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1 Coleman 5.4V Flashcell Cordless Screwdriver - ultracapacitor Posted by opi /09/14 10:54 I've wanted to play with some ultracapacitors but the cost has been a little much for my small budget. However, after reading about the coleman flashcell screwdriver I found that the price for them has fallen from $99 to $33 so I could justify the dual use of a pretty good cordless screwdriver and have the ultracapacitors to play with as well. You can find it here: 20&camp=213381&creative=390973&linkCode=as4&creativeASIN=B001U8FF5Q&adid=1FKCED72672W & and as of this posting it's $33 with free shipping I bought one and took it apart and found inside two D cell sized supercapacitors. They are labeled Flashcell FC4 and there is nothing else that tells me how many farads they hold but I'm guessing it is around 300 or above. Ultracaps of that size are selling for about $25 each from what I can tell. You can use the capacitors in this screwdriver without having to take it apart by attaching your wire leads to the blades of the charge terminals on the bottom. They tie directly to the two capacitors which are connected in series inside the case. You get at least 5V and I'm guessing about 150 farads in it's series configuration. A big plus is that it comes with it's own charger too. Posted by jimnickerson /09/14 13:15 From your description, it sounds like both terminals are on one end of the cell. If you can post a picture, or provide the diameter and length, we can probably connect you to the manufacturer and the data sheet. Posted by opi /09/14 20:24 Here are a few links to the pics of the Flashcell capacitors inside the coleman cordless screwdriver. Tops Length Diameter Posted by opi /09/14 21:26 Here are some pics of how I hooked up to the capacitors inside the tool. Pict showing the bottom of the screwdriver and the blades used for charging, but which also give you direct access to the capacitors inside: A pigtail made using powerpole connectors: How the capacitors look inside the tool, with the pigtail below:

2 Posted by jimnickerson /09/14 22:15 There are only a couple of suppliers for this size. This appears to be a pair of the NessCap 360F devices. Look for the data sheet here: Posted by opi /09/15 00:42 Thanks for that good bit of information. Not a bad set of ultracapacitors in this screwdriver. Posted by Prof. K /09/27 22:37 Received the Coleman screwdriver a few days ago. Interesting that their design places two bare electrodes recessed into the base. I put a voltmeter on these electrodes to see if they were active and sure enough, they were live. It's as if the capacitor terminals exit out the bottom with little protection. I have discharged electrolytic and other capacitors by shorting for safety. I am not ready to try that here because the discharge characteristics are not well known. For example, can the current surge on shorting cause a mechanical shock that damages the capacitor? I fear one could throw this screwdriver into a toolbox and any metal can work its way into the base aperature and discharge the cap. In a toolbox, it may even start a fire. A second interesting observation is that the voltage across these terminals falls in a linear fashion as one operates the screwdriver motor. There seems to be no regulation on the circuit. Posted by Prof. K /10/05 01:27 Well, I wanted to mention the design flaw (as I saw it)about accidental shorting and went to the company website mentioned in their manual. The company 'team products international' seems to no longer exist. It looks like soon after 2007 when they started this, it went belly up. The website no longer exists and old links no longer connect. What they don't mention in advertising is that a charge will not last as long as a charge with a battery. Yes, it will recharge in less than a couple of minutes but when it is fully charged it is not the same as a fully charged Li-ion battery powered screwdriver. In hindsight, the electrical performance in combination with a motor was to be expected. As you load the motor, power is consumed. Freewheeling the motor just uses a little power. Posted by ewitte /10/22 16:59 opi wrote: I'm guessing it is around 300 or above. Ultracaps of that size are selling for about $25 each from what I can tell. Must be going down extremely fast you can get a Maxell 2.7v 2500F for about $45.

3 Posted by saturation /02/06 14:28 I did some research too, its quite long so I'll break it up into pieces. TPI was a US distributor, the actual product is from a VAR in Australia, and its sold there mainly as the GMC brand or the Demain brand. Demain claims they own the patent on the battery, and they seem to be moving into the USA, to be based in Florida. If you research their name, a lot comes up regarding patent applications, so I would presume their energy's are being consumed there too. If Demain does have a direct US branch, it could find better outlets with other distributors. That said, the product seems to have stopped distribution in the USA except for 'left overs', and is also limited distribution in Australia, with the Demain website not updated since 2007, about the same time as the collapse of TDI. Well, I wanted to mention the design flaw (as I saw it)about accidental shorting and went to the company website mentioned in their manual. The company 'team products international' seems to no longer exist. It looks like soon after 2007 when they started this, it went belly up. The website no longer exists and old links no longer connect. Posted by saturation /02/06 14:38 This has been mentioned in many reviews of this product, since it first appeared in Capacitors vs battery, the overall charge density is still not par. See comparisons of the technology here: Prof. K wrote: What they don't mention in advertising is that a charge will not last as long as a charge with a battery. Yes, it will recharge in less than a couple of minutes but when it is fully charged it is not the same as a fully charged Li-ion battery powered screwdriver. In hindsight, the electrical performance in combination with a motor was to be expected. As you load the motor, power is consumed. Freewheeling the motor just uses a little power. Posted by saturation /02/06 15:04 Here are some interesting links: US Coleman Australian GMC The original Demain drill the OEM in China A press release describing the relationship of OEM:

4 Posted by saturation /02/06 15:19 Thanks for the warning. I am not surprised, I have seen many safety oversights from manufacturing in 'that' country. However, being this is the only device of its type and given the properties of the battery I personally would work around it, until I receive mine an effective solution would be to cover the terminal with an insulator such as PVC tape when placed in tool box. Voltage drop output of capacitors is typically linear, regulation usually is not needed in many DC motor applications, even in battery applications, as in most cases the motor simply slows down as the V drops until the flux field can no longer overcome friction. Supercapacitor_diagram.svg.png Prof. K wrote: Received the Coleman screwdriver a few days ago. Interesting that their design places two bare electrodes recessed into the base. I put a voltmeter on these electrodes to see if they were active and sure enough, they were live. It's as if the capacitor terminals exit out the bottom with little protection. I have discharged electrolytic and other capacitors by shorting for safety. I am not ready to try that here because the discharge characteristics are not well known. For example, can the current surge on shorting cause a mechanical shock that damages the capacitor? I fear one could throw this screwdriver into a toolbox and any metal can work its way into the base aperature and discharge the cap. In a toolbox, it may even start a fire. A second interesting observation is that the voltage across these terminals falls in a linear fashion as one operates the screwdriver motor. There seems to be no regulation on the circuit. Posted by saturation /02/06 15:43 Thank you so much for the photos. Of note, the quality of the soldering is sloppy, but it electrically viable. However it does raise quality concerns for other portions if the do not bother wipe off excess flux, as seen in the background of this PC board. In most instances it doesn't do any harm, but some flux is mildly corrosive and could deteriorate the PC board surface over years, also in could partially melt or soften if used in hot environments and attract water vapor in high humidity or stick loose particles that could be mildly conductive and create leakage paths, and all such nuisances are eliminated by simple cleaning. opi wrote: Here are a few links to the pics of the Flashcell capacitors inside the coleman cordless screwdriver. Tops Length Diameter

5 Posted by saturation /02/06 15:50 Demain's patent application describing their Flashcell's properties: Posted by opi /01/11 17:34 I initially bought one of these Flashcell screwdrivers to get the ultracapacitor to play with but I use it all the time around the house for odd jobs and such. It hasn't been a problem to use as a screwdriver, I keep the charger close by and during the times I'm not using it I plug it in and it tops it off quickly for the next use. If I had to be completely untethered from a power source this unit would not be the one I'd use but it size and weight make it an easy tool to grab for those simple around the home tasks. Yes the discharge profile of the ultracap is very linear (which is to be expected) but it does well without regulation though I would love to have a regulator that would work with an ultracap to play with. Does anyone have a regulator that will work from 0.1v to 5.4v and output 5.4 volts?