The BLACK and DECKER BM3B is ideal for keeping your 6-Volt or 12-Volt battery fully charged when not in use. Simply plug the maintainer into any AC outlet and connect to your battery in any one three ways: Battery clips 12-Volt Dc accessory plug or the battery terminal rings. The BM3B will do the rest of the work, monitoring your battery with the Automatic micro processor, so that you can never over charge the battery.
(41 reviews) 41
97%of customersrecommend this product37 of 38reviews
Rating Breakdown41 reviews
97%of customersrecommend this product37 of 38reviews
Have a car that is sitting in garage now and the battery is slowing being tapped , so I hooked this up and in about 24 hrs. , brought it right back to snuff...I followed the next week and it only took about 4 hrs. to top it,,,,,,.I do agree with others the volt. selector switch is too easily moved from 6-12 volts....but just be careful or tape over it....It's better to slow charge a battery than rapid with higher amps in the long run.....and this is about 1.2 amps..vs.. 4-10 amp units....
I found myself in a situation where I had to store my motorcycles remotely, while I moved cities. At home I used a an ultimate unite that I swapped between 3 bikes, but with a move I had to store the bikes a 2 hr drive away for several months and I had to find an alternative, reasonable cost solution. The ultimate is a great device also but way more costly. I decided to order two of these B&D units as I have always been happy with their products. I researched the background and figured if B&D bought the company that designed these they must be OK. I hooked up two of my bikes with these units and left them for 5 months alone in storage hoping I would not need to buy new batteries when I got the bikes out.
When I got back, the green LEDs were illuminated on both units. Turned the keys and both bikes started up like champs. Batteries were strong cranking and kept fully charged. I have since moved the bikes to the new house and these units are on them constantly while we endure winter in the east.
really really satisfied with this product. At 20 bucks each I already exceeded the value from them in saving me over $200 cost in new bike batteries. They saved me in this storage and now are holding me through winter. Enough said!!
Pros: Easy to Use, Easy to Install, Nice Design, supper price
This is the best battery maintainer on the market. A good friend of mine recommended it as it is all electronic and does not require a transformer. Also Home Depot had the best price and I picked it up at my local Home Depot.
Bought the 6/12 volt battery maintainer so I would not have to worry if there was enough charge on my battery to start my "classic" car. My car sits in a separate garage and I don't start it every week, sometimes not for a few weeks and at times the car has a hard time starting and I have to hook up the charger or jump it. Now with the battery maintainer, I never have to worry if there is enough juice to start my 1937 Dodge!!!! I wish I would have done it years ago.
I use this charger on my lawn tractor to keep the battery fully charged, especially in the winter. It works well for me, as it is small, portable and has long enough leads to fit from under my carport to the tractor. Best of all, the price is very affordable and it is very easy to use.
Mr. T El Paso, TX
Pros: Durable, Easy to Use, Easy to Install, Good Size & Weight, Nice Design
I got this from Home Depot with the best price on market, June-2012. Good luck looking for equal or better price elsewhere. It can be found in hardware department where B&K are display. You may want to call first before heading there, not much left. It supports three style of connections, battery terminal, jumbo alligator clips and accessory outlet connections. Me and specially my wife likes the latter.
I test this charger with car battery about 85% full, meter reads 1.5 amp. and reducing over time as the battery is taking charge, during which I recorded 14.7 Volt. This does not imply charge current can't reach factory specification limit, just the nature of current normally reducing approaching full charge. It determined the battery have reached full charge then mode switch to maintenance holding a voltage measured at 13.6~13.7 Volts which is also the open circuit output voltage. The case temperature well into normal charge was noticeably warm to touch but not hot enough to cause my concern on smoke hazard. The case temperature drop next to ambient about half hour into maintenance mode.
I inspect the guts have found a switching regulator, the kind of design we normally find in laptop ac adapter power supply, all have efficiency of 80% or higher. In addition to that is a relay switch toggling between two charging modes. Pulsing green inidcator in normal charge and steady in maintenance and dc open circuit. I am very pleased of what I find inside and out (accessories) for the price I paid at Home Depot. If I buy the these accessories harness separate would cost me more than I paid for this package. Hope this helps.
Our home has built-in 12vdc LED lighting in most rooms that operates from a large, central deep cycle battery. It can operate our house for about a week before needing to be topped off (typically @ 70% charge). The battery was rotated with another one in our solar powered workshop and recharged away from the house. A minor hassle - but worth it for clean, bright Off-Grid illumination. Attaching this BM3B trickle charger to the central battery has made it in effect a Uninterrupted Power Supply - keeping the voltage close to a healthy full charge at all times and eliminating the weekly switch-out. And when the grid goes down for an extended period (as happens in our rural area a couple of times a year) we still have the solar recharge option. It installed very easily. Took a few hours to top-off the deep cycle - but went into float mode overnight and kicks back into trickle charge mode for a few hours after a night of using the lights around the house. Its case gets slightly warm when charging. Expected. Mounting screw holes are very useful in our application. I agree about the 6v/12v switch feeling a little cheap - it needs to be more "clicky" to instill confidence that it won't easily/accidentally be knocked into the wrong voltage setting. Only thing yet to be proven is it's long-term serviceability. Here's hoping - it's a very simple and elegant solution!
Pros: Easy to Use, Sturdy, Easy to Install, Good Size & Weight, Nice Design, value
Have had one for about a year on a boat battery and just bought another for other vehicles around the house. No complaints. Just make sure to check the voltage switch as it easily moves from 6-12volts (like if you brush against it) but has never moved during a charge.
Pros: Easy to Use, Easy to Install, Looks Great, Good Size & Weight, Durable, Lots of Features, High Quality, Nice Design
every one knows that the extreme cold is very hard on batteries. i've always had problems with my 4 wheelers and tractor batteries going dead over the cold winter months. not this year. keeps them fully charged and ready to start for when snow falls. and we got a lot of snow this year. i never had to jump start a unit. i like that it had 3 different ways for connections. you could actually rotate the unit weekly to charge different pieces of equipment. it was pretty inexpensive so i just bought 3 of them. its a lot cheaper than a $65 ATV battery.
Pros: Lots of Features, Easy to Use, Easy to Install, Good Size & Weight
Bought this to keep my boat's battery charged last August. It worked fine until last month,when I plugged it in to my power outlet at the pier,and no lights showed on the unit---neither charging nor fully charged. Up until then it had always started with the blinking green light,eventually switching to solid green when charged. While it is still under warranty, it cost me nearly 1/2 the cost of a new unit to ship it back to the warranty center in Florida,which I did on 7/27 and they received it on 7/29 according to USPS,but I have not heard anything about the unit since it arrived there 2 weeks ago today.
Like Frankenstein.... This trickle charger brought my battery back to life. It's easy to use and works great. I purchased this for my Toyota land cruiser which hardly gets any use. And every time I need to take it for a drive it starts without fail... and for the price... you can't beat it.
I have 2 of these and use it to keep my quad and jet-ski batteries charged. Light on unit will tell when it is fully charged or is in the charging state. Has different type on connections where you can permanently attach an end to the battery and have a quick connect.
Pros: Durable, Easy to Use, High Quality, Good Size & Weight, Nice Design