Replacing Car Battery With Super Capacitors

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techman
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Replacing Car Battery With Super Capacitors

Post by techman » Fri Feb 17, 2017 10:44 am

I am experimenting with using supercapacitors in place of gas engine and car starter batteries.

So far I have used 5 supercapacitors to start an 11 HP gas engine. This works when the engine has been run recently. But when I start the engine after refilling with gas they dont have enough power. The fuel system was totally empty.

I next strung up 10 supercapacitors together. Two sets of five in parallel to double the current. This started the engine after sitting cold overnight in the winter with no problem.

The capacitors I am using are Amperics 400 Farad supercapacitors which are rated at 3 volts. This gives them an advantage over the rest due to their higher capacitance and voltage. You only need 5 capacitors from Amperics to give you 15 volts. With the other capacitors you need six of them for a 12 volt system.

Adding capacitors in series to increase the voltage greatly reduces the overall capacitance. The standard supercaps are rated at 300 Farad and 2.5 volts which gives you a string of 6 capacitors at 15 volts and 50 Farads.

With Amperics supercapacitors you use 5 capacitors to get 15 volts and 80 Farads. A serious advantage.

You can get Amperics SuperCapacitors here: https://www.amazon.com/gp/search/ref=as ... d8a0cd1506

wiggys.shop
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Joined: Fri Feb 17, 2017 6:27 pm

Re: Replacing Car Battery With Super Capacitors

Post by wiggys.shop » Fri Feb 17, 2017 8:15 pm

Hi

I thought I would just post the setup I just finished doing two weeks ago. If anyone has any suggestions to improve this please let me know. I removed the standard car battery and replaced it with six 3000 f Maxwell capacitors rated a 2.7 volts. I am also using a 4.5 amp/hour battery that is connected with a 3 Ohm resistor to the capacitor Bank.


Before I start of the project I measured the amperage voltage and Watts that my car used while turning over.
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After I got the capacitors installed I measured the voltage well the engine was turning over. This data was taken without the 4.5 amp hour battery connected. I'm getting about 5 Seconds of the engine turning faster than what the battery would allow. After that I have 5 Seconds of slower cranking speed before the capacitors are depleted.
battery amps.PNG
battery amps.PNG (36.88 KiB) Viewed 10196 times
https://youtu.be/RhZ9-moZ-dA

https://youtu.be/7llC0ZB-Rf8
Attachments
volts.PNG
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battery watts.PNG
battery watts.PNG (29.23 KiB) Viewed 10196 times

techman
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Re: Replacing Car Battery With Super Capacitors

Post by techman » Wed May 03, 2017 10:47 am

The important things to test are:

1. How long can you let the vehicle rest before the capacitors are so depleted that you cannot start the vehicle again?

2. Does your vehicle start immediately or need a few turns to fire up? I am wondering especially about this point for larger engines or older vehicles that dont immediately fire up.

wiggys.shop
Posts: 4
Joined: Fri Feb 17, 2017 6:27 pm

Re: Replacing Car Battery With Super Capacitors

Post by wiggys.shop » Fri May 05, 2017 8:18 pm

When I ran the car with the capacitors alone I had times that overnight the car would struggle to start in the morning. I'm now using a 4.5 amp hour battery to keep them from discharging. Part of the problem I believe with mine discharging so quickly is that my interior lights stay on for a number of minutes after I close the door. If I have to make multiple trips out to the car and open and close the door it ended up discharging the capacitors quite a bit.

My car does not start up instantly like a lot of new cars. It doesn't take a lot of time but it's not instant. Below is a video of it starting at way to low of voltage to give you an idea of the worst case starting time. Just be careful when I made that video starting at that low of voltage actually tripped transmission error lights in the car. They went away after restarting the car but I would avoid trying to start your car at to low of voltage to minimize the chance of damaging the computer.

https://youtu.be/fnFYPHh0RDg

What is the starting amperarage requirement for your car?

techman
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Re: Replacing Car Battery With Super Capacitors

Post by techman » Fri May 12, 2017 3:57 pm

No idea of the actual starting amps of my car but it is the same as yours and that bothers me. The headlights turn in the second you turn the ignition switch and the interior lights remain on after a while when entering and exiting the car.

These are issues I have to overcome for the car as well.

The truck should be better since it only has one old fashioned dome light and no fancy electronics running. I am going to test a capacitor battery on that first.

My big problem at this time is overcoming the heating of wires with the smaller tabs on super capacitors. I am trying to find a way to solder them with bigger wires to allow for the high amps of starting a vehicle.

wiggys.shop
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Joined: Fri Feb 17, 2017 6:27 pm

Re: Replacing Car Battery With Super Capacitors

Post by wiggys.shop » Sat May 13, 2017 10:49 am

If you need a cheap way of measuring starting amperage I use one of these.
https://www.amazon.com/gp/aw/d/B008SOPJ ... rent+shunt
As long as you have a good meter that can read mVolts it works great. Seems like most DC amp clamp are very expensive.

techman
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Re: Replacing Car Battery With Super Capacitors

Post by techman » Mon May 15, 2017 3:25 pm

That is a good deal. Thank you for that. I will have to get one. I was just trying to figure out if I had any way to read starting amps.

I am going to do some starting and charging and load tests on the capacitor battery this week with a data logging meter.

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