Super-capacitors instead of a battery?

[redpoint5]

Originally Posted by ConnClark

Until then its a unicorn just like these dimpled car wraps.

^^^^^^^^^

...still hasn't read the title of the thread, or the posts within.

[cekic]

@redpoint5: Hi, that’s true that batteries can be replaced with the Ultra caps but modern ultracaps still have many disadvantages over traditional batteries like the capacitors are good to provide sudden surge of energy but it cannot hold the energy for long time and discharge quickly than the batteries and that is the hurdle in replacing batteries with capacitors.

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[ecomodded]

I think the real benefit in the Caps in this situation is that they do not store unneeded energy continually recharging a battery with excess power that you will never use.
Where as in the Capacitors you store only the energy you need at any giving moment and not energy for storage. Its the fast recharge of the small storage that gives the gains, the alternator is not On as often is my deduction and I think its promise.

[Nautilus]

The basic problem of the lead-acid battery is not voltage drop. In fact, on most cars voltage drops under cranking towards 9 volts, and truck industry rate the CCAs as the amps a battery can give under freezing cold while dropping to 7.2 volts. Neither is the (renowned) sluggish charging. Or water loss. Or limited life.

The basic problem which is unsolvable as long as we stay on this side of the laws of physics is weight. Lead-acid does not allow deep discharge below a certain threshhold, and in flooded lead acid this threshhold stays up, no more than 30% frequent discharge. Which means that we carry a battery 3 times as heavy as needed. Only to achieve a reasonable service life out of it. AGM, which is deep cycle by construction, for the same amps is even heavier. Which negates any advantage. Plus, even if by some magic we can size the battery to the exact amount needed to start the car and no more, lead is still heavy. As, well.. lead.

Supercaps alone are only a thread above useless. They can give a start, but they self-discharge in time, store miserable amounts of energy, discharge dangerously when some metal tools hits them inadvertently.

But once lashed to a battery, they can draw, store and fire the exact amount of current needed for a start - while allowing a small, lightweight battery to store energy needed for the car's systems. A 60Ah lead-acid is 15-18kg (33-39lbs), the lightest batteries rated for road cars are in the 10-11 kg (22-24 lbs) range, highly specialized racing batteries like Odyssey or Varley are a bit below 20 lbs. A combo of supercaps and motorcycle lead batteries is barely above 10-11 lbs and can start just fine.

[Mrmacireland]

Dia duit
I work on wind turbines they have large capicitors to even out the grid load they really do have serious storage potentional power in them what you need is a way to charge them up take out the regulator of alternator and put a higher capacity one in say 100volts instead of 14volts I always thought these would be a great addition to a ev battery pack if you watch the amp meter when the load changes it drains the charge from battery with a capicitors set up it would drain them instead of battery and you could extend range milage greatly
Over

[oldtamiyaphile]

Self discharge appears to be a myth.

I pulled my supercap bank out of my Renault when I sold it four months ago and it still sits at over 12v and I've been using it to test a power window install in my TJ.

In that regard self discharge appear to be better (or at least no worse), than PB batteries.

[viya0414]

Originally Posted by cekic

@redpoint5: Hi, that’s true that batteries can be replaced with the Ultra caps but modern ultracaps still have many disadvantages over traditional batteries like the capacitors are good to provide sudden surge of energy but it cannot hold the energy for long time and discharge quickly than the batteries and that is the hurdle in replacing batteries with capacitors.

pcb price

pcba servives

[JockoT]

Anyone who has picked up a charged capacitor that has been lying for a spell will tell you just what a myth self discharge really is.
I pulled a piece of kit off a shelf, where it had been sitting for a couple of years, and got the motherf..... of all belts. It had a couple of 1500v, large capacity, capacitors mounted on the rear, and unbeknown to me the bleed resistor was open circuit. I accidentally came in contact with the ungrounded terminal and it nearly killed me.

[redpoint5]

Since this miserable thread won't be left alone to die, I'll add this even though it's apparent that many aren't reading the posts before they comment...

Originally Posted by oldtamiyaphile

Self discharge appears to be a myth.

Depends on how you look at it. Self discharge is fairly high near the upper limits of rated voltage for a capacitor, but rapidly diminishes as voltage slightly drops.

The real problem with caps as a battery replacement is the constant parasitic draw of the vehicle. Since caps have such low energy storage to begin with, it doesn't take much time for a 25 mA parasitic drain to pull the voltage below a useful level.

[teoman]

https://m.youtube.com/watch?v=Q9WoSDYnLxM

Good video series