Battery keep running down on 96 Chevy. Had alternator changed. Battery...

[learning]

...showing 10 volts after it was charged. Had both battery and alternator re-tested. Can't understand why the battery keeps running down in 30 minutes. Autozone said it may be the cable from battery to alternator. Autozone does not sell them. Where can this be found and how much?
What could be the problem. Need cost estimate.

Just had intake manifold and timing fixed

 

[racer x]

FrankieC has it and I don't think the person at autozone was much help if after a charge you only get 10 volts because a good battery will read 12.4 to 12.6 volts. You need a new battery. Then again you replaced the alternator and if it wasn't the correct one it may not charge the battery back up but I still say a new battery because of the voltage reading you are getting.

 

[SPEEDY]

I do believe this is the cable from the battery to the alternator or from the battery to your starter. Check at a Carquest if you have one local. they should have it if not check at a chevy dealership they are bound to have it in stock. It should run you around 20 bucks.

 

[Frankie Coletta]

YOU NEED A BATTERY. If it's only showing 10 volts then you dropped a cell because it's a 12 volt battery.

In other words. The inside of a car battery is actually 6-2 volt battery's in a row. So one of the 6-2 volt battery cells is junk. So now the total battery output is only 10 volts instead of 12 so the whole battery is now junk.
Sometimes like right after a jump start or charge the bad cell will pop back to life but then go dead again while sitting. That is why it may have passed the test at Autozone. Then, on the ride home the bad 2 volt cell drops again.
Battery's do wierd stuff.