Batteries are an essential part of the modern automobile, but they can also prove to be dangerous when not handled properly. This is why it is recommended to install switches on car batteries. Switches allow for an effective means to cut off the battery from the rest of the car without having to remove the battery cable, preventing accidental discharge as well as electric shock or fire when conducting welding tasks on the vehicle body.
One of the more popular brands that offer automotive battery switches is Battery Doctor. Battery Doctor offers a wide range of battery switches of various designs to match the specific needs of car owners. In this review, we checked out one of the best selling models of the Battery Doctor battery switch - the low profile knife switch - and put it to the test.
- Dimensions: 3-1/2" x 3-3/4" x 1-1/2"
- Knife switch design that opens and closes horizontally
- Suitable for situations where clearance above battery is limited
- Knife blade rotates to a full 180 degrees
- Includes post for receiving standard battery clamps
Things we liked
- A simple yet effective way to disconnect your car's battery. Once the knife blade is detached from its contact, electrical current from the battery is virtually cut off. It also has basically one moving part, so malfunctions are almost non-existent compared to more complex switch mechanisms.
- The knife blade is quite thick and resists bending, while the end has a plastic cap for insulation. We do, however, find the insulating cap a bit too small, so we still recommend using a pair of insulated pliers to turn the switch.
- Does not require a shim to connect to a standard battery cable. We didn't encounter any serious compatibility issues with battery cables using this switch.
Things we didn't like
- The switch's design makes it more exposed compared to other switch types. You're certainly more likely to get an electric shock from this switch, and we certainly don't advise getting it wet either.
- The terminals are a bit too small for the battery posts. We did manage to solve the problem by sanding the posts to size.
The bottom line
If you want a simple, no-fuss switch for your car's battery, the Battery Doctor knife switch is a good choice. Though it is not as beginner-friendly as other switches, it's highly reliable and completely shuts down the battery when you need it.