Solar trickle charger....

[drboyd]

Originally posted by Darryl
How are two panels wired in? Do I plug one in the bathroom and one in the living room? Just using the 12 plugs? That way they can be mounted to the glass from the inside. I admit I am not a wiring so just plugin' em in to the cigerette lighter type outlet would be the easiest. I just do not want to cause any damage to the univolt. She's old and needs to last me.

Darryl, they have cigarette lighter plugs on the ends. Right now, I have one of these dual cigarette lighter adapters hooked up, so I can plug them both into the same outlet.

Don

[Darryl]

The battery I bought is too big for the box behind the axle. It's a Marine 29, by the label it doesn't show anything other than cold cranking amps of 675 and marine cranking amps 875. What that means I have no idea.

I more than likely will buy a smaller battery, one that will fit in the compartment. My neighbor who owns SOB put a dual battery box on the tongue but I have read here that can cause weight distrubution challenges.

If I get another Marine 29 and put them in a box up front that will give me loads of cranking amps but I don't know how long they will last in my trailer.

The last time we camped (before trailer) we just built a big fire outside. But who knows now. On our first outing I intend to bring along my 5kw generator just in case. Based on our electricity usage here in the house I can envision killing a battery in a matter of hours. Furnace all day and nite (only heat source), loads of florescent lights and a to be installed later stereo. Although when it comes to a stereo I'm tempted to just buy a boom box that runs on its own cells.

Another thing I need to be cautious about is there are lots o' trees here in Oregon. Finding a camp site that has enough direct sun may be a challenge and render any solar useless.

My waterpump is 4.9amps, furnace NT30000 is 4.5amps and who knows about the florescents in the ceiling or the stock bedroom, reading and porch lights.

If all else fails I know that I can recharge with the generator during the day.

[74Argosy24MH]

If all else fails I know that I can recharge with the generator during the day.

If you run the generator during the time of highest usage it will recharge and cover what you are using all at the same time, no worrying about the batteries overnight.

John

[diesel]

For those airstreamers with large parasitic drains, i.e. automatic refrigerators, entertainment systems, etc. and use their kill switch when in storage, cannot charge their batteries via the OEM 12 volt DC outlets. You must connect to the battery side of the kill switch.

[WolfSong]

Today my hubby purchased a 5 watt solar panel from Harbor Freight for $50.00. We want to try it out for keeping the batteries charged. The interesting part is going to be how/where to install it.

[WolfSong]

Well we spent the better part of our day today out at the A/S. It is so very sad that we don't have a place to park it at our house (yet).

We had fun! After a few considerations for mounting the solar panel we decided to place it in the area of the sky light. So far it works just great.

Sheila

[davidz71]

Darryl,
Maybe this will help. Car batteries are designed for high initial cranking amps to start a car and for shallow (10% or less) discharges. They are not designed for deep cycle discharges. Deep cycle batteries are designed for prolonged discharges at lower current and not for high current discharge rates. Plates in the car battery are more porous and thinner than in deep cycle batteries. Those deep cycle batteries are used for applications that will consume 20 to 80% of the battery's capacity but I have heard not to discharge them past 50% or suffer earlier demise, the battery that is. The "dual" or starting marine battery is a compromise between car and deep cycle. A deep cycle or "dual marine" battery will work as a starting battery if it can produce enough current to start the engine but not as well as a car battery. You need a true deep cycle battery such as used in RV or marine trolling motor use, not a marine starting battery.

Deep cycle batteries are rated in amp/hours. It is calculated by multiplying the current in amps by time in hours the current is drawn i.e. An 80 amp. hr. battery drawing 4 amps will last 20 hrs. before being discharged. You may also see them rated with Reserve Capacity. RC is the number of minutes a new, fully charged battery at 80 degrees F. will sustain a discharge load of 25 amps to a cut-off voltage of 1.75 volts per cell (10.5 on a 12 volt battery). This rating is a little less useful because the common loads that RV use puts on a battery are much less. I've seen one formula to convert RC to amp. hrs. as RC X .6 i.e.
120 X .6=72 amp hrs. With this example you can run a 1 amp draw for 72 hrs or 10 amps for 7.2 hrs. To convert RC to amp. hrs. at the 25 amp hr rate, multiply RC by .4167. More amp hrs or RC are better in every case.

Check out www.geocities.com/bjb_darden/dcfaq.htm or http://bart.ccis.com/home/mnemeth/12volt/12volt.htm for great battery info.

[davidz71]

Wolfsong,
If the solar charger comes with a cigarette lighter plug then plug it into one of the receptacles in your unit and mount the panel against a window any way you can. This will not be quite as effective as placing it on top of the trailer but maybe safer if it is not parked in your back yard. Mine came with terminal rings which I slipped over the screw terminals and tightened down. I then ran the wires out the top of my battery box door and set the 5 watt panel on top of one of my 40# propane tanks. I have also placed it on top of the trailer near the front vent. Since both batteries are wired into the same system then they both get charged. I have seen clamps with wires connected to a female cigarette lighter socket the male plug fits into. The clamps connect straight to the battery terminal. If you have really long wires with your panel then you could run them down the air conditioner vent and connect to a 12 volt source near the frige if you have one.

[HaulinOats]

Found this thread useful... but cracking up about the "trickled-on" economics statement that started the thread.

"Trickle Down" is what you meant... "Trickled-On" is likely what happened to the orange guy in Russia.

Originally Posted by drboyd

...not to be confused with "trickled-on" economics!

Anyway, the way I'm envisioning it now, my Airstream will be stored away from the house most of the time.

How to keep the battery charged up? Here's what I've done.

Seems like Volkswagen ships a lot of their new vehicles with solar panels "suction-cupped" inside the windows, to keep the batteries charged. They don't sell these over the counter, but they sell the heck out of them on eBay. I got two panels, which are shown as being 3.4 watts each, and stuck them on the inside of the front corner windows, which just happen to be facing south right now.

They are made to plug into a cigarette lighter, so I've taken a double lighter adapter cord, and made an extension so I can plug them both into the 12v outlet by the sink.

My theory is that they should get enough sun to keep the batteries charged while I'm not using the trailer.

Opinions? Better ideas?

Don

[uncle_bob]

Originally Posted by HaulinOats

Found this thread useful... but cracking up about the "trickled-on" economics statement that started the thread.

"Trickle Down" is what you meant... "Trickled-On" is likely what happened to the orange guy in Russia.

Hi

Given that this thread is almost 20 years old, it's a pretty good bet that very few of the original participants are still running around the forum.

Bob

[HaulinOats]

Hey... it speaks volumes that this forum has been going for that long!

Originally Posted by uncle_bob

Hi

Given that this thread is almost 20 years old, it's a pretty good bet that very few of the original participants are still running around the forum.

Bob