How about a 4 pound "battery"?

[Amdkt7]

I'm considering the super caps, put in parallel with my current perfectly new battery. For one thing, when my battery needs replacing I will already have charged caps. Second, the battery may last for ever with the caps taking the brunt of the starting process.

[nookandcrannycar]

Originally Posted by CTScott

The voltage regulator module, within the alternator, would be the first to fail if the current draw by the caps is too much. Thus far I have seen a peak current draw of 45A, which is well within the 70A rating of the stock alternator.

The zener diode is not a bad idea to prevent damage from over voltage, but there again the voltage regulators in modern cars generally prevent that type of failure mode. I will eventually add a large rectifier diode to the pack to prevent the possibility of reverse polarity, as that would result in the most catastrophic failure.

I have a somewhat related question. IIRC, it was the voltage regulator that was the 'failure issue' re the alternator on 2007 (only) Yarii. Sears put a remanufactured alternator from a local company (this happened near Minneapolis) in my Yaris. Would that remanufactured alternator have to have been from a 2007 to work properly long term? If not, I assume I could currently have a 2008, 2009, or 2010 alternator (I did this replacement in 2010)? Is there any way I can tell the 'model year affiliation' (for lack of a better phrase) of this remanufactured alternator that is currently in my Yaris? (Sorry re the extra question).

[CTScott]

Originally Posted by nookandcrannycar

I have a somewhat related question. IIRC, it was the voltage regulator that was the 'failure issue' re the alternator on 2007 (only) Yarii. Sears put a remanufactured alternator from a local company (this happened near Minneapolis) in my Yaris. Would that remanufactured alternator have to have been from a 2007 to work properly long term? If not, I assume I could currently have a 2008, 2009, or 2010 alternator (I did this replacement in 2010)? Is there any way I can tell the 'model year affiliation' (for lack of a better phrase) of this remanufactured alternator that is currently in my Yaris? (Sorry re the extra question).

Any year alternator will work, but ideally you want a late 08 or newer to have a post TSB voltage regulator. If yours is remanufactured you would have to open it to check the part number on the voltage regulator to see if it is pre or post TSB.

[CTScott]

Originally Posted by Amdkt7

I'm considering the super caps, put in parallel with my current perfectly new battery. For one thing, when my battery needs replacing I will already have charged caps. Second, the battery may last for ever with the caps taking the brunt of the starting process.

That would actually be a pretty ideal way of using them. A light weight battery, like a Braille, paired with the SuperCaps would give the combination of reserve capacity of the battery along with the efficient power transfer capability of the caps.

[UberSilver]

Originally Posted by Amdkt7

I'm considering the super caps, put in parallel with my current perfectly new battery. For one thing, when my battery needs replacing I will already have charged caps. Second, the battery may last for ever with the caps taking the brunt of the starting process.

Summer heat will still kill the battery.

[nookandcrannycar]

Originally Posted by CTScott

Any year alternator will work, but ideally you want a late 08 or newer to have a post TSB voltage regulator. If yours is remanufactured you would have to open it to check the part number on the voltage regulator to see if it is pre or post TSB.

Thanks so much for the great info! I'd like to know, but not enough to open up the alternator.

[CTScott]

Update: Left the car off for a full 24 hours. Voltage this morning read just under 11 Volts. Turned the key and it started with no problem.

[CueBall]

Awesome Scott.. subscribed!

[CTScott]

Update: I've been running it on the road since Wednesday on Crashy2 without a problem. 3 to 4 short trips per day (typically 20 miles or less) and some with headlights and/or AC running.

[JonS]

Any new updates?

[CTScott]

Originally Posted by JonS

Any new updates?

I have been driving with it for nearly a month now with no issues. I drive the car daily, so it never goes more than 24 hours without being recharged.

[fnagornov]

Can anyone who understands the physics/electrical part of this explain how the capacitors don't overpower the starter? I understand that the supercapacitors are impressive, high surface area, static electricity devices and that they can 'dump' the power over a period of several seconds, as opposed to an instant it takes old capacitors to release their energy. But is only enough energy to turn the motor released? or is it just a coincidental match that these caps release energy at the appropriate rate to start a little typical 4 cylinder car? What i'm saying is: if I hypothetically had a large bank of these supercaps (lets say a 100 of them, same ones as Scott used) in a configuration that would produce 14-15V, would they overpower and burn/blow-up the starter or the motor? I just don't understand how this is giving it just the right amount of power and not zapping/ruining it.

BTW, I've found a few articles mentioning 'the future' of batteries and how the hybrids batteries coupled with a supercap would work and some DIY assembled pieces similar to yours, but not an actual working unit, installed in a car!! I think you're on of the first. This is so impressive!

[Amdkt7]

An understanding of Ohm's Law explains why this is. The voltage is the same, more current is available, however the resistance of the starter motor is the same.

Think about it like this, the power at the outlet in your house can run a space heater, or a cell phone charger. A lot of power is present, but not delivered to a load that does not draw it.

[jcboy]

Originally Posted by Amdkt7

An understanding of Ohm's Law explains why this is. The voltage is the same, more current is available, however the resistance of the starter motor is the same.

Think about it like this, the power at the outlet in your house can run a space heater, or a cell phone charger. A lot of power is present, but not delivered to a load that does not draw it.

^^correct.

[fnagornov]

thanks!