Portable Battery Wonder Box with TV charging

[John Linck]

After 6 days of camping under a heavy forest canopy in Yosemite Valley our battery dropped below 12 volts. The cool nights and furnace use probably were the main culprit. And the darn trees kept our solar panel in the shade.

So, I thought, "This calls for a project". How about a battery wonder box. My arm chair imagination leapt into action. How about a small 20 amp hour battery that I can carry in my TV to charge on our occasional sightseeing trips while the Scamp is parked in the shade? This could give me a day or two of power when the house battery hits 50%. I could build a small wooden box for it. Intercept the 7 pin trailer connector wiring for charging perhaps. Certainly I would want a digital voltage display, a master switch. How about a 12 volt socket and a couple of USB sockets? Maybe even tuck in a small inverter to feed a 120 volt receptacle. Its starting to sound like the Chinese offerings that even include an air compressor. I don't expect to go that far. But it sounds like lots of fun to build. But would it be useful? You might say just add another house battery, but what fun would that be. On the other hand we are seldom without sunshine and the whole purpose may just temporarily satisfy my gear lust.

Does any to this make sense? What features would you add? I have already considered and rejected cupholders.

Maybe this whole post just shows that I need to get out camping.

Cheers, john

[David Tilston]

Ummm..... This is already made, more or less. Just plugs into your 12 outlet in your car. Available at your local automotive store. In my case Canadian Tire.
http://www.fiberglassrv.com/forums/f...one-57925.html
Power Packs | Canadian Tire

[Bob Miller]

Quote from Post #1
"And the darn trees kept our solar panel in the shade."


Anyone that refers to the magnificent trees of Yosemite in anything but positive terms (even if one falls on your car) should be given the opportunity of taking a short step off of El Capitan. Remember, they were there first..... LOLOLOL.....


And, as mentioned by Dave, that "Box" you described is available at your local Friendly Auto Supply Store, aka FLAPS. The one I have is about 10 years old.

[Byron Kinnaman]

Two things I've done that helps. One I'm an Amateur Radio Operator so I carry a 50 amp hour gel cell 12 volt battery that can double as a house battery in low battery cases. Two my solar panel is portable so that I can move it around and chase the sun.
I added pigtails with Anderson Power Pole connectors on the ends to both batteries. Put the same connectors on the portable solar panel. Now it's all plug and play.

[whip2001]

i have made a heavy cable plug going from the house battery.
in additional another plug connected to the alternator in our Tahoe.
when i connect the two plugs with the engine idleing i get a high amperage charge of the house battery. i do have AGM batterys which can take the heavy fast charge. i eliminate the need for an external generator and it's much quieter than even the best small generators. i don't need to run for more than 40 to 50 minutes to bring back a low battery back to full charge. of course we conserve energy by using LED lighting ect.
we camped for over a week in Rocky mountain national park without any solar panels. recharged only twice and bothered no local campers.

[Bob Miller]

Yep, there's nothing as enjoyable in the camping experience as having your next door neighbor come back to their campsite and run their TV's engine for 45 minutes to recharge their coach battery, all while your family is eating dinner outside and downwind from the exhaust. It's almost as enjoyable as dining in the center divider of I-90, but without the noise.


More and more campground I frequent are specifically banning running vehicle engines for recharging coach batteries, a trend I hope continues. Certainly not as noisy as most generators, but that 300+ cubic inch engines exhaust is not good for children and other living things.....

[John Linck]

Originally Posted by Bob Miller

Quote from Post #1
"And the darn trees kept our solar panel in the shade."


Anyone that refers to the magnificent trees of Yosemite in anything but positive terms (even if one falls on your car) should be given the opportunity of taking a short step off of El Capitan. Remember, they were there first...

I agree, I would rather have a dead battery and freeze at night than to give up camping in the magnificent Yosemite forest.

John

[John Linck]

Originally Posted by David Tilston

Ummm..... This is already made, more or less. Just plugs into your 12 outlet in your car. Available at your local automotive store. In my case Canadian Tire.
http://www.fiberglassrv.com/forums/f...one-57925.html
Power Packs | Canadian Tire

David,

You may have missed my point. Its the design and building of tech gadgets that's the fun. Whether they are useful or even used is far less important. And buying one from China is way less interesting. Plus, mine would be housed in beautiful wood, making it very useful as a paperweight, since it wouldn't get used much as a power source. And in an emergency it would also make good fire starter material.

More seriously, 6 days of "boondocking" on a Group 27 battery seems pretty great. True we did move the rig on day 6. We took it to a meadow below El Cap, hiked, lunched and read in our beach chairs while the Scamp with its 100 watt solar panel bathed in full sun. Topped off the battery in 4-5 hours. Really wasn't unpleasant at all. Then we returned to the forest for another 5 days.

John

[Steve L.]

I'm with you in terms of having fun with the projects. I made up what I think of as a kinda cool kit box that can be inserted between the trailer and the tow (not while towing) to digitally read off the volts and amps passing between them. Necessary? No. Especially since it turns out to dispprove some of popular wisdom with respect to being able to recharge the trailer battery. Fun? I had a ball researching, learning, and making it. I had to back off when I found myself researching how to make printed circuits at home. (There's a mess of wires in that box.)

I even made another box I could plug the trailer into that would test all the lights and flash the marker lights if for some reason I had to leave the trailer on the side of the road. Another project answering a question that wasn't asked.

I took a cheeep plastic battery box from the local marine supply store and grafted onto the domed top cover a 7 blade RV receptacle and a 12V lighter socket. I wasn't looking to recharge while camping so I stopped there. After plugging the trailer into the spare battery, most of the spare's "juice" went towards recharging the trailer battery as the two tried to balance out but that didn't bother me as those amp-hours were in the now 2 battery system (less assorted inefficiencies) somewhere.

[David Tilston]

Hey, don't get me wrong, I get the urge to invent stuff, it just has to be something that I can't buy in the store:
http://www.fiberglassrv.com/forums/f...rol-50954.html

[RogerDat]

Gadgets be good, gadgets be fun, making own solutions most fun of all but.... beware the vampire project! You know the one that sucks all the time & money out of every other project.

Hmmm maybe something that fits in the hitch receiver to haul it around plugged into the TV 7 blade plug when sight seeing? Or to just haul around the house battery? I could see a tube & frame for a battery box and just take the house battery for a ride. Maybe folding or with quick fasteners so it packs away well.

Actually I like the smaller portable solar panel as a backup too. Can always find a use for a 20 watt panel. Hey I know make a battery pack with controller to use with the panel on it's own with outlets for USB and 12 volt and.... didn't we start here?

[Steve L.]

Speaking of gadgets; With all the news about self driving cars these days and GPS in the car as well, we'll shortly be able to send the trailer on vacation without us. Probably post pictures on Facebook too.

[Timber Wolf]

I think something like that that uses a standard-size (automotive) battery would be great. I always have a pretty decent battery or two sitting around. I occasionally buy a new battery for the car or truck and downgrade the old but still serviceable “take out” to tractor duty. Since the tractor sits most of the time (remotely, unsupervised) I keep the battery in a marine box in the back of my pickup (tow rig) “just in case”. I usually charge it at home every once in a while if I have not used it in the tractor enough to keep it topped off. Some way to charge it off the tow rig while out and about would be nice, in addition to maybe a loose panel I could throw on top of the camper shell out from under the tree canopy. Let us know how your project progresses!

[CAMPER DOUG]

GOAL ZERO YETI 400 & TWO BOULDER 15 PANELS
$639.97 $579.97
★★★★★
★★★★★ 4.6 out of 5 stars. Read reviews. (54)
Quiet, portable power for base camps, cabins and unexpected outages. The Goal Zero Yeti 400 Solar Generator allows you to live life off the grid, camp in luxury, or power through an outage without the noise and fumes of traditional back-up generators.

Need a More Portable Solar Solution? - Use the Nomad 20 Solar Panel with the Yeti 400. See Here More...
Recharge by: AC, 12V, Solar
Power Output: USB, 12V, AC
Ideal for: Laptops, CPAP, TV

[CAMPER DOUG]

GOAL ZERO YETI 1250 SOLAR GENERATOR KIT
$1799.95
★★★★★
★★★★★ 4.3 out of 5 stars. Read reviews. (77)
Back in Stock - May 2015
Best kit for safe, silent power generation. Use indoor or outdoor to backup critical appliances including refrigerators, freezers & home health care equipment like a CPAP machine. Store 1250 watts of power.

No noise, no fumes, no gasoline, no wasted power. Charge from the sun with solar panels or from the regular wall outlet. More...
Recharge by: AC, 12V, Solar
Power Output: USB, 12V, AC, Power Pole
Ideal for: Laptop, Mini Fridge, TV, Backup, Emergency, Lights

[John Linck]

As usual with my armchair schemes their level of complexity grows and is paralleled closely by increased cost and labor. My lovely dream wonder box proved to be no exception. So the pragmatist in me said, "Why not just add a second battery to my current set up?". This is a hard question to refute. It would double my boondocking time making independent stays longer than I would probably ever really need. Wiring would be dead simple only needing a fuse and a battery switch to choose which battery to use. Then I thought, "Who needs another 50 pounds of lead to haul around?" So lethargy may win out in this scheme and I will probably just enjoy camping without the cost, weight, and complexity. Then again I may change my mind next week. Isn't owning a fiberglass RV fun?

John

[David Tilston]

Or, put a solar cell on the roof of your trailer and stay as long as you want.

[Steve L.]

Originally Posted by David Tilston

Or, put a solar cell on the roof of your trailer and stay as long as you want.

HA! John is from Wisconsin, and like my Michigan, we're practically nothing but trees here. (I don't know much about Alberta, most of what I know about Canada is from Doug and Bob Mckenzie!). Unless he's happy to chase a sunny patch around his campsite, or camp in Walmart lots, he's going to have problems keeping his batteries up. It may extend his stay but I'm not buying off on the "stay as long as you want" theory.

And I know I'm tweaking a sacred cow here so I know I'll catch heck!

(Where have all the good Canadian TV shows gone? SCTV, Prisoners of Gravity, Red Green. Is Don Cherry still on Hockey Night in Canada? My satellite service doesn't give me Canadian channels)

[David Tilston]

Yeah, Bob and Doug are exactly like all Canadians. Other then the fact that they don't seem to live in an igloo.

I must admit that my perspective on solar is affected by the fact that I live on the prairies. Calgary gets more then it's fair share of sunshine.

[David Tilston]

OK, I would like to apologize to the OP. I feel like I was way snide, and his challenge is ACCEPTED!

Here's what I think would ROCK. My wife thinks it's a money maker. Let me know.

I have an abundance of 35Ahr gel cell batteries. They weigh about 25 lbs. They are too small for the trailer battery, but too big to walk away from, (I am a complicated person). I think they would make a good battery for a "portable" power pack.

But not one that you charge up and take with you. More something like a brief case with a solar panel on one side, including a solar controller. What do I want it to do, (other then store power)? I want a good light source, and a radio. For a radio, I think a DIN socket with a no moving parts car stereo for about $20:
Practical Car Stereo in Dash FM with MP3 Player USB SD Input Aux Receiver Remote | eBay

And removable speakers.

Now, how to make it a tracking array?

............hmmm.........