No, parking lights don't do it. I have LED headlights, so not much wasted power.
Overriding a "smart" battery management system
- Thread starter circuitsmith
- Start date
This metaphor just doesn't line up with reality though.Sure, and get my oil changed at Iffy Lube every 3000 miles too?I don't think so.
Maybe a better approach is to ask exactly what you're trying to get out of this.
Extended battery life?
Peace of mind around battery performance?
Help me to understand what about the OEM charging system makes you think it is sub-par to the point that you need a solar charger on your dash.
Then we can have a good conversation about that.
It'd be a bro-moment if they added a wire loop hanging below the BCM that one could cut "for export only".
First, the "smart" charging system does not try to keep the battery 100% charged. That shortens life of any lead-acid battery.
Second, as explained in my first post, I don't drive a lot, even pre-COVID. This is far from the typical use these systems are designed for.
I had a friend who got a job just a couple miles from his apartment; he made the short drive every day.
His battery only lasted about 2 years.
My point is some people are satisfied to give little thought to their car's motor oil needs; and some, like many on this forum are focused on getting the best performance.
The same applies to batteries. Since my profession centers around electronics I strive to make use of my above average knowledge of the subject.
Since 2012 I've worked with BMW's similar system. It's not as aggressive as yours (the lowest voltage is still in the 13s). BMW's does not disable for headlight and fan use. Were I in your position, I would just do the headlight thing. Other attempts to disable it could have "unintended consequences". I plug my car in frequently - I know that's not a good option for you but great job with the solar cell. I've been thinking about doing that myself
That's why I will politely decline the more invasive measures others have suggested.
Besides, I can enable/disable from the driver's seat.
The voltage regulator on my engine computer is hooked to a 10 ohm 50watt resistor instead of the alternator's field terminals.
I use a transpo540 adjustable vr to control the externally regulated alternator.
The resistor keeps the check engine light off, but it will come on if i allow 14.8v + for 30 seconds when engine computer vr decides 13.7v is fine and dandy
I use a transpo540 adjustable vr to control the externally regulated alternator.
The resistor keeps the check engine light off, but it will come on if i allow 14.8v + for 30 seconds when engine computer vr decides 13.7v is fine and dandy
That's certainly an option. But if I'm doing that much, I am going to wire the 12v outlet so it's always live so I can charge a cell phone without having to have the car turned on to charge my phone. Double win!
I know it was posted otherwise, but my *limited* knowledge is that battery management does shorten its life, as batteries need a long time to achieve a finishing charge and simply don’t get it with battery management tech. One reflection of this is the shortened warranties now. batteries used to have 3, 4 and 5 year warranties and now nobody goes beyond three. Autozone told me it was specifically due to this.
I nerded out and mounted a 50w PV panel on the camper shell of my truck. It spins fast at every start and the battery is 6 years old, older than the truck. It gets charged to 14.4 and the settles to 13.8 daily. I wish I could do this to our other cars, but only blends well on the truck.
I nerded out and mounted a 50w PV panel on the camper shell of my truck. It spins fast at every start and the battery is 6 years old, older than the truck. It gets charged to 14.4 and the settles to 13.8 daily. I wish I could do this to our other cars, but only blends well on the truck.
A healthy 80% charged lead acid battery cannot be recharged to 100% state of charge in less than 3.5 hours, even if one has a 350 amp chromed alternator, recently polished, while being spoken lovingly to.
Those 3.5 hours assume it is being held in the mid 14 volt range that entire time, and that the battery is still newish, and healthy..
A battery held at 14.7v will accept about 3 times as much amperage, than one held at 13.6v, but when well aged this drops closer to 2x as much amperage and that 3.5 hours increases to 5.5+ hours.
Assuming one's vehicular charging system is perfectly recharging their battery for maximum longevity, is unwise in the extreme.
Insuring a true full charge regularly occurs is an easy way to get 5+ years from a starting battery.
Keeping it 80% and less charged is the best way to insure they barely last 2 years, and many vehicles intentionally hold it in this range.
I Modified my voltage regulation in order to quickly get to 80% State of charge and if I drive for 3.5+ hours, to insure the battery can actually be recharged fully from a well depleted state in the minimum time possible.
My last battery lasted 6 years and 1200 deep cycles and thousands of engine starts, but solar, and quality adjustable voltage high amperage grid powered charging sources played a huge part in that accomplishment.
The battery to battery dc to dc chargers are often used in newer camper vans to step up that 13.2 engine battery voltage to 14.4v to 14.8v house battery voltage to actually have a chance of achieving 80%+ charged before shutting of the engine.
DC to DC step up/boost converters can be had for pretty cheap. I got a 150 watt one that cost under 3$, That I added a 60mm fan and better potentiometer for changing voltage more precisely, but this wont do anything for a single battery vehicle.
So many vehicles if they see a voltage outside that which is commanded by the voltage regulator while the engine is running, will throw codes, perhaps even revert to a limp home mode. I'm not sure how to properly trick them.
I came across this link earlier this year:
www.usalternators.com
Perhaps a circuit smith could fabricate one of their own, but I think its safe to say hooking a diode in the voltage sense line is not going to cut it on a modern vehicle.
Those 3.5 hours assume it is being held in the mid 14 volt range that entire time, and that the battery is still newish, and healthy..
A battery held at 14.7v will accept about 3 times as much amperage, than one held at 13.6v, but when well aged this drops closer to 2x as much amperage and that 3.5 hours increases to 5.5+ hours.
Assuming one's vehicular charging system is perfectly recharging their battery for maximum longevity, is unwise in the extreme.
Insuring a true full charge regularly occurs is an easy way to get 5+ years from a starting battery.
Keeping it 80% and less charged is the best way to insure they barely last 2 years, and many vehicles intentionally hold it in this range.
I Modified my voltage regulation in order to quickly get to 80% State of charge and if I drive for 3.5+ hours, to insure the battery can actually be recharged fully from a well depleted state in the minimum time possible.
My last battery lasted 6 years and 1200 deep cycles and thousands of engine starts, but solar, and quality adjustable voltage high amperage grid powered charging sources played a huge part in that accomplishment.
The battery to battery dc to dc chargers are often used in newer camper vans to step up that 13.2 engine battery voltage to 14.4v to 14.8v house battery voltage to actually have a chance of achieving 80%+ charged before shutting of the engine.
DC to DC step up/boost converters can be had for pretty cheap. I got a 150 watt one that cost under 3$, That I added a 60mm fan and better potentiometer for changing voltage more precisely, but this wont do anything for a single battery vehicle.
So many vehicles if they see a voltage outside that which is commanded by the voltage regulator while the engine is running, will throw codes, perhaps even revert to a limp home mode. I'm not sure how to properly trick them.
I came across this link earlier this year:
PCM Module | US Alternators
www.usalternators.com
Perhaps a circuit smith could fabricate one of their own, but I think its safe to say hooking a diode in the voltage sense line is not going to cut it on a modern vehicle.
With my previous 2006 Toyota Matrix I replaced the original battery after 9 years.
It was still going strong, but I didn't feel comfortable going through a 10th winter.
I used to take the battery out and charge every 3 months in my basement overnight at 14.5V.
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1200 deep cycles over 6 years. Hundreds of those well below 50%. State of charge.
Engine starting only. is a walk in the park in comparison, but your experience shows how long aead acid battery can last when they are truly fully charged regulary.
Engine starting only. is a walk in the park in comparison, but your experience shows how long aead acid battery can last when they are truly fully charged regulary.
I know its battery colloquialism, the 'still going strong' thing
But does anyone who makes such a claim actually know/measure the voltage maintained during engine cranking?
Vehicles today use so little of battery capacity to start a modern fuel injected engine, the level of degradation/capacity loss that can occur, and still have it start the engine, is rather stunning.
I had a 7 year old battery once, that spent its first 2 years being cycled, mildly but regularly, then was relegated to engine starting duty only. At year 7 it could still easily start my engine, but it could not fully charge my small flip phone from dead, then still start my engine.
Without the flip phone to reveal a stunning loss of capacity/performance, I could have easily made he claim that it was 'still going strong'
The voltmeter dropping into the low 7's during engine cranking would have revealed otherwise too, but I did not bother with collecting such data back then.
Each engine start can be considered a load test, if one watches a voltmeter during engine cranking, and nobody who does this will be surprised when their battery is a goner. Those who see 10+ volts might be able to legitimately claim it is 'still going strong', those who see low 8's and make that claim, cant, but still likely do.
A battery that is indeed kept at high states of charge always, can last an impressive lifespan, but ironically, the bitog way seems to majorly attribute performance and longevity only to who made the battery, rather than how it was treated.
But does anyone who makes such a claim actually know/measure the voltage maintained during engine cranking?
Vehicles today use so little of battery capacity to start a modern fuel injected engine, the level of degradation/capacity loss that can occur, and still have it start the engine, is rather stunning.
I had a 7 year old battery once, that spent its first 2 years being cycled, mildly but regularly, then was relegated to engine starting duty only. At year 7 it could still easily start my engine, but it could not fully charge my small flip phone from dead, then still start my engine.
Without the flip phone to reveal a stunning loss of capacity/performance, I could have easily made he claim that it was 'still going strong'
The voltmeter dropping into the low 7's during engine cranking would have revealed otherwise too, but I did not bother with collecting such data back then.
Each engine start can be considered a load test, if one watches a voltmeter during engine cranking, and nobody who does this will be surprised when their battery is a goner. Those who see 10+ volts might be able to legitimately claim it is 'still going strong', those who see low 8's and make that claim, cant, but still likely do.
A battery that is indeed kept at high states of charge always, can last an impressive lifespan, but ironically, the bitog way seems to majorly attribute performance and longevity only to who made the battery, rather than how it was treated.
I'm with you too. Why this obscession on battery charging? Do you not trust the countless hours of engineering that went into optimizing these designs? So he says, "I turn on my headlights to get the system to go into charge mode". So you are draining your battery to get it to charge? And one of the posters actually pulls his battery every 2-3 weeks to charge them? What the???? It's bordering on absurd.
Some of us make an extra effort to take care of our stuff. Strange concept I know.
Optimized to save fuel. Not optimized for infrequent short trips.
Turning on the headlights increases battery voltage.
Couldn't do much night driving if turning on the headlights drained the battery.
Perhaps you should look on youtube for a tutorial on electrical basics.
Not if a comparison has been made between the terminals and the display.
Someone on another forum suggested I go on a 30 minute joyride each week.
I think LED headlights on for 15 minutes is a little less wasteful.
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It's obvious some people don't understand what these charging systems were designed to do, and how they do it.
They are designed to get the last .0001 mpg out the car, not keep the battery in a good state of charge. It was a trade off, better mileage at the potential cost of shorter battery life.
By lowering the alternator output to the absolute minimum required to keep a good battery charged just enough to start the car tomorrow morning, they get that last bit of mileage. This perpetual state of being under charged ages the battery rapidly, plus frequently leaves the owner with a dead battery if they haven't driven it for as little as a week or two.
Now factor in that many manufacturers use much smaller batteries these days, and the parasitic draw from the monitoring systems in new cars, and the problem is compounded.
Keeping a battery charged at 12.4V isn't desirable, but that's typical for new Hondas and others.
When the headlights or other things are turned on the system senses the load and increases the alternator output to 14.2 +-.
You aren't draining the battery to increase charging.
Since people haven't been driving as much for the last 7 months this has become a much bigger issue. The sale and use of small battery charger/maintainers has gone up dramatically. I use one on my CRV.
The old school charging system on my 2001 F150 keeps the battery fully charged and with very little parasitic draw I don't need to use one on it even though it doesn't get driven much.
Lots of "how to" stuff online for fitting larger batteries in Hondas. And in the latest models they did increase the size and design of the battery to help with this problem. The Canadian models came with a larger battery for a long time.
They are designed to get the last .0001 mpg out the car, not keep the battery in a good state of charge. It was a trade off, better mileage at the potential cost of shorter battery life.
By lowering the alternator output to the absolute minimum required to keep a good battery charged just enough to start the car tomorrow morning, they get that last bit of mileage. This perpetual state of being under charged ages the battery rapidly, plus frequently leaves the owner with a dead battery if they haven't driven it for as little as a week or two.
Now factor in that many manufacturers use much smaller batteries these days, and the parasitic draw from the monitoring systems in new cars, and the problem is compounded.
Keeping a battery charged at 12.4V isn't desirable, but that's typical for new Hondas and others.
When the headlights or other things are turned on the system senses the load and increases the alternator output to 14.2 +-.
You aren't draining the battery to increase charging.
Since people haven't been driving as much for the last 7 months this has become a much bigger issue. The sale and use of small battery charger/maintainers has gone up dramatically. I use one on my CRV.
The old school charging system on my 2001 F150 keeps the battery fully charged and with very little parasitic draw I don't need to use one on it even though it doesn't get driven much.
Lots of "how to" stuff online for fitting larger batteries in Hondas. And in the latest models they did increase the size and design of the battery to help with this problem. The Canadian models came with a larger battery for a long time.
What's ridiculous about this sacrificing of the battery to get a tiny % more MPG, is how it subverts the intention.
Manufactures try to get their fleet MPG averages up, to save gas/reduce emissions, as commanded by the federal government, and do so at the expense of the battery's life.
Seems well accepted that thinner oils are just a way to increase fuel economy, but somehow the engineers have really designed a system to perfectly maintain a battery, rather than also designing the charging system for max MPG?
The cost of transporting and recycling prematurely failed lead acid batteries is way more energy intense and introduces far more pollutants into atmosphere and surrounding recycling center, than is saved by the mediocre fuel savings of using voltage regulation to keep a battery at an intentional low state of charge.
Also, while many will say that a lead acid battery when fully charged is 12.6 or 12.8 or any point in between. The thing is if one has a current source, which holds the battery at this exact level, and presents a load to the battery/ current source, the battery will not remain fully charged. The battery needs to be several tenths of a volt higher than its full charge rested voltage in order to be kept at full charge and for the current source to power the DC load rather than the battery.
So seeing 12.6v going down the road does not mean no charging is going on, but that some slight discharging is occurring and will keep the battery in the 80 to 90% range or less. The bigger the DC load the more voltage is required to keep the current source providing the current to the load, rather than the battery.
My AGM specs a 13.6v @77f float voltage, but it rests fully charged at 13.06v. If I truly fully charge it then float it at 13.2v while running DC loads, then boost voltage back upto 14.7v, the amperage it accepts and the length of time it accepts this amperage indicates the battery is being discharged when held at a voltage 0.14v above its full charge resting voltage. The bigger the DC load the more voltage is required, the colder the battery the more voltage is required to keep it at full charge. If I don't float it at 13.6v or higher, it does not remain fully charged.
If one really thinks their vehicle's charging system is optimized for maximum battery life, they are delusional and need to seriously rethink all the things they believe they have a firm grasp of..
Most people seem to think their alternator can defy physics, but the fact is alternators are only 55 to 65% efficient and they are controlled by a voltage regulator that is not designed to keep a battery at top charge, but instead designed to insure overcharge can never happen and that any tiny method which might cause an uptick in fuel efficiency, is adopted.
Beancounters and marketing wins again, but it requires ignorance of the population for this to occur, and they are having a field day as the population has never been more easily manipulated, and average IQ never so low and, seemingly willful ignorance, never so widespread.
Manufactures try to get their fleet MPG averages up, to save gas/reduce emissions, as commanded by the federal government, and do so at the expense of the battery's life.
Seems well accepted that thinner oils are just a way to increase fuel economy, but somehow the engineers have really designed a system to perfectly maintain a battery, rather than also designing the charging system for max MPG?
The cost of transporting and recycling prematurely failed lead acid batteries is way more energy intense and introduces far more pollutants into atmosphere and surrounding recycling center, than is saved by the mediocre fuel savings of using voltage regulation to keep a battery at an intentional low state of charge.
Also, while many will say that a lead acid battery when fully charged is 12.6 or 12.8 or any point in between. The thing is if one has a current source, which holds the battery at this exact level, and presents a load to the battery/ current source, the battery will not remain fully charged. The battery needs to be several tenths of a volt higher than its full charge rested voltage in order to be kept at full charge and for the current source to power the DC load rather than the battery.
So seeing 12.6v going down the road does not mean no charging is going on, but that some slight discharging is occurring and will keep the battery in the 80 to 90% range or less. The bigger the DC load the more voltage is required to keep the current source providing the current to the load, rather than the battery.
My AGM specs a 13.6v @77f float voltage, but it rests fully charged at 13.06v. If I truly fully charge it then float it at 13.2v while running DC loads, then boost voltage back upto 14.7v, the amperage it accepts and the length of time it accepts this amperage indicates the battery is being discharged when held at a voltage 0.14v above its full charge resting voltage. The bigger the DC load the more voltage is required, the colder the battery the more voltage is required to keep it at full charge. If I don't float it at 13.6v or higher, it does not remain fully charged.
If one really thinks their vehicle's charging system is optimized for maximum battery life, they are delusional and need to seriously rethink all the things they believe they have a firm grasp of..
Most people seem to think their alternator can defy physics, but the fact is alternators are only 55 to 65% efficient and they are controlled by a voltage regulator that is not designed to keep a battery at top charge, but instead designed to insure overcharge can never happen and that any tiny method which might cause an uptick in fuel efficiency, is adopted.
Beancounters and marketing wins again, but it requires ignorance of the population for this to occur, and they are having a field day as the population has never been more easily manipulated, and average IQ never so low and, seemingly willful ignorance, never so widespread.
