My buddys 986, batt drain/small leak?

[haste]

Hello
my friend has a 98 986. He didnt drive it for about 3 weeks, and came back to it with the battery fully dead. The battery looks 3-4 years old minimum and wont hold a charge.

So he swapped in his tiny nissan battery and it drove on it for 2 days..then the next morning it wouldnt start either. This battery was also 5 years old.

So could a new battery fix all these issues? Or could it be something else draining the battery?


Also on the rear end area. He has spotted 4-5 micro drips of oil, which he saw none on the floor for the 5 months he daily drove it. Is this just from setting? He is showing all the bars minus one on the oil gauge on startup.. He only has 3k miles on his synthetic oil change.

He is really frustrated with these issues, as he has had 0 with his 92 bmw e30 with 200k lol..