--- product_id: 81903514 title: "BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp" brand: "black+decker" price: "£41.25" currency: GBP in_stock: true reviews_count: 13 category: "Black+Decker" url: https://www.desertcart.co.uk/products/81903514-bm3b-fully-automatic-6v-12v-battery-charger-maintainer-with-cable store_origin: GB region: United Kingdom --- # Auto float mode 1.5A smart charge Built-in circuit protection BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp **Brand:** black+decker **Price:** £41.25 **Availability:** ✅ In Stock ## Summary > 🔌 Keep your ride ready, always charged, never left behind. ## Quick Answers - **What is this?** BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp by black+decker - **How much does it cost?** £41.25 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/81903514-bm3b-fully-automatic-6v-12v-battery-charger-maintainer-with-cable) ## Best For - black+decker enthusiasts ## Why This Product - Trusted black+decker brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Safety-First Design:** ETL certified with built-in protection against overcharging, reverse polarity, and short circuits—charge with confidence. - • **Smart Float Mode Maintenance:** Automatically stops charging and switches to float mode to keep your battery at peak capacity without overcharging. - • **Universal Connection Options:** Includes sturdy battery clips and O-ring terminals for versatile, secure connections on any battery type. - • **Compact & Convenient Mounting:** Built-in mounting bracket lets you place the charger exactly where you need it—garage, workshop, or storage. - • **Effortless Dual Voltage Charging:** Seamlessly switch between 6V & 12V batteries with a simple selector—perfect for all your vehicles. ## Overview The BLACK+DECKER BM3B is a compact, fully automatic 1.5 Amp battery charger and maintainer designed for 6V and 12V AGM, GEL, and WET batteries. Featuring dual connection options (battery clips and O-ring terminals), it automatically switches to float mode once fully charged to preserve battery life. ETL certified for safety, it protects against overcharging, reverse polarity, and short circuits. Ideal for maintaining batteries in vehicles stored long-term, it includes a built-in mounting bracket for easy installation and comes with a 1-year limited warranty. ## Description 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. Review: Battery Charger - Reliable, easy to use, durable Review: Working well for 8 years now - 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 desertcart these days. ## Features - Charges and maintains 12 volt and 6 volt AGM, GEL and WET batteries - Easy connection to vehicle battery using battery clips or O-ring terminals - Stops charging automatically when battery is fully charged or topped off, switching to float mode monitoring - Built-in circuit protection guards against overcharging, reverse polarity, or short circuit; ETL certified for performance and safety - Mounting bracket built-in to charger for convenient placement - Fit type: Universal Fit ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0051D3MP6 | | Amperage | 1.5 Amps | | Best Sellers Rank | #18,860 in Automotive ( See Top 100 in Automotive ) #105 in Battery Chargers | | Brand | BLACK+DECKER | | Built-In Media | charger | | Color | Multi | | Compatible Devices | Vehicles and equipment that use 6V or 12V AGM, GEL, or WET batteries | | Connector Type Used on Cable | Battery Clips, O-Ring Terminals | | Current Rating | 1.5 Amps | | Customer Reviews | 4.4 out of 5 stars 13,246 Reviews | | EU Spare Part Availability Duration | 10 Years | | Input Voltage | 12 Volts (AC) | | Item Dimensions D x W x H | 5"D x 1.6"W x 2.6"H | | Item Type Name | Battery Maintainer/Trickle Charger | | Item Weight | 1.2 Pounds | | Manufacturer | Baccus Global LLC | | Mfr Part Number | BM3B | | Model Number | BM3B | | Number of Ports | 1 | | Output Voltage | 12 Volts (DC) | | Product Dimensions | 5"D x 1.6"W x 2.6"H | | Specification Met | ETL | | UPC | 814632012306 885911216357 | | Unit Count | 1.0 Count | | Warranty Description | Limited One Year | ## Product Details - **Brand:** BLACK+DECKER - **Color:** Multi - **Item Weight:** 1.2 Pounds - **Output Voltage:** 12 Volts (DC) - **Product Dimensions:** 5"D x 1.6"W x 2.6"H ## Images ![BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - Image 1](https://m.media-amazon.com/images/I/81xP3NK1SmL.jpg) ![BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - Image 2](https://m.media-amazon.com/images/I/61AZWtGGFSL.jpg) ![BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - Image 3](https://m.media-amazon.com/images/I/712Vxf+NeRL.jpg) ![BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - Image 4](https://m.media-amazon.com/images/I/91iQpb4z4NS.jpg) ![BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - Image 5](https://m.media-amazon.com/images/I/81W8vrHDCdL.jpg) ## Available Options This product comes in different **Style** options. ## Questions & Answers **Q: How is it compare to Axtra 3.6 amp car battery charger?** A: This is only a 1.2A charger. Yes, Mr. Krueger, IT IS A BATTERY CHARGER. The more amperage, the better because a higher amperage charger will charge much quicker. I really can't believe that there are so many chargers out now with such pathetically low amperages... **Q: How is Black Decker 1.5 amp battery charger compares to Axtra 3.6-amp battery charger maintainer?** A: The Black & Decker battery charger has been out a while and gets good ratings. The Axtra 3.6 battery is new but has very good specifications. If you are in an area with wide temperature ranges, the Noco Genius 5 has a temperature sensor so it's operational range is -4 F to 110 F. **Q: What is the float voltage? When the charger indicates it is done charging what is the voltage of the battery?** A: As this is a "true float charger", the maintenance voltage is dependent upon the Full Charge Voltage (FCV) of the battery, which is usually anywhere from 12.6 to 13.2 depending on battery design and how much sulfation has taken place on the internal plates. Unlike chargers that use a "trickle maintenance mode" with a fixed voltage output, the B&D unit senses when the battery will accept no more current (full charge) and then stops sending voltage and rests until the battery voltage drops below that threshold and then it should "wake up" and start charging again. **Q: how fast does it charge** A: Math will tell you. If it's a 1.5 Amp charger and you're trying to charge a 7 Ah battery, 7/1.5 = 4.7 hours till full charge. If it's a 50 Ah battery, 33.3 hours till full charge (50/1.5 = 33.3). But, there's typically about a 20% efficiency loss, so it's really more like 5.6 hours and 40 hours for these examples.However, you may not need full charge if you're wanting to charge a battery that will be installed in a car or bike that has an alternator which will continue to charge it while it's running. Also, it's not a good idea to use too powerful of a charger to charge the battery quickly. For example, using a 5 Amp charger on a 2 Ah battery will charge it VERY quickly, but could overheat and shorten the live and cycles of the battery. Different battery chemistry allows for different charging amps. But in all cases, low and slow is better for the life of the battery and safety than fast charging. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Battery Charger *by R***R on May 4, 2026* Reliable, easy to use, durable ### ⭐⭐⭐⭐⭐ Working well for 8 years now *by M***R 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. ### ⭐⭐⭐⭐⭐ Solid. Works. *by N***F on April 18, 2026* way better and cheaper than what you find in most autoparts stores ## Frequently Bought Together - BLACK+DECKER BM3B Fully Automatic 6V/12V Battery Charger/Maintainer with Cable Clamps and O-Ring Terminals, Multi, 1.5 Amp - SinLoon Cigarette Lighter SAE Battery Charger Cable,12V 15A Cigarette Lighter Plug to Waterproof SAE Quick Release Adapter Extension Charging Cable with Fuse and LED Light(10FT,3 Meter) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/81903514-bm3b-fully-automatic-6v-12v-battery-charger-maintainer-with-cable](https://www.desertcart.co.uk/products/81903514-bm3b-fully-automatic-6v-12v-battery-charger-maintainer-with-cable) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-24*