Where can you get a battery bank?

Answer 1

A battery bank is a group of batteries, wired together, to get the voltage and amp hour reserve power required for the installation. There are 2 types of circuits used to wire up these batteries, parallel circuits and series circuits, used to build the battery bank. For our example we will use 12v 33ah batteries :) to make the math easy.

Simply multiple batteries can be wired together to add either amperage or voltage. You can't add both at the same time.

A Series connection adds voltage, not amp hour rating. To group batteries in a series connection, hook them up in a line, positive of battery a to negative of battery b, like so...

to load <===| - battery a + |===| - battery b + |===| - battery c + |===> to load

With 3 batteries at 12v 33ah, hooked up in series, your battery bank would have the following characteristics.
36 volts at 33 ampere hours.

A parallel connection of the same three batteries would increase the ampere hours, not the voltage. This is how you increase the run time of a system and would look like this.

To Load<= POS C
Battery 1 Battery 2 Battery 3
NEG A > To Load

This battery bank would net 12 volts at 36 ampere hours.

If you want a 36 volt install, at 100 ah, it would require 3 strings of 3 batteries to make the 36 volts. Then those strings would be wired together parallel to increase the ah.

Remember to account for wire voltage drops when you raise the amps up. This is a bunch of physics and math that determines heat and drag. To do things the easy way, use the wire calculator on the bottom of this page.
http://www.bdbatteries.com/wire.php

Remember to buy high quality batteries as they have low internal resisitance. High internal resistance creates heat, wastes power, and will negatively affect larger battery bank efficiency. UL puts their mark on these quality batteries.
http://www.bdbatteries.com/ul.php