If you leave a vehicle sitting for a prolonged period of time, or 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
1. Gama Electronics Top Post Battery Master Disconnect Switch
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.
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
- The male post may be too small for a negative battery cable
2. Ampper Side Post Battery Disconnect Switch
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.
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
- The knob and bolt are a little flimsy
3. QuickCar Racing Products Battery Master Switch
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.
PROS
- The 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
4. Orion Motor Tech Master Battery Disconnect Switch
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 a full range of motion.
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
5. BEP Battery Switches
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.
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
6. Zoostliss Battery Kill Switch Isolator Disconnect
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.
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 Best Battery Disconnect Switches
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.
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.
Types
Knob
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.
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.
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.
