Pandora 2 running on a capacitor?


Link

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Just saw a capacitor powered flashlight tonight. No batteries, very lightweight, super bright, could last 3 hours on a 60 second charge.


Lets dump the battery and run the Pandora 2 for 20 hours on a 60 second charge. It would be much lighter.


Peace & Pandora,


Link
 
The energy density of capacitors is quite a bit less than lithium-ion batteries. That 20-hour ultracapacitor isn't going to be smaller or lighter than the battery it's intended to replace. Also do you have any idea how much waste heat you'd get from a 900-watt charger, which is what it would take to charge the equivalent of the Pandora's battery in 60 seconds? You'd never get UL or any other safety certification for that.
 
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The flashlight I held was the same size that holds 4 D batteries. It weighed a fraction of what the D batteries would weigh.


The battery weight of the Pandora is significant. I'm no physicist and don't know much about heat generation etc. I do know the flashlight was bright and it didn't weigh much. Things I look for in a handheld are power and size/weight.


I'm interested to hear people entertaining the idea, not someone telling me it's a pipe dream.


Peace & Pandora,


Link
 
The flashlight I held was the same size that holds 4 D batteries. It weighed a fraction of what the D batteries would weigh.


The battery weight of the Pandora is significant. I'm no physicist and don't know much about heat generation etc. I do know the flashlight was bright and it didn't weigh much. Things I look for in a handheld are power and size/weight.


I'm interested to hear people entertaining the idea, not someone telling me it's a pipe dream.


Peace & Pandora,


Link

just for you to know, typical lithium-ion battery have a specific energy twice greater than NiMh cell, so comparing your capacitor with regular D cell is not really correct...
 
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The flashlight I held was the same size that holds 4 D batteries. It weighed a fraction of what the D batteries would weigh.
It also gives you a fraction of the power that 4 D batteries would. If the same flashlight were using 4 D batteries instead of a capacitor, you would see days, possibly weeks of constant use.


The same would hold true in the Pandora (or any other electronic device): replace the battery with a capacitor, and the 10 hour life drops down to 2 or less, possibly only minutes.


I've considered creating a capacitor/resistor combo with the same connections as the battery to serve as a fake battery so that years from now people will be able to still use their Pandora at least plugged, and maybe a few minutes of unplugged use, if batteries can no longer be purchased, but it is basically impossible for it to ever have the same capacity as a real battery would.


You're being told it's a pipe dream because it is.


A 20 hour flashlight from a capacitor is really good, but pales in comparison to the actual power stored in a real battery, power that is needed in something more complex than a flashlight.
 
I'm interested to hear people entertaining the idea, not someone telling me it's a pipe dream.
Sorry, but it is.


Capacitors fill a different niche than batteries. They might have a higher power density, but their energy density is much lower, so you'll always have reduced runtime.


And as Neko pointed out, you can fast-charge capacitors, but a fast charger would be larger, more expensive, and produce more heat than a normal charger.


And who would care about fast-charging the Pandora, say, every 2 hours, when a Li-ion battery could let you run it for 15 hours continuously, and then just charge all night?


Also, I don't know if supercapacitors have improved on this, but regular capacitors leak charge pretty quickly.
 
Also, I don't know if supercapacitors have improved on this, but regular capacitors leak charge pretty quickly.
Electrolytic capacitors leak charge pretty quickly, but capacitors with solid dielectric materials can hold a charge for months. I don't know what the leakage current of modern supercapacitors is, but seems to be low enough that these can be used as a replacement for electrochemical batteries in certain applications.


Also, Link's flashlight probably uses less than 1 watt, so 3 hours on a charge isn't all that impressive. A typical alkaline or NiMH D-cell battery would be around 15 watt-hours.
 
Where is the flashlight you're talking about? That does sound pretty cool. Did someone make it or is it sold somewhere?
 
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