I bought a data acquistion system for my experiment to record battery voltage readings. The problem so far is that the charging output voltage curves I have are distorted. Can any one tell me how the battery charging curve should be looked like in real world? Is it be very smooth curve keep increasing all the time to MAX voltage or it varies when you look at it in a small scale? And how to set the sampling rate if I doing voltage and temperature recording? 100Hz? or can be much less?