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Assuming a 'modern' car - a few years old, how long (or how many miles) does it take to charge the battery after you've started the car? Lets assume the car is in good condition, and it takes no more than 1 to 2 seconds for the engine to 'catch' after turning the key.
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I would say 10-15 minutes at better than idle speed if you're not using headlights or any significant electrical accessories, but I dare say someone will be along to argue with that.
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Here I am!
j/k
It is dependant upon many factors.
State of initial battery charge, size/capacity of battery, temperature, alternator output etc etc
A 15-20 minute run with no electrical consumers on *may* be enough to breathe some life into a battery but don't expect it to start the next morning...
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groups.msn.com/honestjohn - Pictures say a thousand words.....
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A 60 amp alternator would take 1 hour to charge a 60 ampere-hour battery from flat, assuming no significant other current drain.
Work it out pro-rata from that. If it's half flat it would take half an hour, etc.
In simple terms, if the battery and alternator are in good order the battery should be pretty adequately charged after any reasonable journey. If it again fails to start the engine then something is not working 100%.
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I have hazy memories of a Ford TSB of two or three years ago. Can't remember the vehicle details but the general gist was as follows.
From a totally flat battery 8 hrs of normal use (whatever that is) should fully recharge the battery.
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I used to have a renault 5 - smallish battery - but new.
For five years my journey was 4 miles in 5 minutes each way 5 days a week.
I think I may have done a 20 mile round trip once a month 60 miles once a year.
Never had to manually charge the battery in that time except once when I left the sidelights on overnight.
I was doing the same mileage in a year as I was doing a week in my previous job - ahhh bliss. Now I do less!
Martin
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T'would have been cheaper to take a Taxi?
or....dare I say it......Ride a bicycle to work?
I wish I could ride a bicycle to work....trouble is, there are too many hills!
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groups.msn.com/honestjohn/problems.msnw?Page=1 - Pictures say a thousand words.....
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What doesn't kill you makes you stronger, DL!
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Never a truer word said ;-)
LOL!
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groups.msn.com/honestjohn/problems.msnw?Page=1 - Pictures say a thousand words.....
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Cliff Pope. You are way off the mark and the battery would boil and probably destroy itself. A flat 60 amp hour battery would be best charged at a maximum of 1/10th of the capacity ( 60/10 = 6amps ) for 14 hours. Your normal cheap and cheerful charger usually starts at 5 or 6 amps but soon falls to 2 or 3 amps so some 24 hours may be requires to fully charge a really flat battery.
A starter takes around 150/200 amps for 3 or 4 seconds, this is less than an amp/hour in real terms so the battery will recover very quickly, even with all the lights on the alternator will still deliver 6 or 7 amps of charge above 2000 rpm so 10 minutes will restore the lost charge although 15 minutes is more like the real time as the charge current soon tapers off as the battery voltage rises to 14/14.2 volts.
Regards Peter
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I stand corrected Peter!
I was thinking of those big garage booster chargers that can charge a flat battery in minutes. I agree the rate of charge has to be managed carefully, and a fully flat battery won't take 60 amps.
All the same, experience has shown that you can run a battery flat trying to start a car, then push start it, and it will be back to fully charged after a remarkably short time, if the battery is in good condition.
I think batteries can take higher charge currents than you imagine.
The ammeter on my Triumph 2000 (still on original generator not alternator) can read over 40 amps when first started up after inactivity, but rapidly tails off as the battery comes back to full charge. The battery has not boiled or melted - it is 8 years old, and will hold a starting capability for a month easily.
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Hi Cliff. Triumph 2000, Collectors Item dynamo and regulator included. Yes your observation is correct you do get a high current initially but not for long. Your original post referred to fully charging a 60 Amp hour battery in One hour i.e. 60 amps for one hour. That would boil and no doubt buckle the plates. You can not escape the physics that to fully charge a battery so its specific gravity is correct in all cells and the interanl resistance is as low as possible i.e. provides maximum cranking current a flat battery benefits from a conditiona charge as previuosly mentioned and for the 14 hours or so. Many batteries after 3 years are only about 1/3 of the quoted capacity but still provide good cranking, leave the side lights on overnight and they are flat and that is only 4 * 6 watt bulbs so 2 amps for 12 hours thus 24 amp hours and its flat. Happy motoring in your Triumph. What year was it made. ?? Regards Peter
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>>. Happy motoring in your Triumph. Whatyear was it made. ?? Regards Peter
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OK, bit of an exaggeration, but I still say it charges at a high current when it needs to replenish itself.
1964. Reasonable original condition, used daily as a second car.
I've never had any trouble with the generator - never seen any reason to convert to alternator.
I do think good batteries (I assume it must be good, it came with the car 8 years ago) pay for themselves in terms of robustness, capacity-holding, ability to give a good starting current for a long time.
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Usually around 5 miles of driving at whatever speed.is normally the case will be enough to charge the battery assuming correct battery and alternator is fitted.let me know if wrong but doubt it
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Cliff, Cool, I agrre spend 30/40 % more on a good battery and double the life and reliability. Regards Peter
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