I
J
K
L
battery has a 240 amp-hour rating at 6V, so the solar charge controller voltage, and the solar panel
4 batteries connected in series yield a power rating configuration, are all tied to the inverter.
of 24V at 240Ah. This particular lead-acid battery is One of the main features of the OutBack GVFX3524
considered a “deep cycle” battery, which is different inverter (Figures J and K) is that it can charge batteries
than a car battery because you can drain its energy as well as sell power back to the utility grid. I’m into
capacity by up to 50% without damaging the battery. electronics, and being able to utilize DC power for
The Trojan T125 battery requires adding distilled my electronics projects in addition to selling excess
water on a regular basis, because charging and power back to the grid was my ultimate goal, which
discharging consumes water and releases small is why I chose the GVFX3524.
amounts of hydrogen into the air. Since hydrogen Most grid-tie inverters don’t work with battery
is flammable, venting is required by code if you banks, which means they’re usually more effi-have a battery bank inside a house or workshop. cient than off-grid inverters, because 10% of the
I recommend reading “Battery Enclosures” from electricity is lost when charging a battery (and
Home Power magazine #119 for details on how to further losses occur when inverting DC power
build your own code-compliant battery enclosure. to AC). However, grid-tie inverters that don’t use
Using three 10" 4/0 gauge cables, I connected batteries require a DC input voltage as high as
the positive terminals to the negative terminals 150V to 250V. This high voltage requires a lot of
of all 4 batteries. This series connection leaves solar panels wired in series to meet the minimum
open 1 positive and 1 negative terminal, to which voltage. Because I didn’t want to buy or build nine
the 72" cables coming from the DC enclosure 24V solar panels, I decided to use the OutBack
box connect. inverter instead of a typical grid-tie inverter.
7. INVERTER
The components in a solar system must be carefully matched with the type of inverter you use. My
inverter requires a 24V battery source. Many other
items, such as inverter cable gauge, breaker ratings,
8. AC BREAKER ENCLOSURE
An OutBack AC enclosure (Figure L) connects the
inverter to various AC loads in my workshop. Any
standard AC breaker box would work, but the OutBack AC enclosure has punch-out holes that line up
Make: 165
