NOCO GENIUS2: 2A 6V/12V Smart Battery Charger – Automatic Maintainer, Trickle Charger & Desulfator with Overcharge Protection & Temperature Compensation – For Lead-Acid & Lithium Batteries

I would go through the problem of not having to use my car for long periods of time which would ultimately drain my battery. I would suffer through by using a portable jumper, but the problematic battery would persist. I started investigating in alternatives like unplugging the battery from the car while it is not in use, but I would still have to get a new battery regardless. I luckily stumbled into this product that changed the game entirely.My battery was absolutely drained and would not even crank the starter motor. I got this product and set it up using the instructions and it charged up right away. It was very practical to use with ease. All that is needed is to latch on to the terminals in the appropriate order, plug it in, and in the push of a button it revives the battery. I was able to recharge my battery back to 100% over time and it starts without a hitch. I would just leave my battery connected to this product and check up on it every once in a while. Very simple, very effective. Highly recommended.

Our newer cars have many features that draw down the battery. We now drive short distances in this small city so there is no charging beyond the current being drawn as I understand it. So I hang this tender on overnight about monthly and have no battery problems.

Easy set up and works as advertised. Use it on my car that I leave parked majority of the time and my car battery has been charged up when I need that car.

Keeps my project car charged and ready to go. Very lightweight and compatible with any battery. The LEDs are bright and and the connectivity of the probes are easy. Good value for the money.

I have had the Genius2 since July of 2024. The following is my experience so far.I have found it very easy to use on the 12V Batteries of my two Ford Escapes (2010 Model and 2014 Titanium Model). Both these are ordinary Lead-Acid Batteries (and not AGM, Lithium or any other fancy battery). When we start the Genius2 up by connecting the Output Alligator Jaws to the Car Battery Terminals, I believe the "default" is set to the ordinary "12V Battery Mode". Therefore, we do not have to set it to the 12V Mode ourselves.To completely "top off" any Battery, the best thing to do is to leave it connected throughout the night. I will say that it will take at least 12-hours to completely top-off any normal 12V Car or SUV Battery. Of course, if one is in a hurry he can disconnect it and drive off at any point he wants, as long as he is confident that there is sufficient power in the Battery to restart while trying to get back.The Charger has 2-Red Light Indicators, then an Orange Light and then the Green Light (showing Full Charge). It starts with the first Red Light on the left and then as the charge progresses, it shows 2 Red Lights, then the Orange Light comes up and then finally the Green, all of these being "additive". As long as there are 2-Red Lights, one can disconnect and drive off if the car is needed immediately for some reason; there should be enough Battery Power from then onwards to start and stop the car several times.I have used the Genius2 many times over the last year, merely to top-off my Batteries. The only thing is, because this is a "trickle charger", it takes quite some time to do its job. We have to be patient with this model.However, I have to mention one "failure" I have experienced. My 2010 Ford Escape Battery had completely died once because I had not used it for over a month and forgot to top-off the Battery using the Genius2. I have to say that the Battery was "nearly dead" - with Voltage well below 1-Volt even I think. So, I connected the Genius2 wishing that it would recharge it completely. However, that it failed to do because it did not even "sense the presence of the Battery". The Genius2 remained in "Standby Mode" and the 12V Mode did not come up.At this point, I used the "Force Mode". To do that, we have to "keep pressing the Mode Button for 7 seconds". When we do that, all the lights start flashing. At this point, pressing the Mode Button again gives us the 12V Mode. I got up to this point. However, after trying to go through the "cycle" several times (with some lights flashing as is normal), the Genius2 simply returned to "Standby Mode". I did this many times - every ten minutes - for several hours, hoping it would come to a point when it would begin charging the Battery but it did not. The "Force Mode Operation" failed for the Genius2 (in that condition of my Battery, which was nearly dead, I have to add).Finally I "Jump Started" my Car and took it out for a drive for about 30-40 minutes. After coming back into the garage I stopped the car and then tried starting again. The car started normally. That told me the Battery now had "sufficient power" back again to start the car a few times.After that, I reconnected the Genius2 just to see what happens. This time it did sense the Battery, went to the default 12V mode immediately and started charging the Battery. It was working once again - to my great relief. I kept it connected and after about 12-hours of charging, the Green Light came up - telling me that the Battery was now completely "topped off". So, the Genius2 did do its job but it required "some Voltage" in the Battery to start the process. My Battery had drained so much that even the "Force Mode" could not charge it. So, I consider it to be a case of "failure" for Genius2. That is why I haven't given it a full 5-Stars.My question remains as to whether a "Genius5" would be able to do the job in "Force Mode" or not for this kind of Battery Drainage, where the Voltage had gone to nearly "Zero". The Genius5 has "5 Amp" capacity and maybe that would do the job. I am not sure of it though because I do not have the Genius5. The question also remains in my mind as to whether a Genius10 would do the job in this condition, if the Genius5 also fails in the situation. Maybe others with a similar experience can tell us more.My SUGGESTION to Potential Buyers is to skip the Genius2 and go for Genius5. For only $20 more, get the higher model. Having higher Power, it should perform better and top-off your Battery in "less time" compared to the Genius2. There is also hope that if your Battery really goes down to almost "0", the "Force Mode" of Genius5 will still be able to revive the Battery and recharge it fully. I am not sure of it as I said above but at least, it has more of a chance compared to the Genius2.The Genius5 also has an "additional mode" and that is the "Repair Mode". Apparently, it can execute "repairs" deep down in the Battery Cells which improves Battery Performance in a big way. At least, that is the claim in the advertisement. The Genius2 does not have that ability at all.HOWEVER, please NOTE right away that you SHOULD NOT attempt to use the "Repair Mode" while the Battery is still connected to the Car. You have to detach the Battery from the Car to do it. To do that, you can only disconnect the "Negative Terminal" of the Battery and keep it away from the Battery (it should not touch anything on the Battery). The Battery can still sit inside the Car; you do not have to remove it physically. Then you can use the Repair Mode of Genius5.Of course, as soon as you disconnect the Battery the "Car Electronics Memory" gets wiped out and so, before you do that you have to ensure that a "steady 12V supply" keeps going to the Electronic Circuit. The way to "input" 12V into the Electronic Circuitry is through your Car's OBD-II Socket. I have identified several, inexpensive components to be able to feed a steady 12V supply through the OBD-II into the Car's Electronic Circuitry but I have not used it yet and therefore, will not recommend them right away. This is just to make readers "aware" of the problems of disconnecting a Car's Battery without feeding 12V into the Electronic Circuitry to maintain the "Settings" stored in the Memory, and that relatively inexpensive items are available to be able to do that (say another $50 or so maximum).In any case, I think the Genius2 is a good product which I have used for nearly a year. I will suggest though that if you were going to buy it, think hard about buying the Genius5 instead.

NOCO make the best products… I use this on a vintage car that’s stored most of the year… no issues cranking once a month.

Works great to charge up my car battery. Nice to have in the car in case of emergencies.

Great battery charger