25
AQ-OP-00010_E
Appendix B: Operational Settings for Off-Grid Power Control
Electronics
B.1 Operational Settings for Off-Grid Power Control Electronics
The 48 V Battery Stack is designed to be compatible with the majority of charge controllers and inverters
that are compatible with lead acid batteries. With the appropriate voltage, time, and temperature
compensation settings, the Aquion Energy battery can use the common lead acid charge profile of Bulk,
Absorb, Float. The Aquion Energy battery does not require a float current, as lead acid batteries do, but
there is a regulation voltage at which the battery can be held following its absorption charge cycle.
The inverter settings in this appendix are recommendations only. They are intended to keep the
batteries within their operational limits (maximum voltage, maximum current, etc.). These settings can
be changed to optimize the performance of your particular system. Please contact Aquion Energy
support for any further assistance.
B.1.1 Definitions
Bulk current – Maximum current at which the battery can be charged.
Absorption voltage – Voltage at which the battery can be maintained in the constant voltage
“absorption” stage of the charge profile. This condition allows the battery to charge at a faster rate.
Absorption time – Length of time that the battery should be held at absorption voltage.
Hold (float) voltage – Voltage at which the battery can be held following the absorption stage. The
hold stage allows the battery to maintain a full state of charge when the system is generating more
power than is required by the system loads.
B.1.2 Voltage Limits vs. Temperature
The table below shows the maximum voltage (absorption voltage) as a function of average charge
current per stack and temperature.
Ambient Temperature (°C)
Current (A)
>=5
10
15
20
25
30
35
2
62.8
62.8
61.2
59.6
58
56.4
54.8
4
64.8
64.8
63.2
61.6
60
58.4
56.8
6
66.8
66.8
65.2
63.6
62
60.4
58.8
8
68.8
68.8
67.2
65.6
64
62.4
60.8
10
70.8
70.8
69.2
67.6
66
64.4
62.8
>12
72.8
72.8
71.2
69.6
68
66.4
64.8
B.1.3 How to Charge Aquion Batteries
All off-grid power control devices that have temperature compensation have a battery temperature
sensor accessory. Affix the battery temperature sensor to the side of the module, on the side of the
topmost battery in one of the eight-battery stacks. For groups of modules, install the battery
temperature sensor on the most central module. Aquion recommends that the sensor be attached with
high-quality tape, in addition to any self-adhesive included with the sensor.
