i am trying to overcome a large voltage drop on the vsense pin of the bq24003. my charge cable has to be a minimum length of 25 feet. i am gettingabout .08 amp loss and about .4 volt drop. is there a resistor i can change on the eval board to compensate for this drop? also, is there any way to change the bi-color LED state to "off" when charge is complete?
There is a sense pin on that part that allows the battery to be connected to Vsense. This would cancel out the drop from OUT to the battery but does not cancel out the return drop.
You can put a divider in the feedback to the sense pin to boost the output voltage, but the issue here is that when the IC goes into voltage regulation the current tapers off and the IR drop is less which not the boost voltage is too high.
Since the current does taper, the battery should still get full, it just rolls off the fast charge CC phase a little. This should not be a big deal unless charge time is a factor.
This part is set up to continue to charge for ~23 minutes after the LEDs have changed state. The cell is considered full once the STAT1 goes high, but is like a top off mode over the next 23 minutes. The user typically does not know that charge continues for 23 minutes.
does TI offer a single cell lipo charger to better suit my needs? more specifically, is there one with 3 leds? ( a charge indicator, a done charging indiator and a nother when no battery is present that turns off when a dead battery is plugged in)
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