[EMAIL PROTECTED] wrote: > This chip uses an exernal shunt. Yes, the voltage drop required > is .25V, but that works out nicely to an available 0.01R shunt > for 25A - so the 6.25W dissipation is not a problem.
OK, that helps. Be aware that the peak charging current may be several times the average, when the charging is done at the peak of the AC line cycle. Therefore, the peak voltage drop across the shunt may be also considerably higher. Make sure the chip's current sense input has enough dynamic range to cover the peaks. > the pack voltage sensing is independant from VCC. Again, that helps. Make sure you know its maximum voltage, and that you don't run into trouble if the pack sensing pin is more positive than the VCC pin (if, for instance, the power supply that is running the chip is slow to come on). > The bq2031 uses an external NTC thermistor, on the end of a wire > if you like. Again, that will help. Does it detect an open, shorted, or missing temperature sensor? Or does the charging algoritm commit batricide if the sensor is damaged or missing? > This one doesn't seem too bad (it is designed for lead acid, > with the correct voltage/temperature compensation), in fact the > Constant Current / Constant Voltage / Float profile looks > similar to the Zivan - so, not ideal maybe but useable.. Sounds hopeful, at least. I am not criticising the BT2031 in particular; I haven't used it (and don't have the time to pull out its data sheets and learn it just to provide free engineering advice :-). I am just offering some general comments on my experiences with other battery charging chips. -- Lee A. Hart Ring the bells that still can ring 814 8th Ave. N. Forget your perfect offering Sartell, MN 56377 USA There is a crack in everything leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
