# Mobile Charger using Supercapacitor

#### lornfate

Joined Jan 25, 2012
3
I am thinking of creating a mobile charger using supercapacitors. Is this possible? I read that supercapacitors act like batteries.

Thanks for your help. Any idea is highly appreciated.

#### MrChips

Joined Oct 2, 2009
22,107
Nice idea. You have to plug in the numbers and calculate the capacity of the supercap. You will find out that you will need a lot of Farads to make it worthwhile.

#### evilclem

Joined Dec 20, 2011
116
I've not looked terribly much into supercapacitors but I think the question would be how much energy they can store and how effectively they hold it. If they are simply larger capacitors then I would expect the charge to dissipate prior to the charger requiring use.

If used in conjuction with a solar cell however then they may be able to level out the dips in voltage when a cloud passes over perhaps, initial charge may take forever though.

#### lornfate

Joined Jan 25, 2012
3
I've not looked terribly much into supercapacitors but I think the question would be how much energy they can store and how effectively they hold it. If they are simply larger capacitors then I would expect the charge to dissipate prior to the charger requiring use.

If used in conjuction with a solar cell however then they may be able to level out the dips in voltage when a cloud passes over perhaps, initial charge may take forever though.
I am going to used the supercapacitor for energy storage. It will be used in conjunction with a dynamo generator. I am still in the process of gathering data to check the feasibility of the project.

Do you have any suggestion?

#### PaulEE

Joined Dec 23, 2011
423
I am going to used the supercapacitor for energy storage. It will be used in conjunction with a dynamo generator. I am still in the process of gathering data to check the feasibility of the project.

Do you have any suggestion?
I would like to save you time and energy by telling you battery molecules store more energy per unit than electrons in a super capacitor.

And, high density super caps at moderate voltages are $. Thread Starter #### lornfate Joined Jan 25, 2012 3 I would like to save you time and energy by telling you battery molecules store more energy per unit than electrons in a super capacitor. And, high density super caps at moderate voltages are $.

How much does it cost if you don't mind PaulEE? I checked some sites and they have a feedback that the cost is high but the advantages they get as compared to a battery is sophistically high too.

Anyways, does anyone here tried using supercapacitor?

#### THE_RB

Joined Feb 11, 2008
5,438
The energy density per volume for supercaps is terrible compared to just about any battery type.

So if you use a battery it will be cheaper, smaller, and hold a heck of a lot more energy,
and hold that energy for longer too (ie will work better in every way).

#### PaulEE

Joined Dec 23, 2011
423
The only advantage a supercap might have to a regular battery (I've built projects using supercaps as the main power source and had to think through what you're thinking through) is charge time. You can charge a supercap very quickly as compared to a battery. In theory, if your charge source can supply infinite current, charging is instant. Practical limitations are non-ideal current sources, internal resistance in the capacitor, etc.

Meanwhile, the voltage on the capacitor continuously drops as charge decreases. This isn't too big a deal if you're powering a microcontroller or IC with a wide supply voltage range; but anything volt-magnitude-dependent would need a regulator circuit, which may waste valuable charge in energy-sensitive applications.