Best Battery Disconnect Switches: Prevent Battery Drain

Avoid dead batteries and unauthorized vehicle use with these top battery disconnect switches

byTrey Williams|
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BYTrey Williams/ LAST UPDATED ON September 29, 2020

Battery disconnect switches are an easy and cost-effective way to improve your vehicle’s battery life and to protect against theft. Completely disconnecting battery power while your vehicle is in storage will prevent full battery drain, so your car, camper, ATV, or boat is ready to be fired up when you need it. Below are our picks for the best battery disconnect switches.

Best Overall

Blue Sea Systems 350 AMP E-Series Battery Switch

Summary
A marine-rated disconnect switch with a range of options to cover all uses. It comes with ignition protection for safe use with diesel or gasoline and is suitable for both rear panel and surface mounting.
Pros
Unit is used and recommended by professional boat builders as their battery cut-off switch of choice. It’s a heavy-duty and professional-looking switch but is sleek enough to be mounted internally.
Cons
The switch may be uncomfortable to handle. Also, it does not include mounting hardware or an instruction manual.
Best Value

Waterproof Heavy Duty Battery Isolator Switch

Summary
A heavy-duty battery kill switch suitable for devices up to 48V. Package includes removable sides, backplate, and mounting screws for easy installation. Its Contour Locking System means it can stand alone or be locked alongside other switches.
Pros
Covered by a one-year guaranteed replace or refund warranty. Fully enclosed to protect wiring from dirt, corrosion, and rain.
The switch is smooth but solid and stays securely at either position.
Cons
Positive/negative labels on the faceplate are back to front. Connecting battery cables requires a whole side to be removed, which is not as tidy as channels within panels for wires.
Honorable Mention

BEP Battery Switch

Summary
This waterproof battery master switch is available in panel-mounted and easy-fit options for any setup. It comes with a removable control knob for added security and a rear insulating cover to guard against short circuits.
Pros
The fully-enclosed, waterproof casing provides extra protection against corrosion. The switch is smaller than others available but is robust and easy to turn with a mechanism to prevent accidental application.
Cons
Because the wiring and proper installation are universal, no instruction manual is included. On/off labels on the faceplate are small and in a difficult to read position.

Benefits of Battery Disconnect Switches

  • Battery drain prevention. The main benefit of the battery disconnect switch is drain prevention. The device protects the battery when not in use, especially when stored for long periods. With it, drivers can relax knowing that their vehicles are safe and ready for quick start-ups.
  • Protection against thefts. A battery disconnect switch also works as an efficient anti-theft device. It's just good to have peace of mind when storing your vehicle for an extended period, and this device is quite reliable. Even if the thief gets hold of your keys, a battery disconnect switch can keep your vehicle safe.
  • Power maintenance. If you have two batteries, this little device can help you maintain the power of the one that is not in use. This way, you can be ready to hit the road all the time, without experiencing unexpected drain and power issues.

Types of Battery Disconnect Switches

Knife Blade

This type of battery disconnect switch got its name based on its unique shape. The model is made in the shape of a knife blade and is rather easy to use. It installs directly onto the battery terminal and controls the electrical current produced by the battery. The installation is rather simple because the knife blade type can be mounted both vertically and horizontally. It comes in handy when there's a little clearance above the battery. 

Knob-Style

Knob-style battery disconnect switches are very common and popular among users. They feature a switch or a knob that turns clockwise or anti-clockwise to provide or cut off power from the battery. This model is incredibly easy to use, and it proves to be an efficient anti-theft device. 

Knob-style battery disconnect switches come in either a top post or side post design and mount directly onto a battery terminal. They are most commonly used in limited and tight spaces. 

Keyed and Rotary

This type of battery disconnect switch is mostly used in boats, RVs, and industrial and agricultural equipment, but they can be found in cars too. They use keys or rotary switches to operate, ensuring more security. Once you turn the switch in the right position, you get to lock it down and take the keys with you. It's one of the best ways to keep your vehicle safe from theft, so this model is highly popular. You just need to make an extra set of keys or be extra careful not to lose the one you have. 

Top Brands

Blue Sea Systems

Blue Sea Systems manufactures marine electrical products and is based in Bellingham, Washington. The company offers all kinds of machines, devices, and accessories. From battery switches to fuse blocks and insulators, Blue Sea Systems are there to meet the needs of customers all around the world. Blue Sea Systems 350 AMP E-Series Battery Switch is one of its most popular products. 

BEP Marine

BEP is located in New Zealand and specializes in electrical products, especially when it comes to marine and RV equipment. BEP has a large team of engineers and other professionals that work on designing unique batteries, power distribution panels, monitors, and other tech devices. One of its widely popular products is the Waterproof Heavy Duty Battery Isolator Switch

Gama Electronics

Gama Electronics is located in Crystal Lake, Illinois, and is widely known for producing all kinds of electronic devices, including battery disconnect switches. What makes Gama Electronics stand out from the others are high-quality products that come at attractive prices to meet the needs of both professionals and DIYers. Gama Electronics Battery Disconnect Switch is one such product. 

Battery Disconnect Switches Pricing

  • Under $15: At this price point, you can expect to find most of the standard battery disconnect switches. They might lack some extra protection from outdoor conditions, but they are still highly reliable and efficient.
  • $15 and up: For some extra cash, you can get battery disconnect switches that have impressive performance. Pricier devices are often more durable too, as they are protected from overheating, impacts, and weather.

Key Features

Amperage

Depending on the type of your vehicle or equipment, you might want to check the amperage rating before opting for a particular battery disconnect switch. Not all vehicles have the same alternators—the power output can vary a lot depending on whether it's an RV, a car, or a truck. 

If you have a vehicle with a high-power battery, make sure that the switch can handle the amperage. Check for durability, too. The switch should be able to handle the high power output for an extended period without experiencing short circuits. Also, by choosing a switch with a proper amperage rating, you will protect the battery. 

Design

It's also crucial to pick a battery disconnect switch that is perfectly designed for your vehicle. The device should be big or small enough to fit the battery. It should also have some extra protection to prevent short circuits and other potential damages. 

Another thing to consider is the Ingress Protection (IP) rating. That will tell you how well the device is protected from outside elements. A battery disconnect switch with a high IP rating can withstand heavy abuse as well as dirt, dust, and water. 

Installation

Battery disconnect switches are simple devices that are very easy to use. Still, the installation might be less or more demanding, depending on the type of device. Top post models mount just above the battery and are easy to handle. Most drivers prefer this option because the installation doesn't require any extra accessories. For installing the side post model, you might need extra housing or a mounting plate. Consider which option works best for you before making a purchase and only then opt for a particular model. 

Other Considerations

  • Proper Use. Battery disconnect switches are simple devices that don't require any extra maintenance. Still, there are a few simple hacks one can do to prolong their lifespan and prevent accidental damage. For example, avoid random power cuts and always turn off the vehicle before disconnecting the battery. Also, make sure to disconnect the switch when replacing the battery.
  • Mounting Options. Once you determine which mounting option works best for you, consider what you'll need for the installation. If the provided instructions are not clear enough, you can always check for additional ones online. Sometimes, it's also smart to consult a professional and avoid system failure.

Best Battery Disconnect Switches Reviews & Recommendations 2020

Coming from a reliable company that specializes in marine electrical products, this battery disconnect switch is ideal for all kinds of batteries. You can use it on your car, truck, RV, boat, and more. All you need to do is to make sure that 350 amps are enough for your battery. 


The device is quite versatile and suitable for both professional and DIY purposes. You can mount it both on the top and rear panel. The installation is quite easy, and the device is impressively durable. It comes equipped with ignition protection and heavy-duty housing. The ratings IP66 and ISO 8846 state that the device is waterproof and protected from the ignition and flammable gases. 


The main drawback concerns the overall design of the knob. It's quite stiff and might be a little uncomfortable to handle. Also, the package doesn't include a manual or mounting hardware of any kind. That can make installation a lot more difficult, especially for first-time users. 

This is a heavy-duty battery disconnect switch is suitable for devices that range from 6V to 48V. With two positions that allow you to turn your battery on and off, it's a rather simple and easy-to-use device. You can mount it on cars, boats, RVs, trucks, ATVs, and other vehicles and devices. 


The package includes four removable side plates, a backplate, and mounting screws. All of these pieces make the installation very easy, although there's also a comprehensive manual to help you out. The device is stable and secure, and it can be locked alongside other switches. It's also important to mention that this model is well-protected from outside threats. It's fully enclosed to prevent dirt, dust, and water from reaching the unit. It’s also very sturdy and durable.  


One drawback with this product is the process of connecting the device with battery cables. The whole side needs to be removed, which is a little challenging and can be messy. Also, the positive and negative labels on the front are reversed, so this might be confusing.

BEP delivers quality products, and things are no different when it comes to this battery disconnect switch. It's a versatile 275A device you can use on all kinds of vehicles and industrial equipment, making sure your possessions stay safe and in the best condition. 


The device mounts in a breeze on the top and the side of the battery. The installation is quite simple, and no special tools are needed. Once mounted, the device stays securely in its position. It's reliable and also very durable. The knob is removable, and the rear insulating cover protects against short circuits. Additionally, the casing is waterproof and corrosion resistant. 


You can, however, experience a few issues with this product. Although the installation is quite simple, first-time users might have a few problems because there are no instructions included. Also, the on/off labels on the front are small print and difficult to read. 

This is a quality battery disconnect switch that you can use on your car, truck, boat, or RV. It's a knob-style device that is widely popular among drivers. All you need to do is to twist the knob and provide or cut off the power from your battery. 


The switch features a low-profile design. It's compact and perfect for those tight spaces where other, more bulky switches can't fit. Overall, the device works to reduce battery drain and prevent theft. With 200 amps of power, it's quite efficient and reliable. 


What can be an issue with this product is the installation. It might be a little challenging to tighten the screws tightly enough for a snug fit. Also, some users noticed that the mounting bolt was installed backward and unable to pass voltage. You might need to unscrew it and put it back in properly. 

Ampper features a 125A knob-style device you can use on all kinds of vehicles. It's suitable for cars, trucks, RVs, and boats, as well as industrial equipment. Thanks to the long-bolt design, it's quite easy to install. 


The device features heavy-duty construction. It's made of rust- and corrosion-resistant material that can withstand outdoor conditions and daily use. Also, the device is highly secure and safe to use. It's very efficient in reducing power drain and preventing thefts. 


The main drawback is the lack of instructions. Beginners might have difficulties with the installation, although there's a useful online manual to help. The second drawback comes from the bulky design. The device might not fit in tight areas and is more suitable for mounting on the side.

The Fastronix battery disconnect switch offers 180A and is suitable for most cars, trucks, RVs, and other vehicles. It's ideal for those who plan to store batteries and want to keep them at peak power. It also works great for theft prevention.


The device is quite simple yet incredibly durable. It has rough construction that can withstand some abuse and outdoor conditions. Also, it's very easy to use. Allow power flow or cut it off by simply turning the screw right or left. 


There are a couple of things to keep in mind with this product, however. The installation might be challenging, especially because the holes run a little small. You might need to drill new ones and tighten the screws enough to prevent possible wiggling.

If you're searching for a high-quality battery disconnect switch, you might want to take a look at the Perko 9601DP. It's a reliable model that saves your battery from possible drains and keeps it at peak power. 


The device is built of highly durable materials. It features a polycarbonate body with brass terminals and ignition protection. That ensures more stability and prevents possible overheating. Additionally, the switch is protected from outdoor threats such as sun, rain, and dirt. 


The installation might be quite tricky, however. Some users complain about the bolts not being suitable for the mounting holes. You'll probably need to buy new ones. The device is also a tad bulky and might not fit in tight spaces.

If you're looking for a high-end battery disconnect switch that will last for a while, this one from Flaming River is an excellent option. It's a highly reliable device you can use on a wide range of vehicles and ensure excellent battery performance. 


The device offers 250A and a simple design for easy use. It also features a fully-sealed housing that protects the internal parts from water and dirt. Thanks to the solid, quality materials, it's very stable and durable. Additionally, it comes with the necessary instructions and is simple to mount. 


The main drawback is the price. The device is on the expensive side, so it might not be suitable for those who are on a tight budget. Also, the switch is a little uncomfortable because it has sharp edges. You might want to be careful when using it.

This is a 125A battery disconnect switch that prevents drains and keeps batteries at peak power. It also works as a theft-prevention device. Overall, it's a very useful item you can use on your car, truck, RV, and other vehicles and equipment. 


The switch comes in a durable housing that can withstand heavy abuse and weather elements. Because it's made of quality materials, the unit is stable, secure, and incredibly durable. Even better, it installs on the top and the side of the battery. The mounting panel is included in the package along with the comprehensive manual. 


There are a few things to keep in mind with this product, however. First, the mounting holes might need to be modified for a proper fit. Second, some buyers noticed that the device is not waterproof, which can be an issue for marine applications.

Tips

  • Waterproof options are not just for boats. A marine-rated switch will better resist corrosion, especially if you’re attaching it directly onto the battery terminal.
  • Make sure you measure the battery posts on your battery and check what amp rating you need before choosing a master battery disconnect switch, so you can be sure that it will fit securely.
  • Most switches don’t come with wiring instructions since they’re relatively universal, but there are lots of helpful how-to videos online. If you’re not confident in connecting the switch, seek advice and assistance for proper and safe installation.

FAQs

Q: What does a battery disconnect switch do?

A: They disconnect batteries from boats and RVs that are either in storage or used infrequently as a way of protecting against battery drain while the vehicle is not in use. It’s also a great theft deterrent and a super easy way to guarantee safety during vehicle maintenance.

Q: There’s no space on my dash. Can I put a switch on the battery itself?

A: Yes. While most disconnect switches are fully enclosed in plastic and are designed to be wired up at a distance, there are options for attaching the switch directly to the battery terminal.

Q: What causes the battery drain?

A: Battery drain is caused by electrical appliances or parts of your vehicle that continue using very small amounts of battery power even though you’re not using them, such as digital clocks or security features.

Final Thoughts

The marine-rated, multi-option Blue Sea Systems 350 AMP E-Series Battery Switch stands out as our best overall battery disconnect switch, while the Waterproof Heavy Duty Battery Isolator Switch is our top pick for the best value.

Why Trust Us

Our reviews are driven by a combination of hands-on testing, expert input, “wisdom of the crowd” assessments from actual buyers, and our own expertise. We always aim to offer genuine, accurate guides to help you find the best picks.

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