Had a new thought about charging

[mikeschn]

Oh you mean something like this...



http://www.webpal.org/webpal/b_recovery ... erator.htm

Mike...

[mikeschn]

Or if you don't want to make so much noise... how about turning your alternator with a bicycle wheel?



Hmmmm... we need a good boat designer to come up with a good way to recharge our deep cycle batteries...

Mike...

[mikeschn]

Here's another lawnmower engine!!!



http://theepicenter.com/tow02077.html

Mike...

[mikeschn]

And finally if you have a 30mph wind, you might consider something like this, but on the front of your tear, not the front of the truck!!!

http://www.otherpower.com/bdwm53.html

[Nitetimes]

Of course, you could just leave the blade on the lawnmower and cut the grass around the TD while the battery is charging.

[angib]

And finally if you have a 30mph wind, you might consider something like this, but on the front of your tear, not the front of the truck!!!

You could try the ready-made wind chargers for yachts such as from e-marine. But they're boaty bits so the price is twice what it oughta be.

Oh, and no camping in the woods - stops the wind.

But these are nearly silent and that's a lot better than a converted chainsaw motor with no pipe.....

Andrew

[Q]

Because my whole house runs on solar (photovoltaic) power, I always have a couple of backup generators around for long term cloudy periods. My generators are exactly as you describe, an engine and an automotive alternator. At the moment I have a large and a small unit.

The small unit is a 5 hp Honda horizontal shaft engine driving a 65 amp Motorcraft (Ford) alternator. The large unit is a 16.5 hp Briggs vertical shaft lawn tractor engine driving a 100 amp truck alternator. Both units have large mufflers to quiet the sound.

It's important to use an alternator without a built in regulator because you want to be able to control the load on the engine. If you were to put a 65 amp alternator with built in regulator on a 3.5 hp engine and attach it to a dead battery, the engine wouldn't be able to turn it. The regulator will give full current to the field until the voltage reaches about 14 volts.

What we do is use alternators made for external regulators. Then you attach a wire with an allagator clip to the positive alternator lead, and a piece of nichrome wire (heating element from a dryer) to the field lead. By adjusting how much nichrome wire (resistor) is in the circuit, you control the load on the engine, and the amperage output. It's nice to be able to let the engine run at low power sometimes for less noise.

You will have to monitor the voltage so you don't overcharge the battery.

Q

[TomS]

Most of us already own a highly portable gasoline powered 12 volt charging system? I take mine with me wherever I go. It's currently parked in my driveway.

Is it feasable to charge the trailer battery using jumper cables from the car's battery to the trailer battery with the car idling?

Would 10 to 20 minutes a day on the jumper cables be enough to keep the trailer battery topped off, assuming average reasonable power consumption ( no high wattage appliances such as toasters or microwave ovents)?

Running a lawn mower engine in a campground has got to be a sure fire way of pissing off all your neighbors. My car isn't nearly as loud as a lawnmower.

[mikeschn]

That's a good question.

I was under the assumption that I would have to charge the battery for 2 hours. But I don't remember all the parameters of that assumption.

Q, do you have any thoughts on this?

Mike...

[Q]

When charging a lead acid battery it's best to charge it at somewhere around the C-10 to C-20 rate. That is if you have a 100 amp hour batter you should charge it at 10 to 20 amps, with 10 amps being better. Of course that isn't always practical. If you have an 70% discharged battery, you would have to charge it at 10 amps for more than 7 hours (since the process isn't 100% efficient).

So.... for a single 100 amp hour RV battery the best generator would be something like a 2 hp Honda engine coupled to an alternator from a little car like a Geo Metro.

Q

[Nitetimes]

Most of us already own a highly portable gasoline powered 12 volt charging system? I take mine with me wherever I go. It's currently parked in my driveway.

Is it feasable to charge the trailer battery using jumper cables from the car's battery to the trailer battery with the car idling?

I could be wrong here but an alternator repair man told me that your engine has to be running between 1000-1200+ RPM's for the alternator to charge, this is supposed to help keep the battery from over-charging/over-heating when the car is sitting for long periods. So I imagine it would work if you wanted to sit and keep your car revved for an hour or so.
If you have ever jumped another vehicle with a dead battery, notice that it won't do much until you bump up the RPM's on the running vehicle.

[Ron Dickey]

Q... you have a big blank space hit edit in the upper left corner and back it off if that is where you were stopping

I would Use solar and it has no noise will charge even on cloady days and could be used for other stuff too.

http://www.batterystuff.com/categories. ... r_chargers
http://www.cetsolar.com/solarbatchargers.htm
http://www.homepower.com/


Ron D.

[Arne]

I've bookmarked those sites.. thank you. 10w for a bit over a hundred bucks seems pretty good. I've ordered the 5 w from h/f already, so will give that a try and might upgrade if it works out for me (have to figure out the position and experiment with it)..... being neurotic, am a bit concerned about it 'walking away' if I leave it unatended all day at a camground.

[mikeschn]

I have a 65 Watt panel, which in Michigan in the afternoon puts out about 2 amps. Hopefully in the summer it gets closer to the rated 4 amps.

I hope to be able to replace 32 amps a day...

But what to do if I end up in a shady campsite?

Mike...

[Arne]

Mike that sounds expensive, it is in the order of my 5 watts for 50 bucks (around $10/watt)?

Down road, I might try and build one into the roof, water proof, with a travel cover, but am getting into this slowly for now...

The battery box is done and undercoated... when dry in a day or two, will mount it and start wiring it into my existing system.... then new shelves, the inverter, etc......