Xantrex Technology 815-3524, 815-2524-02 manual Battery Information, Battery Bank Sizing

Battery Information

Battery Bank Sizing

Battery capacity Battery size or capacity is just as important as the battery type selected for use with the Freedom SW 230V. The batteries are the most important part of your system, so It is recommended that you purchase as much battery capacity as possible. A large battery will extend running time and ensure that your inverter/charger delivers full rated surge.

It is recommended a minimum battery size of 200 amp-hours (Ah) for moderate loads (< 1000 watts) and greater than 400 Ah for heavy loads.

See “Estimating Battery Requirements” for information on a more detailed calculation.

About Amp-hoursA number of different standards are used to rate battery energy storage capacity. Automotive and marine starting batteries are normally rated in cranking amps. This is not a relevant rating for continuous loads like an inverter. Deep-cycle batteries use a more suitable rating system such as amp-hours (Ah).

Amp-hour capacity is the number of amps a battery can continuously deliver during a specified number of hours. It is represented by the product of the two —amps multiplied by hours.

A typical single marine or RV battery rated for 100 Ah can deliver 5 amps @12 volts for 20 hours (5 amps × 20 hours = 100 Ah @12 volts). This same battery can deliver a higher or lower current for less or more time, limited approximately by the 100 Ah figure (50 amps for 2 hours or 200 amps for a half hour), but usually the capacity figure given is only accurate for the specified duration (20 hours).

For Freedom SW 230V inverter systems requiring a 24-volt battery bank,

•a pair of 200 Ah@12 volts batteries may be connected in series to create a 24-volt bank of 200 Ah@24 volts capacity,

•while two of these series pair branches may be connected in parallel to create a higher capacity 400 Ah@24 volts battery bank.

52 Freedom SW 230V Installation Guide