Charging your battery, Solar, Generator, or TV

[parnold]

I just got my tax return back, so I'm looking at prices on solar panels. The best deal I have seen so far is a 50 watt with controller for $155.00 of FeeBay. I can get the 45W at Harbor Freight for 196.00 with coupon and tax. Then I started wondering about just using my battery charger with an inexpensive generator. A $100.00 generator from HF has more than enough capacity to run a 6 amp charger.

I started wondering where I would put all this junk, panels, or generator and charger. I have a very small car, and what used to be a simple and quick setup, is becoming more complicated.

Then I realized that I already carry a set of jumper cables in my car. They take up almost no room, and during the winter I run my car 15 to 20 minutes every morning to warm it up with negligible fuel impact, so running for a few hours every other day would cost very little.

Now my thought is.. since I have a Dr Wattson, to hook up my car to my battery, and run it for one hour. Give the battery a few hours to stabilize and see what I get. With my typical usage, I estimate 4 days on the battery with no problems, I only use the lights a little, and sometimes charge my tablet, laptop, or cell phone. The big draw is when I happen to use my fan, but even then, I still can go two nights and only draw the battery down to about 70%.

Has anyone else thought of this, or tried this?

[Corwin C]

Yes, I have done this with plain old jumper cables in my Aristocrat. If I keep it up daily, it only takes 10-15 minutes to stay close to 100%. It seems that people in crowded campgrounds don't seem to get upset at an idling car like they do a genny.

My electrical usage is very light and pretty much limited to a couple of lights for a few hours each evening and occasionally a computer fan to enhance ventilation or keep the heater from stratifying the air inside. It doesn't take very long to put the power that I use back in. Most of the time I can get 4-5 days out of a 110 Ah deep cycle if I do nothing. I charge my cell, iPod, etc. in the TV mostly due to the lack of 12v jacks in the trailer.

[Wimperdink]

My solution would be to cut a heavy extension cord 4' or so from the female end.... Hook it to your TV battery keeping in mind which color went to which terminal.... Hide the female end behind the grill of your vehicle.... Wire the male end of the cord to your td battery (same color wires to same posts as car).... Park your car with the nose towards the tear to keep exhaust fumes away... when you need to recharge, just fire up the car, then plug the two ends together. (a spare female extension cord replacement end could be plugged into the tear side of the cord when not in use to prevent accidental zaps)

$10 done.

(want easier? add remote start to your tow vehicle)



Edit: if you want to make it much more difficult to install, I could show you how to install using a relay so that it only draws from your car battery if the car is running. (so if you forget to unplug the cord it wouldn't drain your car battery)

[newrollo]

Hi Wimperdink. Nice simple solution. So often simple is safest too. Thanks for the idea. Hows that new trailer working out. Do you miss the Wazat?

[Wimperdink]

Hi Wimperdink. Nice simple solution. So often simple is safest too. Thanks for the idea. Hows that new trailer working out. Do you miss the Wazat?

Thanks.... I really miss my Wazat. Its best it sold though as I won't have a lot of opportunity to use it anymore with all the new family members here. The bigger one however will house us all so I'll still be able to get out. The "new" trailer I've actually had longer than wazat. I bought Wazat when it was just my wife and I for quick and easy camping.

[eamarquardt]

How bout having two batteries for your trailer and a "nest" in the tow vehicle for one of them. When we're out and about, we set up camp, and branch out driving to various places. With two batteries, set up with power pole connectors or terminals with wing nuts, you could swap them out in a couple of minutes each day or two. As you toodled around each day, one battery would be in the trailer and one in the tow vehicle being charged as you go about your business.

It would, though, be a good idea to factor a relay into the setup so that when you're not running your engine the tow vehicle's battery and your spare trailer battery are not connected as batteries so connected tend to self discharge. When somewhere with hookups you just leave em in the trailer connected to a battery charger.

Cost of this setup would be nominal except the cost of a spare battery (and I like spares).

Cheers,

Gus

[bdosborn]

45 watt solar panel

I have a panel from these guys and the quality is much better than the harbor freight panel. Lighter and smaller too.

SunGuard Charge Controller

Morningstar has some of the best controllers out there IMHO.

This system should keep up with your usage. Mount the panel flat on your roof, don't worry about tilting it and now you're maintenance free. Yeah, you can charge using battery cables but the trouble is your alternator doesn't put out much current at idle and it would take hours to charge the battery. The solar panel will probably charge your battery to 100% everyday so your battery will last longer.
Bruce

[ERV]

Hi Paul
If you are just using the battery for 12v, the easiest is to use your TV to keep it charged. I use an inverter that is in the back of my truck to give me 120v . I have to big batteries to run that. With my inverter I can run power tools, coffee maker, and most anything I want. I use it for work and side jobs. Camping is just a plus.
To charge them I have a wire going back from the truck battery, which if I want gives me a bank of three batteries. They charge while I am going down the road. I have switches on them to keep them isolated from the truck when not in use. If I am pulling big loads on them with the inverter I let the truck sit and run. A lot better than a generator making all that noise. Fuel cost is a lot better than using a generator and the folks that I am working around don't even know what I am using for power.
Just make sure you unplug it if you don't have the car running.

[len19070]

Paul
I love the "charging from the tow vehicle" method. No muss, no fuss, If you have to drive there...your battery is charged Plain & simple.

If it goes down,just plug the trailer into the car and run it for a while. same thing as the jumper cabels with out the cabels.

That said, How long will your battery last?

I'm a reality based sort of guy. the figures and computations on what a battery will do at sea level on a tuesday with 18' of #10 wire and a .000875 amp load on the positive Creatasfirm on the wassanot if the riggatutu is adjusted properly means nothing to me.

With a charged battery, Turn on a light and the fan and let it go. it will amaze you at how long it will last.

Happy Trails

Len

[Yota Bill]

to wire for a charge wire on offical collor coding charts for diagrams for a charge wire.

just so everyone is safe, there is no "official color coding chart", or any standards set for the color code of trailer wiring. Most manufacturers and even novices follow generally accepted color code applications, but you cannot assume it is that way on all trailers. If you did not wire it yourself, test it and go by function only, dont assume any color is a specific function just because that is the norm.

[Shadow Catcher]

The care and feeding of deepcycle batteries is important for them to reach their full capacity potential and life expectancy. This means they must be fully charged and that is dependent on the output of the charging source and line loss… Bulk charging at the batteries should be at the manufacturers specification, typically 13.8V.
Automotive alternators are designed to produce the most power at idle HOWEVER idle speed is typically less than it used to be. For many years, the industry standard was 2,500 RPM and many/some still are, and your engine probably idles somewhere between 700 and 900 RPM. Alternator output in your vehicle may or may not put out its max when actually idling and it is likely that voltage at the battery is not optimal.
Solution a separate regulator i.e. http://balmar.net/duo-charge.html

[len19070]

Just another note on small Solar Chargers.

Though they won't "raise the Dead" They do serve an important duty.

And that duty is that they create activity in the battery while in storage.

Even the real small dash board models.

And by creating constant activity in an otherwise dormant battery it will last longer.

Happy Trails

Len

[Visionsbydarrah]

If adding solar? I would use something like Uni-Solar products.
Very very low profile if add directly to your teardrop.
It's more like a solar film, very cool stuff.

[Mukilteo]

I did all 3.
Solar panels on the canopy. (no room on trailer)
A 3500 watt propane fueled generator. Only used when I'm in in the middle of nowhere because of the noise it makes. Al tho it doesn't seem to be as loud as my 3500 watt gas gen.
And the truck charges the trailer battery when it's running.

[bdosborn]

I did all three as well and the PV worked so well I'm addicted (which is why I post on every PV thread I can).

30 watt for the truck/refrigerooler.



80 watt portable in case the trailer is parked in the shade.


220 watts on the trailer.


The 1000w generator with LED lighting in case the sun goes out.


I'd buy more panels but I don't have anymore room. Now I'm talking the neighbors with campers into buying them.

Bruce