Battery charging query
Discussion
My car has been struggling to start after being parked up with minimal use for 3 weeks thanks to a mix of being sent away on a training course and the recent snow. It already gets less use in winter, so this really did not make the car happy.
Over the last couple of weeks the car has needed the aid of a jump starter on Monday morning and occasionally evening, then got somewhat better throughout the week. However if the car is laid up for a couple of days at the weekend, come Monday morning it won't start up the engine.
My commute is about 5 miles (20-30 minutes) in the morning through West London traffic, and in the evening either 5 miles of city streets or 12 miles of motorway for half an hour. I did notice that after commuting through the streets the car took longer to crank the next morning, so I am thinking that the higher speed motorway driving was doing a bit more for the battery. I assume I am charging the battery just enough to start the car again, but it's right on the edge, so I reckon that the battery needs a proper charge up.
I currently live in an apartment without any way of getting my car near a power outlet. I also don't have any friends with a house nearby who can spare a parking space for a night, so a CTEK charger is not an option.
Do any of the fast fit type garages or would your typical independent mechanic offer battery charging, or are they more likely to try to sell me a new battery? Or are there any other suggestions? (apart from taking the car on a long run, might be a few weeks before I can do that especially with the damn snow warnings this weekend!)
Over the last couple of weeks the car has needed the aid of a jump starter on Monday morning and occasionally evening, then got somewhat better throughout the week. However if the car is laid up for a couple of days at the weekend, come Monday morning it won't start up the engine.
My commute is about 5 miles (20-30 minutes) in the morning through West London traffic, and in the evening either 5 miles of city streets or 12 miles of motorway for half an hour. I did notice that after commuting through the streets the car took longer to crank the next morning, so I am thinking that the higher speed motorway driving was doing a bit more for the battery. I assume I am charging the battery just enough to start the car again, but it's right on the edge, so I reckon that the battery needs a proper charge up.
I currently live in an apartment without any way of getting my car near a power outlet. I also don't have any friends with a house nearby who can spare a parking space for a night, so a CTEK charger is not an option.
Do any of the fast fit type garages or would your typical independent mechanic offer battery charging, or are they more likely to try to sell me a new battery? Or are there any other suggestions? (apart from taking the car on a long run, might be a few weeks before I can do that especially with the damn snow warnings this weekend!)
Put a multimeter on it while it's idling and make sure voltage is over 14v. If so it should be charging ok. Check voltage with engine off after it's stood for a while or put sidelights on to give the battery a bit of load. Voltage should be 12.6. If static voltage is much less than this battery is knackered. It should charge itself up fine with the driving you're doing.
Voltage while idling is over 14, so it's definitely charging. I checked the voltage of the car earlier this evening after the car had been parked up for 3 hours after a 40 minute drive (to cover 4 miles 
). None of the electrics apart from the boot light were on, so no load to speak of on the battery, and it was showing 12.1v.
Just to add some more detail, battery (and the car) is about 14 months old, and it's an AGM battery trying to start up a 3 litre petrol engine.
). None of the electrics apart from the boot light were on, so no load to speak of on the battery, and it was showing 12.1v.Just to add some more detail, battery (and the car) is about 14 months old, and it's an AGM battery trying to start up a 3 litre petrol engine.
You need to full charge the battery using a battery charger.
Just driving it around is not going to recharge a flat battery. If you keep trying to do this you're likely to damage the alternator as well as you're asking it to do something it isn't designed to do. That's not just my opinion: https://www.optimabatteries.com/en-us/experience/2...
Just driving it around is not going to recharge a flat battery. If you keep trying to do this you're likely to damage the alternator as well as you're asking it to do something it isn't designed to do. That's not just my opinion: https://www.optimabatteries.com/en-us/experience/2...
TooMany2cvs said:
A shagged battery due to short, lights-on journeys and lack of use will not be covered.
Twenty minute journeys should be sufficient to charge it, and if the battery won't hold charge over the weekend it's knackered. I think it's a reasonable claim, and I don't think you have anything to lose by making it.paintman said:
You need to full charge the battery using a battery charger.
Just driving it around is not going to recharge a flat battery.
Just driving it around is not going to recharge a flat battery.
I figure that the car needs a full charge before I can draw any meaningful conclusions on the battery health anyway, but my problem of not having anywhere to charge remains.
Is battery charging a service that is offered at your average local garage?
I had thought of that, though two things put me off.
1 - the previously mentioned electronic gubbins in the car. Good knows how much things could be messed up in a 2017 BMW without electrics for a night
2 - I don't fancy leaving the car parked outside in London without being alarmed. Not sure what insurance implications could be.
1 - the previously mentioned electronic gubbins in the car. Good knows how much things could be messed up in a 2017 BMW without electrics for a night
2 - I don't fancy leaving the car parked outside in London without being alarmed. Not sure what insurance implications could be.
Either the battery is the problem, or the car use is the problem. Either way, a new replacement battery would be a good idea.
If the battery is the problem, swapping the battery will solve it.
If the car use is the problem, having a second battery would let you trickle charge one at home so that you can swap it into the car when the existing one gets run down.
If you use a memory saver (small battery that keeps the car electronics powered up while you disconnect the main battery) a battery swap would be relatively painless to do.
If the battery is the problem, swapping the battery will solve it.
If the car use is the problem, having a second battery would let you trickle charge one at home so that you can swap it into the car when the existing one gets run down.
If you use a memory saver (small battery that keeps the car electronics powered up while you disconnect the main battery) a battery swap would be relatively painless to do.
GreenV8S said:
Twenty minute journeys should be sufficient to charge it, and if the battery won't hold charge over the weekend it's knackered. I think it's a reasonable claim, and I don't think you have anything to lose by making it.
Contrary to popular belief, it won’t. 70ah car battery will take about 12 hours to charge from flat at the 5 amps the average alternator will charge at. Best thing is to stick it on a proper charger and hope it recovers. Short journeys will kill it as the battery is constantly running on empty. I take my car 2 miles to the station each day during the week. Every other weekend I put it on charge over the weekend. OP, sell your car and get a pushbike.
rs990 said:
I had thought of that, though two things put me off.
1 - the previously mentioned electronic gubbins in the car. Good knows how much things could be messed up in a 2017 BMW without electrics for a night
2 - I don't fancy leaving the car parked outside in London without being alarmed. Not sure what insurance implications could be.
Who is going to steal it without a battery? 1 - the previously mentioned electronic gubbins in the car. Good knows how much things could be messed up in a 2017 BMW without electrics for a night
2 - I don't fancy leaving the car parked outside in London without being alarmed. Not sure what insurance implications could be.
Short runs are going to do nothing & as you can read in the Optima link you're likely to end up damaging the alternator.
May also be the case that the alternator on yours is ECU controlled so you may not be seeing 14 plus volts when running & testing with a multimeter across the battery, but you'll need to check that's the case.
If there is no way of getting your car to a charger & you are not confident about disconnecting the battery to be able to take it to a charger then you are left with having a new battery fitted by a garage.
May also be the case that the alternator on yours is ECU controlled so you may not be seeing 14 plus volts when running & testing with a multimeter across the battery, but you'll need to check that's the case.
If there is no way of getting your car to a charger & you are not confident about disconnecting the battery to be able to take it to a charger then you are left with having a new battery fitted by a garage.
In the old days a garage would have taken the car in on an evening, stuck the battery on a charger, and let you have it back in the morning. Goodness knows how a BMW dealer would deal with it.
Probably cheaper to buy a second battery from wherever, get a Ctek charger, while the car is running around flattening the new second battery with such a lousy unfit usage patterns the OP has the chance to get the CTEK on the old knackered battery and try to recover it. If it does it can keep the battery ok while the second battery is being knackered.
Twenty minutes drive on the motorway isn't anywhere enough to do anything significant. Even with runs 30 min in each direction twice a day, an overnight charge once a month in the middle of winter is a decent idea to deal with the much more numerous short journeys and poor battery output in cold weather.
Considering the short journeys hope it ain't a diesel.
Probably cheaper to buy a second battery from wherever, get a Ctek charger, while the car is running around flattening the new second battery with such a lousy unfit usage patterns the OP has the chance to get the CTEK on the old knackered battery and try to recover it. If it does it can keep the battery ok while the second battery is being knackered.
Twenty minutes drive on the motorway isn't anywhere enough to do anything significant. Even with runs 30 min in each direction twice a day, an overnight charge once a month in the middle of winter is a decent idea to deal with the much more numerous short journeys and poor battery output in cold weather.
Considering the short journeys hope it ain't a diesel.
I have a similar but different problem from the OP:
Car is in storage for several months, battery becomes heavily discharged, however I cannot leave a trickle charger connected to it for long periods (due to car park location).
Rather than constantly removing, reconditioning and then reconnecting the one battery (which I don't like as there are potential for spikes in current on reconnection, and you lose various vehicle data and settings this way) - I would like to use a 2nd car battery to maintain charge to the vehicle via jump leads on the car's connectors, then swap the reconditioned battery back in later (and so on...).
Will the voltage difference between the two batteries be a problem if they are only connected for a short period? I have read this might not be a good idea. I won't be trying to start the car with both batteries connected.
Many thanks!
Car is in storage for several months, battery becomes heavily discharged, however I cannot leave a trickle charger connected to it for long periods (due to car park location).
Rather than constantly removing, reconditioning and then reconnecting the one battery (which I don't like as there are potential for spikes in current on reconnection, and you lose various vehicle data and settings this way) - I would like to use a 2nd car battery to maintain charge to the vehicle via jump leads on the car's connectors, then swap the reconditioned battery back in later (and so on...).
Will the voltage difference between the two batteries be a problem if they are only connected for a short period? I have read this might not be a good idea. I won't be trying to start the car with both batteries connected.
Many thanks!
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