Okay guys don't say I never gave you any of my secrets now hehe. secret sauce.....

WARNING: DO NOT ATTEMPT THIS ON YOUR OWN UNLESS YOU ARE TRAINED IN ELECTRICAL, VERY DANGEROUS!
KNOWING HOW TO CHARGE A SUPERCAPACITOR IS ESSENTIAL.

Super Capacitor Battery replacement weight is 10 pounds
no messy battery rerouting and a 26 pound reduction over the autozone gold battery I had in there that weighed 36 pounds

The capacitor bank should last 10 years from new but I bought these at supposedly 1 year used. so estimated 5-9 years life

It has less energy density than a battery meaning it holds less total power compared to a battery of the same weight. For those in the know it's a series array of 2600F supercapacitors which equates to 433 Farads and it has 5.4 KiloJoules of usable energy before voltage drops to around 9V. The whole 14 volt charged array holds about 42,434 Joules. (Joules is watt seconds.)

However there are differences to a regular battery and the car starts in 1 or 2 cranks now opposed to 3-4 with a battery due to higher current capabilities over batteries.

The handling, acceleration, and braking and shifting and front rear weight balance feels much better now I just drove my beta unit shown here for like 30 minutes and I loved it, cornering is much faster now.

I have an extra set of supercapacitors and will be constructing another array to maybe sell (On here) or use for other projects I have in mind like solar power.
Don't mind my bummish cardboard cover, I needed to cover the metal plates so nothing shorts out, and I built it in a few hours.

 

Update: I made a box for the capacitors out of scrap carbon fiber I had. Not show quality, but I could care less it's under the hood in bad conditions anyways.

 

So you used a capacitor instead of a battery? Everything that I know about capacitors which mind you isnt much but nonetheless tells me that a capacitor releases its charge all at once. Therefore this sounds silly for starting a car. What happens when it doesnt fire that one time due to some other issue? Now you've lost all the juice...Also how does it integrate with the alternator to recharge itself?

 

Yes it's an array of 6 supercapacitors, or ultracapacitors, 2600 Farads, new cutting edge technology uses activated carbon for electric double layer characteristics. It's really the infancy of carbon technology in the electronics world. But brand new right now, these caps would probably cost about $1000 for 6 of them.

Capacitors (the small ones) only seem to release the charge all at once, because those types of small capacitors only hold a tiny amount of charge, usually in the micro farad(uF) range, and with a high voltage rating. These supercapacitors hold ALOT of charge(millions, maybe hundreds of millions times more than those regular tiny capacitors you think of) and will kind of act like a battery, the released charge depends on the load, the equivalent resistance of the load/circuit along with the voltage source actually dictates the amount of current flowing through that circuit.

If it doesn't fire, depending on what the voltage level is....if I start from a full 14V I probably have at least 3 tries to keep cranking, I also have a quick charger I made in my garage, if I leave the car there too long or drain the caps by turning on my headlights and radio, I can top up the capacitors to over 12V in 1 or 2 minutes with my charger and start the car very fast. Supercaps can charge and discharge faster than a battery.

I'm also making a small portable emergency battery boost pack out of rechargeable double A, for a lightweight self car jump starter, I doubt I'll ever even need it, and my car can also still be jump started the old way with another car hooked up in parallel with jumper cables.

The alternator has a built in voltage regulator(14.4V max) that makes sure the caps don't charge over their 15V limit (w/6caps in series)(and makes sure your battery isn't being overcharged), and once a capacitor is charged it doesn't accept anymore charge because it's own voltage opposes the charging voltage, and with equal voltage levels it essentially looks like an open circuit to the source. The alternator has a max 90amp output, far below the limits of the capacitor, I think maybe 500 amp is the max but I should check the specsheet, it's a ridiculously high rating. (Oh and after I start the car the caps are at a full 14.4 Volts after about 30 seconds or so, very quick)

I've been using this for over a week now I think, and I'm pretty sure I'm going to keep it on(I love the handling and weight reduction), if you want a good website for researching the subject, check out laserhacker forums, there's a relatively high amount of members who are adept at electrical theory and there's a lot of good info.

 

i think for the price its absurd....

you can find a lot of other mini batteries weighting probably less for a lot cheaper.

 

I got it for $100 used and good condition, but brand new it would be $1000.

It will probably last as long as a regular battery in it's used state. Normally it would last twice as long as a battery.

I considered the small battery for my car a while back but I thought this was much funner and probably cheaper for me too. I also got to gain more electrical experience by doing this project.

 

Certainly an interesting concept. So what happens if you want to go to a drive in or something and need the radio on without the car being on? How would you say its performance compares to a normal battery and a mini battery?

Im guessing in order of best to worst it would go:

normal > mini > capacitor

 

So essentially you made a really complex setup that is more dangerous, weighs more and costs more then a mini battery?

 

It wouldn't last too long, I dunno it depends on the wattage of the radio too, I have the SSL sound system, so it probably drains a lot faster than a regular radio.

On a guy's scion, he ran the radio for 30 minutes and still started the car. My evo seems to suck up a lot more juice than his scion though.

But you are absolutely right, the capacitor as I've already said, has less energy density than chemical batteries.

There are many ups and downs to using capacitors, I never said they are better than batteries. Just different.


I don't have to worry about cold cranking amps because the caps work even better when cold up to -40C.

I can top them up in 1 or 2 minutes. And I have virtually unlimited discharge cycles(500,000), they will never die from sucking all the power out of it, which a small battery might do. The ecu data stays stored even though the voltage gets as low as 9V, so I don't have to worry about that.

They are also more environmentally safe. Not as hazardous as battery acid. The only thing more dangerous is the possibility of shorting them out with greater current but a battery is plenty dangerous in the same respect. The battery actually holds more energy in total so it might be more dangerous. It's only working on it that could pose a threat if you don't know what you are doing.


By the way, that guy with the scion, lasersaber on youtube who made laserhacker forums, started his car with 6 x 350F supercaps that weighs 1 pound. He also let his car sit for the weekend and started it, and ran the same radio for 30 minutes and started his car after. But I doubt I can do it on the evo like that. You can tie in a small battery in parallel for a hybrid system for long lasting charge and really good cranking performance, I just didn't feel like using a battery for now.

When these caps die on me I will buy the 350F supercaps and tie a LiPo4 battery or whatever with it, it'll probably weigh like 2 pounds.

 

It's not complex just the lingo is, if you saw how I built it, you would think it's easy.

How much does a mini battery cost and how long will it last?

Maybe a mini battery in parallel with a smaller capacitor setup would work good because the heavy cycling probably kills the small battery fast.


Yea later on I'm gonna add a really small battery, the biggest would be like a motorcycle battery, to run the radio and let the car sit longer keeping the caps topped up, the capacitors will take care of the high amps for starting the car.

It'll only be like 2 more pounds and I'll still shave plenty of weight while still keeping the car comfortable, and the cap battery combo is synergistic the caps will actually charge the battery when you shut off the car until the voltage equals out, and the battery keeps the cap voltage up afterwards.

There are stories of people running this combo for 10 years without replacing anything.

 

http://www.specopsmotorsports.com/St...0-mini-battery

So this mini battery costs more at $145, weighs more at 14 pounds, and will last a min-max of about 3 months to 3 years which is about half as long as my used capacitors will last(So all that stuff was bull**** about the battery being all around better, which it is obviously not) The only thing the battery is better at is energy density, other than that I don't see it outperforming the capacitors. This odyssey one is a deep cycle battery so it's probably why it lasts longer compared to the cheap ones.

Over the course of the next 5 years, you will probably end up buying 2 of these mini batteries and spending over double what I spent, while my setup will probably be alive and kicking. The battery I'm buying is going to cost $15 and weighs 2 pounds, lead acid.

Here's a drain test on my capacitors, I can run the radio pretty loud for up to 15 minutes and have enough juice left to still start the car. Even as low as 9.5V can slowly crank and start the car.

 

Hyrbrid Supercapacitor with battery testing, with starting the car shown (just realized I never showed starting the car). 11 X AA NiMh batteries at 1.2V each are used for my particular setup for 13.2V full charge, the capacitor to battery ratio can affect performance in big ways. The digital readout is Voltage and the multimeter is on Amps setting between the battery and supercapacitors, when positive the battery is supplying the capacitors/car when negative it is being charged by the capacitors or the alternator......

 

Interesting, I've never read up much on capacitors. The little I've read makes me surprised about the guy with the Scion being able to run the radio for 30min and then start the car. I just put a LiFePO4 battery in mine. I'm sure it will do great, just a bit concerned about how the winter will treat it. Went with a large 20cell to have extra capacity (daily driver) even though a smaller one would start it.

 

Interesting, what's the specs on that battery? Well let me know how it goes I guess.

 

In the meantime I've been enjoying the longer lasting charge with the AA setup, but there is room for more charge in the batteries almost always, so I thought of a way to charge the batteries fuller with solar power while I park in the sunlight during the day, solar cells are also more highly tuned to the infrared wavelength and can still perform decently in cloudy weather, as long as it's not raining pretty much. And I can take advantage of that with one of the components in the circuit.

So I drew up a kind of crude looking schematic, and the zoom in is like a cutaway of the faceplate I will make for it with carbon fiber. I'm putting this in the empty spot under the radio where I usually put my garage opener, but I can put them in the armrest after I install this.

There's also like 2 undecided details so it's incomplete, but yea i'll update after I make the real thing, I already ordered the solar cells, but have a lot of other parts to order. but total it will only cost me like $25, I already have a couple parts for it laying around. But after this my setup will be awesome and reliable. I can keep adding to the solar too with the rear window, just a small piece.