MG Car Repair: battery issues, internal regulator, volt meter

Question
My 1978 MGB keeps killing batteries. I have replaced the battery three times in the past six months and cannot seem to trace the problem. When I put a new battery in it seems to work fine but within a month or so will be dead when I got to start the car. When I put it on the charger, it will start to charge then the charger will show an error code indicating a bad cell. Is something shorting out the battery or could it be a defective voltage regulator? Any direction you can point me in would be appreciated.
Thanks,
Larry

Answer
Hi Larry,
You can check the car easy enough. Just put a volt meter across the posts of the battery after it is charged up and read battery voltage. (12+ volts) Then while the volt meter is still on the battery start the engine and set the idle at about 1500 RPM and read the volt meter again. 13.8 to 14.5 volts. If it is higher than that, something is wrong with the alternator (internal regulator). Then remove one of the battery posts and be sure everything is turned off. (doors closed too) Place a 12v test light between the battery post and the cable. The light must not light up or you have a drain on the battery somewhere.

That's all you need to do to test the car. I doubt it has anything to do with the car anyway. I can't think of anything that can destroy a single cell in a battery in a matter of months. Even though a very high charge rate can destroy a battery and one cell may die before the rest, it would have fried the whole battery and emptied all the cells of water. You need to have the charger tested or find a different brand of battery.

Howard