Super capacitors vs batteries

[mramoo]

I was just reading a thread on Cruiser Forum about the use of super capacitors to replace batteries. there was also a link to a new battery chemistry.(https://www.slashgear.com/honda-rev...kthrough-for-next-gen-power-storage-06557121/ )
They both look like something that is very interesting new ideas.

 

[psneeld]

My son touts thier future....he has seen them in action at substations.

The future is racing towards us, should be intetesting

 

[Boat]

I talked an engineer who has been using surplus capacitors instead of batteries in his home solar system. Said he had years of reliable service and better performance for a fraction of the price.


Since then I have wondered about using capacitors in electric cars, etc.


Fluoride may be controversial.

 

[wwestman]

We put fluoride on our teeth, why not in our batteries?

 

[Boat]

Blamed for cancer and bone issues. I'm no expert and haven't paid it enough attention to give you a useful answer but the controversy goes back seventy years or so. Part of it had to do with the nuclear energy industry and part was the earlier lack of controls, precision and accuracy in mixing with water. I saw a mixer in the early nineties, it was impressive. Looked like something from an operating room. And of course the pervasive, ubiquitous perception that all chemicals cause cancer.

Alum was the drinking water treatment that I found most repulsive. Treat mud with mud.

The topic of water treatment could easily be a lifelong pursuit.

 

[High Wire]

Its unconventional but it works excellent for starting engines. Charge up the cap from the house bank when needed. Allows a bigger house bank. Some day in the near future, the car starter battery will be replaced with a lightweight capacitor and the charging battery will be the size of a pack of smokes or smaller.

 

[diver dave]

Yep; dont want to brush your teeth with soluble uranium tetrafluoride (UF4).

Said in jest, but the issue is more of the unintended consequences of industry.

 

[FF]

The most likely replacement for LA batterys will have a nano carbo fluid that carries the charge.

Advantages 3x the power density in the same volume , but the real biggie is as you drain and replace the charge fluid the energy left can be measured...As can the energy put into the battery.

This (plus the rapidity of fluid change ) will allow the various gov agencies to TAX the energy , as they do today with fuel.

A rapid refill and the ability to easily have battery cars pay for the "transportation fair share" (trains to nowhere empty buses) will get a big push from our rulers.

 

[CaptTom]

In the linked article, it mentions "room temperature."

My car is rarely at room temperature. Half the year it's far colder. And of course, the coldest days are when you need your battery at its best.

Granted, many boats never see cold weather. But for for a mass-market solution, I think a battery would need to work quite a bit below room temperature.

 

[High Wire]

Car start with D cell sized capacitiors

 

[diver dave]

HW; awesome find! I just checked out the data sheets on the D cap. They are really cost effective. This is a rapidly emerging technology. I suspect one limiting factor is the balance of charge in this series arrangement. A single low C cap will have a higher V across it during charge. Not clear what will happen then. 2.85 V across an individual cap is the Vne.

 

[High Wire]

HW; awesome find! I just checked out the data sheets on the D cap. They are really cost effective. This is a rapidly emerging technology. I suspect one limiting factor is the balance of charge in this series arrangement. A single low C cap will have a higher V across it during charge. Not clear what will happen then. 2.85 V across an individual cap is the Vne.

Funny thing is that video was from 2013!!! There has to be even better out there.

 

[Ventana]

Marine starting solution:

https://www.skeletontech.com/skelstart-engine-module-2018


They were at the last marine trade show.

 

[hmason]

How about capacitors for dummies? I know a capacitor stores electrical power but where does the stored power come from? The batteries?

 

[diver dave]

Both caps and batteries store energy. Batteries store chemical energy that is transformed into electrical energy on demand.
Capacitors store energy directly as electrical energy in the form of an electric field in the dielectric. Of course, both have limited energy content, and each require (charging) from a different source of energy. Alternators, solar cells, etc.
In theory, a battery can charge a capacitor, but also a capacitor can charge a battery. All depends on the numbers. The energy in a cap is 1/2 * F * Voltage squared. A battery is usually described as kWh for energy (not Amp-hours).

 

[MurrayM]

Interesting stuff... https://www.wired.co.uk/article/superdielectrics-supercapacitor-electric-car-battery

 

[gsholz]

Capacitors are great in delivering lots of amps for a short time which is a good match for starting loads. They are not great for storing lots of energy.

Example: A good sized capacitor of 75000uF (microFarad) would only store 5 Watt seconds of energy at 12V versus a 100 Amphour battery would provide roughly 3,600,000 Watt seconds of energy. You'd have to parallel 720,000 caps to be equivalent to one 100Ah battery.

Now, if the charging voltage of the cap was 1,000V, it would store 37,000 Watt seconds. You would need only 100 caps in parallel to equal a 100 Amphour battery. But that 1,000V cap would probably be pretty big and expensive and one would have to up/down convert for 12/24V devices.

 

[88FuHwa]

I purchased a Winplus 12v Car Jump Starter at Costco the size of a very thick smartphone. It starts up my Audi A8 or our Volvos without hesitation. I believe the technology is Lithium Ion. Probably won't work for a house bank but should start up my boat's Perkins engine. I can charge the pack from my laptop USB port or a 12 volt source.

 

[rolomart3]

I was just reading a thread on Cruiser Forum about the use of super capacitors to replace batteries. there was also a link to a new battery chemistry.(https://www.slashgear.com/honda-rev...kthrough-for-next-gen-power-storage-06557121/ )
They both look like something that is very interesting new ideas.

The questions in my mind is:

Does this fluoride battery technology use any scarce material? How abundant is the availability of the fluoride element.

 

[boomerang]

I purchased a Winplus 12v Car Jump Starter at Costco the size of a very thick smartphone. It starts up my Audi A8 or our Volvos without hesitation. I believe the technology is Lithium Ion. Probably won't work for a house bank but should start up my boat's Perkins engine. I can charge the pack from my laptop USB port or a 12 volt source.

My thinking is a capacitor for starting wouldn't have enough backbone to get my perkins going on a cold morning. For both our current Perkins & the Detroit in our previous boat, on a cold morning I have to hold the stop (fuel shut-off solenoid) down for a few revolutions to get some heat built up in the cylinders. Upon releasing the solenoid, the cold fuel is introduced into the warmer cylinders & the engines will begrudgingly start. Most of the time I'll even parallel the house bank with the starting battery to help things along. I just don't see a cap as continuing the burst of power I need to get the engine to fire

 

[jimisbell]

The questions in my mind is:

Does this fluoride battery technology use any scarce material? How abundant is the availability of the fluoride element.

lts very abundant and cheap

 

[Boat]

Maybe a byproduct of the fertilizer industry.

 

[stubones99]

I have posted here about the supercap start batteries but with a $1000 purchase price, it isn't worth it. I like the idea of a 20 lb battery vs 150lb for a 8D or even 4D battery. A 24-volt supercap is also 20 lb, and can be charged by 12 volts.

The downside to supercap batteries is that they have about 20 seconds start power. If you're not running in 20 seconds, you'll need 10+ minutes to recharge, and the power source to recharge them. Capacitors love to dump their power in one massive discharge. That does not make them a very good battery, and most of the new technology is the tech to dole the stored power out as needed. They can be charged and discharged thousands or even millions of times with no problems, but I can't say the same about the technology to slow down the output to usable voltage & amperages. All electronics have a lifetime... we just don't know it is.

If you're one to sit in your car with the radio playing, a supercap isn't for you. Anything with minimal power draw will waste more power than needed, just to supply the minimal draw.

Over-the-road trucks are replacing their 24-volt starting banks with 24-volt supercaps due to weight. Their 12vdc charging ports off the house bank boosts the voltage to charge the supercaps up but they have the 20-second limit.

Note that it takes a lot of amps to charge it back up, since it can't create the energy, it can only store it.

Maxwell Technologies Engine Starting Module
https://www.maxwell.com/products/esm/24v-esm

 

[stubones99]

Maxwell said their technology was not approved for Marine applications...

But at $1000 per battery, it's not viable either, so it's a moot point.

 

[bayview]

IMO they don't store energy well over a long time frame. If you don't use and recharge them frequently they will be dead. Many boats don't get used all that frequently. Dock power can keep them charged but then what is the advantage over batteries?

 

[stubones99]

The primary advantage of Supercaps is that they work in all temperatures, have nearly infinite life, and weigh very little compared to a battery. They do have a self-discharge problem but can be charged from dead to operational in a few minutes.

They make sense in a hybrid car, for an example. When you slow down, the inertia drives a generator that charges the supercap up. When you accelerate, you drain the supercap, so you get the effect of having a more powerful engine because the engine and the generator/motor are pulling the car up to speed. They weigh very little, compared to even Lithium Ion batteries and far less than lead-acid batteries.

Does it make sense in a boat? No, since it would not replace your house bank. It might replace your starting bank, and be charged off the house bank. It certainly would make wiring simpler, since all you ever need to charge is the house bank.

 

[ben2go]

There are people making and using capacitors for automotive batteries. Back when I was a kid, I used several in some of my vehicles to power the sound system without killing the battery.



Here is one that's touted to have made it 3 years and still going.

 

[stubones99]

Maybe a byproduct of the fertilizer industry.

Also a byproduct of the aluminum industry converting basalt to aluminum with electricity.

 

[jimisbell]

It also is mined out of the ground in large purple crystals in the northern US

 

[FF]

Trucks have federal weight limits , an extra 100 or 200 lbs for cargo is extra money per load .


Might be worth it to them.