Best Battery Disconnect Switches: Prevent Battery Drain
Avoid dead batteries and unauthorized vehicle use with these top battery disconnect switches
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BY Trey 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.
The switch is smooth but solid and stays securely at either position.
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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
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 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.
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 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 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.
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.
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.
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.
- 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
- 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.
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.
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.