Blue Sky IPN Pro - Manual (Page 5)

Installation and Operation Manual
4
LCD DISPLAY AND BACKLIGHT
The Liquid Crystal Display (LCD) may be backlit for improved readability. Switching backlight ON increases IPN-ProRemote power consumption from
roughly 0.25W to 1.0W. Backlight can be set for ON, OFF or AUTO from the Advanced Setup menu. The default setting of AUTO will cause backlight to
remain ON for one minute following the last key press. When backlight has turned OFF in AUTO, the first press of any key turns backlight ON only without
performing that key’s normal function. The keys perform their normal function once backlight is ON.
CHARGE STATUS INDICATOR
An LED charge status indicator is provided on the face of the unit. The charge status indicator will be OFF when the charge controller is not charging, and
will be ON solid or blinking when the battery is being charged.
CHARGE STATUS INDICATOR
CHARGE STATUS INDICATOR CHARGE MODE
OFF CHARGE OFF
CONTINUOUSLY ON BULK
BLINKING • 1 SEC ON / 1 SEC OFF ACCEPTANCE
BLINKING • 0.2 SEC ON / 1 SEC OFF FLOAT
RAPID BLINKING • 0.2 SEC ON / 0.2 SEC OFF EQUALIZE
TABLE 1
REMAINING BATTERY CAPACITY
The IPN-ProRemote provides a high accuracy indication of remaining battery capacity based on amp-hour counting. The resulting remaining battery
capacity computation is displayed as both Percent Remaining and as a Bar Graph. Note that the amp-hours from full counter and the associated remaining
battery capacity indication will show dashes (
– – –
) until the accompanying charge controller fully charges the battery which is required to initialize amp-
hour counting.
How Remaining Battery Capacity Works
A battery stores electrical charge in units referred to as “amp-hours” (AH). An amp-hour is the product of current (in amps) times time (in hours). 10
amp-hours could be consumed by a 10 amp load operating for 1 hour, a 0.2 amp load for 50 hours, or 100A load for 1 /
10
hour. The IPN-ProRemote uses net
battery current as displayed in the Top Menu Battery Volt/Amp screen to compute amp-hours which is displayed in the Top Menu Battery Amp-Hrs From Full
screen. As the battery is charged (positive current) or discharged (negative current) the IPN-ProRemote keeps a running total of how many battery amp-
hours have been removed or restored. Discharge amp-hours are applied directly to the amp-hours from full counter causing amp-hours from full to increase.
Charge amp-hours cause the amp-hours from full counter to decrease, but are reduced by the Charge Efficiency Factor to account for the fact that batteries are not
100% efficient at receiving charge. Additionally, batteries loose charge on their own due to self discharge which is periodically computed and added to the amp-
hours from full counter. Self discharge changes with battery temperature and will be corrected for temperature if the accompanying charge controller includes a
battery temperature sensor.
Counting amp-hours into and out of the battery and using charge efficiency and self discharge rate arrives at the amp-hours from full value displayed in the
Top Menu Battery Amp-Hrs From Full screen. This value is used with the battery’s published “20hr rate” amp-hour rating to compute remaining battery
capacity. If the battery was 220 amp-hours and the amp-hours from full counter value was at –110 amp-hours, remaining battery capacity would show 50%.
The battery amp-hour rating is specified at 25
°C, but actual battery capacity changes with temperature. If the accompanying charge controller includes a battery
temperature sensor, the IPN-ProRemote will correct available battery amp-hours based on battery temperature. Cooler batteries have reduced capacity, and if the
battery was at 0
°C, then actual battery capacity is reduced to 79% of 220 amp-hours and remaining capacity would show 37%.
Charge Efficiency
Charge efficiency refers to how many amp-hours are absorbed by the battery compared to how many charge amp-hours are delivered. A charge efficiency
factor of 94% means that for each 100 amp-hours of charge delivered, the battery increases charge by 94 amp-hours. Charge efficiency is typically very high when
the battery is highly discharged, and becomes lower when the battery is near full charge.
The Charge Efficiency factor can be set to a Fixed number or can be set to automatically update based on past battery behavior. Most systems will
benefit from the Auto Adjust setting which is the factory default. In Auto Adjust, the IPN-ProRemote will compute actual charge efficiency if the battery was
discharged at least 10%, and the accompanying charge controller is what brought the battery back to full charge. The Charge Efficiency factor update rate is
filtered so that it takes approximately 5 charge/discharge cycles to completely update the Charge Efficiency factor.