Electrical problems????

[amc1957]

Should the alternator be charging all the time? mine doesnt seem to be when you first start it up & I dont know why - the power draw across the battery gets down to around the 10 to 11 volts with the motor running & then after a while (~30 mins or so) for some reason it kicks in and goes up to the 14 mark.

I recently replaced the battery & now I am thinking I wasted my money as I have the old battery in the garage running a portable fridge and is going fine.

Reason I replaced the battery was I was tinkering around with the car one morning (car hadn't been started that day) & I had the doors open etc - later I went up the road, stopped for fuel and then the car was dead, got a jump start and died again soon after. Situation wasnt good so I just went and got a new battery.
All was good for a few days and then one morning I drove the car to the tyre garage for a wheel alignment (~10 mins drive) - when they finished the wheel alignment the battery was dead again, got it jump started and all good again.
Since then I have been running some tests with a multimeter & noticed the battery wasnt charging on initial start-up - Hope there is a logical reason for all this & appreciate any comments.