17 November 2017

iPhone USB can be made faster too.

With the fast charge capability of the iPhone 8 and iPhone X generating hype since this is the first time Apple started supporting what is considered a fast charge, however, multiple iPhones support faster charging than the charger in the box allows

These Models support a Maximum of 5 watts from the adapter:

  • iPhone
  • iPhone 3G
  • iPhone 3GS
  • iPhone 4
  • iPhone 4S
  • iPhone 5
  • iPhone 5c
  • iPhone 5s
These models support a maximum of 12 watts with an upgraded Adapter such as used with the iPad:
  • iPhone 6 and 6 Plus
  • iPhone 6s and 6s Plus
  • iPhone 7 and 7 Plus
These models support (about) 36 watts with a USB-C to lightning cable and a USB-C adapter with Power delivery. In addition these support 12 watts with an upgraded adapter such as used with an iPad. These models support 5 watt (soon to be 7.5 after an iOS upgrade) wireless charging.

  • iPhone 8
  • iPhone X
This means that every iPhone since iPhone 6 can support faster charging than the included iPhone power adapter allows with the lightning to USB and presumably the Lightning to USB-C cables. The lighting to USB option requires an iPad (or compatible 2.1 amp third party) adapter.

25 October 2017

The Low Self Discharge NiMh Cell or How Rechargeable batteries are now ready for Prime time

Rechargeable batteries in standard household sizes have been on the market for decades they all have their problems. NiCd had issues with chargers and the misunderstood memory effect. Rechargeable Alkaline can't fully recharge, is limited in number of charge cycles, and usually fails by leaking. Traditional NiMh has a self discharge problem and charging is not convenient.

A new technology arrived in the past decade that changed the way rechargeable batteries are used. It has the power density of NiMh, it has low self discharge (although not as low as Rechargeable alkaline), and smart chargers prevent the charging issues of the NiCd era. What is this technology? It's actually NiMh! Low self discharge NiMh cells were introduced by Sanyo under the Eneloop name in 2005 (now made by Panasonic) and other companies soon followed.

What does this mean in terms of usability? It means a few things, firstly these cells are sold with a partial (approx 70%) charge so they can be used out of the package without recharging first. Instant usability was a major advantage of Rechargeable Alkaline. It is still NiMh technology which means the ability to handle heavy loads is still there. The mass availability of smart chargers eliminates the overcharge problem of NiCd. Of course the memory effect never occurred in consumer applications anyway (but was the blame of other issues, namely overcharging). The only two disadvantages that remain are to make sure people don't throw them away in error and that you don't have the full 1.5 volts.

This new technology means a major change in how the cells are used and stored. Low self discharge cells can be stored charged in battery organizers, ready to go, and used cells can then be stored in another organizer full of cells ready to be recharged (hint, put the used ones upside down in the same organizer to easily determine which ones need recharged). The instant availability of spare cells isn't the only game changer.

This new technology can also be used in equipment that stands by waiting for emergencies or even low drain devices such as clocks. Just make sure you check for voltage compatibility in clocks and older radios. My 1970s Panasonic transistor radio is a wonderful set, but it won't work for long on NiMh of any type. This means you can use these cells in your pre-staged emergency flashlights, just remember to top off the charge from time to time.

Now, in order for this to work well, you need good cells and good chargers. I recommend chargers with negative Delta V termination with single cell channels. Chargers that have two cell channels (require two cells to charge) are okay for anything used in Multiples of 2.

For specifics, I recommend Panasonic's Eneloop chargers for AA and AAA sizes and Tenergy's T-9688 for AAA, AA, C, and D, but not 9V. In fact I don't recommend NiMh for 9V, but I'll get to that later.

For cells, I recommend standard Panasonic Eneloop AA or AAA, don't bother with the Eneloop pro, the extra capacity reduces overall lifespan too much. The standard Eneloop can be recharged 2100 times where the Pro can only be recharged 500 times. If you don't mind the Capacity loss, you can also get Eneloop Lite which can be recharged 3000 times. There are other brands including the Tenergy Centura I recommend for C and D, but be sure you don't get cheap, low capacity types (pay attention, especially when buying the big brands).

For C and D size I recommend Tenergy Centura. This is because this is only other reputable brand I found with good capacity. In these sizes I highly discourage the big name brands, Energizer only goes up to 2500 mAH (which may not even be Low Self Discharge) and Ray-O-Vac up to 3000 mAH. These are near or slightly better than AA. Tenergy is around 4000 mAH for C cells and 8000 mAH for D-Cells.

For 9-Volt size I do not recommend NiMh as smart chargers for this size are difficult to find. In addition 9-Volt is rather complex. A Carbon Zinc or Alkaline 9-Volt has six cells. For a NiMh based battery to have the best compatibility more cells are needed. Six cells gets 7.2 volts, but the better types have seven cells for 8.4 volts or eight cells for 9.6 volts. The more cells needed in the same space, reduces the amp-hour capacity. However, there is another way to reach 7.2 to 8.4 volts with different technology. Two lithium Ion Cells in series will produce 7.4 volts nominal, but with 8.4 volts at a full charge. Lithium ion offers a few advantages, even lower self-discharge, good voltage compatibility, and even more power. In addition, lithium Ion charging requires a smart charger and in this case, probably a balancing circuit inside the pack as well.

The last question I need to answer is what you should do where you can't use NiMh cells for reasons of voltage compatibility, safety certification, internal charger compatibility, or for safety equipment (smoke detectors). If the issue is voltage compatibility, the best answer for AA, AAA, and 9V types is to either continue using standard cells that you normally buy or switch to Lithium. The lithium type will allow you to retain the reduction of leak risk that NiMh provides. If the issue is safety certification (unlikely in household use), you must follow the requirements of certification. Some equipment may allow you to use other types and simply change back to the permitted type to restore certification. Internal chargers can either be disabled as for Alkaline or not used, if neither is an option, NiCd cells are still available in the US. Lastly, I don't recommend rechargeable batteries for smoke detectors as most types state not to use them in the manual. For these I recommend a lithium replacement or if the detector is near end of life, replacing with a 10 year sealed battery type.

08 May 2017

What's this, a blog update?

Yes, I am finally around to updating this blog again. It's been quite a while. Let's see what I'm working on.

Photography:

Earlier this year I bought a Canon EOS A2e at a secondhand store. This near top of the line 35mm SLR from the 1990s is working out for me quite well and I've been taking quite a few photos. I have a roll of film in there right now I need to finish. I also plan on shooting some slides coming up this year as well. I also bought a point and shoot 35mm camera for when I wish to have a compact camera. This is a Pentax IQZoom 160 which has a 35mm-160mm focal length and was a high end camera for its' time.

Video:

I just upgraded my video equipment. I finally have a handheld traditional camcorder that is capable of high definition. I plan on shooting some video as well. I can now capture 1080p video at 60 frames per second on something other than a smartphone. Using this type of camera also allows me to speed up the import part of my workflow since I can import video into iMovie faster than the real time limit of my previous MiniDV camcorder. Of course this doesn't help on the upload side since uploads will max out at a fraction of real time on my home internet connection.

Typewriters:

I haven't been messing around with typewriters too much lately, but I now have a Brother electronic machine that doesn't have any typebars and has changeable fonts. Correction is a real plus on this too. I need to work on my accuracy since I use the correction way more than I should.

The Geek Group:

Of course, I'm still with The Geek Group and actually managed to make a trip out there this past September. While I mainly spent my time getting to know the people and the facility better, this time I aim to be more productive by doing projects that I know will work out well. My one project wasn't even really started, but that was more of me getting some anxiety of the project. I also assisted in some work in the High Voltage Laboratory during my time there.

Additional Audio/Visual Updates:

Since the last update I have obtained some additional projection equipment. I now have both a slide projector and an LCD video projector. The slide projector is a Kodak Carousel, while the video projector is an Epson. While not a high definition video projector, it is capable of downscaling and letterboxing high definition content as required as input via VGA or component connections. This projector uses three LCDs (one each for Red, Green, and Blue) with a native display resolution of 1024x768 pixels.

Blog Update:

I will be reviewing the comments on this blog, apparently there was a spam comment posted back in September that I did not notice until today. I will be cleaning that up and also checking the spam filter.