Xantrex Technology Link 20 User Manual

Xantrex Link 20 Battery Monitor

Link 20

Owner's Manual

TABLE OF CONTENTS

Introduction, Battery Facts 3 Front Panel Description 4

Using Your Reading Dual Watch

Link 20 Battery Management 7

Battery Capacity Testing 8 Synchronizing Setup 10–20 Setting Up Functions 16–20 How to RESET your unit 22

DATA: Your Battery History 23 LOCK: Kid proofing 24 Peukert (High Discharge Rate) Exponents 25–27 Typical Peukert's Exponents 28–29 Set Up and Historical Data 30 Required Reading Prior to Installation 31 Wiring Connections 34 Wire By Wire Check 35 Start Up Procedure 38 Warranty 39 Specifications 43

Notice of Copyright

Disclaimer

UNLESS SPECIFICALLY AGREED TO IN WRITING, XANTREX TECHNOLOGY INC. (“XANTREX”)

(a) MAKES NO WARRANTY AS TO THE ACCURACY, SUFFICIENCY OR SUITABILITY OF ANY TECHNICAL OR OTHER INFORMATION PROVIDED IN ITS MANUALS OR OTHER DOCUMENTATION.

(b) ASSUMES NO RESPONSIBILITY OR LIABILITY FOR LOSS OR DAMAGE, WHETHER DIRECT, INDIRECT, CONSEQUENTIAL OR INCIDENTAL, WHICH MIGHT ARISE OUT OF THE USE OF SUCH INFORMATION. THE USE OF ANY SUCH INFORMATION WILL BE ENTIRELY AT THE USER’S RISK.

Date and Revision: November 2002, Revision 1

Part Number: 445-0196-01-01

Contact Information Web: www.xantrex.com Email: CustomerService@xantrex.com

Phone: 1 800 670 0707 (toll free in North America)

1 604 422 2777 (direct)

Fax: 1 604 420 2145

Link 20 5

Light Bars 6

Link 20 to Batteries 9

LINK 20 INTRODUCTION

Congratulations! You have purchased the world's only Dual Watchtm battery monitor. In order to understand, use, and install it, PLEASE read this manual. It provides important information. Please contact us with suggested improvements. For Link 20 installation, operation, warranty support, and repair questions, please contact Xantrex. The Link 20 provides instrumentation of two banks of batteries. The Link 20 does not control an inverter/charger. For installations involving a Freedom Inverter/Charger and two battery banks, Xantrex recommends the Link 2000. If a Freedom Inverter/Charger and one battery is anticipated, Xantrex recommends the Link 1000. For instrumentation of a single battery bank with no inverter/charger controls, the Link 10 is ideal.

This symbol is used to point out very important sections of this manual or to indicate items that may need to be changed through Set Up routines. Please take the time to read these sections.

The following warnings must be considered during the installation of the Link 20. Failure to read and follow these special notes can lead to damage to the Link 20 or other electrical equipment.

POWER CONNECTION WARNINGS

1. When installing your Link 20, make all shunt and ground connections BEFORE

applying power to the unit.

2. The wires connecting the battery to the dual shunt, and from the dual shunt to your

system ground, will carry large current. Size the wire appropriately. Large batterry

banks contain enough energy to start a fire if improperly sized wire is used.

3. Disconnect all charging sources during the installation process.

IMPORTANT BATTERY FACTS

1. An amp hour (Ah) is 1 amp of current flowing for one hour, or 2 amps for

1/2 hour, or 4 amps for 1/4 hour, and so on.

2. Many batteries designed for deep-cycling service are rated at their 20-hour rate.

This means a 12-volt, 100 amp-hour battery will sustain 5 amps for 20 hours before

its voltage under load drops to 10.5 volts. A 12 V lead-acid battery which will not

maintain 10.5 volts under load is considered "dead"—it's completely discharged.

3. Our Mid-Capacity Rule says discharging more than 50% of a battery's capacity

shortens life. Charging more than 85% takes too long with an engine-driven charging

system. So, 35% of the battery capacity is all that is normally available. If you regularly

need 100 amp hours of energy, your battery capacity should be about 300 amp hours.

FRONT PANEL OF YOUR LINK 20

The exclusive Dual Watch glance. It's easy to train your whole crew, even the kids, to turn off loads and start charging

when the light bar shows two yellow lights. When the light bar is green, you've got plenty of energy. With one flashing red light, you'd better charge or start hunting for jumper cables!

This light bar shows Battery 1 This light bar shows Battery 2

light bars give you battery state-of-charge information at a

i4.25

SEL selects the units being displayed: volts, amps, amp hours, Time of Operation Remaining.

SET picks from among choices. You'll SET a battery size from a list of choices when you first install your Link 20.

When BAT 2 is pressed, the display numbers are for battery 2.

When BAT 1 is pressed, the display numbers are for battery 1. The light above each button reminds you which battery you're looking at.

USING YOUR LINK 20

STATUS LIGHTS

These green lights tell you what units are displayed.

Volts is the electric potential to do work. Voltage is useful to assess the approximate state-of-charge and to check for proper charging. Examples: An at-rest, fully charged battery will show about 12.8 V. A 20-hour rated battery is 100% discharged when it reaches 10.5 volts with a 20-hour rated load applied. Typical charging voltages may range from 12.9 to 14.9 volts.

Amps is the present flow of current into (or out of) the battery. For example, a refrigerator may draw 6 amps of current. This is displayed as - 6.0 (6 amps are being consumed from the battery). Discharge is shown as a negative number. Charging is shown as a positive (unsigned) number.

Amp hours (Ah) consumed represents the amount of energy removed from the battery. When a 10-amp load is on for one

hour, 10 amp hours are consumed. If you started this discharge with a full battery, your Link 20 will show -I0 in the display. During charging the Link 20 compensates for charging inefficiency and counts back up toward 0.

Time is an estimate of how many hours the battery will sus- tain a load before it reaches a settable discharge floor. The estimate may be based on the instantaneous load or averaged. Four-minute load averaging is the default. During charging the Time display reads

CCCCCC

CCC , indicating the battery is charg-

CCCCCC

ing. When charging, amps is a positive number.

For the TIME function to operate correctly, you must correctly enter your battery capacity, type, and check that an appropriate Peukert Exponent has been selected through

the SET UP routines.

READING THE LIGHT BARS

Above the Link 20 numeric display are two light bars, each with four lights. They show you battery stateof-charge at a glance.

Four green lights means your battery is nearly full (80–100% charged).

A single flashing red light means it's nearly discharged.

Light bar scaling is independently settable. As the Link 20 comes from the factory, it is set to show a flashing red light whenever your battery is more than 80% discharged (20% charged). The default setting usually indicates enough energy remains with two yellow lights showing to start an engine-driven charging source. If desired, you may scale the light bar to show a flashing red light when your battery is more than 40% discharged, however, this is not recommended. To set a discharge floor other than 100%, see page 19, Function F09.

EMPTY Symbol FULL Symbol

Percent Full

Default Optional

100% 100%

80–99.9 90–99.9

60–79.9 80–89.9

40–59.9 70–79.9

20–39.9 60–69.9

0–19.9 50–59.9

100%

floor

50%

The Light Bars operate on rate-corrected amp hours. If you have heavily discharged a battery bank, the light bar may tell you to charge before you would normally make that decision based on the amp-hour display. See High Discharge Rates, page 26.

WE RECOMMEND: Charge your batteries when the Light Bars tell you to!

floor

LINK 20 BATTERY MANAGEMENT

SIMPLE BATTERY MANAGEMENT RULE:

Recharge When the Battery is 50% Discharged!

The Link 20 is a guide to the battery's state of charge. Our Mid-Capacity Rule

says you should begin charging when your Link 20 shows that 50% (or more) of battery capacity has been consumed. In marine and RV systems, which are trying to minimize charging time with an engine-driven alternator or genset, the battery is normally charged only to the 85% level. This means only 35% of the battery capacity is actually available for use.

The Mid-Capacity Rule is a very conservative approach to battery use. Occasionally discharging a battery more deeply is perfectly acceptable. The Mid-Capacity Rule is intended as a design and operating guideline, not a law which must be obeyed without exception.

We recommend synchronizing your Link 20 to the 100% charged level of the battery. You should begin recharging when 50% of the your battery capacity has been consumed.

When recharging from an engine-driven alternator or generator supplied

battery charger you do not need to charge until the meter counts back up to 0 amp hours consumed. You may end charging even though the final 15% of battery capacity

has not been restored. Later, when you are able to charge for a long period of time, the remaining amp hours consumed will be replaced.

Periodic conditioning or replaced during normal charging.

equalizing removes any negative amp hours that are not

OVERCHARGE AMP HOURS

If the batteries are 100% charged and the Link 20 is in sync, overcharge amp hours are displayed as a positive amp-hour number. Some accumulation of overcharge amp hours is normal with systems continuously connected to a charger. For example, a 100 Ah battery at Float voltage will normally have about 0.1 amp flowing into it. This means you would expect about 2.4 amp hours of overcharge to accumulate each 24 hours. If your battery system is larger, proportionately more current flows and amp hours accumulate.

With a constant voltage charging system set at 14.2 volts, as much as 1 amp of current may be flowing all the time even after the battery has reached the charged parameters. This causes a small overcharge amp-hour reading to appear in the Ah display. When discharging begins, these overcharge amp hours are erased and the Link 20 resets to zero and begins to report amp hours consumed.

Prolonged high voltage applied to a fully charged battery will probably cause gassing. So, if you see a large amp-hour overcharge occuring daily, consider it a warning to check your system. It could indicate that you are destroying your battery by overcharging.

When you equalize your batteries, you will accumulate some overcharge amp hours. This is normal and keeps the Link 20 synchronized with the battery state of charge.

BATTERY CAPACITY TESTING

Your Link 20 can be used to conduct periodic capacity tests that tell you the actual

amount of energy your batteries can store. A capacity test should start with a battery that has been properly charged and equalized. The objective is to find the maximum available capacity.

Many times, deep-cycle battery capacity is stated as a 20-hour discharge rate. A 100 Ah battery will provide 5 amps for 20 hours. At discharge rates above 5 amps, the battery will not supply 100 Ah. For example: If you are drawing 100 amps out of the battery it will last less than half an hour. Consider the following table:

CAPACITY AT VARIOUS DISCHARGE RATES

(As a percent of 20-hour rate)

Hours to Discharge Capacity (percent of rating)

20 100% 10 84% 5 67% 3 56% 1 47%

To test battery capacity, reset amp hours to zero. Then turn on a load that draws approximately 5% of the expected battery capacity. Measure the current with Amps display. The load should be constant, such as incandescent lighting. Now put the Link 20 in the Volts display mode. When the battery voltage drops to 10.5 volts (or 21 volts if you're testing a 24 V system), hopefully about 20 hours later, turn off the load and look at the amp-hours display on your Link 20. The amp hours displayed is your actual battery capacity.

If less than 20 hours passed before the battery voltage fell to 10.5 V you can still determine the capacity with some arithmetic. For example: Assume a 12 V battery rated at 100 Ah. Apply a 5-amp load. Suppose it only took 10 hours for the voltage to reach

10.5 volts. The Link 20 would display -50 Ah. This is the 10-hour capacity. Dividing 50 by 84% (10-hour rate) from the table above, you determine that the actual 20-hour capacity is about 60 amp hours. You could repeat the test at 5% of the tested capacity (3 A) to verify the actual capacity.

USING YOUR INVERTER

TO TEST BATTERY CAPACITY

Your inverter might be the type which makes testing battery capacity easy. First, fully charge (equalize if necessary) the battery to be tested. Use a load like incandescent lights running on the inverter whose amperage consumption is 5% or less of the battery capacity. Many inverters will shut down on low voltage below about 10.2 V. When the inverter shuts down, read the number of amp hours that have been consumed from the battery. If it is not close to the expected number use the procedure outlined above to estimate the capacity.

CAUTION!

Be sure to completely recharge your battery after a discharge test.

SYNCHRONIZING TO YOUR BATTERY

A charged battery has zero amp hours removed. Synchronizing your Link

20 to read zero when the battery is charged ensures that you always know the net number

of amp hours removed.

There are two ways to synchronize your Link 20:

1) Install the Link 20 on a fully charged battery and it will be in sync.

2) If the Link 20 is installed on a partially charged battery, simply charge until

the charged parameters are met. The Dual Watch light bars show this by flashing the right green lights. The Link 20 will begin counting up and will display overcharging amp hours as a positive number. When the battery is fully charged, turn off the charging source. When discharging begins the Link 20 resets amp hours to zero, starts counting down, and is in sync.

If the Link 20 should ever get out of sync with the battery state of charge it must

be resynchronized. The best way is to be sure the battery is discharged at least 10% of the declared battery capacity and then recharge until the charged parameters are met. When the next discharge cycle begins, the amp-hour display should reset to zero.

Remember: Periodic controlled extra charging ensures that the Link 20 remains

in sync with the battery's state-of-charge.

SETUP PROCEDURES

Your Link 20 comes with default

values chosen to work with most systems. Normally the only values that need to be

i4.25

Holding the SET button for five seconds accesses the Set Up and Advanced Functions. The display will read SEL. If you press SEL once, you will display the first

Setup variable: Charged Voltage. Pressing SEL repeatedly will step through more variables: Charged Current, battery amp hour capacity, and averaging period for Time Remaining. Corresponding status lights come on for each.

If you continue pressing SEL, you will step through functions named in small text below each of the lights on the Battery 1 Light Bar. Some functions have multiple displays. These are described in later pages devoted to RESET, DATA, and LOCKing of your meter. The next (right) battery status light indicates you've entered the Advanced FUNCtions area (see page 17).

When a desired variable or function is displayed, pressing the SET button will display the present value of the function. Pressing SET again will display the next choice. If you hold the SET button, the display begins scrolling. When the desired value appears, release the button. If the button is held down longer, the display will increment to the end of its range, then roll over to its minimum value and continue to scroll.

changed are the battery capacity, battery type (liquid or gelled), and high discharge rate compensation (Peukert) exponent. Please be sure you understand each function before changing the factory default values outlined below.

If this sounds complicated, relax! It's not. Once you go through it a few times, it will become second nature. On the next page, we'll go through this again step-by-step.

FACTORY DEFAULT VALUES

Monitoring Functions:

Charged Voltage = 13.2 volts for 12-volt systems

= 26.4 volts for 24-volt systems

Charged Current = 2% (of battery capacity, 4 amps @ 200 Ah) Battery Capacity = 200 Ah

CEF = 95% (Charge Efficiency Factor)

Ambient Temp. = 70 Battery Type = #1 (Liquid cells) Peukert Exponent = 1.25

USING SET AND SEL BUTTONS

Pressing and holding the SET button for five seconds enters the Setup and

Advanced Functions modes. The word the SEL button to choose what function you want to SELect.

PRESS BAT 1 OR BAT 2 TO PICK THE BATTERY YOU WISH TO SET UP.

Pressing SEL chooses a variable or function. The Setup mode always begins at

the

a variable or function is selected, its corresponding light and present value is displayed. To change a variable, press the SET button until the value appears that you wish. The order displayed and brief descriptions are below.

LIGHT DESCRIPTION

(Volts) function. Each press of the SEL button scrolls to the next item. When

Charged Voltage ( Battery must be above this voltage to be considered "full.")

Charged Current % (Charging current in amps must remain below this

percentage of battery capacity to be considered full.)

Battery Capacity in amp hours

Time interval over which current is averaged for Time Remaining function.

SELSEL

SEL appears in the display, prompting you to press

SELSEL

Each light will come on in sequence.

Advanced Functions. See page 16.

Locks out SET button and Advanced Functions. See page 24.

Displays CEF, # CEF Recalc's, Average Depth of Discharge, Deepest Discharge.

Resets amp hours and allows reset of every- thing to factory default values. See page 22.

Now let's SET UP your system. We'll explain Charged Voltage, Charged Current Percentage, Battery Capacity, Time of Operation Remaining averaging, and set an appropriate rate compensation (Peukert) exponent.

WHEN TO SET UP AND

The C

The Link 20 depends on correctly set Charged Parameters to stay in sync with

battery state-of-charge, to automatically reset to zero, and to automatically calculate the Charging Efficiency Factor of your battery. The two numbers which define Charged Parameters are Charged Voltage and Charged Current Percent.

What these Charged Parameters mean is simply this: If you charge a battery above a given charging voltage and hold it there until the charging current drops below a few percent of battery capacity, the battery is effectively FULL. Although you could continue charging, once voltage is held high and charging current drops to a few percent, any additional energy going into the battery will be turned into heat.

Based on extensive studies, we have selected a default Charged Voltage of 13.2 volts and a Charged Current of 2% of declared battery capacity. This means a 200 Ah liquid cell battery held over 13.2 volts until charging current drops below 4 amps is effectively full. (4 amps is 2% of 200 amp hours.) Once your system is able to fully recharge your battery, we can then calculate battery efficiency when five conditions are met:

CONDITIONS TO RESET TO ZERO

1. Discharge 10% of declared battery capacity to trigger algorithm.

2. Recharge until kWh becomes a positive number.

3. The voltage must be above the Charged Voltage Parameter.

4. The current must be below the Charge Current % Parameter.

5. Conditions 3 & 4 must be met for 5 minutes (1 min. for AE [F05] mode).

If your battery voltage is other than 12 or 24 V, you must set up an appropriate

Charged Voltage.

If the charged parameters are not set correctly, the Link 20 will never recalculate

the CEF. If you accumulate negative amp hours, check your charged parameters.

Please consider changing only the battery capacity unless your system falls into one of the following categories:

1) Battery chemistry other than lead acid.

12 Volt NiCad (and NiFe) systems would normally use 15.5 to 15.7 as the Charged

Voltage. See your battery specifications for guidance. The Charged Current % can probably stay at 2% of declared battery capacity.

2) Charging normally ends before current drops below 2%.

If the charging system is normally shut down before charging current drops below

2%, the Charged Current % will have to be changed.

3) Your system operates at extremes of temperature. For example, below 45 °F

or above 90 °F.

HOW TO SET

Your Link 20 automatically selects an appropriate charged voltage for 12-volt

liquid and gel cells when you set battery type. (We'll cover setting battery type on page

19). If you operate a 24-volt system, or if extremes of temperature are involved, here's how to change charged voltage:

1. Press SET for five seconds. SEL will appear in the numeric display.

2. Press SEL once. The light will come on and 13.2 will

appear in the numeric display.

3. Press and hold SET. The numeric display will move up in 0.1 volt

steps until 50.0 volts is displayed. The display will then "wrap around" and start counting up from 8.5 volts. Stop at the desired voltage.

4. After 10 seconds, the displayed setting is stored in memory and normal operation resumes.

HOW TO SET

The Link 20 is factory set to use 2% of battery capacity as Charging Current

Percentage. If you normally end charging before 2% is reached, or use a very large battery bank, such as might be encountered in an alternative energy installation, a different value may be appropriate. Here's how to change it:

1. Press SET for five seconds. SEL will appear in the numeric display.

2. Press SEL twice. The light will come on and 2 will

appear in the numeric display.

3. Press and hold SET. The numeric display will move up in 1 percent

steps until 7 percent is displayed. The display will then "wrap around" and start counting up from 1 percent.

4. After 10 seconds, the displayed setting is stored in memory and normal operation resumes.

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