Smart charging alternators.
- Thread starter Burnerman
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???
Well, sort of but it's not actually a 'net' amount, as such. That is whatever is left over.
It is what the battery requires plus what all the other things require.
Having read Johns comments and the replies I'm pleased that its unlikely that I will ever own one of these complicated things. we run a Citroen C5 estate, two in fact, the wife has one as well. They are both Mk3 2008s and are - I wouldn't say 'simple' electronically but certainly understandable. I was an electronics engineer for 50 years but don't have a clue as to this modern 'power saving' design, I grew up in the days of valves and analogue.
Having said that one of ours had a battery voltage related problem which I have only just solved (or at least I think so). The windscreen wiper motors only worked intermittently, sometimes they work when you turn them on and sometimes not. I removed the motors and found nothing amiss. Just recently the car has not been starting as well as it used to, I checked the battery on a 100amp load tester and it showed up OK but not brilliant, I replaced it and not only does it start instantly but the wipers have worked every time.
I am assuming that the battery wasn't able to supply sufficient amps to the starter so the voltage dropped to a level low enough to deactivate the wipers - only time will tell.
Peter
Having said that one of ours had a battery voltage related problem which I have only just solved (or at least I think so). The windscreen wiper motors only worked intermittently, sometimes they work when you turn them on and sometimes not. I removed the motors and found nothing amiss. Just recently the car has not been starting as well as it used to, I checked the battery on a 100amp load tester and it showed up OK but not brilliant, I replaced it and not only does it start instantly but the wipers have worked every time.
I am assuming that the battery wasn't able to supply sufficient amps to the starter so the voltage dropped to a level low enough to deactivate the wipers - only time will tell.
Peter
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Pretty much got to the nub of it, just unsure about the neg (grnd) lead amp reading - Only found the vid where the author says neg cable (+ve) amps, engine running is the current flowing into battery - So what happens at tick over with headlights on and climate control working - the current is shared twixt loads and the battery charge requirement ?
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It's all one system, the alternator is maintaining 14.4v across the whole system.
The alternator doesn't pump a fixed current, the current is a variable depending on accessory load and battery condition AND a 14.4v target voltage
With SMART charging the PCM pushes the system voltage above 14v (much higher in some instances) this creates a current draw at the battery that the alternator supplies.
There are multiple grounds on a car, so you can use the -ve from battery to ground to gauge amps to the battery (thats how the shunt on the -ve terminal works on SMART alternator cars).
Once running you could in theory remove the battery and it would run just off the alternator output alone.
So to sum up the Load (battery plus accessories/ PCM etc) and target Voltage (14.4 in your case) determine the current output from the alternator.
If you want a fixed current you would have to adjust the Voltage for a given Load.
The alternator doesn't pump a fixed current, the current is a variable depending on accessory load and battery condition AND a 14.4v target voltage
With SMART charging the PCM pushes the system voltage above 14v (much higher in some instances) this creates a current draw at the battery that the alternator supplies.
There are multiple grounds on a car, so you can use the -ve from battery to ground to gauge amps to the battery (thats how the shunt on the -ve terminal works on SMART alternator cars).
Once running you could in theory remove the battery and it would run just off the alternator output alone.
So to sum up the Load (battery plus accessories/ PCM etc) and target Voltage (14.4 in your case) determine the current output from the alternator.
If you want a fixed current you would have to adjust the Voltage for a given Load.
The current required is determined by the battery (and/or electronics), just like any other accessory, and is flowing from the alternator to the battery and back to the alternator.
Well, 'out of' the battery back to the alternator.
It has to have the same current on (the relevant part of) the negative as the positive.
The return current from the other accessories to the alternator flows through the car body; not the battery negative lead.
You can have more than one circuit on the same wiring.
Probably not depending on the draw and how much the alternator can supply at tick-over.
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With the old AC308 CAV alternator there was a steel shunt to measure amps connected across the M1 and M2 terminals of the regulator and also often an ammeter, the AC308 was the only alternator I have found with current regulation, it could burn its self out without it, mainly used on buses. But it was also used with milk tankers, the idea was in the farm engine off an electric vacuum pump would suck the milk into the wagons tank, and the driver had to ensure before he went into the farm yard the battery was fully charged, as otherwise the engine may not start when he came to leave, so he was taught to watch that ammeter. If it showed more than 5 amp charge, he would wait outside the farm yard until the ammeter needle dropped.
Some wagons had lead acid, and some had nickel iron batteries we are talking about the late 80's early 90's, now the nickel iron battery would be like flicking a switch, on leaving the farm yard the ammeter showed 60 amp and after around 2 miles it would drop to around 5 amp, but the lead acid would also show 60 amp, but they would return to 5 amp far more gradual, however nickel iron batteries are expensive, so the longer runs the wagons had cheap lead acid, the nickel iron batteries however would outlive the wagon, it was common for wagon to be sold and batteries kept for use with replacement wagon.
Clearly if lights were used the base charging rate went up, but the whole problem with lead acid batteries is the time taken to recharge, the AGM has improved this, but they have also mean that the charging needs to be controlled far better, the narrow boat was the first time I saw the problem with using and charging a battery at the same time, with older cars the alternator does most of the work, a car is started and within minutes the charge is replaced, but with the narrow boat the battery was discharged over night and recharged next day, if the battery is not being used at the same time a simple stage charger will work, the voltage is held at 14.8 volt until current drops to 6 amp then the voltage drops to 13.8 volt, however if your using the battery at over 6 amp, then the charger will not reduce the charge voltage so over charges the battery, not too bad with a flooded battery, but would kill an AGM, so the modern car has used the same technology the laptop has used for years, it measures energy out of battery and then puts same amount plus a bit back in, that is the only way without drying out the battery it can replace the charge fast enough.
However it has caused problems, and can be dangerous, with caravans we had split charging, and it was a simple device that measured voltage and once over a set amount connected the two batteries together and when it drops to set amount disconnected them again, idea was it would work with any car, and did not need detailed knowledge of that cars charging system. As caravans progressed they started fitting an electric anti snake device, to reduce number of caravans scrapped on M5, however to work it needs power from the car, so if the car alternator fails so does the anti snake, so the caravan people did not want smart charging, it was dangerous, so the ability to disable it while towing was good, although normal method was drive with head lights on. But if your doing a long distance then likely you don't need smart charging, but with a short distance with AGM battery there is really no option, it is fitted so must use it.
There has been talk about defeating the measures used by the manufacturer to fit the car into a taxation class, my wife and son both drive a Jaguar XE my wife's car has the engine management set for around 165 output from engine so £30 year road tax, son's set to around 190 output so £100 plus a year road tax, both same engine, it is only the mapping which is different. So if the wife's car was re-mapped without paying the extra road tax, that's fraud, many do it, and even tell their insurance they have done it, otherwise insurance invalid, so there is a record its been done, as yet not seen a court case, seems the government turns a blind eye. But the turning the alternator charging system back to old system will likely impact on the emissions so also technically illegal, at the moment only thing they seem to watch for is turning off the ad-blue system, but remapping and turning off smart charging is really in the same group, it affects emissions.
Some wagons had lead acid, and some had nickel iron batteries we are talking about the late 80's early 90's, now the nickel iron battery would be like flicking a switch, on leaving the farm yard the ammeter showed 60 amp and after around 2 miles it would drop to around 5 amp, but the lead acid would also show 60 amp, but they would return to 5 amp far more gradual, however nickel iron batteries are expensive, so the longer runs the wagons had cheap lead acid, the nickel iron batteries however would outlive the wagon, it was common for wagon to be sold and batteries kept for use with replacement wagon.
Clearly if lights were used the base charging rate went up, but the whole problem with lead acid batteries is the time taken to recharge, the AGM has improved this, but they have also mean that the charging needs to be controlled far better, the narrow boat was the first time I saw the problem with using and charging a battery at the same time, with older cars the alternator does most of the work, a car is started and within minutes the charge is replaced, but with the narrow boat the battery was discharged over night and recharged next day, if the battery is not being used at the same time a simple stage charger will work, the voltage is held at 14.8 volt until current drops to 6 amp then the voltage drops to 13.8 volt, however if your using the battery at over 6 amp, then the charger will not reduce the charge voltage so over charges the battery, not too bad with a flooded battery, but would kill an AGM, so the modern car has used the same technology the laptop has used for years, it measures energy out of battery and then puts same amount plus a bit back in, that is the only way without drying out the battery it can replace the charge fast enough.
However it has caused problems, and can be dangerous, with caravans we had split charging, and it was a simple device that measured voltage and once over a set amount connected the two batteries together and when it drops to set amount disconnected them again, idea was it would work with any car, and did not need detailed knowledge of that cars charging system. As caravans progressed they started fitting an electric anti snake device, to reduce number of caravans scrapped on M5, however to work it needs power from the car, so if the car alternator fails so does the anti snake, so the caravan people did not want smart charging, it was dangerous, so the ability to disable it while towing was good, although normal method was drive with head lights on. But if your doing a long distance then likely you don't need smart charging, but with a short distance with AGM battery there is really no option, it is fitted so must use it.
There has been talk about defeating the measures used by the manufacturer to fit the car into a taxation class, my wife and son both drive a Jaguar XE my wife's car has the engine management set for around 165 output from engine so £30 year road tax, son's set to around 190 output so £100 plus a year road tax, both same engine, it is only the mapping which is different. So if the wife's car was re-mapped without paying the extra road tax, that's fraud, many do it, and even tell their insurance they have done it, otherwise insurance invalid, so there is a record its been done, as yet not seen a court case, seems the government turns a blind eye. But the turning the alternator charging system back to old system will likely impact on the emissions so also technically illegal, at the moment only thing they seem to watch for is turning off the ad-blue system, but remapping and turning off smart charging is really in the same group, it affects emissions.
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My Smart charging vehicle and the effect upon emissions :- I have disconnected my smart charging, I do very little in town driving.
During the last few weeks, no smarts, no idle stop (start stop) usually switched off anyway (the option button is there on my Civic). -
Computer says 60mpg - I expect at next refill around 55mpg. So no more fuel burned therefore probably no more emissions than previous.
Using smart charging average fuel consumption fueled brim to brim, mileage noted, by calculation circa 55mpg. (computer on average 7-8% optimistic) this was over a period of about 18 months from new- every refill using auto resetting trip read out, recorded without fail.
Manufacturer boasts of 78mpg.
Sorry but from what I see and measure - it is more bullshit potentially at the cost of more batteries.
BTW the 2016 civic has an Enhanced Flooded Battery (EFB) touted as excellent at relieving battery electrolyte stratification, I recently replaced this at 3.5 yrs, with identical Honda battery. (my third battery purchased in 50 odd years).
I do not believe the computer strategy employed by Honda for my car with regards battery smart charging, fits the bill for my driving profile - one size does not fit all.
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During the last few weeks, no smarts, no idle stop (start stop) usually switched off anyway (the option button is there on my Civic). -
Computer says 60mpg - I expect at next refill around 55mpg. So no more fuel burned therefore probably no more emissions than previous.
Using smart charging average fuel consumption fueled brim to brim, mileage noted, by calculation circa 55mpg. (computer on average 7-8% optimistic) this was over a period of about 18 months from new- every refill using auto resetting trip read out, recorded without fail.
Manufacturer boasts of 78mpg.
Sorry but from what I see and measure - it is more bullshit potentially at the cost of more batteries.
BTW the 2016 civic has an Enhanced Flooded Battery (EFB) touted as excellent at relieving battery electrolyte stratification, I recently replaced this at 3.5 yrs, with identical Honda battery. (my third battery purchased in 50 odd years).
I do not believe the computer strategy employed by Honda for my car with regards battery smart charging, fits the bill for my driving profile - one size does not fit all.
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Some neat kit - not such a well produced video - facts a bit off - But the kit looks handy.
The 'kit'.
https://www.radioworld.co.uk/west_mountain_radio_cba-iv_battery_analyzer
'A simple explanation of surface charge (and surface discharge).'
http://www.smartgauge.co.uk/surf_chg.html
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The 'kit'.
https://www.radioworld.co.uk/west_mountain_radio_cba-iv_battery_analyzer
'A simple explanation of surface charge (and surface discharge).'
http://www.smartgauge.co.uk/surf_chg.html
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Regular trip Llanfair Caereinion to Shrewsbury and never seem to get same MPG twice, we see no real change in road conditions, but the MPG goes up and down like a yo-yo, can't see how any one can ever see the difference in MPG even if you stopped the alternator charging and recharged the battery at home after every trip.
In the same way my son can get better MPG with his Jaguar XE to my wife in her Jaguar XE even when the spec says hers should do better, his as the ability to produce more power so can do less to the gallon so he pays more road tax, so the road tax is based on what it can use with heavy right foot, not with light right foot, and few of us drive to the limit of the car.
Be it the manufacturer cheating, or the user cheating, it clearly is wrong, be it disabling the ad-blue or disabling the alternator smart control both are likely braking the law.
In the same way my son can get better MPG with his Jaguar XE to my wife in her Jaguar XE even when the spec says hers should do better, his as the ability to produce more power so can do less to the gallon so he pays more road tax, so the road tax is based on what it can use with heavy right foot, not with light right foot, and few of us drive to the limit of the car.
Be it the manufacturer cheating, or the user cheating, it clearly is wrong, be it disabling the ad-blue or disabling the alternator smart control both are likely braking the law.
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Is it illegal to let your engine idle when parked?
Rule 123 of The Highway Code looks at ‘The Driver and the Environment’. It states that drivers must not leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while the vehicle is stationary on a public road.
Local authorities have the power to issue £20 fixed penalties for emission offences and stationary idling under The Road Traffic (Vehicle Emissions) (Fixed Penalty) (England) Regulations 2002. The Government even plan to introduce higher fines for the offence.
However, it is important to note that fines are imposed only if a motorist refuses to switch off their engine when asked to do so by an authorised person.
How can I be worse than someone in a big engined car I am getting 55mpg true as I can make out -(not in-car computer readout ) 12.1 miles per litre of diesel - 82.6 CC fuel per mile - volume of a cube 4.36cm length of edges...
https://www.airportwatch.org.uk/201...ntly do not pay,than other means of transport.
'...Airlines currently do not pay fuel tax on their fuel, due to historic international agreements. The injustice leads to (f)lying being significantly cheaper than other means of transport...' I inserted the missing 'f' in flying - was maybe appropriately left out !
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Rule 123 of The Highway Code looks at ‘The Driver and the Environment’. It states that drivers must not leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while the vehicle is stationary on a public road.
Local authorities have the power to issue £20 fixed penalties for emission offences and stationary idling under The Road Traffic (Vehicle Emissions) (Fixed Penalty) (England) Regulations 2002. The Government even plan to introduce higher fines for the offence.
However, it is important to note that fines are imposed only if a motorist refuses to switch off their engine when asked to do so by an authorised person.
How can I be worse than someone in a big engined car I am getting 55mpg true as I can make out -(not in-car computer readout ) 12.1 miles per litre of diesel - 82.6 CC fuel per mile - volume of a cube 4.36cm length of edges...
https://www.airportwatch.org.uk/201...ntly do not pay,than other means of transport.
'...Airlines currently do not pay fuel tax on their fuel, due to historic international agreements. The injustice leads to (f)lying being significantly cheaper than other means of transport...' I inserted the missing 'f' in flying - was maybe appropriately left out !
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