We have been developing protection circuit for 3.7V li-Ion battery.My end application is electronic pipette controller. As of now we have using battery part no ICR18500NM. The problem is that battery drain upto 0V and then while we charge it, it does not pick up and life cycle of battery also deteriorate.

Now we want give Over discharge and overcharge protection. We have implemented this by using MM3280 and Mosfet AP8205. The problem we faced is the instrument does not power ON. Its ON/OFF ratio is 50%. So we were unable to get the desired results.

Now we have tried with IC-XB4301D and the same problem still facing. We have got output voltage at no load but as soon as we connect the load , we do not get any output across the load or if instrument is.connected, it does not power ON even for atleast once.The same schematic we have used as per datasheet.
Can anybody show me the right way.

 

Wouldn't it be easier just to buy a pcb off ebay that does ypur exact purpose for about $1.00 shipped ??