hey everyone.
I have a mini cooper from hell. It is nothing but problem after problem. I have researched everything I could, with no success.

I replaced my alternator last week (which was ridiculous, tearing the whole front end apart). Everything was fine, until today. I tried starting my car, and my battery was completely dead. I have no idea why. There is obviously something draining it.

So, i decided to jump it with a truck, and be on my way. Nothing. It would click, but not turn over. So after about 20 minutes of fighting with it, I gave up. I took the cables off, and not even a light turned on. I would have thought that the battery would have held some kind of charge right?

I took the battery to auto zone to get it tested, they said that battery was fine after they charged it up a bit. I put it in my car, and it started right up.

I have no idea what is going on here. I go to school an hour away from home, I do not want to be stranded out there. This is only one of my problems that I have with this car. If anyone knows what is going on, any help would be appreciated. Please help.
Thank you!
Mitch.

hmm that sounds annoying. I would say I was told my AA man that I could not recharge my battery properly as it was "too drained" or something. So I had to buy a new battery as it would never be able to hold the charge. That is what he told me. I bought a new battery, so Im not sure if what he said is true or not.

So I would say that your battery might not be able to hold the charge if its the original battery from the car depending on how old it is? Just a thought anyway.

Incidentally clicking is a good sign, it usually means its the battery (again according to AA guy). So it might just be that your battery isnt great.

Yeah thats what I have been hearing with the battery.
My mom drives a jeep lliberty. I know batteries are different. But do you think it would be okay If I swapped them out for a bit to see if anything changes? It couldnt hurt anything right? I just want to make sure that is what is wrong with it before I go out and buy a brand new battery.

Maybe it was a bad connection, removing and refitting fixed it, Check the earth points, remove and clean, check starter motor connections also...

How old is the battery..........is it still the original?
5-7 years is average life, modern car batteries can last much longer although they often give less warning of an impending failure than in the past.

I believe the battery is around two years old. It has been through a lot though. I had one of those "Sunroof Tube Leaks." Which was not very fun. But I have ran the battery multiple times between diagnosing the problem, and now. (I bought the car not knowing it was like that, But I think it was like that for a while.)
But since then, My gauge lights, and my Tachometer has stopped working. Do you guys think a new battery would fix this problem as well? I know that MINI's are tempermental with electric stuff, so I dont know.

Found out the hard way when I let the battery in a Z3 get too low (the car was only driven every 3 months or so). Apparently lead acid batteries (even sealed ones) don't like dropping below 11 volts. Mine did it once and never recovered. :(

Electrical problems are the hardest to pinpoint out all car problems, drive you to the point of pulling your hair out. My brothers Saab just had a battery issue. There was a dead cell in the battery and the specialist told us it was due to him having a battery that was not strong enough for his car. The battery tested good and would charge up, but would die within a couple of days. With your gauges glitching out, that is the first thing that I would think it could be. If you do replace the battery, get something with a little more power, something around 850-1000 CCA. Look into getting an Optima Red cap or a Duralast Platinum.

A good investment for a seldom driven car (or extended storage periods) is a "charge & maintain" unit. These units charge the battery then cycle up and down charging and decharging as if the car were being driven. I've had one for more than 8 years on my: MX-5, then Valiant Charger, then MF TF160 and the batteries have always lastest - never changed even one in that time.

My Cooper S is a daily driver with a 70+ klm commute so don't use the charger currently - save it for the next weekender car I suppose.

If the sunroof leak was internal to the car you may have water ingress in some connectors or a control unit somewhere, worth having a look to see if anything looks corroded or wet..