Friday, March 30, 2012

Part 3 .. The Battery .... Suburban Solar

In an "Off Grid" system the storage battery is a key part of the system, too small battery,  you may not have enough capacity to operate your devices or equipment long enough before you run out of power.
Too big,  a battery,  the amount of solar you have would never charge it to 100% charge (in charging terms this is the float charge)

In today's world there are two types of batteries available to us, the older style flooded (or batteries with liquid acid) and the AGM battery that uses a lead paste instead of a liquid acid, these batteries are somewhat sealed and require no need to fill them with water.

Since solar panels have been going down in cost dramatically, solar charging systems are getting more affordable.

The same size and make solar panel that I installed on the suburban, I also installed on the travel trailer in 2005.
In 2005 the panel cost was over $600.00, today that almost same panel cost is around $350.00, due to the governments finally getting out of the solar subsidy business.

The only part of the system that is going up in price is the battery.
An AGM battery with 100amp hour rating cost around $300.00 pretty pricey if you ask me.

A flooded 12volt battery with an amp hour rating of 125amps cost approx $80.00 at Sam's Club.

So, here is my battery story: :)
I needed to take the waste oil I had collected from doing oil changes to our local Advance Auto Parts Store, to dump in their recycle tank, while emptying the container I noticed they battery cores on a pallet.
After finishing, I asked the manager if they sold used batteries, I would like to pickup some deep cycle batteries to start a battery bank for an off grid project..

He said they probably could sell them when they came in, and could let me know when the deep cycle ones came in.
Then, He thought for a minute and told me he had a (not so new) deep cycle battery on the shelf in back that had been on the self for over a year.
Having been on the shelf that long he could no longer sell it for full retail price, my obvious question is how much?

$40.00..................  Sold...
That is how I settled on a 180 amp hour battery for $40.00

Now to the battery install

I built a plywood box to house the battery, making it as small as possible to save space since it is in the cargo area, some of you may notice the sides of the plywood have galvanized metal, the folks that I purchased the wood from build horse barns, this material is used in the doors.

I sealed all of the interior seems with silicone in case there would be any spills.

 Battery wiring:
All battery cable ends are soldered to prevent loose connections.
I also use Anderson Connectors for cable connections, the advantages of using these are, they are all soldered lugs, they can only be connected in one way, preventing any incorrect positive to negative mistakes, I also found out that the different colors are not interchangeable, this is great. I use red connectors for battery connections, and blue connectors for solar voltage connections eliminating mistakes.  

Here is the battery sitting over the rear axle area of the cargo compartment, I still need to make a hold down so it cannot move.
   Up next time 
The inverter and power distribution..

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