[otp57]

Originally Posted by kens0105

that will be great. thanks

Super capacitors helping the batteries will help a small EV

[major]

Originally Posted by kens0105

Is the super capacitor here the same as that of the i-ELOOP system?

http://www.mazda.com/publicity/relea...1/111125a.html

Originally Posted by otp57

i will look into that thanks

Originally Posted by otp57

Super capacitors helping the batteries will help a small EV

O.K. So how did you reach that conclusion The original premise you laid out was:

Originally Posted by otp57

Have anyone use super capacitor with lead battires to help with the surge of current when a motor starts up.

This iELOOP system is for an internal combustion engine car which has no electric drive motor and no propulsion battery. It is simply a wimpy KERS system using a capacitor to store a very small charge delivered by the alternator during deceleration and then used for auxiliary electrical loads. At 24V such a system could not effectively recover but a small percentage of the vehicles kinetic energy without huge current which I am sure the alternator would not support.

The iELOOP system has nothing to do with EVs. Or helping batteries.

[otp57]

Originally Posted by major

http://www.mazda.com/publicity/relea...1/111125a.html





O.K. So how did you reach that conclusion The original premise you laid out was:
This iELOOP system is for an internal combustion engine car which has no electric drive motor and no propulsion battery. It is simply a wimpy KERS system using a capacitor to store a very small charge delivered by the alternator during deceleration and then used for auxiliary electrical loads. At 24V such a system could not effectively recover but a small percentage of the vehicles kinetic energy without huge current which I am sure the alternator would not support.

The iELOOP system has nothing to do with EVs. Or helping batteries.

Thinks for the info.

[PStechPaul]

A quick way to estimate how long a capacitor will provide a certain anount of power is to use the RC time constant. So if you have a 100 volt system and 10HP it's 13000W or 130A and 0.77 ohms. So 0.7F is 0.54 sec. You might not even get that much because the TC is to 37% of peak voltage which is just 37V. The maximum sag of lead-acid batteries is probably to 50% and more reasonably to 70%. So you might only get 1/2 TC.

One way that might work better is to use a DC-DC converter or switching supply that can handle the full capacitor voltage at maximum and work down to about 33%, like a universal supply that works on 85-264 VAC. It could give your battery pack a boost of, say, 24 VDC on top of the 100V nominal. But it would have to be capable of full load current so that was just a brain fart.

Adding a small LiPo pack may be better, especially if it can handle 30-40C. There was another thread on that...

[otp57]

Originally Posted by PStechPaul

A quick way to estimate how long a capacitor will provide a certain anount of power is to use the RC time constant. So if you have a 100 volt system and 10HP it's 13000W or 130A and 0.77 ohms. So 0.7F is 0.54 sec. You might not even get that much because the TC is to 37% of peak voltage which is just 37V. The maximum sag of lead-acid batteries is probably to 50% and more reasonably to 70%. So you might only get 1/2 TC.

One way that might work better is to use a DC-DC converter or switching supply that can handle the full capacitor voltage at maximum and work down to about 33%, like a universal supply that works on 85-264 VAC. It could give your battery pack a boost of, say, 24 VDC on top of the 100V nominal. But it would have to be capable of full load current so that was just a brain fart.

Adding a small LiPo pack may be better, especially if it can handle 30-40C. There was another thread on that...

Thanks for your info.

[mizlplix]

I am using a small pack of 10AH Headway cells in parallel with my DC/DC converter to be my Aux power supply.

I am running my lights, 3 air blowers, 3 liquid pumps and a 1/3HP 16" Spal fan on my radiator.

The headlights would flicker when idling and the pumps cut in and out.

I installed 2- 3000MFD/300VDC caps in parallel. It stopped the flickering. The cap-self discharge rate does not seem to be a problem as yet. It seems to be small.

But my alternative is to place a contactor between the caps and the cells to stop the discharge. But even that has a complication, a current in-rush every time I turned on the key. That calls for a precharge resistor, that requires a delay relay to operate the contactor to provide a precharge jnterval....Sheesh....

So, for now, I live with the small parasite.

Miz

[otp57]

Originally Posted by major

http://www.mazda.com/publicity/relea...1/111125a.html





O.K. So how did you reach that conclusion The original premise you laid out was:
This iELOOP system is for an internal combustion engine car which has no electric drive motor and no propulsion battery. It is simply a wimpy KERS system using a capacitor to store a very small charge delivered by the alternator during deceleration and then used for auxiliary electrical loads. At 24V such a system could not effectively recover but a small percentage of the vehicles kinetic energy without huge current which I am sure the alternator would not support.

The iELOOP system has nothing to do with EVs. Or helping batteries.

I found this information and that is how I reach that conclusion !
http://spectrum.ieee.org/green-tech/...ridfor-hybrids

[PStechPaul]

Note that the article is from 2008 and refers to using lead-acid or NiMH batteries in a hybrid. It mentions Lithium batteries as "experimental". I think there is no question that ultracapacitors may help batteries with high ESR for short bursts of power, as well as for regeneration, but with advanced Lithium batteries the old limits to discharge and charge have been largely eliminated.