Full-featured Battery Tester Puts Them Through Their Paces

When working on battery-dependent projects you want accurate performance information where a datasheet may not be available. [E. Lelic] set out to build a device that would meter internal battery resistance but ended up with a bench tool that can do much more than that.

A PIC 16F88 microcontroller takes center stage on the meter, taking voltage level readings, monitoring a DS1820 temperature sensor, and controlling an LM2575 step-down regulator. The components provide functionality for measuring Lithium Ion, Lithium Polymer, Nickel Cadmium, Nickel Metal Hydride, and Alkaline batteries. It is capable of fully discharging and fully charging the batteries, measuring time and power consumption during this cycle, and monitoring temperature changes for the NiMH and NiCad versions.

Look for the little red ‘Download’ icon at the bottom of the post linked above. That archive includes a schematic (which we’ve also embedded after the break), board layout in .LAY format, and a HEX firmware file.

If you enjoyed this build you might want to look at this other battery capacity tester.

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Chill Your Phone For Longer Battery Life?

The first specs we look at when choosing a cellphone are the battery life numbers. We know that eventually we’re going to see performance loss, and [Dr. West] wanted to see if there’s a way to delay the inevitable. What he found is that ambient temperature affects the battery throughout its life. He set out to build a phone chiller to slow the degradation of the battery.

The research that he points to shows that at room temperature, a Lithium battery will lose 20% of its capacity each year. This seems like a dubious number so do share links to studies that state otherwise in the comments. Whether that 20% is right or not, the point is that cooling the battery will preserve it. With that in mind, [Dr. West] put together a pod that uses a peltier cooler and a heat sink to host his Blackberry while he sleeps. He figures he can reduce the capacity lost per year from 20% down to 14%. This of course comes at the expense of running that cooler every night (in addition to charging the phone when it needs it). But perhaps this solution will spark an idea that leads to a better one.

Portable Bench Supply Carries Around 10 Amp-hours Of Juice

[Punish3r] wanted to have power for prototyping on the go. What he came up with is this little thing above. Inside you’ll find common components that let the unit provide 10 amp hours of current with a 12V 500mA output.

The storage capacity is provided by a dozen Lithium batteries. These 3.7V cheapies are wired in parallel behind a protection board. For charging and discharging, a Sparkfun LiPo charger board was used, taking care of all the work necessary to top off the batteries using a wall-wort. The final piece in the puzzle is a boost converter that provides the regulated 12v connected to the red and black banana plug receivers on the bottom of the case.

This is very much a plug-and-play design… just make sure you hook the parts up correctly and you’re up and running. We would love to see a roll-your-own boost converter circuit that include a switch or dial that lets you select common PSU voltage levels. If you’re going to the trouble to make your own board you might as well incorporate the charging circuit at the same time.

[Thanks Paul]

Electric Scooter Sings As It Travels

[youtube=http://www.youtube.com/watch?v=MaQuRnZYKPc]

This scooter has been fitted with a three-phase induction motor. It reminds us of the sound effects from vehicles in the Jetsons. Right now they’re using lead-acid batteries and get about 15 miles of range from one charge. Once they switch over to lithium polymer they calculate the range will be closer to 45 miles due to the reduced weight and increased capacity. Not bad for $600 in parts, and we’d bet it’s both faster and more stable than the one-wheeled-wonder we saw last week.

Malware Posing As Change.gov

change

PandaLabs has identified a botnet running a malware campaign impersonating president-elect Obama’s website. The front page of the site features a sensational story titled “Barack Obama has refused to be a president”. Clicking the link will download the malware and make the target’s machine part of the botnet. They’re using fast-flux to assign the malicious domains to the massive number of compromised nodes that are hosting the actual site. The team has contacted the domain name registrar in China to get the domains removed. Using a sensational headline is not new to malware; it’s how the Storm Worm got its name.

[via lithium]