vintage cars in a barn

m37bill

we have multiple toys in our cabins barn in the woods of the

Hiawatha national forest.

everybody talks about battery banks and charge controllers.

i;m lost and have no experience.

 can i put a solar collector on the roof, hook up to multiple

toys with different size batteries? we go away for months

and coming back to dead or weak batteries is a problem.

is there a controller for such a purpose?

i have had good luck with a small unit on one battery at a time.

but wish to figure out a system for all the old cars to be maintained

at the same time.

BB.

If you wanted to go with good quality components and keep the costs relatively low, I would get one of these for each battery you want to charge:

http://www.solar-electric.com/inverters-controllers-accessories/chco/mochco/stpwmchco/sg-4.html

And get an ~80 Watt (maximum) solar panel. You can charge 4-8 typical car batteries (maximum) with 4-8 of these controllers all connected to the one panel.

Kyocera SM-83KSM 83 Watt Solar Module with MC4 Connectors

$30 for each charge controller (I have paid much more for quality car float chargers), and ~$170 for the 85 watt quality crystalline solar panel.

In theory, you can put multiple batteries in parallel and float charge them--But I am not a big fan of that.

Also, if you have a short in one battery, paralleling a bunch of PWM charge controllers on one solar panel/array, the shorted battery could draw all of the power from the single panel and leave nothing to charge the rest of the batteries in the building (if you are an engineer looking for single point of failure issues).

-Bill

sub3marathonman

BB. said:

If you wanted to go with good quality components and keep the costs relatively low, I would get one of these for each battery you want to charge:

http://www.solar-electric.com/inverters-controllers-accessories/chco/mochco/stpwmchco/sg-4.html

...

$30 for each charge controller (I have paid much more for quality car float chargers

-Bill

I don't know that I would trust them on an automotive battery.  And then you've spent $30/battery, plus the $170 for the solar panel, and are you really going to save anything near what the $170 panel could be doing if working in a real PV system?

Hopefully this isn't a violation, since Arizona Wind and Sun doesn't sell it, but it is not really in the same category as what they sell either.

I've been happy with the CTEK US 0.8 charger:  http://smartercharger.com/battery-chargers/   That one is $49 each.  There is no mention of any temperature range for using it.

They also have a "Polar" model which might be useful in the cold northern parts of Michigan.  That one is much more at $109 each, but maybe it is worth it?  It says you can use it down to -22° F.

You can put the leads permanently on the battery, and just connect the charger when you're wanting to use it.  That is how I have it with my relatively inaccessible Prius battery.  I believe, but am not sure, that the CTEK chargers can be left connected for many months, but I'd verify it with them before doing it.

BB.

Links to other products that move the discussion forwards is fine.

Those are 120 VAC chargers (at least the couple I have checked). If the original poster has 120 VAC available (see an extension cord in the picture), I would agree that a good quality AC float charger is better.

If there is not any AC available, then solar (such as small panels wired to each battery bank) or some other main solar with individual chargers would seem to be the way to go.

-Bill

m37bill

i am the poster. yes we have electricity but shut it off when we are gone. i would be comfortable having those 30 dollar controller units for each car. i have found a 10 watt unit from my farm supplier for 50 bucks. we only need a trickle to keep it up. http://www.ebay.com/itm/171437698838?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

sub3marathonman

m37bill said:

i am the poster. yes we have electricity but shut it off when we are gone.

OK, well that makes it much more interesting!

I don't know if it would work, but I seem to remember a lot of those little solar chargers that were used on VW's or BMW's or something while the car was shipped to the U.S. to keep the battery up, and I thought those were extremely cheap.  And I have no idea of the quality, but it might be another possibility.  You might have to park the other way to face the window though, as I'm also not sure about the length of the cord.

I'm wondering though, how much is actually saved by having the electricity turned off?  Do you then avoid the monthly service charge, but don't you get a reconnection charge when it is turned on again?

WaterWheel

Just get a 3-5 watt solar 12v battery charger.      All the local chicken houses use them to maintain their required battery based alarm and curtain systems.       The wattage is so low that they don't use a charge controller since the battery bleeds off the excess energy.

BB.

Here is an example of the VW shipping float chargers:

http://forum.solar-electric.com/discussion/350013/www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR3.TRC2.A0.H0.Xvw+solar+panel.TRS0&_nkw=vw+solar+panel&_sacat=0

I think most (all?) of them need to be behind glass--They are not intended for exterior mounting.

-Bill