Speedtoys

Alan, or other electric dudes...

What would be needed once you had in-hand a supercapacitor kit that did proper balancing, etc, to work this into the 928 starting operation?

Goal is to reduce stress on the battery long term..turn the key and this is engaged to spin the starter, once started or disengaged it is charged back up from the battery/alternator and not used until the next start cycle.


The technology is certainly here, but integrating it is beyond me, but wouldnt seem that hard..but still, what do I know.

Randy V

Can you explain the benefits of this arrangement?

Seems like just a new potential failure point.

Speedtoys

Faster RPM startup, less draw on the battery...which will give it a longer life.

This is what start-stop hybrids are doing to prevent wiping out batteries for starts.

Alan

You will need a very large supercapacitor for the start current at 12v (hybrids use higher voltages) - then you will need to replace the charge you used ... Since we aren't doing stop/start with regenerative braking there really isn't so much benefit - adding complexity in very high current environments is not such a good idea IMO.

A super-capacitor can be recharged quickly which allows energy recovery from short term events (like braking/coasting down in a hybrid) - but in a 928 we'd have to recharge it from the battery or alternator - the battery can do it quite quickly - but will be depleted as a result (contra to your goal) while the alternator will likely be more stressed charging the battery & capacitor as well as supplying all vehicle power (in fact it would need to limit its charge rate of the capacitor which is not self-limiting like the battery)

For the added complexity here it would be much easier to add a backup lead acid battery for better redundancy/reliability.

Alan

69gaugeman

The battery is a super capacitor. Why would you think one is needed? They are cheap. They work. And you have way many more important things to worry about.

If you have slow rotation at start, look at having the starter rebuilt. Greasing it and replacing worn bushings will do miracles for your starter speed.

Alan

Not really - its charge rate is very slow - however for the purposes of starting its pretty ideal. Huge instantaneous current available, very high total charge capacity at a quite low cost & space. Only weight is any real dissadvantage. I agree with your conclusion though - there are many other things on the car that will need work before a correctly operating stock power system.

Refurbing the system wiring can fix many issues of degradation over time...

If I were to improve the stock system - I'd be focussing first on a better alternator configuration (for better power recovery under adverse conditions) - then on a better starter motor (in addition to the previously mentioned backup battery set-up).

Alan

69gaugeman

I wasn't talking in the literal sense. But the function he is talking about is already in the car. No point of replacing one with the other. I still stand by the fact that if the starter speed is slow, fix the starter (or wiring if this is the issue). The alternator issue while valid, is not a direct contributing factor. It may be secondary causation in that the battery is not full, though.

Mike Frye

I installed one in my car but it requires 1.21 gigawatts of power to engage.

Ed Scherer

There's some fairly good reading here: How practical would a car booster using supercapacitors be?

IcemanG17

interesting concept....assuming I remember right (good luck) I used one on my "super" stereo system back in the day...1 farad if I remember right to improve amp performance under high loads-short duration....

Speedtoys

Truck drivers install one group 31 battery that is all caps, to take over start duties and increase main battery life exponentially.

Maxwell makes a Group31 that includes the isolation hardware to charge off the main battery (1 or 2 depending on the truck) an then on it's own take over start duties.

It's an interesting concept coming down into the consumer world from the OEMs..that was all I was thinking.

Starts a cold 10L diesel in 1sec, and weighs 17lbs.

docmirror

If you install a 10L diesel in your shark and live in a cold climate, I think you are on to something.

Speedtoys

Ya...point missed.

69gaugeman

Not really.

Solving a problem that doesn't exist is certainly one way to spend time.

TexasDude74

My father in law has converted a few vehicles to ultra capacitors for starting, a Toyota Yaris, a couple F-150s and some diesels.

The advantage are that ultra capacitors virtually never wear out, they're rated for a million+ cycles. So you can reduce the size of your lead acid battery substantialy, reducing weight. Usually 30 lbs on gas and 200 lbs on commercial diesels.

The technology is sound, Lamborghini and several other oem's use it. However, there are easier ways to take weight off a 928