# Turning a Dumb Charger into a Smart Charger



## Zemmo (Sep 13, 2007)

Here is the info I found the Landis Controller I mentioned earlier :

http://stormselectric.blogspot.com/search?updated-max=2008-04-07T11:06:00-05:00&max-results=10

The below link is a picture of the one he has:

http://picasaweb.google.com/stormco...murai?authkey=br5eIwNQ3i0#5159898365802713010


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## WSJ (Sep 18, 2008)

I designed a programmable charger controller, which uses a programmable timer to shut off the charger after the charge output current falls below preset value. The timer drives a solid state switch, which is connected to the charger AC input. The amount of time before the current sensor trip point varies depending on the DOD, however, the amount of time required to fully charge the pack after a given current at the end of the charge cycle is relatively constant. I’m using 3.5 ADC to start the timer; the timer is programmed for 1 hour. If your charger does not have 3.5 A output indication, you could use an AC Current Sensing Relay. 

Components: Timer; Omron H3CA-8, Solid State Switch; Carlo Gavazzi, RN1A23D30, AC Current Sensing Relay; Dayton, 1EJF5.

See picture 47 & 50 for the programmable charger controller timer installation:
http://public.fotki.com/WAYNEWANG/electric-car-beetle-ev-/
http://www.evalbum.com/1798

Wayne


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## Zemmo (Sep 13, 2007)

That sounds like what I am looking for. As far as I know my charger doesn't have a 3.5 Amp DC output indicator. It is just the K&W charger. It is the 108 volt charger but I have the line booster so it boosts it's charging potential to 120 volt. Of course that is nominal voltage. My pack's voltage is getting up to 148 volts when charging. I can push it more but it won't go much higher. My charging amps runs about 6.8 amps going into the battery and lowers down to about 6 amps at the end. But the voltage would drop from 148 or 149 down to 144 or 143 (if left to run/charge long enough). I would just like the charger to be turned off once the voltage has dropped a few volts.

Do you have a schematic of this charge controller you built?


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## Zemmo (Sep 13, 2007)

Well I came up with a solution for shutting off the charger automatically. I didn't get anywheres with something detecting fully charged and shutting off the charger. But after owning my EV over a year now I have a good general idea of how long it will take to recharge my EV at a certain DOD. So what I did is ran to Lowes (one of my favorite stores) got an AC outlet, wall box, power cables and an industrial timer capable of handling 15 amps. This timer is not the auto on and off ones where it will come on every day at 8 and shut off at 10 (or what ever you set yours too). This is a count down timer to run a device for a specified amount of time shut off. This timer is the "Hours" timer which will do 2 thru 12 hours (they also have a minutes timer). I assembled the outlet and timer in the wall box and ran power to it. So now I plug my car into that and twist the timer to how long I need it to charge for. I have been using it for a week now and it works great. I figure this will cut out about 180 hours of excess charging a month (6 to 7 hour a day, well actually over night). I use my EV as my every day car, we take it over our spare gasser car just because of how cheap it is to run. So it really is an every day EV car (gets used a lot). I will be building a case for the box to clean it up and then I will see about posting a picture of it.


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## WSJ (Sep 18, 2008)

Zemmo said:


> Well I came up with a solution for shutting off the charger automatically. I didn't get anywheres with something detecting fully charged and shutting off the charger. But after owning my EV over a year now I have a good general idea of how long it will take to recharge my EV at a certain DOD. So what I did is ran to Lowes (one of my favorite stores) got an AC outlet, wall box, power cables and an industrial timer capable of handling 15 amps. This timer is not the auto on and off ones where it will come on every day at 8 and shut off at 10 (or what ever you set yours too). This is a count down timer to run a device for a specified amount of time shut off. This timer is the "Hours" timer which will do 2 thru 12 hours (they also have a minutes timer). I assembled the outlet and timer in the wall box and ran power to it. So now I plug my car into that and twist the timer to how long I need it to charge for. I have been using it for a week now and it works great. I figure this will cut out about 180 hours of excess charging a month (6 to 7 hour a day, well actually over night). I use my EV as my every day car, we take it over our spare gasser car just because of how cheap it is to run. So it really is an every day EV car (gets used a lot). I will be building a case for the box to clean it up and then I will see about posting a picture of it.


That should work better than setting your alarm clock to 3:00 AM so you can remember to unplug your charger. I used a shut off timer in 1986. One time I plugged in, but forgot to set the timer, the next day I almost didn’t make it home.

_____________________

http://public.fotki.com/WAYNEWANG/electric-car-beetle-ev-/ 
http://www.evalbum.com/1798


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## Zemmo (Sep 13, 2007)

Yeah, that will be something I will need to remember when plugging in. Always set the Timer! But even if I forgot one day, I could still make it to work and back no problem. Plus I could always charge up at work. I always carry a cord to plug in anywhere that I can find.


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## WSJ (Sep 18, 2008)

WSJ said:


> I designed a programmable charger controller, which uses a programmable timer to shut off the charger after the charge output current falls below preset value. The timer drives a solid state switch, which is connected to the charger AC input. The amount of time before the current sensor trip point varies depending on the DOD, however, the amount of time required to fully charge the pack after a given current at the end of the charge cycle is relatively constant. I’m using 3.5 ADC to start the timer; the timer is programmed for 1 hour. If your charger does not have 3.5 A output indication, you could use an AC Current Sensing Relay.
> 
> Components: Timer; Omron H3CA-8, Solid State Switch; Carlo Gavazzi, RN1A23D30, AC Current Sensing Relay; Dayton, 1EJF5.
> 
> ...


 
This is a plot of my automatic charger controller performance. The controller maintained a +/- 6% accuracy, for a 50% change in range.


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## Zemmo (Sep 13, 2007)

How much do one of these timer chargers run for? Not the time, the $.  

So far my timer has worked great! I have cut out a lot of excessive charging. My watt/mile has gone down a lot! I am now over 100 mpg when calculating mileage. That timer has been the best result mod that I have done to improve my mileage and its not even on the car!


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## WSJ (Sep 18, 2008)

I bought a used timer for $11 with a DIN rail socket. New timers are $130.


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