21 of 26 people found the following review helpful.

I Really Like The Genius10

We have a 2005 Cadillac STS we keep in the garage and rarely drive. We told ourselves we would drive it every couple of weeks to stop the battery from going dead, but that never happened. A year ago, we bought a new battery. Now the new battery has died. I called AAA to start this newer dead battery which had been sitting undriven for a couple of months and AAA got the battery working and I was able to start the car. The guy they sent recommended I purchase and use a “trickle charger”, so the battery won’t drain just sitting in the garage.

It is now about 3 months later, and the battery is dead again. I thought I am going to have to call AAA again, but before I did that, I decided to look up trickle chargers that had been recommended, and one of the chargers that came up in my search was the Genius Chargers. I started reading about them and thought maybe I can get my dead battery to come back to life without calling AAA.

I purchased this Genius2 to charge my car battery still attached to the 2005 Cadillac STS. I am not that mechanical, so my first obstacle was trying to figure out how to get to the battery. I never was able to figure how to take off the battery cover or shield? Tried YouTube, tried Google, ugh!! I needed to be able to figure out what type of 12V battery it was. I was finally able to pull the battery cover back enough to read that this was not an AGM and was a wet 12V battery. Now I could figure out some other specifics about the battery, so I knew the 12V battery setting to charge it.

I read up on this charger both from the company and from the reviews before I received it. I was ready when the charger came in. I figured the battery is dead, so it would take a while.

I hooked up the Genius 2, making sure to plug in the battery first, before plugging the charger into the electric based on some reviews I read. Pressing the mode button didn’t work, but I was able to get “force mode” going for 5 minutes. After 5 minutes I was now able to normally charge the battery, or at least I thought.

20 hours later and I checked the Genius2, and I still had only one red light slowly pulsing red. I write to NOCO Genius2 support chat and they respond by email within a few hours, “If the battery was severely depleted or sat undercharged for a period of time the charger will spend more time on the first few charge steps as it attempts to recover and desulfate the battery and restore any damage that may have happened”. He went on after describing his experience. “…So, the charge time will vary depending on the condition of the battery. I would allow the charger to complete the first few steps to restore the battery. The charger does not have set times for each step, rather it will progress through the steps according to how the battery accepts the charge.”

After letting it sit overnight (now the second night), I still only see the one red pulsing light indicating I don’t have 25% of the battery charged, so I figured I will just wait.

It has now been a total of over 36 hours and still only one red pulsing light on only the first light (still less than 25% charged). I will be so happy when the I see the second light, so I know it is beginning to work!

I don’t know at 39 hours, I decided to try to jump the car with a GOOLOO TITAN Series GP2000 Jump Starter my wife had purchased 3 months ago. I took off the NOCO Genius2 and hooked up the Jump Starter. It worked and the car started with the Jump Starter on my car. I took the Jump Starter off the car and left the car running for 30 minutes.

I turned off the car and tried to start it again without a Jump Starter. It didn’t start. I placed the NOCO Genius2 back on the car. it was still less that 25% charged with just the first light pulsing. Now I will wait again and see what happens, at least I know the car will start with a jump, and without me calling AAA. We don’t really use the car, so I will try to be patient while the Genius2 slowly does its work.

A few hours later, I got tired of waiting and thought maybe the car itself, still attached to the battery was drawing from the battery was drawing too much energy and the battery wasn’t charging for that reason. I reasoned 10 Amps was more than 2 Amps so I bought the NOCO Genius 10 to see how that would work. It arrived within 12 hours and my NOCO Genius 2 was still only showed the one red flashing LED light.

After about 50 hours of charging, the NOCO Genius 10 arrived. I replaced the NOCO Genius 2 with the NOCO Genius 10 and the battery’s state of charge was so still so low, the Genius 10 would not allow me to set the battery to the 12V setting. I had to force charge the battery. Obviously, the Genius 2 did not provide enough energy after 50 hours for the battery to even be strong enough to be recognized by the new NOCO Genius 10.

The lights on the Genius 10 after a few hours stayed with just the first light blinking and now the second light would start to go on and it would go back to the first light blinking again. Every minute or so the second light would start to go on and then stop. I let it charge overnight.

Again, I am not that great mechanically, but I am tenacious. I reasoned it was time to charge only the battery, without the battery attached to the 2005 Cadillac STS. I had just read that some cars can draw a charge from the battery even though the cars are off.

Nothing is ever that easy. With a regular 12V car battery you would just remove the connection to the car from the battery post, but this battery was a side charge, and I was charging the battery, connecting the charger to a bolt that was also attached to wires from the car that went into the side of the battery. When I removed the car wires there was now no posts only a positive and negative socket the car wiring attached to from the car’s built-in bolt.

To recap, I had been charging the battery connecting it to the bolt that went into the car from the car wiring attached to its own positive and negative bolts. While jump starting the car worked, I knew that something was stopping the battery from receiving and keeping enough of the charge from my Genius chargers to recharge the nearly dead battery. I reasoned that the battery was not receiving enough energy from my chargers to overcome the draw from the car and charge the battery at the same time. How could I remove the car wiring from the car and still charge it without a post?

I researched and found I just need to purchase two 3/8” bolts and put it into the battery sockets. The bolts needed to be long enough to have some of the bolt outside the battery so I could now attach the Clamps from the Genius 10 to my bolt in the battery and remove the rest of the car wires.

It worked. It has now been 5 days since I purchased the Genius2, and 2 days since I purchased the Genius10 and now within two or three hours of just charging the battery with the Genius10 I am now 100% charged. I now have 2 steady red LED lights, 1 steady orange LED light, and 1 pulsing green LED.

A few hours later, it is just 1 green LED light pulsing.

2 days later, I noticed the 1 green LED light is just a steady on. I noticed no pulsing, but a few days later, I noticed it pulsing again. I figure it is working fine.

My problem now is what is causing there to be a drain on my battery with the car off? How bad is it? To fix this and figure this out, I will have to purchase a multimeter, ugh!! I think for now I will just keep only the battery hooked up to the NOCO Genius 10 and only hook the battery up to the car only when I need to use it, because we are just storing the car, and this will help maintain the battery.

As a user with enough knowledge to be dangerous, I really like the NOCO Genius 10. It has so many built-in automatic safety features. Like if you accidentally hook up the positive and negative to the wrong part of the battery, it warns you and does not complete the connection! I believe the Genius 10 has enough amps to be worth the buy for a car battery. The NOCO Genius 2, may or may not be strong enough to work on your car battery if you hook it up directly only to your car battery, but I recommend the NOCO Genius 10 for your car battery. My review of the product is overall very good. I wish the Guidebook that comes with the product describing the LED lights matched the description of what 100% charged shows on the company website under “Charge Levels” on this web page: https://no.co/genius10.

Yes, I recommend this product.