Just the other day, one of my friends was talking to me how his BMW 335i hits 0-60 in under 5 seconds and that it is an impressive figure. I could agree to that fact but also said that I’m not a fan of BMW as they come quite sensitive and you need to be extra careful with those gorgeous vehicles. He strongly disagreed with me and said how he never had any problems (2 years and 5 months) with his four-wheeler. I must have jinxed him. His battery died the next day and he called me and said that I owe him a new battery, I helped him with a new one and we had a great laugh on that.
Are there ways to prevent this?
So, your car is constantly monitoring the battery state and if the battery is not drained by some circuit. And before it happens, before your battery gets completely depleted or it’s so old and damaged so that you’ll not be able to start your car there will be some symptoms that will tell you that you should service your vehicle and that you should check your battery state.
The first thing is your welcome lights. If you have your headlights switch set to the AUTO position or to the ON position you should see all the lights (in front and the back of the car) turning on when you’re unlocking your car. Of course, if you have that setting enabled in your instrument cluster or your iDrive system. So that’s the first tip that your battery should be checked.
The second thing that you can notice is when you are using your radio with the engine OFF. For example – you are cleaning your car, and you turn on the radio just to listen to some tunes. And after few seconds or few minutes on the dashboard, you can see the yellow batter indicator that will tell you that the battery level is going low and you should limit power consumption in order to preserve power to start the engine. So that’s your clue number two.
The third thing that you should look for is the clock. If it resets by itself, that means that the car detected low voltage in your system and it’s keeping the battery from being drained. There’s a relay responsible for cutting off any system that is not essential to start the car (that includes your instrument cluster at the moment), so those systems are shut off completely. They are not in standby mode, but their power is cut off from them just to make sure that the battery will not drain, that the voltage will not drop below the level that is required to start your engine.
So next time you are in your car, you put the ignition on, you’ll see the clock reset, you know that this system worked correctly, it detected that the battery could go very low, that the voltage will drop, and to prevent this it shut off some systems in your car.
So that was tip number three. And of course to be 100% sure what’s your battery state you can check the battery with a battery tester. Such a test will give you also a lot of information about the battery state but just remember that the battery is not everything in the car.
You should also check the alternator and if it makes the correct voltage. If it can provide amps required to keep the battery charged all the time. Also, remember that big engines and diesel engines that have higher compression ratio require a lot of amps to get the moving.
So the starter motor is draining more power, and if you’re making a lot of short trips and you’re constantly shutting the engine off and on (also you have your glow plugs, your electric power steering) there’s a lot of systems that are consuming this power and it’s a good idea to take your car for a longer ride or keep it once a while connected to a battery charger just to make sure that your battery is charged when you need it the most.
I hope that this will help you keep your car in the best condition.