1) Batteries do fail without warning once in a while.
2) It appears that you have evidence that you couldn't jump-start the car.

Maybe you could have push-started it and gotten it running.
(Is it an MCS or a MC 5-speed?)

GREAT to hear you are back on the road.

There IS one more thing you need to do though......

Go to a service center like someone else suggested and have them test the battery/alternator/voltage-regulator system.

It is (slightly) possible that you have a fault in one of those parts that will cause your new battery to cook fairly quickly.

My thoughts are better test now than have the same problem in 6 months at 3:30 AM in a bad part of Oakland. (In your underwear)

 

Good advice, i'll get it checked out. Hopefully next time the battery fails it does so when the MINI is parked on a hill. I have a 5 speed cooper so at least i've go that going for me.

 

sorry that your battery was dead adn it wasn't the security lockout.. but for future refrence I believe iti is, the lock button you press, I will double check that when I get my mini back from the service shop.

 

FYI... if you do buy a new battery make sure you get one that is ventilated. Due to the fact that the battery is inside the car if you do not get a ventilated battery.... well, it wont be good.

Most of the causes of battery failure are 2 things... heat and vibration. With the mini battery in the rear it keeps it much cooler than under the engine and if you have not messed with the battery, it is strapped down well. Also MINI batterys are rated for aprx 4 years. Since you are out of warrenty I wonder how old is your battery? I live in Sacramento and the life span for a battery here is about 3.5-4 years. In Las Vegas the life span for a battery is 2.5-3 years-- due to the heat. Ok, well, this is just my two cents. I hope that it was helpful!

 

He has a MINI Cooper 5-speed so the battery is in the engine compartment.

 

What is this security lock out that u are talking about?

 

Just for everyones INFO. :smile:
Charles

How to test a lead acid battery?

Here are some tests you can do to determine a battery's charge status and whether a battery is good or bad:

First, be sure to follow these important safety tips:

• Put on protective eye wear, rubber gloves and work clothes and remove all jewelry.

• Don't smoke, have open flames, or sparks near the battery.

Headlight Test - If your car will start, in the dark, pull your car up to a wall or a garage door. Turn off the engine and leave on the headlights. If they're bright, then your battery is probably fine. If the lights are dim, but get brighter when the engine is started, this tells you the battery could be bad and requires further testing. If the lights are dim and stay dim when the engine is started, this tells you that your charging system requires further testing.

Open Circuit Voltage (OCV) Test - An OCV test may be performed with a voltmeter.

1. To determine if the battery is experiencing a problem, turn off all electrical loads and the charging source.

2. For an accurate reading, allow the battery to sit with no electrical loads applied for at least one hour.

3. Connect a voltmeter to the positive and negative terminals and measure the terminal post voltage with no loads or chargers connected to the battery.

4. To determine the battery's state of charge, compare the OCV reading on the voltmeter to the OCV chart below.

Open Circuit Voltage VS. State of Charge
12.66V 100%

12.45V 75%

12.24V 50%

12.06V 25%

11.89V 0%

It is not recommend that you substitute the OCV test for a specific gravity test, which is more accurate. The OCV test is the only way to determine the state of charge of a sealed no-maintenance battery.

Specific Gravity Test - This test is performed with a hydrometer, which is the most accurate hand held tool for determining the state of charge of a lead acid battery.

1. Draw electrolyte into the hydrometer a few times so that the float reaches the same temperature as the electrolyte. This will increase the accuracy of your readings.

2. Hold the hydrometer vertically so that the float is free and does not touch the inner walls of the barrel.

3. Hold the hydrometer so that the liquid is level in the barrel and at eye level.

4. When you draw the electrolyte, make sure that the hydrometer is full.

5. To get the most accurate hydrometer reading, you should adjust your hydrometer reading according to the temperature. If the electrolyte temperature is ABOVE 80?F, ADD .004 (called "four points") to the hydrometer reading for each 10 degrees above 80?F. If the electrolyte temperature is BELOW 80?F, SUBTRACT four points from the hydrometer reading for each 10 degrees below 80?F.

6. Check each individual battery cell. If the specific gravity varies more than .050 or "50 points" among the cells while the battery is at a 75% state of charge or above, then the battery is bad and should be replaced. The cells that have a specific gravity of 50 points less than the highest cell are bad cells. A hydrometer reading of 1.265 or greater at 80?F indicates a full charge for most batteries. To determine the battery's state of charge, compare the hydrometer reading to the Specific Gravity Chart below.

Specific Gravity VS. State of Charge
1.265 100%

1.225 75%

1.190 50%

1.155 25%

1.120 0%

Load Test - This test is a 15-second discharge of the battery at a 1/2 cold cranking amp level. A more accurate testing method than a voltmeter or a hydrometer, the load test is often required to determine whether a battery is good or bad. This test requires special equipment but parts houses such as AutoZone will usually do it free.

 

First off good show with the posting of the the info....great stuff....through out this post I never had a doubt it was the battery....ofcourse in the desert out here when it hits 110 batterys fail constently.....

My question to you is this...What about those of us with Xenons...or can you use this "headlight Test" using the fog lights and/or parking lights

since this was an FYI for everyone.....I figure we should cover that....