Replace your car battery with capacitors!

[justme1969]

Hey redneck might use a motorcycle batt or similar sized for a night driving set-up.
Im sure one of our electric car engineers here can figure up a amp hour requirement for night driving. shoot those guys have thier loads calculated to the last mv.

[sheepdog 44]

Originally Posted by redneck

"Little Blue" is way overdue for a new battery.

So I ordered the parts to make the same Hybrid battery shown in the last video.

We're going to find out if this will meet our needs.





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Any update on this? I'd like to get my power to weight ratio up.

[101Volts]

I didn't watch the videos yet but thanks for the post, I might be back to consider things about a car battery.

[serialk11r]

I think the point is that a typical battery has a good amount of Ah on tap for cranking purposes but needs to be big to deliver the necessary current, which is where the capacitors come in; When the power demand is higher than the battery can supply, the voltage in the battery drops faster due to internal resistance and the capacitor will then help provide more power for a short period of time.

When my battery needs replacing though, I will probably just grab an AGM battery with a healthy amount of CCA over what is required and forget about it. The capacitors may extend the life of the battery but I could just buy another battery with that money.

[redpoint5]

Originally Posted by kach22i

I wonder what the long term effect on his car computers will be.

How would the computers be affected differently than with a standard battery?

Originally Posted by RiceCake

Capacitors have self-discharge.

So do batteries. From what I've read, lead acid batteries discharge at 5% per month. What is the self discharge of a typical ultra capacitor?

Originally Posted by California98Civic

Really quite cool. But I would think that the benefit in weight-loss causes a problem for FE by loading on the alternator, which will have to charge the capacitors pretty often.

Does the more frequent cycling of the alternator reduce efficiency? What is the efficiency of charging a battery compared to charging a capacitor?

Originally Posted by California98Civic

I had the same reservation about the "eco" possibilities.

Why would this reduce MPG?

[Occasionally6]

Originally Posted by redpoint5

Does the more frequent cycling of the alternator reduce efficiency? What is the efficiency of charging a battery compared to charging a capacitor?

I think that is one of the advantages. Like ICE's, alternators have efficiencies that vary with (alternator) speed and load. Having the capacitor as a buffer allows the alternator efficiency to be optimised more readily. (Using the capacitor's higher charging current capability.)

[redneck]

Originally Posted by sheepdog 44

Any update on this? I'd like to get my power to weight ratio up.

I have purchased the ultra caps and LiFePo4 battery pack. Just need to find time to work on it. One problem though is that the caps are now PCB mount, not tab mount anymore. This will require a different way of attaching them together in series and I'm not sure on the best way to do this.

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[redpoint5]

Originally Posted by redneck

I have purchased the ultra caps and LiFePo4 battery pack. Just need to find time to work on it. One problem though is that the caps are now PCB mount, not tab mount anymore. This will require a different way of attaching them together in series and I'm not sure on the best way to do this.

>

Any updates?

I see a lot of people complaining about the 12v battery longevity on Priuschat, and I wonder if it could be replaced entirely with this "boostpack" supercap/battery combo.

I'm still curious if the frequent cycling of the alternator would cause more wear, and even more curious about the efficiency of charging capacitors/LiFePo vs a lead acid battery. Specifically, what percentage of the input charge is captured and stored, and what is wasted. Self-discharge rates would also play a role in the overall efficiency.

Do supercaps self-discharge at higher rates than regular capacitors? I realize the answer will vary depending on what type ( electrolytic, etc).

[Occasionally6]

Because it's a static charge, capacitor charging and discharging is very efficient, like in the high 90's%.

[redpoint5]

Originally Posted by Occasionally6

Because it's a static charge, capacitor charging and discharging is very efficient, like in the high 90's%.

That's what I thought. No chemical change occurs in a capacitor charge/discharge, so the process should be efficient... charging the LiFePo, however, is a chemical change, and I have no idea what the efficiency comparison of that is to lead/acid, nor do I know what the self-discharge rates of any of these things are.