Bmw Battery Discharging While Stopped

The Optima 400 has an extremely long clamp cord, the wires that run from the device to the clamps in the engine bay or on the battery. A car would decelerate if there was not enough fuel or electricity to keep the car running. Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. I'll report back if there's a problem, but it is unlikely. BMW cars equipped with the intelligent charging system may display a warning message stating Increased Battery Discharge or High Battery Discharge. 9 volts, so it can never be run flat (again, for the geeks, it has a low. With the launch of the production BMW i3 battery-electric vehicle (also available with a range extender) looming, the BMW Group provided more details about the first series-produced model from its new i brand, offering customers electric mobility in a premium small car package. The pre-test drive required 0. I have never had that experience on any car ever I drove. A battery is packed with chemicals that produce electrons. This page was made for the BMW driver in mind to help you with the Dash Warning Lights. 2013 BMW 3-Series Sedans and Sports Wagon models are built on a new-generation (F30) platform that made its debut with the 2012-model sedan--and is slightly longer, lower, and wider, while Coupe and Convertible 3-Series models remain built on the. I did not drive it for ten days. If one of those cells goes bad, the battery can be jumped and perform fine. It is preferred to slow charge all batteries, slow charging rates vary depending on the battery’s type and capacity. Im not to sure what it really means, everything appears to be working fine. Estimate does not include taxes and fees. Testing options • BCI load test—Using a carbon pile or similar discharging device, load the battery at ½ of the CCA rating. It lasts long with 400 cycle at 80% depth of discharge. A dead battery happens to all of us. 7) today, I received a call from the dealership and they said, BMW-usa did not found the any cause that may have caused the issue but given engine intermittently stopped, they are going to replace. There has been no recall on battery discharge. The IBS contains a micro-processor that is used to monitor/measure various battery conditions such as: Terminal voltage via measurement from B+ to Gnd, Charge/discharge current via. And then limp mode. From there you will have to do the draw test. be diminished when testing a battery that was recently charged. Battery Discharging when vehicle stopped Used to get this message when I first got my 2016 M235x in March-17 (6 months used; 2K miles). If this is the original battery from 2008, then the battery is six or seven years old. I disconnected it by removing the two connectors at the back of the nav unit. Car Battery Drains Overnight. People often think that a dead battery should be discarded and pay huge bucks to buy a brand new one. You would think that replacing a battery in a car would be one of the easiest things you could possibly do. While electric motors are much more efficient than internal combustion engines, batteries can store only a small fraction of the energy in fossil fuels. 8-Sep-2019-PM : Battery Discharging While Stopped Bmw @ Battery Discharging While Stopped Bmw Battery Reconditioning Best Best Battery Discharging While Stopped Bmw. The odds of this happening are very low with a small motorcycle battery. However, there are four common problems that can cause a battery to drain slowly. I did not drive it for ten days. Essentially a microchip built into every Full Spectrum battery, IPT stops the battery from ever discharging below 12. Getting Battery discharging while stopped. If charge and discharge current are inverted, the power cables on the shunt must swapped: see the quick installation guide. I ignored the warning for about two months, as the car started fine, and showed no. “The attempt would likely discharge the Prius battery. 2 mA draw enough to worry about discharging the car’s battery? Probably not. However, the alternator will not be able to generate enough of a charge even after running a while. This will monitor the battery for draws while in sleep mode and if the battery drops to low is will shut off consumers to make sure the battery can start. The indicator lamp changes from green to red. I installed a battery cut-off. After running the motor for a while, turn the car off. At the same time, the yellow lifting symbol in the instrument cluster lights up. A dead battery happens to all of us. Of those recalls, 31 have been for the BMW 750LI starting in 2012. My battery tender comes with a couple of connectors. Depending on the age of your car, the starter may also be suspect. Shallow charge and discharge cycles are also better for battery health than deep discharges. 1), it seems abundantly clear that the battery will have positive and negative potential on respective terminals. Take the battery to a professional battery specialist who knows AGM technology. One of the best ways to trouble-shoot a discharging battery is to use the fuses. See our lemon odds and nada odds page to see vehicles with no repairs or vehicles with more than three repairs. com was created to help BMW drivers find a trustworthy and reliable independent mechanic to service their BMW. BMW Repair Shops by City. com for sale are available!Talk with suppliers directly to customize your desired product and ask for the lowest price, good discount, and shipping fees. It is not unusual for a car battery to fail after that period. 6 (normal temperature),. Battery tenders provide a trickle charge and exercise to the battery to keep it healthy. Car battery drain is a common enough problem. Now the bike stays charged and no clicking noise when plugged in. The pre-test drive required 0. One thing I might add, the unit limits the amount of current it draws from the USB cable to 500 ma (1/2 amp) because that is the maximum a USB port can deliver. While recharging any battery, if the battery becomes hot when you touch it, stop charging it (a battery being charged should not get above 125 fahrenheit). Browsing for used car batteries for sale? The best online shopping experience is guaranteed! 7,826 used car batteries products from 2,608 used car batteries suppliers on Alibaba. A simple circuit looks at the voltage that the alternator is producing, and turns the battery light on if it is low. If you discharge a battery past this 11 volt minimum, you may damage it, especially the newer batteries. Battery discharging while stoppedelectrical devices were temporarily switched off I have been leaving my old iPhone 4s connected via aux USB in my arm rest basically using it as a iPod. Save money. Or check out our battery finder. I just disconnect my battery if its standing for more than 4 weeks to stop the alarm draining it. 2 mA draw enough to worry about discharging the car’s battery? Probably not. If the battery is not charged enough it will not deliver its amps. One of the best ways to trouble-shoot a discharging battery is to use the fuses. replaced the alternator first, and also fitted a fresh battery as the diagnostics showed it wasn't charging the battery enough. If you have a BMW accessory outlet and want to charge the battery while it remains hooked up to the bike, I would say no. Check out free battery charging and engine diagnostic testing while you are in store. The battery currently on the bike is about a year old. 6V with the engine idling. Idiot lights where coming up, stability control, and, steering, adaptive headlights, you name it it was on. BMW's system is not smooth. I have read all of the other threads on this and I don't have anything plugged, lock the car and I have a battery tender. A car battery should last about six years, but like most car parts, that all depends on how you treat it. 2) damages your battery, the lower the charge the more the damage 2) cold crank amps are batteries rated for starting engines NOT camping and regular discharging. I have a 2005 525i E60 BMW and in my research for replacing the battery I came across a tonne of conflicting information. If you let the battery discharge completely and leave your device in a closet, the battery may become incapable of holding a charge at all, dying completely. The first place to check for such a problem is at the battery. Had it checked today. Similarly, an E-rate describes the discharge power. The battery is almost dead or the connection between the battery and battery cable is poor. What does increased battery discharge mean? I recently sent my BMW 3series to get the cable wire done in the battery, it was a defect in all 3series. Regardless, I wasn’t about to leave this thing plugged in while I was at work. My car battery light comes on goes off while driving! I took it to a mechanic and when he checked the battery while the engine was running he got a reading of just below 12 volts, something like 11. This new-generation AGM battery also supports sailing as well. 4L 2009, D-Series 12V AGM Battery by XS Power®. Over the years, car manufacturers have learned how to minimize the possibility of a dead battery: by getting headlights to turn off by themselves, for example. But after a while, the charging current will taper off and go down continuously until the battery is full, since the alternator is a constant voltage, high current capacity charging source. I replaced the alternator and battery each more than once to no avail. While the installation of the ­battery may be the same for the two battery styles, some vehicles require an extra step to tell the vehicle that the battery has been replaced. why does my key fob battery keep dying 04 jetta tdi i have replaced the KEY FOB battery 3 times in the last 2 weeks, i replace it with a new battery and it works for 4-5 days and then nothing , i hit the button no light no response from car. DIY maintenance and battery charging – what to note. What can cause a car battery to drain? Over time, we came across many problems where a car battery would drain quickly, sometimes even overnight. The battery is fully charged and balanced when all the LED’s are lit. battery only charges when the engine is on (when the alternator works and charges the batt), and the charging will not be sufficient if the engine is switched on for a short while, e. He is storing it for a friend in his garage and the battery is low and it won't start. Here's Why BMW’s N63 4. bro on power magic or any device that support parking mode recording, do you a. Electrical consumer were temporarily switched off. the only actual tip i ought to furnish you is make beneficial your macbook professional isn't plugged in and charging the entire time. It is not intended to supply power to a low voltage electrical system other than in a starter-motor application. About 3 minutes after turning the engine off, the battery voltage is 12. Labor costs are estimated between $123 and $156 while parts are priced at $231. How we store energy will be critical to the future of the electric car. Problem disappeared. While recharging any battery, if the battery becomes hot when you touch it, stop charging it (a battery being charged should not get above 125 fahrenheit). Lights Dim at Stop Lights, Battery Discharged, If the battery is in a low state-of-charge. There has been no recall on battery discharge. Dealers get the electrolyte for the batteries locally - not from BMW - so this aspect of the battery is not really BMW-controlled. If you have ever woke up with your battery dead for no good reason you know exactly what we are talking about here. 5 volts, the damage is done. Typically, a deep cycle battery will have two or three times the RC of a car battery, but will deliver one-half or three-quarters the CCAs. They work in cars, personal computers, MP3 players, video games, and cell phones. When the battery gets to 60%, all regen is stopped and your FEH uses 100% brake pads for stopping. Try to work the CD either in or out using a small tweezers or flat blade screw driver. There is a DIY illustrated in the owner's manual to replace the battery. In December 2014 BMW announced the group is planning to offer plug-in hybrid versions of all its core-brand models using eDrive technology developed for its BMW i brand plug-in vehicles (BMW i3 and BMW i8). I installed a battery cut-off. Replacing BMW batteriesyes it is ridiculous. My 2002 525it's battery kept discharging when not in use. Skipping the battery registration process can dramatically shorten the life of a battery in these vehicles, be it an AGM or a conventional battery. BMW cars equipped with the intelligent charging system may display a warning message stating Increased Battery Discharge or High Battery Discharge. Don't mix size and types of batteries. It can also be loose or corroded terminals connections on the battery preventing it from charging or cranking, next the alternator may have stopped functioning,(100,000 miles there tired) letting the battery discharge and stalling the car out then only a click when you try and restart. A standard installation of BMW’s Wallbox costs 15 000 SEK here in Sweden according to BMW. But battery warning still comes back and some smart mechanic or independent shop tells you its okay as long as battery is new and registered! So here is the story: One 2003 BMW 745li with very low miles came over with ABS module errors and with battery discharge warning. The BMW service people were again helpful and patient as I asked more questions than I imagine they were. If the battery drops below this starting point that light your seeing will come on. Many ideas found in the new range were first developed in our original equipment business, where we design batteries for leading carmakers. If the battery still won't hold a charge, this indicates that the battery is defective and will need to b e replaced. Except vampire drain. While the installation of the ­battery may be the same for the two battery styles, some vehicles require an extra step to tell the vehicle that the battery has been replaced. I find that it will last much much longer than that. Representatives from Ford, BMW and Porsche all dismissed ultracapacitors solely on cost, even while recognizing the greater performance. Supposedly according to the owner of a. For these vehicles, leaving the car plugged in allows for the battery’s thermal management system to function optimally. Store Batteries at 50% Charge. It is ideally suited to cars with Start-Stop and/or regenerative braking systems. Anyway when i started my car the other day it warned me that there is an increased battery discharge, and that was a day after i got it fixed. True or false? Battery myths that need to die most batteries never truly fully discharge. For a better inspection, it is a good idea to disconnect the battery and check it on a bench or similar surface. The charging system cannot top off your battery while driving if the battery connections have corroded. Measuring and knowing the SOC of a battery or battery bank is useful when applying towards alternative energy, or any other situation where you need to know its condition. In the event of recurrence, have the system checked by BMW service'. I replaced the alternator and battery each more than once to no avail. a few days later, the warning message returned - BMW did some further testing and traced the problems to the main cabling that ran to the battery. Made Easy Free Download PDF Battery Reconditioning Step-By-Step Free A Step-By-Step Guide Battery Reconditioning, Battery Desulfator. remove these (2) fuses under the hood "#1:Passive motor L & #2:Passive motor R " make sure u unplug while battery is connected ign (ii) and driver door shut, so u can keep your top sliding buckle all the way back where u can always use it,****fixed my battery draining over night issue , after new alt new cables new battery it turned out to be these *2 fuses = SOLVED DYING OVERNIGHT ISSUE. He needs to move it to get access to his lawn tractor. A 36v pack, at 42v is fully 100% charged and holding as much energy as it can and at 30v it should shut down and stop giving power before causing permanent damage. The loose wires may cause the connector to melt, resulting in a fuel leak. In addition to the storage tips for our conventionally-powered vehicles, our hybrids require additional steps for each battery, as the hybrid vehicle battery and auxiliary battery will discharge. Scott have you tested the battery to make sure it is holding the charge properly? Otherwise start with locking the car and make sure the start stop button back lighting goes out after a bit. Don't let a battery get hot to the touch and boil violently when charging. Wrong relays installed. It is preferred to slow charge all batteries, slow charging rates vary depending on the battery’s type and capacity. When you think of a dead car battery, you probably think about it being the dead of winter. In fact, I've never seen a small battery blow up, but I've sure seen bigger ones blow, and it's not a pretty sight. It's main purpose is to start the car, but it can also be used to provide extra power to accessories when the engine is off. I figured it only charged it when the car is on but now I am not sure. Welcome to BMW of Towson, located in Towson, MD. With the key off while being very quite listen closely to the player, if you hear a motor running a CD is stuck. except sometimes thr battery light will go off and will charge but. Chalk up another to a faulty hfl module. that 12V jack doesn’t stop. The self-discharge of a battery increases with age and usage. bro on power magic or any device that support parking mode recording, do you a. A Short Lease on Life. In order to simplify your shopping process, we have examined motorcycle batteries reviews, c. you probably have a short somewhere. In order to complete the chemical process, which recharges a battery the electrolyte, must reach 104°F. During riding breaks of more Correct battery maintenance Start engine of vehicle with dis- than 4 weeks, connect a combined with proper charging charged battery in usual way;. When you consider all the differences between how people use and store their cars; some are in blisteringly hot parking lots, others in garages, others in freezing temperatures, etc, frankly, the software has to monitor the voltage of the battery and adjust the charge profile anyway. Li‑ion battery's self-discharges about five percent in the first 24 hours and one to two percent thereafter in the following months of use. In order to complete the chemical process, which recharges a battery the electrolyte, must reach 104°F. Under these preconditions, the battery is adequately charged when the charge current drops below 2. While Tesla’s interest is clearly in the battery technology, by buying Maxwell, Tesla also acquired the company’s main business: ultracapacitors. At my next stop, I removed the key from the ignition and made my exit, but first I popped the trunk to access some cargo in there. There are situations when you want to send current somewhere, but not all at once in an instantaneous rush, and then have the current flow stop. Current can leak across the top of a dirty. If you have a Chevy Volt, a Ford Energi, or a BMW i3, then yes, please do keep it plugged in while you're away. Sunday got in the BMW to go to SILs, "battery discharging while stationary. Replace the battery in your 2011 BMW X3 xDrive28i 3. A relatively common “side-effect” of replacing a battery and/or alternator in a car is to have the voltage (battery) warning light come on. If your battery is not in good condition, you will likely need to replace it anyways and a battery discharge prevention device will just delay the inevitable replacement for a few weeks. Over the years, car manufacturers have learned how to minimize the possibility of a dead battery: by getting headlights to turn off by themselves, for example. When it comes to your GMC Envoy, you want parts and products from only trusted brands. They work in cars, personal computers, MP3 players, video games, and cell phones. Find out what you can do if your car battery is dead with this quick guide. Car batteries can lose their charge for a variety of reasons. Battery Discharge While Stopped Bmw: Batteries lose charge over time and replacing them can be expensive. IMO, stop asking on the forum and take it to the dealer. It took a while trouble shooting but after disconnecting the factory navigation system it would go into sleep mode. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it. If you park outside. BMW Trickle Chargers: https://amzn. The loose wires may cause the connector to melt, resulting in a fuel leak. Trying to start your vehicle with a dying battery can cause your car alarm to keep going off. If you keep the old battery in the bike it will try to suck up the power from the fully charged battery. With the CT5 start/stop battery charger, you can avoid unexpected and costly replacements. He needs to move it to get access to his lawn tractor. BMW 750i / 750Li 4. Measure it`s terminal voltage at the start of the charge. There has been no recall on battery discharge. The best part is, our GMC Envoy Battery products start from as little as $129. Therefore, if the car is used for city stop & go driving or longer steady-state highway driving the battery will discharge more than it is charged. The battery had already been replaced, twice, and the alternator overhauled and given a clean bill of health. I am getting the warning "Battery Discharge while Stopped: All electrical devices temporarily switched off". 1st time in they told me to trickle charge the battery and lock the car at night. If I ride it on my usual short trips around town without using the BMW Charger, within about 2 days it will read down around 35%. Several issues can cause premature battery failure, see post on Energy Diagnosis , but on a late model BMW, skipping battery registration can be one of them. Best Answer: You only need to disconnect one terminal of the battery to minimize battery drain while you are gone. Thanks for reading our Sony Xperia Z3 Battery Drain and Overheating Fix tutorial, I hope you have enjoyed it and that you will be able to get the most out of your Z3 battery. The contact owns a 2008 Dodge caravan. 6) While changing the fob battery, do not let dust or oil get on the components. There is a protective circuit underneath the shrink wrap of this battery as well. 1), it seems abundantly clear that the battery will have positive and negative potential on respective terminals. Car batteries can go flat for a number of reasons, which is why we have gathered these top tips to help prevent the worst happening A flat battery can be a real pain, especially on those dark. put new alt on new battery still no charge coming from alt. The charging system cannot top off your battery while driving if the battery connections have corroded. Get a new battery and see if the issue still occurs. However, the alternator will not be able to generate enough of a charge even after running a while. The wire runs from the alternator through the bulkhead and up to the warning light mounted in the dashboard. "Battery discharged while stopped; electrical devices were temporarily switched off" thats the message I got on the idrive yesterday. I just disconnect my battery if its standing for more than 4 weeks to stop the alarm draining it. 7) today, I received a call from the dealership and they said, BMW-usa did not found the any cause that may have caused the issue but given engine intermittently stopped, they are going to replace. once replaced, problem solved for good. It is vital though, that the battery is recharged while the engine is running so that it is ready for the next start. After it’s removed from storage, it may require 20 minutes of charging with the original adapter before you can use it. I purchased a 2013 BMW model X3 SUV in Aug. The car will just die on me while driving and the battery just drains to about 8 volts. BMW’s built from 1999 through about 2003 do not respond well to a jump start, and pretty much every BMW built after 2004 needs to follow an exact procedure in order to change the battery properly. EDIT: I remember a BMW mechanic having a right whinge at me years ago because id disconnected a battery while Mig welding on a car, this was a 7 series though so a bit more complicated than a 1 series. It's at this point that I realized that what I held in my hand (the remote) would only start the car and would no longer get me inside the car. Storing cold energy while the vehicle is running and discharging it while the vehicle is stopped Mode A Mode B Mode C Use refrigerant to cool the supplied air and the cold insulator. In the not-so-distant past, and despite the major manufacturers naturally investing in improving the performance of their products, most batteries were all generally of lead-acid type, designed to cater for large current discharge when starting the engine and subject to continuous charging while the vehicle was in use. Today it still has the yellow warning triangle by the mileage and I get the message on start. Lithium batteries do not like being charged when they are cold (lithium plating and dendrites), but discharging when cold is not an issue. Dead battery. This problem often happens when you first start your BMW in the morning, especially during extremely cold weather. bro on power magic or any device that support parking mode recording, do you a. BATTERY CHARGING TUTORIAL. While this is one option to retrieve. While the base BMW i3 uses the same 21. Car Battery Goes Dead After a Few Days: This is my 2012 Hyundai Sonata. If those are staying on then the vehicle is being kept awake by something. Extremely cold temperatures have a negative impact on batteries, and as the temperature drops, the battery will produce less power. Battery is vented to outside of vehicle. Let's look at common problems causing a battery to drain and ways to fix them. What's causing battery drain? Q. It's at this point that I realized that what I held in my hand (the remote) would only start the car and would no longer get me inside the car. Dynamic recharging capability and up to 4 times the number of discharge / charge cycles compared to conventional starter batteries, meeting the toughest requirements. According to BMW, if the key is not used it will discharged in approximately 18 months. The other day when it was really f'in cold, my X3 was also saying to charge the battery and "Battery discharging while stopped". My wife's X3 is getting the "Battery discharging while stopped" message. Anybody else with "Increase Battery Discharge" Been having this problem for over a month. Leaving a battery connected in a vehicle can also increase the discharge of battery due to the additional parasitic (ignition key-off) load. It is far easier to discharge a battery than to recharge it. Starter relay, BMW number 61 31 1 243 207, Bosch 0 332 014 118. There is a protective circuit underneath the shrink wrap of this battery as well. electrical devices were temporarily swithed off. I realize this post is a few months old, but I was wondering if anyone knew if the battery drains from leaving a USB/lightning cable plugged in. About 3 minutes after turning the engine off, the battery voltage is 12. Wrong relays installed. The average cost for a BMW 750Li xDrive battery replacement is between $354 and $387. Just as the observations of the physical world around us have. You would think that replacing a battery in a car would be one of the easiest things you could possibly do. Recovery came and can't start this time. E39 Battery drain guru's but I might borrow my mates battery discharge tester and check it just to be safe. During riding breaks of more Correct battery maintenance Start engine of vehicle with dis- than 4 weeks, connect a combined with proper charging charged battery in usual way;. put new alt on new battery still no charge coming from alt. Session Chairman: Frank Moebius, Head of R&D High Voltage Battery, BMW Group Dr. Many new car batteries are of the sealed 'maintenance' free variety. Beware Car Battery "Vampires" system is used often while the vehicle engine is switched off. BMW Trickle Chargers: https://amzn. It is not unusual for a car battery to fail after that period. I have a 2005 525i E60 BMW and in my research for replacing the battery I came across a tonne of conflicting information. BMW never acknowledged the problem. My R60 S 2011 61k (since i've owned it have done all required service no hard driving). Most, actually. Before I knew it my electric power steering was out my electric cooling fans no longer worked. If the battery does become discharge, it requires approximately 30 hours of use to fully charge. But we're on the verge of a power. Car battery drain is a common enough problem. 4L 2009, D-Series 12V AGM Battery by XS Power®. It's at this point that I realized that what I held in my hand (the remote) would only start the car and would no longer get me inside the car. They have a really good side hustle going on, here we go. BMW wanted $500 for a replacement. In December 2014 BMW announced the group is planning to offer plug-in hybrid versions of all its core-brand models using eDrive technology developed for its BMW i brand plug-in vehicles (BMW i3 and BMW i8). By my experience, if you "deep discharge" a battery, it will fail within a year or two, even if it takes a full charge. The BASE of the battery was surrounded by the powder. If your battery was running fine the last time you drove and now won't start the car, one of the following problems may be to blame. I measured voltage at 12. Depending on how long you store your device, it may be in a low-battery state when you remove it from long-term storage. We're a big fan of BMW's here at BlackboxMyCar and one of our vehicles is a 2013 F30 328xi with a dash cam hardwired via multi-safer. BMW will notify owners, and dealers will replace the fuel pump module, free of charge. It's main purpose is to start the car, but it can also be used to provide extra power to accessories when the engine is off. An old battery that is completely dead can easily be replaced, but other issues with wiring, fuses, or starting and charging systems can cause battery problems as well. Generally, the electrical system will only use a fixed amount of power from the battery based on the requirements of the starter motor and electrical system. When it comes to your GMC Envoy, you want parts and products from only trusted brands. Update to the latest software. The charging process could then be effectively managed so that none of the cells are charged above 4. hold down 5 sec hear 1 buzz. If you have any of the below symbols appear on your vehicles instrument cluster, please make note of the corresponding number when you call us so our team have the best chance of advising you in the correct way. Do not use battery charger for. When your car's battery light comes on, you may feel alarmed and unsure of what to do. The system is part of a larger BMW. While this is one option to retrieve. Voltage: most ebike kits are rated for a specific voltage range. Supposedly according to the owner of a. If possible, the battery temperature should be between 15 °C and 25 °C during charging. Two phrases I hear most often are "my battery won't take a charge, and my battery won't hold a charge". Buy car and truck batteries and get free installation at participating locations. In fact 80% of all battery failure is related to sulfation build-up. The battery is fully charged and balanced when all the LED’s are lit. I am getting the warning "Battery Discharge while Stopped: All electrical devices temporarily switched off". In cold weather (<10°C) people tend to drive short distances more often while also using more accessories (battery consumers). It is typically recommended to disconnect the negative terminal because it is a somewhat safer procedure: If your wrench should accidentally contact the car chassis while doing so, it is no big deal, as the negative terminal is connected to the chassis, anyway. It's main purpose is to start the car, but it can also be used to provide extra power to accessories when the engine is off. Hybrids and EVs recapture some of their energy back into the batteries through regenerative braking. Draws about 6kW to operate the battery heater and about the same for the cabin heater at full blast. My car(2008 528i, 49300Miles) recently showing battery discharge at a higher rate warning. The contact stated that while parked in a driveway, the horn, door locks, windshield wipers and fluid started operating independently. BMW cars equipped with the intelligent charging system may display a warning message stating Increased Battery Discharge or High Battery Discharge. Well, he replaced the battery and it was "professionally registered". If you don't own a battery charger, you don't want to make the investment, or you're not the do-it-yourself kind of person, this is the option for you. to fully compensate for the discharging of the battery. This BMW had a complaint of intermittent no start caused by the vehicle battery discharging.