Fixing your battery discharge issues – The solution is to recognize these issues and adjust your driving habits to allow the battery time to recover such as:
Reducing the number of short drives or allow the car to idle for an extended period of time during or after a short trip in cold weather; Install a to plug the car in while it sits in sub zero weather and recharge when the car is not operating; Use as few accessory features as possible; Shut of the auto Start/Stop feature to preserve battery usage.
If none of these ideas work, then call our shop and we can diagnose potential alternate sources for the lower power message. It may be due to
a battery that is older than 3-4 years old and has reduced capacity; a current drain from a module staying on in the car when it is shut down and supposed to have gone to sleep; a battery IBS unit that is faulty; a programming update to adjust computer sensitivity.
Atlantic Euro Cars has made significant investments in our diagnostic and programming abilities. We can help get your battery discharge warnings, or any other issues fixed right here in Saint John. don’t hesitate to with any of your concerns. : Increased battery discharge warnings and how to fix them
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- 1 What causes BMW battery to drain?
- 2 What is the main reason for battery drain issue?
- 3 Does fully discharging a battery damage it?
- 4 Can you save a discharged battery?
- 5 How long should a car battery take to discharge?
- 6 What affects battery discharge?
- 7 Why is my BMW battery discharging when stationary?
What causes BMW battery to drain?
‘ Electrical devices or lights left running, a defective charging system or alternator, and extreme weather are some common reasons but maybe it’s just time to get a new battery.’
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Should I be worried about battery discharge warning?
As with many vehicles, this warning is a failsafe to guard against an unexpected dead car battery. For example, this might happen if you’re playing the car radio (accessory or key-on) while the engine isn’t running. The warning will indicate that continuing to drain power will cause your battery to die.
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What is the main reason for battery drain issue?
4 Reasons Why Your Car Battery Could Be Getting Drained Sooner Than You Think Car Battery, Battery Tips, Bike Battery – October 27, 2020 One of the scariest situations that you can or even might have faced is that you’re running late for a meeting and your car refuses to start.
- Rush to your car, only to find out that it won’t start.
- The headlights are dim, the ignition is feeble and the engine simply stutters and dies with every turn of the key.
- It is only in such situations that we realize we’re dealing with a dead battery.
- But, have you ever wondered what are the most common causes of this? They are simple human errors – like leaving the headlights on, not shutting the trunk of your car or maybe even leaving on some light inside the car.
Here are the 4 reasons why your car battery could be getting drained sooner than you think: 1. Accidentally leaving the car headlights on after parking: This is an error majority of the drivers have made at least once in their lifetime. Leaving the headlights on is one of the reasons why the car battery drains out sooner than expected.
2. Leaving electronic devices charging for long periods: 3.Leaving the music system on: 4. Faulty Charging:
This has lately become the biggest reasons behind the car battery draining out. We put our Smartphone’s or tablets for charging unknowingly while it’s on battery mode. These gadgets drink up your battery power when left unattended for a long period. But with TATA Green Batteries longer battery life, #WeGotYourBack even when you leave your device plugged in and charging.
- The music player in our car requires electricity to play your favouritemusic.
- The source of this electricity obviously is your car battery.
- One of the most usual mistakes we all have made at some point in time in our lives is playing the music without running the car engine.
- With TATA Green Batteries longer battery life, the music never needs to stop.
#WeGotYourBack with any entertainment you need for your car. If your car charging system isn’t working properly, your battery can drain itself even while you’re driving. Most cars power their lights, radio, and other systems from the alternators which makes the battery drain worse if there’s a charging problem.
The alternators usually have worn-out tensioners or loose belts that keep it from working properly. TATA Green Batteries ensure your battery comes free from all such small troubles so that faulty battery charging is never an issue. #WeGotYourBack with our easy-to-charge batteries. Take long trips or short, power up your phone or the phones of all your road trips, when it comes to longer battery life and hassle-free maintenance, rest assured #WeGotYourBack.
Take to the roads with confidence only the best car batteries and two-wheeler batteries can provide you with. Switch to TATA Green Batteries! : 4 Reasons Why Your Car Battery Could Be Getting Drained Sooner Than You Think
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Does fully discharging a car battery damage it?
It only needs to drop down to around 10.5 volts to be considered fully discharged. If it drops down below that, the battery will become damaged due to excessive sulfation. Sulfation refers to the formation of lead sulfate crystals on the surface of the battery’s lead plates.
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Does fully discharging a battery damage it?
1. A lead battery should never be fully discharged – Lead-acid batteries can only be discharged up to 50% before irreversible damage occurs. In practice this means that you will only be able to use half of your battery capacity. Semi-traction batteries such as AGM en Gel lead-batteries are often used as Marine batteries for water sports and angling.
These batteries can often be discharged up to 70%. This means that in practice 30% cannot be used. Lithium batteries can be fully discharged which means you have the full capacity available to use. In addition, unlike lead-acid batteries, Rebelcell’s lithium batteries are protected against deep discharge damage thanks to the Battery Management System (BMS).
The BMS willl “automatically” switch off the battery when it drops below 3%.
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Can you save a discharged battery?
Can You Revive A Dead Car Battery? – We have briefly discussed a few ways to revive your dead car battery. Obviously, jump starting your car is probably the most well-known way of doing this. It is important to check out how much a jump start costs and who to call in case you don’t want to do it yourself.
A battery that simply will not start, no matter how much you try while punching the air and cursing the sky, can be brought back to full functionality with a jump start. Also, driving your car around is a great way to fuel up your car battery, but this is not necessarily involved with reviving the battery, since the battery had at least enough voltage to start the engine.
If a battery is completely dead but has been revived by a jump start, there are ways to fully recharge your battery. The first is, as mentioned, by driving around. If that does not seem to work, however, car battery chargers can regenerate all of the charge into a battery.
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What does it mean when it says battery discharging?
NOCO – What Does It Mean To Drain Your Battery – Support Discharging, or draining, describes the process of your battery loosing voltage, or energy. It is important to understand that a battery is always discharging anytime it is not being directly charged.
Discharging your battery can be both an active or an inactive process. When you are using your battery to power electronics in a boat or motorhome application, this becomes an active process. Equally important, you are inactively discharging your battery whenever it is left unused for any period of time, even without a load connected.
: NOCO – What Does It Mean To Drain Your Battery – Support
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How long should a car battery take to discharge?
Most car batteries that are in good condition will last at least two weeks without needing you to start the car and drive to recharge it. But if you don’t intend to drive your car for some time for whatever reason, you should still start it up once a week to recharge the 12-volt battery.
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What affects battery discharge?
Self Discharge Characteristics – The self discharge rate is a measure of how quickly a cell will lose its energy while sitting on the shelf due to unwanted chemical actions within the cell. The rate depends on the cell chemistry and the temperature. Cell Chemistry The following shows the typical shelf life for some primary cells:
Zinc Carbon (Leclanché) 2 to 3 years Alkaline 5 years Lithium 10 years or more
Typical self discharge rates for common rechargeable cells are as follows:
Lead Acid 4% to 6% per month Nickel Cadmium 15% to 20% per month Nickel Metal Hydride 30% per month Lithium 2% to 3% per month
Temperature Effects The rate of unwanted chemical reactions which cause internal current leakage between the positive and negative electrodes of the cell, like all chemical reactions, increases with temperature thus increasing the battery self discharge rate. See also Battery Life, The graph below shows typical self discharge rates for a Lithium Ion battery.
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What happens when a battery is over discharged?
When the battery is over-discharged, the internal resistance increases. It discharges 1.5 to 2 times the capacity of the battery making it difficult to recharge them. First of all, you should check the present voltage level of the battery, which is lower than the cut-off voltage.
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Does a BMW battery recharge itself?
An automotive battery is your car’s life and soul. It powers everything, from the engine to the headlights of your vehicle, and is, therefore, an essential part of your car. However, no car battery, however powerful, can last forever. Once a car battery is dead, you might wonder if it can get recharged on its own. However, even after supplying electrical power to these features, the alternator has excess power left which is converted from AC to DC and reserved for the battery. A healthy automotive battery gets recharged using this power. Since cells do not produce energy, they do not have any other mechanism to charge themselves.
- Simply put, no car battery, whether healthy or dead, can charge itself.
- It always requires an external power source to get charged.
- Can Dead Batteries be Charged? Once a car battery is dead, the alternator will fail to recharge it completely.
- In such cases, you might jump start your car and keep it running temporarily.
Some professionals use special car battery chargers to charge a dead battery temporarily. Therefore, the only permanent solution to a dead car battery is a replacement by a reliable car battery service provider, Signs of a Dead Car Battery Before your car battery dies suddenly and leaves you stranded, you must know some signs of battery ageing or damage.
- Here are some tell-tale signs of a dead car battery that every car owner should be familiar with.
- Slow Cranking Engine Dead car batteries fail to supply your engine with the necessary amount of power.
- As an automotive battery starts weakening, the cranking sounds of your car’s engine become prolonged.
Flickering or Dim Headlights Batteries are responsible for powering your car’s headlights or interior lights when the engine is off. If a car battery is weak, it fails to do the same. As a result, your car’s headlights start to flicker or show reduced brightness.
- Backfiring Due to a weak car battery, your car’s fuel cylinder develops intermittent sparks, which ultimately leads to fuel accumulation.
- As you turn on the car’s ignition, this fuel burns suddenly, causing backfiring.
- Clicking Sound The automotive battery supplies an electrical signal to the solenoid, which then transfers it to the engine.
A weak car battery fails to provide enough power to the starter solenoid of your vehicle. As a result, the solenoid starts emitting clicking sounds. Apart from these, a damaged or dead car battery can also display an abnormal shape, excessive corrosion, or emit bad odour.
- Once you notice any of these signs, you should not wait for long to get a car battery replacement.
- If you are looking for world-class car battery service with PAN India presence, approach Car Fit Experts.
- We stock the highest quality batteries from Amaron and Exide and only use the most suitable ones for your car.
Our experts are trained to handle car battery replacement for a range of car models from different brands. We also offer doorstep car battery service at a mere phone call – +91 9555305044. To get an excellent-quality battery and even better replacement service for your car, approach Car Fit Experts today!
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Do you have to reprogram a BMW battery?
Which BMW models require battery registration? – All BMW models manufactured after 2002 require battery registration, as they are significantly more advanced in terms of electrical environment, which aims to improve the gas mileage. Models developed since 2002 are equipped with the system of Intelligent Battery Sensors (IBS) that contains micro processors monitoring and measuring charge, discharge, voltage, current and battery temperature.
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How do you start a car with a discharged battery?
You can suffer a dead car battery for a whole host of reasons. This is why flat car batteries are the number one reason for call-outs to breakdown services. There are a number of reasons why car batteries die. A few common ones include:
- Leaving headlights, interior lights, flashers, and the radio on when the car isn’t running
- Using the air conditioner when the car is not running
- Not starting a car for long periods of time (e.g., while it’s in storage)
- Lack of battery maintenance (e.g., not keeping terminals clean)
- Failure of the diode bridge or voltage regulator in the alternator; the alternator charges the battery when the car is running
- Low air temperature, which causes batteries to freeze
What To Do When Your Car Battery Dies The most common way to deal with a dead battery is by jump-starting it. All you need to jump-start a car is a set of jumper cables and another car (a good Samaritan) with a functional battery. Keep in mind that you should never try to jump-start a car if its battery is cracked and is visibly leaking acid. To safely jump a start, follow these steps:
- Take out your jumper cables.
- It’s a good idea to buy a set of jumper cables and keep them in your car. If you don’t have jumper cables, you have to find a good Samaritan who not only is willing to assist you but who has jumper cables as well.
- Engage both parking brakes as well.
- It has “POS” or “+” on it, or it’s bigger than the negative terminal.
- Use one of the metal struts that holds the bonnet open.
- If it won’t start, make sure that the cables are properly connected and have the good Samaritan run his or her engine for five minutes. Then try to start your car again. If it still won’t start, your battery may be beyond help.
If the jump works and your car starts, don’t shut off your engine! Drive around for at least 15 minutes to recharge your battery. If the car won’t start the next time you use it, the battery isn’t holding a charge and needs to be replaced. Alex Todd Brand Manager at Its4women commented “If your vehicle will not be used for an extended period of time, it’s wise to invest in a battery charger so you’re prepared if and when you need a charge.”
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How do I find out what’s draining my car battery?
Download Article Download Article If your vehicle is drawing power from the battery and all of the lights and other electrical components are off, you might have a parasitic battery drain (or draw). Luckily, you can usually find the cause of a parasitic draw yourself.
- 1 Unplug all devices from your vehicle and make sure no electrical components are on. Turn off the radio, heat or A/C, lights, windshield wipers, etc. and close your glovebox and lighted mirror covers. Engage the emergency brake, turn your vehicle off, and remove the key from the ignition if you haven’t already.
- Be sure to remove any cables that may be plugged into your vehicle, like a GPS unit or phone charger, as well.
Tip: In some cases, you may need to input a security code when you turn on the vehicle after disconnecting the battery, so check your owner’s manual for the code before you get started.
- 2 Charge your battery fully. In order to accurately detect the parasitic draw, you need to begin with a fully-charged battery. Pop the hood and locate your vehicle’s battery. Use a vehicle battery charger to charge the battery to 100%.
- Many car batteries are 12.6 volts. You can check the power with a multimeter to ensure the battery is fully charged.
- If your battery is old or damaged or isn’t reading 12.6 volts when fully charged, you may want to replace it before moving on.
- 3 Remove the negative battery cable from the negative battery terminal. Find the negative cable, which will be marked with a minus sign (-) and may have a black cover over it. Remove the cover, if applicable, and use a wrench to unbolt the negative cable from the terminal.
- Be sure to use the negative, not the positive, cable to test for the draw to prevent electrical shorts!
- Generally, a 10-mm open-ended wrench is the tool you’ll need to remove the cable.
- 4 Set up a digital multimeter, The multimeter has both a black wire and a red wire attached to it as well as several different input slots. Connect the black wire to the “com” (common ground) input and plug the red wire into the highest amp input (usually 20A). Set the dial on the multimeter to measure amps.
- Choose a digital meter than can read up to 20 amps and down to 200 milliamps.
- 5 Attach the multimeter to the negative battery cable and terminal. Place the red lead through the metal circle at the end of the negative battery cable. Touch the black lead to the negative battery terminal.
- You can use plastic clamps to secure the leads in place so your hands are free and the meter continues to operate.
- 6 Note that you have a parasitic draw if the reading is more than 50 milliamps. There are a few things that constantly draw power in a vehicle, such as the clock on the radio, so it’s normal to have a reading between 20 and 50 milliamps. If your reading is higher than that, it means there’s a draw and something is using too much power.
- 1 Pull out the fuses one at a time while watching the multimeter reading. Locate the fuse box under the hood. Use a fuse puller to remove the fuses, starting with the ones with the smallest amp ratings and working toward the ones with the highest amp ratings. After you pull a fuse, check the multimeter to see if the reading changes. If it doesn’t, replace the fuse and move onto the next one.
- Once you’ve worked through all of the fuses in the fuse box under the hood, check the fuses in the fuse box(es) under the dash. It’s best if you have a friend help you with this so one person can pull fuses while the other person watches the reading on the multimeter. If you don’t have anyone to help, prop the meter against the windshield so you can read it from inside the vehicle.
Warning: Disconnect the multimeter before you open the door to check the fuses under the dash. Disable the door switch by clamping a piece of scrap wood over it so it remains depressed. Then, reconnect the multimeter.
- 2 Stop when pulling a fuse makes the reading drop significantly. Removing a fuse may cause the multimeter reading to drop a few milliamps, which is normal. What you’re looking for is a significant drop, such as if the reading goes from 3.03 amps to 0.03 amps. When this happens, you’ve found the electrical circuit that’s creating the parasitic draw!
- 3 Find out what’s running on the affected circuit. Consult the chart on the fuse box and/or the owners’ manual to find out what components are powered by the fuse that’s causing the drain. You can also check the wiring diagram for the particular circuit to help you narrow down the problem.
- Usually, you can find digital copies of the manual and wiring diagrams online.
- 4 Check each device or component on that circuit. Replace the fuse and disconnect each lamp, heater, or electrical device one at a time. Flip all of the switches that correspond to the components as well. Watch for the reading on the multimeter to drop to find out which component is causing the drain.
- For instance, say the offending fuse controls the power antenna as well as the radio. Unplug the radio and see if the draw goes away. If it doesn’t, unplug the antenna and watch for the reading on the multimeter to drop.
- 5 Repair the component causing the draw, disconnect the multimeter, and reconnect the battery, The repair process will vary widely depending on what the problem is, so if you’re not sure how to fix the component, hire a certified mechanic to make the repair or replacement.
- You may be able to simply flip a switch into the “off” position to eliminate the draw, or you might be facing a more complex problem, such as an issue with a wiring harness.
Add New Question
- Question Why is the ammeter connected between the negative terminal and cable instead of the positive side? The ammeter can be connected to either terminal with identical results with one exception: if you get against a metal object while using a positive terminal, there is potential for a short circuit with a shower of sparks. Use the negative terminal – that is safer.
- Question If a new stereo was installed and it wasn’t done properly, can that drain the battery? Yes, if it was connected straight to the battery rather than through the ignition. It should only draw a small amount for the clock when the ignition is off. If you can use the radio with the ignition in the off position, you have a problem.
- Question Does a car alarm drain the battery? Yes, it can. If checking for a drain, the alarm should be the first thing to be disconnected to see if the drain stops.
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- Don’t forget to check inside the cigarette lighter and power sockets. Leaving a phone charger plugged in for a long time can cause a parasitic draw. Also, sometimes coins can fall in the sockets and cause shorts. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- 50 milliamps is a good rule of thumb for max allowable parasitic draw. Anything over 50 milliamps would require further investigation into the exact device which is drawing power. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- Connect the multimeter to the negative battery terminal, rather than the positive one, to prevent electrical shorts. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- Exercise caution when working with your car’s electrical system. Protect your eyes and skin with goggles and gloves. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- The information in this article is intended to provide general answers for frequently asked questions about this topic, and may not be applicable to all vehicles. Please refer to your vehicle’s owner’s manual for details about maintenance intervals and other vehicle specifications. If you are unsure about your ability to perform any repair, we recommend contacting a certified automotive technician to perform the necessary work. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- Consider having this done by a professional. Disconnecting and reconnecting your battery incorrectly can cause damage to your vehicle’s electrical system, or it could reset the module, causing the drain to stop, but only temporarily. As a small thank you, we’d like to offer you a $30 gift card (valid at GoNift.com). Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy!
- Safety goggles and gloves
- Battery charger
- Plastic clamps
- Digital multimeter
- Fuse puller
- Scrap piece of wood
- Owners’ manual
Article Summary X If you need to find a parasitic battery drain, turn off all of the vehicle’s electrical components, engage the emergency brake, and remove the key from the ignition. Next, use a vehicle battery charger to charge the battery to 100%. Then, unbolt the negative cable from the battery terminal with a wrench and attach a digital multimeter to the negative battery cable and terminal.
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Why is my BMW battery discharging when stationary?
Ever since the start of the Covid-19 pandemic, many countries had introduced country wide lockdown to control the spread of the virus. In Malaysia, we have many iterations of lockdown, MCO/CMCO/RMCO/EMCO/Semi EMCO, etc. For the benefit for our non-Malaysian readers, feel free to refer to this Wikipedia article: https://en.wikipedia.org/wiki/Malaysian_movement_control_order The movement control order forces many car owners to leave their car idle for days, weeks or even months.
- When they start their car after a long idle time, they get a message like below.
- The first reaction would be, “Do I need to change my battery?”.
- The purpose of this article is to answer this question and to equip our readers with knowledge on how the electrical system works and to avoid this issue from happening again.
We will be focusing on modern BMWs and Minis in this article but the concept should apply to all cars. Figure 1: Meter Cluster ‘Charge Battery’ Warning The photo above shows the ‘Charge Battery’ warning on the meter cluster. Figure 2: iDrive Battery Discharge Warning The photo above shows the iDrive warning on a modern BMW. If you need an immediate answer on how you can prevent the messages above, start your car every 2 days and drive around for at least 15-20 minutes to get your battery back to 75% of its capacity. Figure 3: Vehicle Power Supply (image Credit: http://brianesser.com/) We will focus on 2 main parameters which is power supply and discharging,
- Power Supply in the car which is the Battery (Energizer) and Alternator (Generator) – See figure 3
- Discharge of the battery (Parasitic current draw)
The remainder of this article will be split into 4 parts: Part 1 – Battery (Energizer) The battery stores chemical energy which can then be converted into electricity. We will discuss about the following topics:
- Battery Capacity
- CCA (Cold Crank Amps)
Part 2 – Alternator (Generator) The alternator is powered by the vehicle’s engine and it generates electricity by converting the mechanical energy supplied by the engine into electrical energy. The following topics will be discussed:
- Output rating / Capacity
- IGR (Intelligent Alternator Control)
Part 3 – Discharging
Parasitic current draw
Part 4 – Table for charging and discharging duration Part 1 – Battery (Energizer) Battery Capacity Figure 4: Label on a BMW AGM Battery It is fairly simple to read a battery capacity and it is mainly labelled on the battery itself. As an example, Figure 1 shows an AGM battery with 90 Ah capacity with 900 CCA. CCA (Cold Crank Amps) The next thing that we need to understand is the CCA (Cold Cranking Amperes).
Why is this important? This is because the capacity of a battery is important in determining the CCA where is the most important to cold start a car. “CCA is a rating used in the battery industry to define a battery’s ability to start an engine in cold temperatures. Generally speaking, it is easier to start an engine in a warm environment than in a cold one” (1) So, how do we calculate the CCA of a battery and how much our car engine needs it? Basically It is Ah * 0.07 = CCA and the factor of 0.07 is the average of the battery type in the industry.
(2) So how do we determined the minimum CCA needed based on the engine capacity? “The standard recommendation is a battery with at least one Cold Cranking Amp ( CCA ) for every cubic inch of engine displacement (two for diesels). ” (2) So For F30 2000 cc would be 122 cubic inch. Figure 5: Alternator And Its Ratings Typically, 320i would be using 170 Amp alternator and 328i would be using 210 Amp. Let’s take 170 Amp as the variable to study.170 Amp means the alternator generates 170 Amp @ 6000 RPM. So during idling, that would the engine runs at around 1000 RPM only and thus the alternator would be generating 28 Amp @ 1000 rpm.
How much electrical energy does the alternator provide to the battery? In the rules of charging, usually it should provide 10% of the battery capacity (again this is critical to register the battery for BMW after replacement in order to make sure the charging rate is a per the battery capacity). So for example, the battery capacity is 90 Ah, the charging should be 10% of its capacity which is 9 Amp per hour.
Also the alternator would change this rate depending on the battery exhaustion like the chart below: Figure 5: Battery Charge Power Requirements When the battery is at 100% charge level, it only requires 2-9Amp from the alternator. When the battery is drained to 25% charge level, it requires 31 Amp. When it regains about 40% charge, it will require 19 Amp and this will the slowly drop to 13 Amp when it reaches 65% capacity.
When the battery charge level increases the power requirements to charge the battery will decrease. So, if the alternator produces 28 Amp only and the car needs 50 Amp, the battery discharging while stationary would pop up, This message will continue to pop up until the battery is charged to a reasonable level and the alternator can generate enough electricity to both power the car’s electrical components and charge the battery at the same time.
IGR (Intelligent Alternator Control) Before we begin the calculation, let’s see what an IGR or Vehicle with Intelligent alternator control does. “Unlike the normal control of the battery charge, the intelligent alternator control prevents 100 % charging of the battery.
- The battery charge goes to the range of 75 – 85 % of the maximum possible charge.
- This means that the battery remains “chargeable” to permit energy recovery in the vehicle overrun phase.” – ISTA So with these features we can safely assume that the battery is 75% ( let’s take the worst case) of its capacity all the time even if it is “fully charge” mode.
Also this is another reason why you need to register the battery during replacement to the DME – Digital Motor Electronics) in order to perform as per the new battery specification. This is important to allow the DME to know that a new battery had been installed and not overcharge it.
- This means that the capacity 90Ah would be 67.5Ah all the time.
- Part 3 – Discharge Parasitic Current Draw When a car is inactive, there will be a normal parasitic current draw from the radio, clock, anti theft system, comfort access etc.
- A normal draw would be around 30-50mA per hour,
- Anything above that would be considered abnormal and that is the sign there is some device that is drawing the current from the battery without notice.
Anything that exceeds 100-milliamps indicates an electrical issue that needs to be addressed. Battery standalone discharge rate A new AGM typically self-discharges at about 1-2% per month, while an old one may be as much as 2% per week. (4) Part 4 – Table for charging and discharging duration So how do we calculate this? Assuming you manage to drive the car around 2150 RPM on average. Figure 6: Simulation Of Discharge and Charging Duration Conclusion
- Once the car is not started for 11 days, it takes 65 minutes to reach 75-85% battery capacity with an average of 2150 RPM and minimum accessories turning on while driving. The rest as per the chart.
- It takes 32 days to fully drain the battery.
- The car can still be started even at 25% of its capacity as is still stores enough power for cranking (based on minimum CCA required). That is after 35 days but this might not be applicable for diesel with the same engine capacity.
- Above calculation assumes that there is no abnormal parasitic draw and a healthy battery that has 3-5 ohm resistance (result from battery tester) or <100 cycles.
- If let’s say the car is daily driven, it would draw only 1 Ah every 12 hrs of inactive period.
- If your car continues to display the “battery discharge while stationary” warning despite daily driving, there are two possibilities of causes this failure:
- Battery still healthy (Resistance of 3-5 ohm or <100 cycles) - the IBS cable may be faulty or your car may have an abnormal parasitic current draw of more than 50mA.
- Battery cell is getting old (Resistance above 10 ohm). You need to replace your battery.
- Check the alternator as a failing alternator will not be able to charge the battery correctly.
Disclaimer – This article is purely based on research and our understanding of formula and concepts from multiple sources. Calculation and formulas used are referenced below. Our intention is to help our readers to understand the reason behind the battery discharge warning and to understand how different electrical power components work in your vehicle.
We believe that the article will equip the reader with sufficient knowledge to avoid the unwanted situations. Please do not attempt to drain your battery to the final 25% based on the numbers above and assume it is sufficient to crank your car. Note that every vehicle and battery condition are different.
Follow the best practice of keeping your car engine on a regular interval. This keeps not just the battery but all other components in your car in a good running condition. Thank you for your time for reading this article and hope that this would help our readers make a good judgement and decision” References