Black & Decker Battery Maintainer

4.5 stars
80 reviews ratings
Walmart #: 550910978
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  • For use on 6V and 12V battery systems
  • Easy connection to vehicle battery using the included battery clips
  • About this item

    The Black & Decker Battery Maintainer is ideal for use with both 6V and 12V battery systems. You can use it to charge the batteries of RVs, motorcycles, lawn mowers, ATVs, boats or jet skis, classic cars and many other vehicles. You can keep all of your battery-operated vehicles running with the two voltages. The auto battery maintainer offers easy connection to the battery with the included clips. It also includes a DC accessory plug and battery ring terminals. This car battery maintainer features smart charging technology to keep batteries at the optimal charge. It stops when the battery is fully charged. The built-in circuit protection on the auto battery maintainer prevents overcharging or reverse polarity. Your battery is also safe from short circuiting. A built-in mounting bracket allows you to place it in the most convenient location. The car battery maintainer switches from charging mode to float mode monitoring. This Black & Decker Battery Maintainer is fully auto

    Black & Decker Battery Maintainer:

    • For use on 6V and 12V battery systems
    • Easy connection to vehicle battery using the included battery clips
    • O-ring terminals or vehicle DC plug
    • High-frequency smart charging technology keeps batteries at optimal charge
    • Automatically switches between charging mode and float mode monitoring
    • Built-in mounting bracket


    Battery Type: Does Not Contain a Battery
    Model No.: BM3B
    Shipping Weight (in pounds): 1.4
    Product in Inches (L x W x H): 8.0 x 3.0 x 2.0
    Assembled in Country of Origin: Imported
    Origin of Components: Imported
    Walmart No.: 550910978

    Customer reviews

    Customer Reviews | 80 reviews | 4.6 out of 5

    4.5 stars

    80 reviews | 4.6 out of 5

    5 stars
    4 stars
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    1 stars
    Would recommend to a friend



    Dual Charge Capability and Mulitple Attachments

    Customer review by An anonymous customer

    5.0 stars by An anonymous customer

    For the price this unit delivers. Both in 6 volts and 12 volts. It comes with multiple battery attachments which most of the other units out there do not. I used the permanent attachment on my garaged vehicle which rarely sees the road, and then I have the other two attachments remaining which I can use to 'spot' charge my other vehicle/lawn mower/generator batteries to keep them topped up and in their prime. I purchased this B&D Battery Maintainer due to a dead battery found on my garaged vehicle from less than 2 years new!!! The result of not much vehicle road use and a slow discharge brought the battery down so low it could not recover. Now I can spot charge it and keep it in prime condition and avoid another $120 plus battery purchase. I also have the advantage of using it with the other supplied attachments on my lawn mower, portable generator and other vehicles batteries. A great value.

    Was this review helpful? (53) (10)
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    An anonymous customer
    Richmond, VA
    Would recommend to a friend? Yes
    Ownership:1 week or less
    Age:55 - 64
    Usage:Once per week
    Verified purchaser
    Verified purchaser
    Customer has been confirmed to have purchased the item from Walmart.
    Great product

    Customer review by Outdoorsman603

    5.0 stars by Outdoorsman603

    There are battery maintainers that go for around $100 or more. So I was skeptical about this one only being $20, but gave it a shot anyway. First thing I notice is the plug accessories which are very cool. The device is simple to use and the most important thing is that it works. Hooked it up to my old jeep (battery was dead) it took about 2 weeks but charged the battery and keeps it charged. So I hooked one up to my boat battery and it was fully charged in 2 days. Will probably get a 3rd for my atv. These things are great and cheap.

    Was this review helpful? (47) (7)
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    Lake Charles, La
    Would recommend to a friend? Yes
    Ownership:3 - 4 months
    Age:35 - 44
    Usage:Every day
    Verified purchaser
    Verified purchaser
    Customer has been confirmed to have purchased the item from Walmart.
    Great product at a great price!

    Customer review by HappytobeinUtah

    5.0 stars by HappytobeinUtah

    Easy to install, works great, and cheap price! It doesn't get any better than that.

    Was this review helpful? (16) (8)
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    St. George, Utah
    Would recommend to a friend? Yes
    Ownership:2 - 3 months
    Age:55 - 64
    Usage:Every day
    Verified purchaser
    Verified purchaser
    Customer has been confirmed to have purchased the item from Walmart.
    1-3 of 77 total reviews See all

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    I have a 10K watt generator which says I need a trickle charger to keep the battery charged Just make sure it is a 12 volt and no more than 10 amps so my question is would this work and how often and how long do I need to charge the battery
    by fishy 2/20/2014
    • This is a slow charger, 1.2 amps. Either 6 volt or 12 volt, it has a selector switch. When you hook it up it will flash a green to show that it is charging, once fully charged it will turn to a steady green light. It depends on how much charging your battery needs as to how long the initial charge will take. Once it is charged you just leave it hooked up and it will maintain the charge. It is fully automated. I used it on a new riding lawn mower battery, it took I will say around 14 hours to fully charge it. After I used the lawn mower I hooked it back up and it only took around 10 mins until it was back to a full charge. It is at a steady green light now and everytime I look at it. Fully automatic just hook it up and forget it. If your battery is under 2 volts this charger won't charge it back up, you have to have more than 2 volts in the battery. If that is the case have it charged then use this maintainer on it.
      by HandymanIam5/18/2014
      Was this answer helpful? (0) (0)
    • Yes. I also have a 10K watt generator, and you keep the B&D unit connected to the battery and plugged in so the battery stays fully charged.
      by Scotsman1113/15/2014
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    • yes it will work,just leave it on it when your not using your generator
      by pumetti3/14/2014
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    • This would work great. It automatically shuts off when fully charged. I looked at a lot of different chargers but just needed exactly this. It is a maintainer. Quick connect and disconnect from your battery. You can leave the leads hooked to your battery and it disconnects from the charger. Also has alligator clips and can be used with a cigarette lighter.
      by Springer86903/6/2014
      Was this answer helpful? (0) (0)
    • yes this will work no problem
      by lostsole2/24/2014
      Was this answer helpful? (0) (0)
    • The BM3B Battery Maintainer/Trickle Charger should work for the application you have described. It would be best to check with either or both the manufacturer of the generator and the battery to see what they recommend. How often and how long to charge the battery will depend upon how often the battery is used and how drained it is.
      by Black&Decker2/22/2014
      Was this answer helpful? (0) (0)
    For some reason my moms battery is draining nightly having her to have a jump everyday. Could she hook this up at night just to keep the charge?
    by Carol 12/17/2013
    • Not likely. A one amp charge won't keep up with that type of drain. Get the car fixed.
      by Mungo5446/24/2014
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    • this unit can help with that but you will need to find out what is draining the battery in her car. There might be a short in the system,the battery might be faulty. You should remove the negative cable from the battery with the car off key switch off and key out of switch and when removing the cable check for a spark if you see a spark when removing and reinstalling it there is a short or a drain on that battery!
      by lostsole10/24/2014
      Was this answer helpful? (2) (0)
    • Yes. That's exactly what it's for.
      by John8141/3/2014
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    • This will trickle charge and/or maintain an optimal battery charge on your battery, but it sounds like you might possibly need a new battery or to repair something in your vehicle's electrical system.
      by jadetigress4/11/2014
      Was this answer helpful? (1) (0)
    • No, this is a trickle charger, you need to get your car fixed
      by Trikeboy12/21/2013
      Was this answer helpful? (0) (0)
    • Yes, the BM3B Battery Maintainer/Trickle Charger can be used each evening to help maintain the charge in the battery.
      by Black&Decker10/24/2014
      Was this answer helpful? (2) (0)
    1-3 of 29 questions See all

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