a very handy "new" AA battery

The USB batter has to have firmware, or else it would not work.

Something has to control USB function.


I really think this argument is pointless as we have already proved that this "battery" is useless and overpriced
 
I dont see how a battery of this nature is useless. If this is expanded on, it could/would reduce the amount of hazardous waste we as consumers produce. I admit, they are a bit pricey, but with everything else, the price will come down.

as for "firmware" being neccasary on a capacitor - it isnt needed. A capacitor can only be charged to its max capacity, at which point, no further charge can be added.

I believe these will do well in everyday devices such as remote controls, wireless mice, MP3/MP4 players etc.
 
Regular rechargeable batteries do the same thing....

for less money.

If capacitors worked well for batteries, why aren't all batteries cap based?

I just cant see the logic in your argument
 
well, the whole idea of "If its not broken, dont fix it" has pretty much screwed up our planet. Seeing as both alkaline, and rechargeable batterys are made of toxic materials. Disposal of these in LandFills allows for seepage into well and ground water causeing health issues. Capacitor based batterys would reduce this amount of dangerous material we have been placeing into the Earth. I also can recall when 2AA rechargeable batterys cost $10.
 
reflex99 said:
If capacitors worked well for batteries, why aren't all batteries cap based?

I just cant see the logic in your argument
Click to expand...

Uh-oh. I guess I need to clarify some things...

A capacitor is a device that stores energy for on-demand usage. They're like batteries, but can supply LARGE amounts of current, and can go through hundreds of thousands (if not millions) of charge/discharge cycles without damage. As for discharge time, it depends solely on the RC time constant; you can make it discharge over hours with little current, or in a millisecond with a huge surge. When I was working on an electromagnetic launching project, we rigged an array of photoflash capacitors to dump 125 amps of current into a coil in a few milliseconds, creating a huge electromagnetic pulse that fired a .22-sized steel bullet across a room at 35 miles per hour.

Due to the chemistry of standard batteries, they have problems with repeated charge/discharge cycles (the memory effect). Some are more resistant to this than others (NiMH), whereas your laptop Li-Ion and NiCad batteries will suffer over time. As a physics professor of mine once said, "A battery is nothing but a chemist with a wheelbarrow, moving charge."

A capacitor, however, stores the energy within a dielectric between a pair of plates, as an electric field, and draws from that. The discharge should be an exponentially decreasing function with time for a standard RC setup. Caps and batteries are two totally different things, but the major difference is that capacitors are used primarily in precise electrical applications where a quick burst of power (to overcome a motor start-up draw) is needed as opposed to batteries, which supply a relatively constant amount of energy over a specific interval.

You can't ONLY use capacitors for one simple reason: you need to charge them up again! You still need a battery/power supply of some kind in the system. In a computer, it's one thing, because the capacitor is continually recharged, but batteries will still run down, as we all know.

Without any research, my educated guess here is that these really have an N-sized (or a couple rechargeable button cells) battery buried inside with the USB connector and a simple charge monitoring circuit. My best estimate of capacity would be something like 150 mAh at most...it's still a cool idea, but nowhere near as practical at this time as standard rechargeables. Once high-energy-density materials are perfected, this will likely change, but I'll stick with my rechargeable AAs for the time being.
 
jeod66 said:
Uh-oh. I guess I need to clarify some things...

A capacitor is a device that stores energy for on-demand usage. They're like batteries, but can supply LARGE amounts of current, and can go through hundreds of thousands (if not millions) of charge/discharge cycles without damage. As for discharge time, it depends solely on the RC time constant; you can make it discharge over hours with little current, or in a millisecond with a huge surge. When I was working on an electromagnetic launching project, we rigged an array of photoflash capacitors to dump 125 amps of current into a coil in a few milliseconds, creating a huge electromagnetic pulse that fired a .22-sized steel bullet across a room at 35 miles per hour.

Due to the chemistry of standard batteries, they have problems with repeated charge/discharge cycles (the memory effect). Some are more resistant to this than others (NiMH), whereas your laptop Li-Ion and NiCad batteries will suffer over time. As a physics professor of mine once said, "A battery is nothing but a chemist with a wheelbarrow, moving charge."

A capacitor, however, stores the energy within a dielectric between a pair of plates, as an electric field, and draws from that. The discharge should be an exponentially decreasing function with time for a standard RC setup. Caps and batteries are two totally different things, but the major difference is that capacitors are used primarily in precise electrical applications where a quick burst of power (to overcome a motor start-up draw) is needed as opposed to batteries, which supply a relatively constant amount of energy over a specific interval.

You can't ONLY use capacitors for one simple reason: you need to charge them up again! You still need a battery/power supply of some kind in the system. In a computer, it's one thing, because the capacitor is continually recharged, but batteries will still run down, as we all know.

Without any research, my educated guess here is that these really have an N-sized (or a couple rechargeable button cells) battery buried inside with the USB connector and a simple charge monitoring circuit. My best estimate of capacity would be something like 150 mAh at most...it's still a cool idea, but nowhere near as practical at this time as standard rechargeables. Once high-energy-density materials are perfected, this will likely change, but I'll stick with my rechargeable AAs for the time being.
Click to expand...

Thank you
 
i would spend the money cause i would rather spend a few more $ to get that and save our enviroment where we live and have to protect then be lazy and go the cheaper route IMO
 
From that website:

This NiMH AA cell can be used like a normal battery and can be recharged simply by plugging into a USB port.

# Rechargeable AA NiMH Battery 1.2v 1300mah
Click to expand...

NiMH (Nickel-Metal Hydride) is a common rechargeable battery chemistry, and one that doesn't have a memory effect. (Memory effect: repeated cycling to a certain voltage makes the battery "think" that that is its maximum voltage, so you lose capacity.) It's a good technology, very mature, and mainstream, so the comparable cost isn't exorbitant (although they are still more expensive than nickel-cadmium (NiCad) batteries right now).

I was right on the type and technology/chemistry, but I was off on the capacity by nearly an entire magnitude (factor of 10) here. I'm going to attribute that to the fact that my last research on N-cells was 6 years ago ;) Either way, I'm glad to see that they're still improving; I sort of doubt 1300 mAh, but it's possible. While these are handy, I personally don't use rechargeables of this size enough to justify $18 for a 2-pack.

Edit because I forgot...I'm a little biased too because I have a top-end battery charger/power supply setup for doing high-power robotics battery packs and like getting my money's worth of it, for the record :P
 
trollface.jpg
 
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