Xantrex Technology SW Series owner manual Technical Information, Selection of Battery Type

TECHNICAL INFORMATION

TECHNICAL INFORMATION

BATTERY TYPE

This section of the manual is included to help you better understand the factors involved with battery charging, care, and maintenance, by discussing the physical make-up and characteristics of chemical storage batteries. This is not intended to be an exhaustive discussion of battery types, but simply a guideline. The manufacturer of each specific battery is the best authority as to its use and care.

Batteries come in different sizes, types, amp hours, voltages and chemistries. There are nearly as many descriptions of exactly how batteries should be charged, as there are people willing to offer explanations. It is not possible here to discuss all aspects in detail. However, there are basic guidelines you can follow that will help in battery selection and ensure that the batteries are better maintained than the majority.

See the INVERTER/CHARGER TERMINOLOGY on page 115 for a brief description of terms that appear in this section with which you may not be familiar.

SELECTION OF BATTERY TYPE

There are two principal types of batteries: starting and deep-cycle. There are several different types of battery chemistries including liquid lead-acid, nickel-iron (NiFe), nickel-cadmium (NiCad), alkaline, and gel-cell. Batteries are either sealed or vented.

STARTING BATTERY

These are designed for high cranking power, but not deep cycling. Don’t use them. It does not hurt the inverter - they simply will not last long in a deep cycle application. The way they are rated should give a good indication of their intended use. "Cold Cranking Amps", is a measure of the amperage output that can be sustained for 30 seconds. Starting batteries use lots of thin plates to maximize the surface area of the battery. This allows very high starting current but lets the plates warp when the battery is cycled.

TELEPHONE COMPANY BATTERY

Second-hand telephone company batteries are often available at far below original cost. They are often used to power the telephone system for short power outages. They are sometimes used successfully in remote home systems. Typically, they are a lead calcium type battery, similar in construction to a starting battery. Therefore, they should not be repeatedly discharged more than 20% of their amp/hr rating. Keep this in mind when evaluating their amp/hr to cost ratio.

DEEP CYCLE BATTERY

This is the type of battery best suited for use with inverters. The physical dimension of the plates are thicker and the active material that holds the charge is more dense to increase cycle life. The “deep cycle” type of battery is designed to have the majority of their capacity used before being recharged. They are available in many sizes and in either “non-sealed” or “sealed” types.

NON-SEALED LEAD ACID BATTERY

The most common type of deep cycle battery is the non-sealed, liquid electrolyte battery. Non-sealed types have battery caps. The caps should be removed periodically to check the level of electrolyte. When a cell is low, distilled water should be added. The electrolyte level should be checked monthly and topped up if needed after recharging.

The most common “non-sealed” deep cycle battery is the type used with boats and motor homes. They typically are called “Group 27” batteries and are similar in size to a large truck battery. They are 12-volt batteries rated at 80 to 100 amp-hours. Often the deep cycle claim is over-stated. They do work better than a car battery, but are not recommended for anything but the smallest systems.

Another popular and inexpensive battery of this type is the "golf cart" battery. It is a 6-volt battery rated at 220 amp-hours. They can be cycled repeated to 80% of their capacity without being damaged. This is the minimum quality of battery that should be used with SW Series inverter applications.

Many systems use the L16 type of battery. These are 6-volt batteries rated at 350 amp-hours and are available from a number of manufacturers. They are 17 inches in height and weigh up to 130 pounds each - which may be troublesome in some applications such as RV or marine installations.

 2001 Xantrex Technology, Inc.	Telephone: 360/435-8826	SW Series Inverter/Charger
5916 - 195th Street N. E.	Fax: 360/435-2229	Part No. 2031-5
Arlington, WA 98223	www.traceengineering.com	Rev. C: February 2001

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