Black + Decker BM3B Battery Maintainer/Trickle Charger Review


Getting your battery up and running for everyday use is one of the most consequential things to do. There are several types of batteries, but a critical thing with all of them is maintenance. If a battery is well-maintained, there is no doubt that it would perform effectively for the day’s job.

Battery maintenance goes beyond checking the parts every morning to see if something is wrong; sometimes, it involves running checks with a battery maintainer. With a battery maintainer, it is easy to detect something wrong with the battery. In this Black + Decker BM3B Battery Maintainer/Trickle Charger review, there is a lot to know about battery maintenance and its applications.

Black + Decker BM3B Battery Maintainer/Trickle Charger

  • Description

Black + Decker BM3B Battery Maintainer is a product of the Black + Decker brand, known for its effectiveness in checking battery life and quality. While it does exceedingly well in maintaining a battery, it is also useful in charging RVs, marine deep cycle batteries, ATVs, lawnmowers, motorcycles, and specialty cars. This device comes with state-of-the-art technology that makes it suitable for different assigned tasks.

  • Features

Some of the features packed into this classic battery maintainer include;

Charging Selectivity: Black + Decker Trickle Charger is designed to offer 2 charging selectivity modes for performance. It charges and maintains AGM, GEL, and WET batteries at 6 volts and 12volts with 0 – 1.5amps Power. Once the battery is fully charged, it automatically stops working or, better still, switches to float mode monitoring to preserve its working efficiency.

Cable Clamps and O-ring Terminals: There is no way a battery charger or maintainer would connect with a battery without the cable clamps. Black + Decker trickle charger has incredible cable clamps and O-ring terminals that help maintain an easy connection to a vehicle battery.

Circuit Protection Guards: One of the significant problems with charging a battery is that you may overcharge unknowingly. However, this battery maintainer has circuit protection guards that will protect against such. It also works effectively in stopping reverse polarity and short circuits. Overall, it is a safe device, which is why it is ETL-certified for safety and performance.

Mounting Bracket: Another incredible feature incorporated into this device is the mounting bracket that enhances stable positioning and convenient placement.

AC Low Voltage Compensation: There are instances when you have to use an extension cord to charge the battery; if that happens, the performance might be quite average. However, the Black + Decker Battery Charger features an AC Low Voltage Compensation that will enhance its performance, making it seem like there was no issue at all.

LED Indicators: This battery charging device has two LED indicators, with each having its significant description. The red LED means there is a problem, while the green LED shows charging status.

Weight: 1.25 lbs.

Dimensions: 5 x 3 x 8.9 ins.

  • Pros

A reasonable trickle charge with several attachments

Offers optimum performance

Maintains and Charges AGM, WET, and GEL batteries at two different modes


  • Cons

If the battery is too low, it takes days to charge

Buying Guide Questions

While there are notable things about the battery maintainer, there are also questions about its use.

How Does Black + Decker BM3B Battery Charger Work?

Battery Chargers are relatively easy to handle, as long as you have them in great working condition. A Black + Decker BM3B Battery Charger, for instance, has 3 connector sets – DC accessory plug, cable clamps, and O-ring terminals. All you have to do is connect the cable clamps to the battery and let the mounting bracket hold it in position. Next, set a voltage to charge your battery and watch as the Green LED shows the status. When the battery is full, it automatically switches into float mode.

What is the Difference between a Battery Charger and a Battery Maintainer?

The only difference between Battery Chargers and Battery Maintainers is in their response after the battery is full. A battery charger applies constant charge until the battery is full in which must be removed immediately after; a battery maintainer, on the other hand, automatically stops charging.


This Black + Decker BM3B Battery Maintainer/Trickle Charger review centers on finding one of the best and most reliable battery charger options to improve battery life without overcharging. Hence, it would be a good value for money.