Quote:
Originally Posted by Daox
I really doubt thats enough capacity.
So, it looks like you have a 10Ah of capacity, but it will not maintain the voltage you need to start the vehicle. So, you more realistically have maybe... 2Ah of usable capacity.
Putting them in parallel with a small lead acid battery might be a nice combo though.
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If I did have 2Ah, that would give me 2Ah x 60 minutes x 60 seconds = 7200 amp seconds.
Air intake heater calculation: 7200As - (180A x 8s) = 5760As
Fuel pump calculation: 5760As - (10A x 30s) = 5460As
Starter calculation: 5460As - (400A x 3s) = 4260As
Based on this worst case scenario (very cold), the supercap would have 4260 amp seconds in reserve after starting the truck. Even if it only had half that capacity, or 1Ah, it would still be capable of starting the truck with 660As to spare.
I might have more confidence in doing this now that I've run some numbers.
Quote:
Originally Posted by California98Civic
the new Mazda's use capacitors for brake regen, I think because they can absorb the power generated more efficiently, more quickly, more completely, than batteries. So a combo lead acid and capacitor set up might also do a better job of storing DFCO energy too, no?
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To get the most out of this, you would also need the associated circuitry that Mazda uses to step up or down the voltage to the caps.
It would still help with capturing energy from DFCO assuming the cap wasn't already charged to 14.4v; the cutoff voltage for the alternator. The driver would have had to already be drawing down the voltage by either running with the alternator disabled, or by engine off coasting. In this case, the cap might draw down to the voltage of the battery, 12.5v. When engaging DFCO and re-instating the alternator, the capacitors would have about 2v to gain before hitting 14.4v. Based on the numbers from the calculations above, a 3000F capacitor-series could accept about 1.5Ah of charge before hitting 14.4v. That is 5400As, and at an alternator charge rate of 100A, it could accept that charge for 54 seconds until it is full.
Seems like a good idea if someone is running an alternator kill or does EOC.