Generator>BatteryTender>Battery?

[woytovich]

Can I safely run my Honda 1000i generator to power a Battery Tender (021-0128 Battery Tender Plus 12V Battery Charger) to charge a standard 12v battery (standard car or maybe some AGM battery)?

I would like to run the generator when I am away from the trailer to top off the battery for night use. I would like to let the generator run in econo mode (quiet/slow)...

Is there likely any problem with doing this?

Mark

[Shadow Catcher]

The only problem I see is inefficiency. You will need a charger that will utilize the capacity of the generator, they need to match closely. Another alternative is the just to jump the battery from the alternator in your vehicle.

[absolutsnwbrdr]

Yes, you can use your 1000W generator to supply power to your 1.25A Battery Tender, and it will have no problem doing so. That generator is rated at 8A, which is much more than what your Battery Tender will utilize. It will not charge any faster or slower than when you have it plugged into a standard electrical outlet.

[eamarquardt]

According to what I've found the charger you want to use is 1.25 amps. Running a 1000 watt generator to run a 15 watt battery charger isn't the way to go, IMHO.

A 1.25 amp charger is ok to charge a battery but a 100 amp hour batter that is discharged (50%) will take 40 hours to charge. If you're camping and have the charger plugged in 24 hours a day it might be able to keep up depending on how much juice you use. Running your generator for an hour or two is going to put a negligible amount of juice back into your battery, again IMHO.

The max rate you should charge a battery is at about 10% of it's rated capacity so a 100 amp/hour battery should be charged at no more than 10 amps. Although chargers are rated at that and higher, it has been my experience that as the battery comes up to voltage the rate drops off a lot and the amperage is considerably below the rated amperage of the charger.

Depending upon the length of your trip, how often you drive and can charge your battery, if you're gonna have "shore power" available, etc I think that there are better alternatives to provide you the juice you need. Yer just not going to get much bang running a charger off of a generator for an hour (or even several hours) a day.

If your camping in a campground around others I wouldn't think they'd like listening to your generator for several hours a day while you put a minimal amount of juice back in your battery. If you're out driving about a better option would be to remove the battery from your trailer, connect it to your tow vehicles system, and charge it as you toodle around.

Hope this helps.

Cheers,

Gus

[woytovich]

I was just wondering if there would be any electrical reason I couldn't run the charger off of the generator (non-sine wave, somewhat variable output etc).

[eamarquardt]

I was just wondering if there would be any electrical reason I couldn't run the charger off of the generator (non-sine wave, somewhat variable output etc).

Probably not but what's the point?

Cheers,

Gus

[woytovich]

Probably not but what's the point?

Cheers,

Gus

To have a way to recharge the battery at the trailer... just in case?

I will have the generator for other reasons at the event.
the BatteryTender is small and easy to bring along

I already own both.

I don't understand your question.

[absolutsnwbrdr]

Probably not but what's the point?

Cheers,

Gus

To have a way to recharge the battery at the trailer... just in case?

I will have the generator for other reasons at the event.
the BatteryTender is small and easy to bring along

I already own both.

I don't understand your question.

What he's saying is that a 1.25A battery charger is so small that it will take forever to give life back to a dead battery. Even when plugged into a standard electrical outlet that charger will take forever. Will it work? Yes, but it'll take forever. I've typically seen those small chargers simply used as a float charger to maintain a battery level in classic and antique cars that sit for long periods at a time, not to charge them. Charge and maintain are two different animals. At a minimum, I'd suggest upgrading to the 5A Battery Tender. Had one on my last trailer and it worked well - and its entirely waterproof. But my new trailer has a 25A power center/charger.

[woytovich]

Got it... thanks...

Yes, I bought this Tender for just that reason... to be able to maintain the battery in my 71 Datsun 240z over the winter etc

I'll look into a more powerful charger.

[bc toys]

i keep my battery plugged in on my battery tender plus while its in the driveway and it will last the weekend without a charge if I'm running the lights. but then again we only go in to sleep we like to spend our time outside but for my .02 $ your gen comes with a charge cord use it over the tender it will give you a better charge.

[woytovich]

i keep my battery plugged in on my battery tender plus while its in the driveway and it will last the weekend without a charge if I'm running the lights. but then again we only go in to sleep we like to spend our time outside but for my .02 $ your gen comes with a charge cord use it over the tender it will give you a better charge.

But I would have to worry about overcharging it right? The Tender manages that part...

[Martiangod]

I would get the 12 volt charge cord from Honda for the generator, 8 amp output, would charge a lot quicker

[woytovich]

I would get the 12 volt charge cord from Honda for the generator, 8 amp output, would charge a lot quicker

I have it... see above re: overcharging.

[bc toys]

it want over charge with the cord from honda

[eamarquardt]

Got it... thanks...

I'll look into a more powerful charger.

Cheers,

Gus