86 300E Charging / Battery Problems ?
 

My wife's 86 300e ends up with a low battery from time to time. I put it on the charger and it recharges fine. Then in about a week I have to do it again. I have checked the voltage at the battery when the car is running and I read 13.3 to 13.5. All lights and AC on full it drops to 13.2 to 13.4. The battery is about 6 months old. It almost seems that 13.3v is not enopugh to fully charge the battery and over time it slowly looses its charge. I have changed the voltage regulator module and the voltage has not really changed much. I was assuming that maybe the old regulator would fail intermittantly, from heat or something and it would quit charging altogether. Does the voltage im reading sound high enough to fully charge the battery. It is my understanding that 13.8 to 14.4 volts is what is required to fully charge a battery.

sounds like the problem is with the battery not the charging system

you may wish to take the battery back to the place of purchase to have it tested/ replaced

-fad

Your alternator is charging just fine. It sounds like your battery may have a dead cell or two.

You may get the battery bench tested at a battery center. I have purchased "new" batteries before that were ultimately found to be defective months and even weeks later. Then return your battery for a replacement or a full refund (hope you saved your receipt).

Ok guys, thanks for the quick response. I will do just that.