I know that my battery will always be fresh and topped off, even in the coldest New England winter nights

If you own expensive AGM sealed batteries do not buy this charger

No more dead batteries which is awesome for the lake or ocean when you want to have fun with no worries.

I can drain my primary battery in a few hours if I'm not careful, so having this installed helps insure that my primary battery is fully recharged after an outing

The truck sits unused most of the time, but now, i don't have to worry about having a dead battery when I need to use it.

Unfortunately, this doesn't seem like the scenario this charger is really built for -- the battery in my car is very hard to remove and I don't have an electrical outlet within six feet of where I park

It has four batteries and it has kept my batteries in peak condition with no problems -- I highly recommend the Genius for anyone needing to keep their electronics up to par.

After I tested this unit out for a few days in my garage on a couple dead batteries and it brought them

My batteries are just as strong at the end of the day as they were at the start

But in the meantime, I actually had dead battery issue on one of my cars from leaving interior light on for a few days.

Was going to switch leads between batteries, to see if it was a battery issue or a lead issue.

I had to unplug in fear of loosing my new batteries

this charger was very simple to install ,each battery with it own independent leads, works great and keeps my starter battery and both my trolling batteries fully charged and ready to use .

this charger was very simple to install ,each battery with it own independent leads, works great and keeps my starter battery and both my trolling batteries fully charged and ready to use .

Went to use my trolling motor and the batteries were dead.

and I feel it caused some damage to my very expensive batteries because it slowly became unusable and stopped working properly

This charger boiled my batteries on two occasions

I put the 4-bank charger on my UPS (2x 8D battery) with a mechanical timer that cycles the power on it once a day, forcing it to top off the batteries, and this works

, your batteries could be dead or heavily discharged

It recharged an almost-dead battery on a dirtbike.

The battery is usually dead or nearly dead

I have 4 batteries, 3 trolling motor and 1 cranking the 4 bank charger works great

After years of going through expensive batteries while using

Had it a few months, keeps both batteries ready to go, but I only fish every weekend

I had an old unit that had been burning up batteries, this new NOCO keeps my Hattie's fully charged constantly

It boils the batteries just like a previous buyer stated

This unit trashed 2 deep cycle batteries by overcharging them

cool to the touch normally, dead battery just warm. perfect solution.

So I usted this charger and soon my battery was working again.

I actually acquired this NOCO battery charger for use on my dad's old cabin cruiser boat that only gets used a few times per year and has been known to have dead batteries upon revisit.

This will kill batteries pretty quickly

I installed it on my boat and it keeps all my batteries fresh and ready to go.

You can find cheaper charges, but eventually that savings will be lost on more frequent battery change-outs, or worse, battery failure out on the lake.

I constantly had to bring out my portable battery charger in the winter to jump it

I use it on my GMC Sierra with dual batteries and it keeps the batteries nice and charged without over heating.

and they said that they had no explanation as to why the batteries were dead.

Don't have to worry about dead batteries anymore

This charger is now installed in my truck which has a dual battery system (isolated by a solenoid)

What was worrisome, was that my findings are similar to some reviews already posted by other users about this charger boiling off their batteries

I just used this thing to rejuvenate two RV Deep Cycle lead/acid batteries that I thought were totally gone.

Failed in less than a year and ruined a $120 battery.

Now when I plug it in after a trip, the batteries are topped off overnight

Needless to say, the batteries are shot, the charger is going overboard, money lost, lesson learned.

My two expensive deep cycle batteries started getting hot

Both batteries were dead

The boat will stay in the water all winter and have had more than my share of dead battery problems.

My charger never drops below 14.3volts, even if batteries are topped off

Simple install which made my life very easy regarding my boat batteries.

My boat has a couple lead acid and AGM batteries and most chargers require all the batteries to be the same type

Trying to smart charge camper trailer battery

cool to the touch normally, dead battery just warm. perfect solution.

it charges two battery easy to hook to battery

Beware only charges batteries ONCE every 24 hrsNot a continuous charger

It boils the batteries just like a previous buyer stated

This MAY be a good simple battery charger, but trust not tech support's answer to technical questions!

I like the way it works and it seems to keep the batteries fresher

My best guess was the battery was too dead to charge.

First, and most importantly, it won't charge dead batteries

I leave the NOCO charger plugged infall the time so the batteries stay topped off

I attached it to my plow truck's dead (not bad, just dead) batteries and the charge light alternated green and red

This is a great charger battery maintainer, brought back my dual batteries after sitting for a few months

Ruined my battery

The only flaw is that it doesnt charge completly dead batteries

Plug it in the night before and all 3 batteries are ready to go in the morning

My battery recently went dead after I left the ignition key in on position while in my car

If you are lucky you might end up with a dead battery

They are great, love that when your ready to go, battery's are always ready to go

It charges fast and keeps my batteries ready for the next fishing trip.

We have confidence now that all batteries will be in good maintenance and protect our investment for many years to come.

Has kept my poor previously undercharged batteries in perfect shape which in turn has kept my bilge pumps operating

This product works great charges my 2 batteries on my boat very well

I cannot recommend this to anyone due to the fear that it will destroy expensive batteries.

I plugged in the charger immediately after hookup and dead batteries were charged within five hours compared to twenty four hours that it took for the old charger when it worked.

This charger is connected directly and individually to each battery; it seems to give my batteries top-level charging every time

Very happy , charged both battery's in about 12 hrs

Like some of the other reviews, it would not initially charge because the batteries were too dead

I have not had any problems with the charger over-charging or boiling the batteries

Used to charge two Optima Blue Top deep cycle marine batteries and this charger is the best

great battery charger for my boat

This little guy does a great job of keeping 2 27 series batteries charged and ready to go

Maintains the batteries well with no overcharging

My boat is moored on the lake and on those rare days when I get to go fishing, I'd often get to the lake and be disappointed to find a dead battery.

maintains batteries well and never have to unplug

Peace of mind that my batteries are ready while the pontoon rests on the lift.

and it worked fine , then in September it only charges 2 batteries of the 4 , the little green / red dots on 2 ports don't lite up at all , the onher 1 looks like there is moisture in there , and its supposed tobe water proof , I need tosee if I can send it in for repair .

Works great to keep marine batteries charged and ready.

First you must connect the positive (red) cable to the positive (red) battery terminal, then connect the negative (black) cable to the negative (black) battery terminal.

I never worry about dead or dying batteries anymore.

Easy install, worked great on two lead trolling motor and one optima battery!

I forget and it would not hurt the battery

This is an excellent unit, no more dead battery on my RV.

But, it continued that rate, boiling my new battery, for 15 additional hours until I removed it

Excessive heat and/or overcharging can kill a battery.

I don't care, as long as it keeps those expensive marine batteries alive and happy

Installing this permanently and being able to just plug in my truck has saved me countless headaches of going out to find a dead battery

Doesn't matter if there is one trimmer or two, the charge keeps the batteries strong.

He assured me that "the battery manufactures we work with assure us that 14.4 volts is the proper float voltage for gel batteries"

Some of those overpriced units just have one charger that is multi-tasking to charge 3 batteries (and straining to do it)I highly recommend it and this company.

, I just went out to start the boat after having it plugged in and the batteries are dead and the lights are green

I received the Gen1 4a charger, mounted it, and placed it on a new deep cycle lead acid battery

It DOES NOT drain your battery when it is not charging.

I love my genius, it keep my batteries fully charged and let me know when it done

But it's also more powerful, so it charges the battery in less than half the time (about nine hours in 40-degree weather for an old car battery starting to show low charge)

and everyone claims that it will not harm batteries if left plugged in

Always has my batteries charged and ready to go

I keep it plugged in all the time and my batteries hold their charge well.

If you are considering buying a charger or not buying an onboard charger, stop considering and buy one- imagine a world where you never again have to wonder “hopefully the boat will start today...” by having two batteries and an onboard charger you basically eliminate ever having the possibility for a dead battery again- even if one of your batteries is dead

There are other signals indicating battery problems and the like

My husband had what was an unfortunate experience of showing up to our boat and the battery was dead.

At about 6 1/2 x 3 3/4 x 2 1/4 inches and over three pounds, it's quite a bit bigger and heavier than my previous waterproof tender (Battery Tender 800 Waterproof 12V Battery Charger)

I used this on a lead-acid auto battery and also on a deep cycle that I normally solar-recharge, both at warm summer temperatures.

The battery would die in cold weather if it wasn’t started in a day or two

thus the primary battery tends to not be fully charged and thus slowly, over time, the primary battery has degraded performance.

Works great, I have much better battery life on my boat

The charger died, but the batteries are sill good

I don't care, as long as it keeps those expensive marine batteries alive and happy

and I have never worried about a dead starting battery.

Keeps my batteries in my e350 diesel always ready to go!!

We have two 1952 Farmall tractor's (converted from 6 to 12 volt systems) and a 1962 Chevy pickup that sit outside in the weather longer than we like to admit and before this charger we had to haul our large charger out hours before we planned to use them to charge up their batteries well enough to start them

A little slow to charge a very depleted battery

I decided that if I was going spend that much money on new batteries I should get a new “smart” battery charger.

This leaves my RV with dead start batteries all the time.

This is an excellent unit, no more dead battery on my RV.

and it keeps the batteries nicely topped off.

It keeps my expensive Interstate batteries fully charged.

First you must connect the positive (red) cable to the positive (red) battery terminal, then connect the negative (black) cable to the negative (black) battery terminal.

You have to remember to unplug the unit when you are ready to go out on the water and wait for, perhaps, several hours for your batteries to charge or risk getting stranded

Charging all batteries no issues.

This charger is also smart in that it has a desulfation function that actually keeps your expensive batteries running as well as possible.

works as it should, seems well built and heavy.

Works as it should and customer service is among the best I have every talked to.

It works as it should as of this time and is simple to install..

it t keeps my batteries charged and ready for action.

it t keeps my batteries charged and ready for action.