Texas Instruments BQ24450EVM User Manual
Procedure
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Replacement circuit for a 3-cell lead acid battery. BAT+ to BAT– voltage tracks the power supply input
voltage, minus 1 diode drop
voltage, minus 1 diode drop
Figure 2. Battery Load Circuit – PR1010-2
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Procedure
4.1
Pre-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.
conversion factor of 10A/V. This is the pre-charge current.
4.2
Max 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.
a conversion factor of 10A/V. This is the max charge current.
4.3
Charge Termination
Adjust PS #2 such that VM #2 shows 7.5 VDC.
There should be no charge current in this condition.
4.4
Re-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.
by a conversion factor of 10A/V. This is the max charge current.
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bq24450EVM
SLUU464 – November 2010
© 2010, Texas Instruments Incorporated