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Your cart is empty.4.4 out of 5 stars
- #14,837 in Automotive (See Top 100 in Automotive)
- #97 in Battery Chargers
The BLACK+DECKER BM3B high frequency battery charger and maintainer is used to keep batteries in stored vehicles and battery applications at optimal capacity during the off season. Charges 6 volt and 12 volt AGM, GEL and WET batteries in RVs, specialty vehicles, antique and classic cars, marine deep cycle batteries, motorcycles, lawn mowers, ATVs, snowmobiles, and personal watercrafts. Slide the voltage selector switch to either 6V or 12V depending upon the battery you are charging. Connect the battery charger and maintainer with the included battery clips or battery ring terminals. Charging automatically stops when battery is fully charged or topped off and switches to float mode monitoring to maintain charge. Built-in circuit protection guards against overcharging, reverse polarity, or short circuit and is ETL certified for performance and safety. The BLACK+DECKER BM3B battery charger and maintainer has a built-in mounting bracket for convenient placement and includes a limited 1 year manufacturer warranty.
Rob Jeffers
Reviewed in the United States on February 6, 2025
Charged truck battery easily overnight. Was a great price for a good product.
E. Freeman
Reviewed in the United States on February 3, 2025
I have had a lawnmower or motorcycle plugged into this continuously for the last 11 years. No issues. I installed quick connects on both of them.
Matt Armour
Reviewed in the United States on July 16, 2024
Somehow the world has made me come back to this product page a little over 8 years later and I figured I would write a quick review.TL;DR - Charger works well and has given me zero issues.Pros:The cord is plenty long for my garage outlet so I don't even need an extension cord when plugging in my "race car" as my kids call it. I only get to drive it once every few weeks so I throw this charger on there just to not worry about the battery possibly going dead. The power inverter is in the middle and can be mounted so you could possibly run power from an outlet, mount it on the wall or a workbench, and then have a good amount of cable to plug in a battery, depending on your application.It includes several ways to connect to the battery terminals. I just use the clamps and I have not had any issues. They are pretty sturdy and should hold up to normal use without issues.The unit has an easy to understand switch and lights for status. Switch to convert it from 6V to 12V, depending on what you are charging. The status light has simple icons that give a good indication of what the charger is doing.Cons:Not an issue for me but something you should be aware of with this (and likely most chargers of this type in this price range) charger is that it's not going to be super fast at charging a battery that is very low. Most of the time, that's not a big deal as its intended to maintain a battery that is sitting for long periods of time. Just don't assume you can plug this into a dead battery and come back an hour later and have it ready to go. Depending on how empty the battery is and how much power is needed to turn whatever you are powering over, it will likely take longer than that.Overall, well worth the 20 something bucks I spent on it. Not something I can always say with stuff from Amazon these days.
W.A.C
Reviewed in the United Kingdom on February 15, 2024
Good product
C4 Restorations
Reviewed in the United States on October 28, 2024
What is great about this charger is when you plug it in...it starts charging. There is only one switch and it is manual selector switch...to select 6 volt or 12 volt. And the reason this is important is that most of the other chargers have a push button mode select switch that requires you to choose either lead acid or lithium ion. Which is fine unless you have any kind of power blip or power failure. With those other chargers, they revert to a selection prompt, where it asks you to select either lead acid or lithium ion. So in other words, if you have any momentary interruption in power, those chargers are no longer charging. But this charger, being simple and manual, when power is restored, it restarts the charging process.
karen
Reviewed in the United States on October 19, 2024
This is a great tool unfortunately I was unable to use and had to return it
Luiz
Reviewed in Brazil on October 8, 2022
Manter carregada a bateria de alguns carros que tem pouco uso
Tony
Reviewed in Australia on September 22, 2020
How good are they, send a product to Australia with a US power plug on the product.How am meant to use the product?Very disappointed with the distributor.
Nikki
Reviewed in the United States on May 23, 2019
I finally charged the dead and drained battery of my car. It doesn’t charge the dead battery initially, and I read the instructions that it requires a minimum of 2 volts to charge it.So I thought I was out of luck because the battery was completely drained to jump start it. I left my car in storage and hadn’t run it for a while and the battery slowly drained completely.Out of desperation, and after reading the instructions for awhile, then I realized that because it has a polarity sensor to detect the correct positive vs negative poles, so I figured that the minimum of 2 volts in the battery is designed for the polarity sensor to charge it with the polarity in order to prevent shorting the battery if it charges with the opposite polarity at the dead state without any minimum voltage to ensure it’s the correct polarity.So then I decided to trick the charger to start charging the dead battery by giving the dead battery some minimum voltage by connecting the jumper cable to another car’s functioning battery, but not attempt to jump start it yet (because the other car’s battery doesn’t have enough amperage to jump start the completely drained battery).So after I connected the jumper cable to the dead battery to another car’s good battery with the correct polarity first. Then I connect the charger cable to the dead battery. Now the charger detected the minimum 2 volts (borrowed from the other good battery) with the correct polarity, and now the green LED light starts blinking. So it’s a good sign that the charger is beginning the charging process. Then I disconnect the jumper cable and let the charger continue charging without the jumper cable connected.So that did the trick to start charging a completely drained/dead battery by borrowing the minimum 2 volts from the other battery to trick and override the polarity sensor to turn on charging the drained battery from the dead state.It finally fully charged my dead battery after it trickle charged for about 24 hrs because it’s only charging at the rate 1 amp so I expect it to take that long to fully charge a dead battery.After that I can start my car on it’s own and it works fine after that. Now I keep the car battery continues to charge by the charger as maintenance rather than letting the battery to drain dead before charging it for a car that has not run for awhile. And I need the run the car once in a while to circulate the fluid and engine rather than letting it sit there for a month.So the charger can charge a dead battery if you know how to trick it to make it work.
PacketLoss
Reviewed in Canada on November 19, 2017
So far so good. I received this in very short order and as expected, it is a Black and Decker quality product. I have hooked it up to my 1984 Corvette for it's winter hibernation and it appears to have done an excellent job charging then maintaining the battery. I will post an update on this product after it has been operational for a month or so and again in the Spring of 2018. I have used products similar to this in the past and have always been happy with them, I am sure this product will carry on the tradition.Update: This product worked great for me, left it plugged in all winter and just fired up my car this afternoon without any problems. It let me know when there was a problem with a little red light, that happened a couple times when the clips on the battery were bumped. Another great product by Black & Decker!!!
Vivcals
Reviewed in India on April 27, 2017
Excellent product, but it's 110 volts
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