Solar trickle charging

[k0ua]

i can assure you ohms law , at least when I learned it. was expressed with E=Voltage in the calculation. E=IR etc.. If you don't have grey hair.. you might have learned another version..

It looks like us elder-fossils posted about the same time

 

[Soundguy]

i see wiki is using the new V now as well in it's articles. I'm gonna guess new teaching material must be using to then.

I guess I will have to stop calling a capacitor a condensor now..

and a register in a compter must not be an accumulator any more.

 

[k0ua]

i see wiki is using the new V now as well in it's articles. I'm gonna guess new teaching material must be using to then.

I guess I will have to stop calling a capacitor a condensor now..

and a register in a compter must not be an accumulator any more.

You do realize we have stopped using Coherer's for detection of RF for a while now right?

 

[Soundguy]

interestingly.. a bing search on ohms law also turns up a variant using C as current.. but still using E as votlage. E=CR

...

 

[Soundguy]

what?!? no marconi spark detector! ( branly invented it i know. ? edward maybee? ) can't remember..

 

[3930dave]

Thanks, all. I have a unit a lot like the one K0ua linked to. I found its output wasn't enough to keep up with an electric fence energizer, but it might work to keep my tractor battery going in the winter when it sits for a week or two (in the cold!) between snowstorms.
I'm thinking of installing a cigarette lighter outlet connected directly to the battery (ie, not through the ignition switch), so I can easily plug the solar charger up inside the cab...I think I saw a post by another TBNer a few months back who had done something similar.
My original battery lasted 7 yrs, but just won't hold a charge through this winter's cold; I want to take good care of the replacement.

Bob

Many panels will come with a bi-pin quick connect cable; that is one way to attach the panel.

If you do add the cig socket to the cab, if not planned already, be sure to use an inline fuse up at the battery, in the positive wire.

The panel will help, but if you are going for Max battery life, get the battery on a de-sulphating charger for at least a few days, at least every couple of months.

Rgds, D.

 

[3930dave]

I pulled a couple of solar panels (really small 6volt) from some kind of HF gizmo that never worked right, I hooked them in series to get 12 volts of power. I have them mounted to a plywood board and am thinking I can put them on my trailer to keep the brake battery charged up. I cant figure out how to measure the watts with my el-cheapo multi-meter but it should keep the little battery up since there is not any drain on it.
As for my truck (2007 Chevy) it has some parasitic drain from the alarm but that isn't much as I have left it set for up to 8 months and it still cranks abeit a little weak in the battery. I don't have any drain on my tractors that I can tell. The LS has set for 8months at a time and still has a hot battery. I think the most my Kubota has set is 3 months and still cranks normally.
I have a 12 volt 14 watt solar panel that I used to use on my JD mower as it set for 6 months at a time and it never harmed the battery and kept it fully charged. I have a bunch of battery tenders for all the other vehicles that don't see at least weekly use. My GPS and radar detector left on will pull a good battery down in a couple of weeks, not enough to need a jump start but I can tell the battery is weak.

Panels have a spec, which is the Max current they can deliver. You can get a rough idea by taking the panel outside on a really sunny day, point it square at the sun (or lay it down, noontime summer day), and put your ammeter directly across the 2 output wires. You wouldn't normally use an ammeter that way, but the current level on small panels is so low you won't blow a fuse - start on the 10A range just in case.

Been a long time, but I think that is called Isc (as in "Eye" short circuit). I'd have to double check the exact voltage to use, but muliplying each of your panels Isc by 6v should give you a rough wattage figure for each panel.

Measuring Isc on panels when new is a good datapoint, for verifying later. If you are building up networks of panels, you can balance outputs amongst sets of panels, if desired/needed.

Rgds, D.

 

[Jkott]

easy to change with a small relay, and a wire over to the fuse box and a lil time behind the plastic..

Even easier on the Chevy truck. There is an upfit port already setup with a 20a circuit on the ignition behind the brake pedal. I just need to find the time and desire to sit under the console. I'd rather be on the tractor now days

 

[Soundguy]

my time is pulled so thin nowadays I am having to get used to doing farm work in the dark int he morning and at night.

 

[BigE_]

Why Chevy didn't put any switched cig lighter outlets in I will never understand. They are all always powered.

I have often wondered why this is not done too. With the multiple 12v outlets now being installed in most vehicles (my ford has 4), you would think that at least one would be switched so you could leave something plugged in and have it power up when the vehicle was started. Or maybe have one or tow which could be configured to operate either way (always on or key switched thru a relay).

I am currently making use of this fact in my Chevy truck. I have my 5W solar panel on the dash, and it is plugged into the accessory power. I *love* this feature. I can leave my various and sundry portable battery powered devices charging out in the truck while I'm at work or when I run into the store. My BlueTooth speaker phone only gets charged when the vehicle is turned off, for example, because I don't like that cord hanging down while I'm driving. I used to have a van that I always wanted to change up the accessory outlet so that it was powered when the vehicle was off.