48
Selectronic Australia
Rev 41 - Dec 2022
Operation
Battery Temperature Compensation
The SP PRO monitors the temperature of unmanaged batteries via the sensor provided. The supplied battery
temperature sensor must be mounted in thermal contact with the centre of the side of the battery. If the
sensor is not in thermal contact with the battery bank, the batteries will not be correctly charged. Check the
battery temperature is reading correctly in the SP LINK >
Data View
>
Technical Data >
Battery Temperature
.
With managed batteries (where there is communication between the battery BMS and the SP PRO), the
SP PRO reads the battery temperature directly from the battery BMS. The supplied battery temperature sensor
is not installed. When a managed battery type is configured in the SP PRO, battery temperature compensation
is not required, and the configuration setting is unavailable.
The charge voltage set points are compensated by battery temperature. The default compensation applied is -
5.5 mV / °C / cell with zero compensation at 25°C.
e.g. initial voltage = 55.2, battery temperature = 26°C, no. battery cells = 24.
compensated charge voltage = 55.2 + ((26 - 25) x -0.0055 x 24)
= 55.07
absorption voltage = 57.6, battery temperature = 6°C, no. battery cells = 24.
compensated charge voltage = 57.6 + ((6 - 25) x -0.0055 x 24)
= 60.11
During all charge stages, the compensated charge voltage will not exceed the max voltage limit.
Compensation improves battery performance by preventing over or undercharging the battery and protects
against battery overheating.
The charge current is also limited by battery temperature. Battery temperatures above 45°C cause the battery
charger to reduce the charge current limit point. This will also help protect the battery from overheating.
If temperature compensation is set to 0.0 mV / °C / cell, no temperature compensation will be
applied. When a Lithium battery or managed battery type is configured, no temperature
compensation will be applied, and the temperature compensation configuration settings will be
disabled.
The temperature compensated charge voltage target and charge current target at any point in time can be
viewed in SP LINK >
Data View
>
Technical Data >
Target Charge Voltage
and
Target Charge Current
Renewable Management
Solar Hybrid – Grid Available
In Solar Hybrid, the renewable energy can be directed to power the AC Load and recharge the battery bank.
AC Coupled solar from a grid-connected inverter can be directed to export solar power to the grid. The
direction and priority of the energy flow can be varied depending on the time of day, battery SoC or Load
demands, allowing the maximum use of the renewable energy (such as PV solar) whilst taking advantage of
variable electricity tariffs.
Note that the SP PRO will not export active power to the grid, as per the requirements of AS/NZS
4777.2:2200 appendix M.
Solar Hybrid – Grid Outage
When the grid fails, the SP PRO feeds renewable power to the AC Load and any excess is stored in the
battery for later use. If the battery is fully charged and all site Loads are being supplied, the renewable power
is backed off (DC Coupling or Managed AC Coupling) or disconnected (Generic AC Coupling) to prevent
overcharging of the batteries
Off-Grid Systems
In an Off-Grid system, the SP PRO feeds renewable power to the AC Load and any excess is stored in the
battery for later use. If the battery is fully charged and all site Loads are being supplied, the renewable power
is backed off (DC Coupling or Managed AC Coupling) to prevent overcharging of the batteries
SP PRO Operation
