Texas Instruments BQ24450EVM Procedure, Pre-charge, Max Charge, Charge Termination, Re-Charge

Procedure www.ti.com

Replacement circuit for a 3-cell lead acid battery. BAT+ to BAT– voltage tracks the power supply input voltage, minus 1 diode drop

Figure 2. Battery Load Circuit – PR1010-2

4 Procedure

4.1Pre-charge

Turn on PS #1, preset to 10 VDC. Verify voltage on VM #1. Turn on PS #2, preset to 5.2 VDC.

Adjust PS #2 such that VM #2 shows 5 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the pre-charge current.

4.2Max Charge

Adjust PS #2 such that VM #2 shows 6 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the max charge current.

4.3Charge Termination

Adjust PS #2 such that VM #2 shows 7.5 VDC. There should be no charge current in this condition.

4.4Re-Charge

Adjust PS #2 such that VM #2 shows 6 VDC.

Using VM #3, measure the voltage across the current sense resistor on Load #1. Multiply this value by a conversion factor of 10A/V. This is the max charge current.

4	bq24450EVM	SLUU464 –November 2010
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