Specifications

51
In the end, the decision was made to use the Optima D51 battery. Optima is a well
known AGM battery manufacturer, and their batteries generally receive very good
reviews on many different websites. This D51 is the cheapest and smallest battery
Optima makes, costing less than $140.00 on amazon.com and weighing in at a mere
26 lbs, both of which are significantly less than most lead acid deep cycle AGM
batteries. It has a 38Ah storage capacity, which is more than our design requires, but
will increase the batteries cycle life because the typical 2 hour battery cycle will be
reduced to a roughly 30% DOD on this battery. The only downside to this particular
battery is it has an internal resistance of .0046Ω, which the highest internal resistance of
any battery made by Optima. Fortunately, this is still below the internal resistance
provided by most gel cell batteries, so the benefit of using an AGM over a gel cell is still
present in this particular battery. The figure below shows the schematic diagram for the
12 VDC to be supplied by the battery.
Optima D51 Yellow Top Battery
+ -
Solar Array
Charge Controller
Wind Turbine
Charge Controller
12 VDC Power
Outlet
120 VAC Power
Inverter
MSP430 and
Display PCB
+ -
+ -
15A Fuse
60A Fuse
12 VDC
+ -
+ -
+ -
1A Fuse
Figure 39 - Schematic Diagram for 12 VDC Supplied by Optima D51 Battery