I designed a battery charger with BQ2004E for 4 cells Nimh battery(10000mah). I found the charger will always stop fast-charge before it's completely charged and the time seems shifts in the table in datasheet. For example, I set TM1 and TM2 as low/low, fast charge safety time should be 325min, but it always stopped at 150min, which is for next level setting. But if I changed to Float/Low, which should be 154min, fast-charge will stop at 69min.
So the fast charge time in my experiment is 150min, 69min, 35min, 17min, 9min, 77min, 37min, 9min. All of them are only half of the time supposed to be. Anyone can give me an idea about it?
I also purchased an development board which used BQ2004H and it did same thing(same fast-charge time). But it is only quarter of the time supposed to be.