My 2008 ford ranger had a dead battery when I tried to start it . I jumped it with my wife's car and it started fine but now has the little battery life on . I tested battery volts 12.5 with car off and 14.3 with it running . whats going on help!!!!!

 

You need a battery...

 

Welcome to the forum


Test battery AFTER it sits overnight or for at least 5 hours.
12.3volt is the lowest it should go
12.2v or lower is an older battery that needs to be replaced


Battery Light on dash is GROUNDED(turned on) by the alternator.
So Battery light should come on when key is on but engine/alternator is off, because alternator is a ground when it is not working.

After start up Battery Light should go off if alternator is no longer a ground

2008 uses Smart Charging
read here: http://www.valeoservice.com/data/mas...E6E8714173.pdf

So battery needs to be silver calcium type, not lead acid(normally used in vehicles)
But I have read it didn't matter, just that lead acid wouldn't last as long as silver calcium
So 5 years vs 7 years

Also check 2 fuses in cab fuse box, fuse #9 and #10 both are part of charging system