NOCOGENIUS1: 1A 6V/12V Smart Battery Charger – Automatic Maintainer, Trickle Charger & Desulfator with Overcharge Protection & Temperature Compensation – For Lead-Acid & Lithium Batteries

There is a reason the NOCO GENIUS smart car battery charger is so popular. It works well, it is very simple to operate and solves the major headache for car owners who must leave their vehicle unattended for weeks or months at a time.It used to be when you turned off your vehicle and removed the key, all power was off and there was no drain on the battery. Not anymore, there are all kinds of things that always stay on now. If you have a newer vehicle, you know what I am talking about. I went away for just a couple weeks and when I returned my car would barely start. I didn't think too much of it but when I went away on a 6 week trip this past summer, I came home to a super dead battery in a 3-year-old car with 20K on it. Nothing worked, no lights, no locks, no trunk, nothing… I even had a very difficult time getting into the electronically assisted doors. Now to be honest, after a couple weeks away, my car sent me an email saying it was shutting down systems to save the battery. When I returned, I measured the battery voltage, and it said 3 volts, it was so dead. I put a charger on it overnight and the next day it was only 6 volts, and it still would not turn over. I was able to get it started with one of those new micro jump start devices that I remembered I had (amazing little devices) and I took it to the Lincoln dealer and they replaced the battery under warranty but said anytime I go away for longer than a week to put a trickle charge on it or remove one of the battery posts to prevent the battery from completely discharging but they really didn't like that idea and preferred the trickle charge because a bunch of electronic settings will need to be reset once you hook it back up. Moreover, I am seeing the latest luxury vehicles now are coming with two batteries, one just as a starting battery and a separate "house" battery to run all the electronic stuff that is running in the background. That is the way yachts do it. All these car apps that talk to the car via satellite, the various alarm, safety and convenience stuff will kill your battery if you don't regularly use your vehicle, it is that simple.While this can charge your battery from a very low state, keep in mind it will take a very long time, it really is designed only to “maintain” your battery, and does not do an efficient job charging it from a dead state. Batteries require a charging “profile” depending on the type of battery, most have an initial heavy duty “bulk charge” phase followed by a “float charge” or a maintenance level. This charger only addresses the maintenance charger of about 1 amp or so.So, what you want is a SMART trickle charger that is smart enough to know the battery type you have AND smart enough to know when to stop and start charging at a very low amperage just enough to keep your specific battery type at its optimum charge level for the longest lifespan. The NOCO GENIUS does just that. What I like about it the most is that it is super simple, so simple my wife can do it without freaking out about doing harm to anything. The other thing I like about this is the cost. It is very reasonable and on sale it is a screaming buy. Everyone needs this IMO. Get it and it will save you way more $ than it costs, as well as a massive headache when you come home from a vacation to a dead vehicle that will not budge, and you must arrange to have it serviced in your garage!Positives:• Effective trickle charger• Simpe to connect and operate• Will not do harm to your battery (or cause a fire) from overcharging• Safe for long periods of unattended operation• Reasonable costNegatives:• Not the best charger for charging batteries from a very low state• Will not “jump start” your vehicleI think you will like this useful item, and it will provide many years of service for a modest price.5 stars

I picked up the NOCO GENIUS1 to maintain the batteries on my motorcycle and ATV during the off-season, but it’s quickly become one of the most versatile and dependable tools in my garage. Whether you’re maintaining a deep-cycle battery, reviving a nearly dead car battery, or just preserving battery health during long storage periods, this compact charger punches far above its weight.Ease of Use:Out of the box, the instructions are clear, and setup takes less than five minutes. The plug-and-play design is perfect, even for those unfamiliar with battery maintenance. The mode button is intuitive, and the LED indicators provide clear feedback on charge status, voltage type, and battery condition.Performance:This little 1-amp unit handles a surprising range of batteries. 6V and 12V lead-acid, AGM, and even lithium. I used it on a 12V lawn mower battery that had dropped below 8 volts. Most trickle chargers won’t even recognize a battery that low, but the Genius1’s force mode kicked in and brought it back to life over the course of a few hours.Its automatic desulfation mode is a quiet feature that’s easy to overlook but incredibly valuable for extending battery life. I’ve noticed improved cold starts and battery performance across the board since incorporating it into my maintenance routine.Build Quality & Size:The Genius1 is rugged and compact, about the size of a smartphone and built like a tank. The cables are flexible but sturdy, and the clamps feel solid, not cheap or flimsy like on other budget chargers. It stores easily in a glove box or tool drawer.Safety & Intelligence:Unlike traditional chargers, this unit is fully automatic and spark-proof, with reverse polarity protection and temperature compensation. That peace of mind makes it an ideal choice not just for enthusiasts, but also for less experienced users who want something safe and reliable.Versatility:So far, I’ve used it on a motorcycle, ATV, riding mower, and a spare car battery, and it handled each scenario without a hitch. It’s perfect for maintaining seasonal or secondary vehicles and works great as a “set-it-and-forget-it” battery maintainer.Final Verdict:The NOCO GENIUS1 is one of the most cost-effective investments I’ve made for vehicle maintenance. It’s smart, safe, and impressively capable for its size. Whether you’re a seasoned DIY mechanic or just looking to avoid a dead battery during winter, this little device earns a permanent place in your toolkit.

Received and used the very next day, after a jump start got me going. But I apparently didn't drive long or allow it to charge enough. I bought it to use as a maintenance charge in the car I store over winter (my previous one stopped working, thus the need to jump start). I used it to charge the battery to full--the lights would come on but not enough juice to turn over. Within twelve hours it was charged and I was on road. I have no idea how long it actually took because I went to bed but it was between 6 hrs when I first checked and the 12 hr mark when I checked/removed the charger.This will be a nice upgrade to use as a maintenance charger in winter. Worth the money.