NOCO Genius G3500 Charger & Maintainer

NOCO Genius G3500 Charger & Maintainer

I bought this last month and it’s worked great so far. It charged a beyond dead car battery that wouldn’t hold a charge after a jump and has topped up the batteries for my boat lift and boat.

No, complaints from all who received. So, I’m buying more. Yea first buyer!

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Umm, This statement is a little hard to believe. I also own this unit, and from what I’ve seen it’s a little under powered in my opinion to be able to bring back a dead battery. Look at the charging table for a lawnmower in the chart. Who knows, maybe you got the one Superman model.

Will this work for a 6500 watt 120/240V generator?

It isn’t a fast charger but it will get the job done. Someone left their dome light on or something at least 3 times and drained the battery down to nothing in the garage. 2014 Civic. My G3500 did an amazing job each time. You just have to be patient because it takes several hours.

Assuming you’re asking if a 6500 Watt generator will run this?

Since it requires about 60 watts @ 120 VAC, yes. So that size generator would be massive overkill.

But note, this is not a battery “booster“. It is a very smart charger and maintainer. It it is not intended to provide the kind of amperage required to start an engine.

I’ve owned the prior version of this G3500 for many years and have consistently used it every off season to maintain 12 volt and 6 volt batteries. It is bullet-proof reliable.

(We’re all aware the best way to kill a lead acid battery is to let it discharge to less than 50% and even worse, let it sit that way for weeks, right?)

I also own this latest version of the G3500 and it adds lithium ion battery capability and a recovery mode to attempt to recovery fully discharged (12 volt only) batteries.

There are all kinds of well-made handy quick-disconnect accessories for various connecting methods - go to the NOCO site to see them. This means you can leave connectors screwed to your various batteries and swap in the G3500 easily. There’s even an OBDII port connector so you can leave the G3500 inside the vehicle rather than under the hood as squirrel food.

But don’t be expecting to start engines with this smart charger and maintainer - it is not a booster-starter. This means you will need to leave it connected to the battery for several hours, even overnight, to start an engine.

So, to be clear, this is not for jumping a car. But if my car is going to be sitting around for weeks or months unused (e.g, during a pandemic lockdown), I can hook this up and it will keep the battery topped up. Right?

Will this work with AGM (Gel Mat) batteries?

What type of battery is your 6500 watt 120/240V generator?
Are you wanting to charge or maintain this battery?
If you can let me know those answers, I can better answer your question.

Yes, this will work with your AGM (Gel Mat) batteries. There is a specific setting for this very chemistry.

I bought this from Woot when they had it the end of February . I have used it for numerous batteries . The charger does one thing that I do not really understand. When charging a normal 12 volt car battery it has 4 leds that light up over time showing 25% , 50% , 75% , 100% charged. Once it show 100% charge you can disconnect the charger and immediately reconnect the charger… and instead of showing a 100% charge it starts all over again showing zero charge. So I guess the % indicators are more like a timer then showing the actual charge of the battery.

No, I’m asking if I can use this to keep the battery charged/conditioned on the generator, a Honda 6500SX in winter, say-- rather than starting it up every month.

I purchased one of these recently because I came into a stash of older batteries that I thought could use being refurbished a bit.
So far the charger was supposedly able to recharge all of them, even though for some reason it took several attempts on some batteries (it gave a “battery won’t hold a charge” error several times before finally making it to 100%).
But none of them were able to successfully complete the repair cycle. This seems to be a common trend, that the repair mode on this unit is a little picky and only works on a very limited condition of battery. From my experience/research, it seems like it would tend more towards newer, better condition batteries that maybe suffered a few overdischarges vs. batteries that are relatively old or have been left unused for a long amount of time.
Also, I have read several reports of people using the repair mode on larger batteries (like automotive or deep cycle) where the repair mode has taken several days instead of the “4 hours” per the manual.

Absolutely! You’re good to go. How you want to use it with your generator is exactly how this product is designed to be used. Cheers!

This is exactly how we use it. We maintain a generator battery, a garden tractor battery and a solar off-grid battery bank that we bring home from our vacation property off-season.

While you can safety leave it connected all the time since it is smart and will not overcharge a battery, we rotate it around every month or so.

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(Fellow “blue”!) If you think about it, the G3500 does not know you you are reconnecting it to the same battery. ;-). (We rotate it around several off-season batteries to keep them healthy.)

Every time you connect, it goes thru its test cycle to evaluate the battery to which it is connected. After that test, it determines your battery is fully charged.

NOCO actually makes a quick connect accessory cable you can leave connected to the battery that has 25/50/75/100% LED Indicators showing state of charge. I own one, only $8.99. Mothership link:

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‘‘Every time you connect, it goes thru its test cycle to evaluate the battery to which it is connected. After that test, it determines your battery is fully charged.’’
And that is what I was pointing out…if ‘‘after that test, it determines…battery is fully charged’’ then I would expect it to indicate that by showing 100% charge instead of starting all over at zero% charged.
Thanks for the link…that looks like what I was wanting to show the charge with out having to manually test the battery after I charge it. :slight_smile:

So you expect the G3500 to read your mind? It wouldn’t make sense for it to assume it was being connected to an already fully charge battery.

It is perfectly logical and what most folks expect for the G3500 to initiate its test and charge process every time it is newly connected to a battery.

And that test process is really quick so it isn’t clear why it bothers you.