Alternator only putting out 12.8 to the battery drains fast

[Spoolin4Ever]

Is that pretty much normal that if the alternator is only putting out 12.8 volts the battery only lasts about a day and I got to hook it up to the charger again?

Battery tests good but it's a walmart battery testing it at walmart so not sure if they are testing it right. I got another alternator on the way, so this is just in the meantime...

Hooking up a multimeter to the battery posts, it and car running says 12.8 volts...and they should be giving me 14 volts. I am just surprised that it only lasts about a day, I would think a good battery even with alternator at 12.8 would still last longer.

Volt meter shows 12.8 with car turned off, with it running and also when turned off even with battery charger plugged in which I thought was odd, you'd think there'd be more with the charger charging it.

 

[wrencher]

It is definately not charging properly.
Most likely is a bad alternator.

It might be producing a little to keep the battery voltage up some.
But it should be doing 14 volts +.
Without the alternator charging it wont take long to kill the battery.
You have to think just running the engine is going to be about 8-10 amp constant draw.
That will take a battery down pretty fast. A walmart battery goes down even quicker