Battery Bank Sizing Example & Worksheet

Section 7: Batteries

HOURS. This can then be easily converted to an estimate of the battery amp-hours that the appliance requires:

BATTERY AMP-HOURS USED = AC WATT-HOURS / 10 (for a 12-volt battery), or

BATTERY AMP-HOURS USED = AC WATT-HOURS / 20 (for a 24-volt battery)

For example, a 100W light bulb that is used for 4 hours will use 400 watt-hours (Wh) and the inverter will consume approximately 40Ah from a 12V battery, or 20Ah from a 24V battery.

Another useful rule of thumb is that the current drawn from the battery can be estimated from the AC output watts by using these same factors (10 for 12V systems, 20 for 24V systems). For example, when running an 800W microwave oven, the inverter will draw approximately 800 divided by 10 = 80A from a 12V battery.

Motors are normally marked with their running current rather than their starting current. Starting current may be three to six times running current. The manufacturer’s literature may provide more accurate information than the motor nameplate. If large motors will be started, you may need increase the battery size to allow for the high start-up demand.

The following battery sizing example illustrates a typical calculation, assuming an opportunity to charge the batteries every three days:

Table 3: Battery Sizing Example

Appliance	(A)	(B)	Daily watt-
			hours needed
	Power	Operating Time per	for this
	Consumption	day	appliance
			( = A x B )

TV & VCR	200 W	2 hours	400 Wh
Small microwave oven	800 W	15 mins = 1/4 hour	200 Wh

3 lamps, 60W each	180 W	4 hours	720 Wh

Coffee maker	600 W	15 mins = 1/4 hour	150 Wh

Hair dryer	1500W	6 mins = 1/10 hour	150 Wh

Total Daily Watt hours of AC load:			1620 Wh
x Number of Days between charges:			3
= Total Watt hours of AC load between charges:			4860 Wh

Battery Ah used between charges			486 Ah
(divide by 10 for 12V system, divide by 20 for 24V system)

Recommended Battery Bank Size in Ah (multiply by 2)			972 Ah

This example illustrates how quickly your battery needs can escalate. To reduce the required battery bank size, you can either conserve energy by eliminating or reducing the use of some loads, or re- charge more frequently.

Prosine 2.5/3.0 Installation & Operation Guide

PS3.0, PS2.5 specifications

Xantrex Technology has made significant strides in the power electronics sector with the introduction of their PS2.5 and PS3.0 inverter models. These inverters are designed primarily for solar energy applications, offering reliable and efficient power conversion for residential and commercial solar installations. The PS series stands out in the market due to its advanced features, innovative technologies, and user-friendly characteristics.

One of the main features of the Xantrex PS2.5 and PS3.0 inverters is their high efficiency rating, typically above 97%. This means that a minimal amount of energy is lost during conversion, allowing users to maximize their solar energy utilization. Additionally, these inverters come with a wide input voltage range, making them versatile and capable of handling various solar panel configurations.

Both models are equipped with advanced MPPT (Maximum Power Point Tracking) technology. This feature optimizes the energy output from solar panels by constantly adjusting the operating point to ensure maximum power is extracted, even in variable weather conditions or partial shading. This capability significantly enhances the overall energy harvest from solar systems.

Another notable characteristic is their compact and lightweight design, which facilitates easy installation and integration into existing systems. The inverters are also designed with robust thermal management solutions, ensuring they operate effectively even in high-temperature environments. This durability extends their lifespan and increases reliability, critical factors for any solar installation.

Xantrex has also prioritized user experience with the PS2.5 and PS3.0 models by providing a built-in monitoring system. Users can access real-time data on energy production, performance metrics, and system status through a user-friendly interface. This connectivity allows for quick troubleshooting and maintenance, thus enhancing the overall efficiency of solar energy systems.

Safety is paramount in the design of these inverters. They meet stringent international safety standards and come equipped with comprehensive protection features, including over-voltage, under-voltage, and short-circuit protection. This ensures the inverter operates safely, protecting both the user and the connected solar array.

In summary, Xantrex Technology's PS2.5 and PS3.0 inverters are engineered with cutting-edge features and technologies that cater to the evolving needs of solar energy users. Their efficiency, adaptability, and focus on safety make them an excellent choice for those looking to invest in renewable energy solutions. As the demand for sustainable energy continues to rise, Xantrex is poised to play a significant role in the market with these innovative inverter solutions.