6V & 12V Battery Maintainer


  • Spark-resistant hook-up, reverse connection warning and overcharge protection
  • Three easy connections: battery clips, ring terminals & vehicle dc plug
  • Two-stage, high-frequency charging technology for maximum efficiency and performance
  • Automatically switches between charging mode and float mode monitoring to prevent overcharging
  • AC Low voltage compensation ensures maximum performance when used with an extension cord
          4 stars 4 Reviews Print This Page
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Product Details

Key Features

  • Reverse hook-up and overcharge protection


  • Spark-resistant connection

What's Included

  • Battery clips
  • Battery ring terminals
  • Vehicle 12V DC accessory plug

Technical Specifications

  • Input120
  • Output6

1 Year Limited Warranty

Warranted for one (1) years from date of purchase. This warranty does not cover damage resulting from negligent handling, misuse or lack of reasonable maintenance and care. (Proof of purchase maybe required).


    Ratings & Reviews

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    User Reviews for 6V & 12V Battery Maintainer

    0 people recommended the following review
    MarkInArk Wrote:
    Maintains solar power battery bank
    Our primary home lighting system is based on 400 lumen 12vdc LED light fixtures. They are powered by a Group 29, 115 amp/hour deep cycle battery which is primarily charged by the BM3B. (When the power goes out we switch over to solar charging.) Works flawlessly. However. We recently added a brand new deep cycle battery (Exide 27MDCST group 27, 105 a/h)that this thing can't seem to properly charge. It took 3 days to top it off from the store - and then stays in trickle charge mode indefinitely unless you unplug and plug it back in at which point it goes into float mode. Put even the slightest load on the battery and the BM3B will go back into permanent charging status. Volts look good - how can I tell if it is the charger or the battery?

    Charge/Float indicator. Mounting holes. Multiple connection options. All in one rugged case.


    6v/12v switch needs to be "click-ier". Feels cheap and too easily knocked into wrong voltage.

    3/6/2014 7:33:17 AM

    0 people recommended the following review
    05redrex Wrote:
    Works well
    Inexpensive charger that won't kill the battery if you forget. As a charger, I doubt this has a lot of amps, but instead of killing a battery if you forget it maintains it. Brilliant to someone like me that is used to old school chargers and starters.

    Inexpensive, small, nice cord length, multiple adapters.


    Perceived durability... doesn't seem "solid."

    2/8/2014 3:00:33 PM

    0 people recommended the following review
    Mr4Wheeler Wrote:
    Works Great for me.
    Use my 6V & 12V Battery Maintainer BM3B for keeping my tractor battery fully charged during the winter. Just hook it up to my 12v, plug it in and wait until spring. Works perfectly. Iowa winters can get cold!! -10 last week.

    Works as described. charges and maintains charge.


    None. Bought my online from Wal-Mart. Cheap. $17.00

    1/21/2014 2:44:34 PM

    0 people recommended the following review
    steve.r Wrote:
    I was borrowing a friends B&D BM3B and everything was going fine. I ordered one of my own from amazon, plugged it in and it was DOA. So before I returned it I purchased a second one from Amazon and it too was DOA. plugged my friends in again and it charged as normal.

    Was able to purchase two not working ones for around the same price as a really nice working one.


    Was D.O.A Has a very cheap feel to it The fact that two were purchased from different shipping locations tells me that the QA team just pumps them out and doesn't really care if they come out with good specs on power or even work at all. would not currently recommend this product to anyone. we will see how the replacement process goes on both items.

    12/25/2013 11:01:15 PM

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