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# 12V car alternator charging a 12V lead acid battery

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#### fantabulous68

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Does anyone have a circuit diagram for a charging circuit--->

12V car alternator charging a 12V lead acid battery.......

I want to cut down the electricity bill
The charging circuit will be connected to an inverter that gives an output of 240V AC.

Usually the alternator comes with a built in regulator. If it doesn't have one, you could pick one up at an auto wrecker for cheap. What are you going to turn the alternator with? They require quite a high RPM to give any decent output.

What are you going to turn the alternator with?
Will use a 220V electric motor to turn the alternator with regulated rpm

And unless your able to run the electric motor for free then you won't save on any electricity.

And unless your able to run the electric motor for free then you won't save on any electricity.

regulator from van charges battery------>12V battery drive inverter--->inverter drives motor----->electric motor drives alternator----->ac alternator 220V output

Every stage will lose energy via heat. You'll only get a percentage of the original power you put into it.

Gosh I wish schools would start teaching basic practical math and science again.
I really miss the common sense it instills in people.

regulator from van charges battery------>12V battery drive inverter--->inverter drives motor----->electric motor drives alternator----->ac alternator 220V output

Why not just pull your 220 off the first inverter? This chain doesn't make sense.

dude....u have to get ur basics right....u cannot continue otherwise

yikes im never going to ask a question on behalf of someone else again.

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Here's what you could do, but won't really save you any on electricity. Use alternator in Van to charge up a battery while driving, then use an inverter off the battery to get your 220v. Or if you didn't have an inverter you could get a 12v motor, hook it up and spin a 220v generator alternator. Still your paying for the electricity in the gas your using.

hey, its okay fantabulous. even the most experienced guys out there do make mistakes....and making mistakes is the best way to learn...and where is a better place than the forum to make mistakes? where you have experienced people helping you out...so you can always learn from them...dont worry at all...and if its your friend who posed the question, tell him to join the forum too and ask his doubts himself, so he learns too....

cheers,
deepak

Will use a 220V electric motor to turn the alternator with regulated rpm

dude, this is a really good idea because you will get more power out of it, your overall power will be dependant on how big and powerfull your last stage is!!

so to get the most power out use the biggest 220V ac alternator you can find like a 100,000 watt one! then you can stop wasting $on the electric bill altogether!! May I suggest that you have a good idea, but you are looking at it from the wrong direction? If you connect your generator to a windmill and the output across a battery, you have a power source that will keep on working after the wind stops. Chevy alternators only have one connection that goes to the battery. The other lead is the car frame ground. Your problem is going to be the battery. A car, or even a truck, battery is only good for about three years. After that, it won’t hold a charge. First, you need to use a stationary battery like the Absolite line that has a 20-year guarantee. The things are expensive, but not over the expected lifetime. Second, the amp hour rating of a battery is based on a steady discharge over an 8 hour period (with the exception of Gel Cells which use a 24 hour standard so they look better). Discharge a battery in less time and you get fewer amp hours that the stated number. Take longer to discharge it and you get more that specified. Also look at the discharge level specified. A charged led battery will have 2.2 volts per cell output. If on a float charge, the system will read 2.25 volts per cell. Battery specification sheets will give an amp hour rating for a final discharge value of from 1.85 down to 1.75 volts per cell. Discharge below 1.75 volts and there is a good chance the battery will never take a charge again so you have to supply a low voltage cut-off circuit to remove the load to save the battery. As you can see from the above, your 12 volts are not going to be 12 volts very often. Most of the time it is going to be high or low. That is why most commercial systems connect an inverter to the battery instead of using it directly. There is only one exception that I am aware of and that is the telephone company. They use a 48 volt system of 24 led acid cells plus one CEMF cell connected backwards for a total 50.6 volts. The reverse cell acts as a regulator evening out the voltage. Note, if you try this, they make special cells for this use, don’t try using a regular one or you could have an incident that sprays acid all over everything. I really recommend that you add an inverter and static transfer switch; then use your 220 system on either the mains or wind power as conditions permit. He forgot to mention it's a company van that he doesn't pay for the gasoline used. Then just steal some of the company gasoline out if it and sell the stolen gas. Oh wait! That's exactly the same thing! Not only is the extra gasoline used more expensive than the cost of the energy in the battery, the cost of a lead-acid battery which is good for a few hundred cycles if it's a deep-cycle type is vastly more expensive than wall power even IF you had a free source of energy to charge it. 1KWH=$0.10 in cheap parts of USA. Say it's $0.25 in Europe or somewhere. Deep cycle battery=$120, 12v/50AH usable=0.6KWH. Say it lasts for 200 cycles (that's quite a lot for lead-acid). Can move 120KWH over its entire life.
=$1/KWH to move it through a battery! Oh wait... that's 4x/10x more than the wall power would have cost, even if I can charge it for nothing at all. Not only is the extra gasoline used more expensive than the cost of the energy in the battery, the cost of a lead-acid battery which is good for a few hundred cycles if it's a deep-cycle type is vastly more expensive than wall power even IF you had a free source of energy to charge it. 1KWH=$0.10 in cheap parts of USA. Say it's $0.25 in Europe or somewhere. Deep cycle battery=$120, 12v/50AH usable=0.6KWH. Say it lasts for 200 cycles (that's quite a lot for lead-acid). Can move 120KWH over its entire life.
=\$1/KWH to move it through a battery!

Oh wait... that's 4x/10x more than the wall power would have cost, even if I can charge it for nothing at all.

200 cycles isn't that much for a Deep Cycle battery, now for a regular Lead Acid yea that's ALOT. If maintained a Deep Cycle can expect over 350+ Cycles, and really depends on the brand.

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