12V BoostPack. Replaces auto battery?

[BUTCH1]

Interesting, guy is using 6 large capacitors wired in series (for 14v), seems to be working OK for him. One thing of note is he is starting a small 4 cylinder engine, IDK how it would do with a big V6 or V8.
EDIT:, This guy bought these caps a few years ago when they were surplus, they are now way too expensive for this build.

 

[yh125d]

Only change should be that it would be good for fewer starts without giving the alternator time to recharge, which as we saw goes really quick with the motor running. Add a small solar panel (top of dash, forward under the windshield so you don't see it) in case you wind up draining it and don't have a power source, battery maintenance, etc. and then the only thing you couldn't do is run much electrics for very long with the motor off.

I'm not sure how it would respond to temperature extremes. I imagine heat wouldn't really matter, but I don't know how caps would respond under really low temps

 

[BUTCH1]

Only change should be that it would be good for fewer starts without giving the alternator time to recharge, which as we saw goes really quick with the motor running. Add a small solar panel (top of dash, forward under the windshield so you don't see it) in case you wind up draining it and don't have a power source, battery maintenance, etc. and then the only thing you couldn't do is run much electrics for very long with the motor off.

I'm not sure how it would respond to temperature extremes. I imagine heat wouldn't really matter, but I don't know how caps would respond under really low temps

Yea, good points. I would back it up with a cheap AGM battery so the cars BCM won't drain it down if it sits for a week or 2.

 

[feralkid]

He thinks having the A/C on makes a car harder to start.

 

[BUTCH1]

He thinks having the A/C on makes a car harder to start.

Yea, that possibly might have been true long ago but in today's cars the BCM will delay clutch engagement until after the engine is running.

 

[Yuriman]

-Capacitors don't really care about temperatures

-Charge and discharge is generally more efficient than in batteries

-Capacitors self-discharge, so depending on what capacitors you use, you'll have to throw your car on the charger after a few days/weeks if you haven't driven it, or add a solar trickle charger

-Capacitors are lighter

-Capacitors can be cheaper

-Capacitors last a lot longer than lead acid batteries

-Capacitors have much less total storage than batteries

-Capacitors can be run to 0v with no negative effects


Mazda Skyactiv cars have a super capacitor bank in them:

http://www2.mazda.com/en/technology/env/i-eloop/

^ Kindof a big deal - some "hybrid" functions in a non-hybrid car. This is a great way to get regenerative braking and stop-start without all of the expensive batteries that need to be replaced after 8-15 years. Alternators are also responsible for ~15% of your total fuel consumption (before you've added aftermarket stuff which consumes electricity) and this heavily supplements the 12v system during city driving.

One problem with lithium batteries in hybrids has been that you can't safely charge/discharge them quickly enough. Having a bank of capacitors could at least partly alleviate that.

 

[BUTCH1]

-Capacitors don't really care about temperatures

-Charge and discharge is generally more efficient than in batteries

-Capacitors self-discharge, so depending on what capacitors you use, you'll have to throw your car on the charger after a few days/weeks if you haven't driven it, or add a solar trickle charger

-Capacitors are lighter

-Capacitors can be cheaper

-Capacitors last a lot longer than lead acid batteries

-Capacitors have much less total storage than batteries

-Capacitors can be run to 0v with no negative effects


Mazda Skyactiv cars have a super capacitor bank in them:

http://www2.mazda.com/en/technology/env/i-eloop/

^ Kindof a big deal - some "hybrid" functions in a non-hybrid car. This is a great way to get regenerative braking and stop-start without all of the expensive batteries that need to be replaced after 8-15 years. Alternators are also responsible for ~15% of your total fuel consumption (before you've added aftermarket stuff which consumes electricity) and this heavily supplements the 12v system during city driving.

One problem with lithium batteries in hybrids has been that you can't safely charge/discharge them quickly enough. Having a bank of capacitors could at least partly alleviate that.

All true, I might still build a "booster" that would supply most of the current to start the car and hopefully get 10yrs out of a battery, I'm averaging 3 right now.

 

[thomsbrain]

Combine one of these with an alternator relay switch and a volt gauge, and you could do everything the Skyactiv system does, manually. Throw a solar panel up on the roof rack and you'd probably only have to actually use the alternator when the lights or fans were on. One of those lithium-ion glove compartment jump-packs would be all the insurance you'd need for leaving the car for extended periods.

I've toyed with the idea of switching to a deep cycle battery and manually controlling the alternator, but this is much better in terms of handling the constant charge cycling.

As far as weight, though, there are plenty of lithium-iron batteries in the sub-5 pound weight range. I run a 5-pound battery in my S2000 that works great.

 

[Sabrewings]

As far as weight, though, there are plenty of lithium-iron batteries in the sub-5 pound weight range. I run a 5-pound battery in my S2000 that works great.

I had one in my STI. It even managed to start the car at -13*F in upstate NH in February. I had no complaints.

 

[thescreensavers]

Check out http://www.getohm.com/

Its a neat kickstarter type of project. Id buy one but no money right now haha

It combines Capacitor and Batteries.

 

[razel]

Don't mess around with power much less your car which for most people is part of their well being for keeping a roof over your head or food in your stomach. The last thing you want to do is go cheap with wiring or experiment and DIY with your well being.

There are alternatives for lighter batteries in cars, but there is no getting around physics when it comes to power density vs. getting that dense power out safely. Don't go cheap or DIY if you don't have a solid understanding of electricity... it will hurt you without prejudice.