Battery Charging

Battery Charging

Battery charging is possible only when shore power is present and the Freedom HF unit is connected to a battery (or battery bank).

The frequency of battery charging is determined by how much energy in the battery is used up during inverting. Whenever the Freedom HF detects a battery voltage that falls below 12.8 Vdc, the unit will begin charging the battery, i.e., enter into bulk and absorption stages then settle in float stage. If battery voltage does not reach 5 Vdc after 1 minute or 10 Vdc after 15 minutes as shown in the graph, the unit will terminate the charging process and the error code E12 will show on the display screen.

Figure 4-1below illustrates the three-stage charging process used to maximize Freedom HF’s charging efficiency.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Voltage

 

 

 

 

 

 

 

 

 

 

NOTE:

 

 

 

 

 

 

 

 

 

 

 

If an external DC load is

 

 

 

 

 

 

Bulk Stage Absorption Stage

Float Stage

 

 

Absorption

 

 

 

connected to the battery

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

and it drains the battery

 

Voltage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

down to 12.8 Vdc, the

 

Float Voltage

 

 

 

 

 

 

 

 

 

 

 

 

 

charger will start a new

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10V

 

 

 

 

 

 

 

 

 

 

 

 

 

bulk stage.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Time

 

 

 

1 min

 

 

 

 

5 hrs Max

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15 min

 

 

8 hrs Max

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current

NOTE:

Charge Current Setting

Bulk Stage Absorption Stage

Float Stage

Maximum

Charge Current

Setting

During the Float stage, the charger will provide up to the maximum set charge current to compensate for an external DC load on demand.

Float Current

Time

Figure 4-1Three-stage Charging Process

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Xantrex Technology HF 1800, HF 1000 manual Battery Charging, 1Three-stage Charging Process