Black & Decker BM3B 6V and 12V Battery Charger / Maintainer

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I love writing about batteries and battery maintainers, and recently, my research landed me on the Black & Decker BM3B. I evaluated it, in respect to the 3 fundamental attributes of a good battery maintainer namely;

  1. Easy connectivity
  2. Automated or smart charging, and
  3. A powerful protective seal.

Here is a summary of my research findings about the Black & Decker BM3B;

Ease of Connectivity

The maintainer comes packed with a pair of O-rings, charging clamps, and a DC connector which offer a vast set of options for re-charging or maintaining your battery. The variety of connectors also makes it a practical “charger” and maintainer for all types of car batteries such as those for RVs, motorcycles, specialty cars, lawn mowers, marine deep cycle batteries, and watercrafts. This maintainer will come in handy if you are looking to maintain the battery of your stored vehicles in optimal conditions.


The Black & Decker BM3B can be alternated between 12V and 6V as per you batteries requirements, making it suitable for both small and large vehicles having either 12V or 6V.

Compared to its two closer rivals, i.e., CTEK (56-158) MULTI US 3300 12-Volt Battery Charger and Battery Tender 022-0157-1 Power Tender- Plus Battery Charger, the Black Decker BM3B easily picks the win in relation to ease of connectivity.


Here is what one client said about its ease of connectivity;

“This is among the least expensive battery maintainers you can find in the market. It comes with a range of connections options, just like high end maintainers. It is can be switched between 12V and 6V. This is great because most of the maintainers I had used in the past support either 12V or 6V.”


A slight concern about the connectivity of this device, the 12V/6V selector feels a bit cheap every time I switched it, I wondered if it was going to break but it didn’t. It might as a matter of facts be solid, but it doesn’t feel that way.
Fully Automated, Smart Charging

The Black and Decker MB3B is based on Automated/Smart charging and it will retain your battery charge at optimal level. Its 1.5 amp high frequency charging function will re-charge the battery and automatically turn to float mode once optimal charging capacity has been attained. In short, it takes the stress out of charging your battery and maintaining it; you just need to connect and switch it on.

Protection seal

This maintainer has a specially designed protection seal against moisture, oil and dirt. It features a mounting bracket to keep it in a safe position while being charged. Upon mounting it on your vehicle’s battery, you can leave it to work on its own and no complications will arise. The Maintainer is built to withstand possible interruptions caused by issues such as dusty air, slight shocks and violent environmental conditions.

Here is what another user says about it;

“I have been using the black and decker charger for about 4 months now and so far, I am very happy with the purchase. Previously, I had bought 3 other brands of maintainers and although they work, they are more expensive and they require more attention when connected. I prefer to hard wire the maintainer directly to the terminals and easily connect the plug. This makes it very easy to disconnect once I am ready to get on the go and reconnect once I am done. Just bear in mind that his is not a battery charger, it will maintain your vehicles battery in optimal charge conditions, but it will probably not bring back a dead battery.”


It’s normally a great way to consider the pro and cons of electrical and mechanical products before buying. Some of the most hailed features of this maintainer are;

  1. The maintainer has wide range of connection options which saves you the expense of buying another charger since it can cover most of your needs. It’s a cheaper option.
  2. Given this maintainer charging ability, it can boost your battery within 30 minutes. With it, you will never face stating problems whenever you are on a car that had been attached to it, with a charged battery. In addition, it has a rugged built.


There are no major demerits reported by users about this battery maintainer. However, a few customers have reported that it can at times overcharge the battery. But it has a sound history of maintaining the battery in optimal conditions. Also, it does not support PWC and AGM batteries, but the manufacturer is working to fix this.

In conclusion, the Black & Decker BM3B charger is a good and efficient charger and it can resolve a lot of car charging issues. If you would like to buy, I suggest you follow the link below and buy on Amazon. They have the best prices of all the sellers I have reviewed. Amazon is also a secure place to shop. Wishing you a great purchase.



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