How do you tell if it's your battery or alternater that is faulty?

 

 

Not sure if this is important but the car had been sitting for a while and got a slight leak so very damp inside (think leak fixed now)

 

Anyway what happened was drove it after it sitting for a long time and the temp gauge wasn't working and the lights were very dull, got about 15 mile and put my foot down the car completely held back windows moving up n down very slowly so when i got it home took the battery out put in on charge don't think it was a full charge.

 

Gave it another go drove much better all lights were working as bright as usual playing up slightly but assumed it was down to resetting the ecu after diconecting the battery. Anyway got up the city and it slowly started playing up again really badly holding back put your foot down and feels like it's going to cut out, lights really dull, windows really slowly, no powered steering and a christmas tree hicas light.

 

Once i got home lights were on revs droping very low reved the car, it held back, turn all the electrics off reved the car and appeared to be fine.

 

Any ideas if this is my batt or alternater? and how i could do a test to check?

http://www.repairfaq.org/ELE/F_Car_Battery.html#CARBATTERY_006

 

http://www.bcae1.com/charging.htm