Although slightly off topic, I am reminded that National (Panasonic) used to make a range of batteries called "Hi-Top". I am not sure if they ever included an alkali cell and according to this history they used manganese. We were designing our own portable unit for the miltary powered by 6 D cells. I don't know where they got the dimensions for the batteries from, but when we tried to power it up for the first time we wanted high quality batteries and opted for the Hi-Top range. Big surprise- they wouldn't fit. We tried an Everyready D cells and sure enough they fitted fine. It then dawned on us why the product was named "Hi-Top". The top of the D cell was higher than any other. It probably fitted in a commercial product with more give in the spring contact, but it made suckers out of us.
@Antedeluvian: Another great part to your continuing series.
I agree -- I think that once Ivan has finished covering all of the various battery types, followed by his "grand comparison," this series is going to make an invaluable quick-reference guide to battery technology.
I think that once Ivan has finished covering all of the various battery types, followed by his "grand comparison," this series is going to make an invaluable quick-reference guide to battery technology
I think it could be expanded and made into a book. I know I would buy it. Please Ivan, allow Max to persuade you to do it. I am sure he would happily write the foreward. Just don't expect to become rich!
It seems like there would be many books already out there by now. I will take a gander at what is available, and if it looks like they aren't covering the topic like I want, I would consider writing one.
No, I would not be writing it for the money. Besides, I will have already given away most of the really good stuff for free for all the EETimes readers, anyway!
We who have been in batteries for awhile have also been bit by at least one thing or another. Another well-known battery company (I won't slander them here) had a supposed AA-size battery that the comapny boasted something like 15% greater capacity than any other competitor -- sure, until you discover that it had a larger diameter that gave it 15% more volume! When a few select customers complained, the company said the datasheet clearly shows the size, but would consider marking it differently than just plain 'AA'. They never made any change. Needless to say, the production run was short lived.
Another bad experience, is with cheap-spring battery holders. I designed a project using Energizer's L91 ultimate lithium battery in a battery holder. The AA battery delivers quite a punch. In my prototype, I bought a spring battery holder from [R..io Sh..k], which had bright silvery-looking contacts and springs. In about 30 seconds or so, the plastic holder was melted and the circuit quit. Measuring the contact resistance with a good 4-wire ohm meter revealed the problem. Eleven watts dissipated on a tiny spot builds heat, and the hotter the contacts got, the higher the reisitance -- talk about thermal runaway. Since I didn't plan on using that battery holder in production anyway, it turned out OK, but I did check the production version before release.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.