowledge of the automotive landscape to weed out weak products.

Buying Guide/What to Look For 

While they may share many features, not all battery disconnect switches are the same. There are several things you should consider before making a purchase to find the best one for your needs. These features contribute to their ease of use as well as their cost. Check out the following criteria before making a purchase.

What to Consider When Buying Battery Disconnect Switches

Types of Battery Disconnect Switches

Knob Style

This switch uses a knob to disconnect or connect the battery, and it can be used as either a top post or side post switch. Since it’s so easy to remove the knob, it’s an excellent theft deterrent. The switch is easy to install, and the knob is usually made of plastic, while other parts are made of brass. Knob style disconnect switches are a good option if you have limited space in the engine compartment.

Knife Blade

If you don’t have much clearance above the battery, this switch is a good option. It’s made in the shape of a knife blade and is easy to install and use. Compatible with most batteries as long as the amperage is correct, these switches can operate vertically, horizontally, or with a wingnut. It can also be used with two batteries at once. 

Keyed and Rotary

This type of switch is more common in boats and RVs and operates using either a key or rotary switch. Keyed switches require a key to cut off the power. It’s a good idea to have more than one key in case you misplace one. Keyed switches usually have keyhole covers to prevent water intrusion.

Battery Disconnect Switches Key Features

Amperage

It’s critical to choose a switch with the correct amperage. Most vehicles have high-powered batteries, so the disconnect switch needs to be able to handle that power properly over a prolonged period of time. The right amperage can also prevent short-circuiting. 

Ingress Protection (IP) Rating

Switches with higher IP ratings are better able to withstand changing weather conditions, such as heavy rain. The rating indicates the level of protection a switch’s housing provides to the internal components. Look for heavy-duty cases that can provide protection year-round. This is particularly important if you’re using the device on a boat. 

Installation

Battery disconnect switches are installed on the top post or side post. One or the other will make it easier for you to access, operate, and use the switch. Top battery disconnect switches are installed above the battery, so they’re easy to install. Side post installation can require a mounting plate, and you may need to purchase the hardware separately. 


Battery Disconnect Switches Tips and Tricks

As with something you do for decades upon decades, you pick up a few tips and tricks along the way in terms of selecting the right product, and/or using it. That’s the case with us and battery disconnect switches. To help you bridge the information gap, here’s a selection of what we’ve learned along the way.

Tips

  • Avoid random power cuts or you risk damaging the locking navigation system and other anti-theft features. 
  • When replacing the battery, disconnect the switch—starting with the negative terminal. 
  • If you are not sure about installation, consult a professional to avoid system failure. 
  • Always remember to turn off your vehicle before disconnecting the battery. This will prolong the lifespan of the battery, the electrical system, and the disconnect switch. 
  • When you buy a battery disconnect switch, you want it to serve you for a long time. To that end, it is crucial that you take good care of it to reduce replacement costs. 
  • The good news is that once you install a battery disconnect switch, you don’t have to go to great lengths to ensure it performs optimally. However, it’s important to know when to turn the switch on and off as this greatly affects its lifespan. 

FAQs

Battery disconnect switches are quite easy to use. Most come with an instruction manual to make things easy for users. However, there are common questions most users ask when buying or using them. Most of the questions are related to installation, fitting, and replacement. We answer some of these questions in this section.

Q. How do I connect and disconnect a battery cut off switch?

To connect the switch, disconnect the wire on the negative terminal of your battery. Insert the ⅜-inch hole into the battery terminal, and then attach the battery wire to the other end. Insert the screws and tighten them securely with a wrench. To disconnect the switch, use a wrench to loosen the lug nuts, then unplug the switch on the negative side.

Q. Why can’t I connect a battery cut off switch to the positive terminal of a battery?

It’s highly dangerous. What’s more, a normal battery disconnect switch will not fit on the positive terminal. Negative battery terminals measure approximately ⅜-inch or only slightly bigger. Positive battery terminals have larger diameters.  

Q. Do battery disconnect switches go bad?

Yes, they can fail over time. They’re not designed to last indefinitely, so you may need to replace yours once it stops working properly.

Final Thoughts

Our pick for the best battery disconnect switch is the Gama Electronics Top Post Battery Master Disconnect Switch. It is easy to install and use and is compatible with most car, RV, truck, ATV, or boat batteries. It’s also a good theft deterrent. For a more budget-friendly option, consider the Ampper Side Post Heavy-Duty Battery Disconnect Switch.

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