Battery Tender Plus 12V 1.25A Smart Battery Charger & Maintainer for Motorcycle, ATV, UTV - Automatic Float Charger 021-0128 - Perfect for Winter Storage & Long-Term Vehicle Maintenance

I am charging the battery for my motorhome engine and was looking at the latest chargers since mine is getting up in years and has been used many times. Bought it in 2013. From my experience this is a nice easy to carry on RV trips charger. It has never failed to do the job although sometimes it may take a day to charge a large battery.I was not surprised to see all the negative "Top Reviews" as Amazon calls them. Learned when getting a business degree many years ago that the customers with bad experiences yell the loudest and are most listened to. Personally I do not read the "Top Reviews" - all Top means is got most views, nothing to do with quality of review so I always use Most Recent. I see even battery chargers much more expensive than this one get an equal amount of negative "Top Reviews".Best smart trickle charger for money. I use one Battery Tender Plus charger to maintain a SUV in Colorado mountains and another for elderly mother-in-law’s car in Philly. Both vehicles are stored in garages and can go 3-6 months without use. Batteries are beautifully maintained with minimal electrolyte loss and no corrosion. (Tip: Use only indoors, use only distilled water to top off batteries, FILL vehicles with fuel, and slightly over-inflate tires before storing.)I buy longer cables to run overhead from the charger through a partially open vehicle window to the cigarette lighter. No problems.Remember that the Battery Tender Plus is designed to maintain healthy batteries, not to revive heavily discharged or dead batteries.Really good product. I use it to keep my sedan's battery topped off in between driving it every 2 weeks. Without this, my battery would run dry (and it has before) because of all the tech they cram into modern cars. If you only use your vehicle a few times a month, you should invest in one if these. It comes with a quick connect hookup, which I had my mechanic install for me. Now all I have to do is pop the hood and plug it in when I am done driving.This device is one of the less aggressive models. I know that there are faster charging rates when you use a higher amperage, but I don't need my battery to be charged up really fast. I also figure that it must be better for your battery to charge at a lower amperage when possible.This model is for trickle charging, which I think it does well.This was recommended to me by a friend that works for Michaels Corp they use them all the time I have one on my 4 Wheeler all the time and works good so farmy last charger last for 12 years very good companyI have a couple of collector cars that sit too long. I have used Battery Tenders for years, and have found that batteries have typically lasted for about 10 years while using this product. If you just leave a car battery sit without charging, they will wind up discharged, then you do a fast charge to get the car started and drive it; then you let it sit and get discharged again; in this mode car batteries are lucky to make it 3 years. It's not a battery charger (only 1.5 amps), but it is a great battery maintainer.Item was exactly what we wanted.An ...AGM charger...is set to a different specs and needs of the AGM battery. So here a few facts:GM technology became popular in the early 1980s as a sealed lead acid battery for military aircraft, vehicles and UPS to reduce weight and improve reliability. The sulfuric acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.The leading advantages of AGM are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs than the flooded, but cheaper than the gel battery.Most AGM batteries are mid-sized and range from 30 to 100Ah. They can also be found in UPS, big and small for stationary and deep cycle use. They are commonly built to size and are found in high-end vehicles to run power-hungry accessories such as heated seats, steering wheels, mirrors and windshields. NASCAR and other auto racing leagues choose AGM products because they are vibration resistant.AGM is the preferred battery for upscale motorcycles. Being sealed, AGM reduces acid spilling in an accident, lowers the weight for the same performance and allows installation at odd angles. Because of good performance at cold temperatures, AGM batteries are also used for marine, motor home and robotic applications.AGM is making inroads into the start-stop function of cars. The classic flooded type is simply not robust enough and repeated cycling causes a sharp capacity fade after only two years of use. (See BU-806a: Heat, Loading and Battery Life.)As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive. (See BU-403: Charging Lead Acid.)AGM and other sealed batteries do not like heat and should be installed away from the engine compartment. Manufacturers recommend halting charge if the battery core reaches 49°C (120°F). Table 1 spells out the advantages and limitations of AGM.AdvantagesSpill-proof through acid encapsulation in matting technologyHigh specific power, low internal resistance, responsive to loadUp to 5 times faster charge than with flooded technologyBetter cycle life than with flooded systemsWater retention (oxygen and hydrogen combine to produce water)Vibration resistance due to sandwich constructionStands up well to cold temperatureLess prone to sulfation if not regularly topping chargedHas less electrolyte and lead than the flooded versionLimitationsHigher manufacturing cost than floodedSensitive to overcharging (AGM has tighter tolerances than gel)Capacity has gradual decline (gel has a performance dome)Low specific energyMust be stored in charged condition (less critical than flooded)This charger is perfect for all batteries on vehicles and easy to fit. The only point I would like to make is that on the description it does not mention that it is 120v. I had to buy a voltage dropper which was not an issue apart from the fact that had I been aware I could have ordered that at the same timeProduct is 120V only, with a US-style mains connector. This has been deliberately mis-sold into the UK market via amazon.co.uk (the clue is in the name!). Stop listing this product in unsuitable markets, otherwise you're unnecessarily increasing your carbon footprint and wasting everybody's time and money.Ordered Dec. 23 to replace the 4 1/2 year old BatteryTender that died on me. With my car stored 1 1/2 hours drive north of Kingston, and all the winterweather, I couldn't get in the cottage road until Feb. 2....a friend slid off the road taking 24 hours before a tow truck could respond. Then, the BatteryTender didn't work; at all.The company's response was "Sorry, this order is not eligible for a refund under the A-to-z Guarantee"; meaning 30 days. Translation: refunds absolutely must be requested within 30 days. Delving into Amazon's website, I did indeed confirm that is policy; absolute policy, it appears.I've contacted the company on their "warranty" website and will have to chase that option down at my expense.So, just a warning...."Sorry, this order is not eligible for a refund under the A-to-z Guarantee."No complaints, works exactly as advertised and is really easy to use. Practically foolproof, really.EDIT: We recently experienced a bout of extreme cold, and I discovered that the battery tender will not charge a battery in cold conditions. I would connect the leads and it would appear to be charging the battery at first, but after a minute or two the red and green lights would flash, indicating an error. Mind you it was -50c outside. After bringing the battery tender inside to warm up, it worked perfectly fine.I was very leery with regards to purchasing a battery charger as I have heard a lot of horror stories. There is tons of information about different chargers on the market and I spent hours reading and watching videos. This particular charger is the only one that continued to get my attention. I wanted one that I could connect and forget about and I also wanted one with no options (no switches, dials, buttons etc.). All it has is 2 lights - one red and one green. The first time that I hooked it up, it took almost 36 hours to charge the battery. This was perfect because I was confident that the battery was given a good deep charge.