Ill get into more detial actually. Now unfourtantly the voltage im getting in is smaller then the voltage required to power up the PWM chip that will controll the charge voltage. Now i dont want to use a transformer to step up voltage, instead i was wondering if its possible to power up the PWM chip through the batteries that are being charged. I know that anything is possible, but what are the design implications.
my first feeling is that , it is possible , only make sure that the charger can supplu enough "power" ( considering constant current/voltage chargers) to both the ckt and batt
It sounds like you want the battery to charge itself. A battery charger circuit needs another power source. If you don't want to use a transformer then use another battery. A solar panel can charge a battery without a transformer.
Look first you should know what current you need for the chip, then go for steady charging current for battery. I have used the same funda for charging battery as well as to cutoff from the over charging . No need to use another battery as again you might go in requirement for charging the next one. You know what i mean.
Regards,
Yatin