Primary, Ion, and Polymer: a lithium battery primer

EnergizerLithium

Energizer ultimate lithium cells are designed to be a lighter, longer-life direct replacement for the AA alkaline battery.

Lithium primary, lithium ion, lithium polymer…want to know the differences between–and varied uses for–these diverse types of lithium batteries? You’re not alone…so did I.

Recently, a reader asked about the suitability of using AA Lithium batteries in a Tecsun radio.  Several knowledgeable Post contributors–including Richard Langley, Ken Hansen, DL4NO, Eric Cottrell, and Mark Piaskiewicz–responded, and a discussion of the differences in various lithium cells and their chemistry followed.

I was quite intrigued by this discussion, and wanted to learn more; a bit of research ensued. The wonderful folks at Zbattery.com came to my aid, clarifying the compositions of these various batteries and enlightening me regarding their unique applications.

Following is a (nutshell) primer describing what I’ve recently gleaned from these experts on the subject of lithium batteries. First, a brief disclaimer: the scope of this article is modest, explaining briefly the roles and compositions of the most common lithium batteries used by consumers and hobbyists/enthusiasts. So, if you’d like an even more detailed discussion of batteries, please check out the Battery University website.

With that said, there are generally three types of lithium cells:

1. Primary Lithium (non-rechargeable)

Though this SAFT battery looks like a typical AA, it produces a whopping 3.6V and will certainly fry a radio that is expecting 1.5 volts from each AA cell.

Though this SAFT battery looks like a typical 1.5 V AA, it produces 3.6V and will fry most radios.

Primary Lithium batteries are single-use and should not be recharged under any circumstances. These batteries have a high charge density (i.e., a long life), and as a result, cost more per unit than other single-use (disposable) batteries, such as alkalines.

Primary lithium cells generally produce 3.6 to 3.7 volts; however, there are manufacturers (Energizer and Duracell, to name two) who have developed cell chemistry that lowers this voltage down to 1.5 volts per cell, thus creating a safe, direct replacement for the common AA alkaline battery.

Unless you are purchasing a battery with a AA form factor from Energizer or Duracell, you should double check the voltage of the battery you are purchasing. There are many manufacturers who produce a 3.6 volt primary lithium batteries that have the same dimensions, or form factor, of an AA battery (see photo right), but are used in specialty medical, military, industrial and testing applications in which voltage requirements are higher.  These cannot be used interchangeably with conventional AAs, as they will cause harm to a device.

In other words, do your research when purchasing a primary lithium cell! Make sure the voltage matches what your electronic device requires–or as Post contributor, Richard Langley, puts it–“Caveat emptor!” (Buyer, beware!)

2. Lithium Ion (rechargeable)

Lithium Ion packLithium Ion batteries are currently one of the most popular rechargeable batteries for consumer electronics on the battery market. There are a number of Lithium Ion variations with their own unique chemistries–and their own unique characteristics–but in general these have a high energy density, a modest memory effect, and exhibit only a gradual loss of charge when not in use.

Generally speaking, Li-ion batteries are not available in voltages most radios and other electronics would need, from, say, AA, AAA, C, D, and 9V alkaline. There are manufacturers who produce Li-ion varieties in a AA form factor (they look like AAs), but which produce more than double (3.6V) the peak voltage of an alkaline AA (1.5V); thus, these lithium batteries, too, can only be used in devices designed around these higher voltages–such as specialty flashlights, military, industrial, and medical equipment.

There are a number of radio manufacturers using slim Li-ion battery packs like the one in the image above.

3. Lithium Polymer (rechargeable)

Most LiPo batteries come in a "pouch" format, designed for specific applications,

Most LiPo batteries come in a “pouch” format, designed for specific applications,

Lithium Polymer (LiPo, LIP, Li-poly) are rechargeable battery packs that generally produce 3.6 – 3.8 volts when charged. LiPo packs have much of the same charge and  discharge characteristics of Li-ion batteries, however, they are lighter in weight and can be designed to fit almost any shape.

LiPo batteries have a very strong following in the world of radio-controlled aircraft and cars–their feather-light weight as well as gradual discharge curve render LiPos almost ideal for these applications. LiPo packs are also used in consumer electronic, solar, and GPS applications, to name a few. LiPo pack variations are currently being considered for use in electric and hybrid vehicles.

Summary

And so, returning to our original post questioning the use of Lithium cells in reader Philip Dickinson’s Tecsun PL-606, the Tecsun representative was absolutely correct:  these batteries, it turns out, are not suited for this application, as the voltage is too high for safe use in this Tecsun.

Since I didn’t have a link to the batteries Philip purchased, I assumed Philip might be referring to Energizer Ultimate Lithium AA batteries, which are direct 1.5V  replacements for alkaline AA batteries (and why I use an Energizer graphic in the post).

At any rate, it appears that Philip purchased 3.6V primary lithium cells in a AA cylindrical form factor. If he does pop these AA lithiums in his PL-606, it will surely fry the radio as the voltage is more than double what this radio actually requires.

Hopefully, Philip can return these lithium cells and replace them with the Energizer or Duracell 1.5 V AA variety.

Philip, thanks for writing in with this question; learning about lithiums has been most interesting!  And hopefully, this primer you’ve invoked will save other radios from harm: readers, do check your voltage requirements before you insert those lithiums.

Posted in Ham Radio, How To, News, Preparedness, Shortwave Radio | Tagged , , , , , , | 11 Comments

Tecsun R-911: $15.80 with free shipping at Amazon

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Many thanks to SWLing Post reader “RCXB” who comments:

“Another radio deal, if you don’t mind the writing in Chinese, you can get a Tecsun R-911 for just $15.80… A couple dollars cheaper than its already-cheap re-branded Kaito WRX911 namesake that everyone raves about.”

As of this morning, there are still Tecsun R-911s in stock at this price.

While the “911” series of analog shortwave receivers (i.e. Tecsun R-911, Kaito WRX911) isn’t going to win any awards for outstanding performance, they are capable little radios for the price.

Kaito-WRX911

I have a Kaito WRX911 (above) and often use it as a low-end benchmark for inexpensive portables like the DE321. The WRX911 is a decent little mediumwave receiver as well; I especially love the fact that it does a decent job nulling unwanted signals as you turn the radio body.

Perhaps the best thing about the ‘911 series is that they’re dead simple to use. No manual needed. Just turn it on and tune around!

If you’re looking for a great shortwave receiver, skip this deal. If you’re looking for an inexpensive radio to keep in your car’s glove compartment, home emergency kit, or camping pack, click here to check out the Tecsun R-911 on Amazon.

Posted in Deals, News, Shortwave Radio | Tagged , , , , , | 1 Comment

Universal Radio: Used Tecsun PL-680 for $69.95

Universal-Radio-Used-Tecsun-PL-680

I just noticed that Universal Radio is featuring the following used Tecsun PL-680 in their used receiver collection. Here’s the description:

The Tecsun PL-680 receives longwave, AM, FM and SW bands plus VHF Airband. It features a backlit digital display, stereo FM (to ear jack), SSB, clock timer, 2000 Memories, Sync. Detection, ATS and keypad entry. The left side features earphone, external antenna and input voltage jacks. The right side features a variable BFO and tuning knob. The rear panel has a battery compartment for 4 AA cells (not supplied). This PL-680 system includes: box, nice carry case, printed manual and earphone.

The price is $69.95 plus shipping–very reasonable, in my opinion. The best part is Universal Radio offers a reputable 60 day warranty with all of their used items.

I regularly check Universal’s used and demo list. Occasionally, great bargains pop up and I feel I can always buy from them with confidence as they check over each item before posting.

Click here to read our review of the PL-680.

Posted in Deals, News, Shortwave Radio | Tagged , , , | 5 Comments

Bob’s review of the C.Crane CC Skywave

CCrane-CC-Skywave

SWLing Post reader, Bob C., recently shared his review of the C.Crane CC Skywave portable radio:

Well, I just received my new CC Skywave radio and it’s terrific! I own a lot of portable radios (including several Tecsun DSP sets), and the Skywave is a new favorite and will likely become my standard radio for travel.

Good fit and finish, great ergonomics, and easy to use. I was pleased to find that, despite what’s written in the ads and on the back of the radio, you can set the radio to receive FM down to 76 MHz by selecting the a 9 kHz MW spacing.

Great for international travel. The following is my brief review (by band):

Mediumwave

The Skywave is far better than any of the Tecsuns and is almost as good as the C Crane 2E (my best MW receiver). At my location (40 miles N of Chicago), the distant groundwave fringe includes WLW, WJR, and KTRS (St. Louis) – in descending order of reception potential. Most radios can get a whisper of WLW (though not discernible), while the other two are rare. The C Crane 2E gets WLW and WJR well enough that you can listen; KTRS is detectable. The Skywave gets WLW and WJR and you can tell that KTRS is there. That indicates that the Skywave is among the best. And there are no birdies nor whistles on the band. Nice.

FM

Just as sensitive and about 99% as selective as any of the Tecsun DSPs. The shorter antenna doesn’t seem to hamper reception at all. And, with no soft muting and a more logical tuning setup, it’s a pleasure to work with. Lastly, the stereo reception threshold on the C Crane DSP chip is significantly lower than that on any of the Tecsun rigs, so most signals decode stereo and simply sound better. Where I live, I have tons of signals that are 0.2 MHz apart (i.e. 101.9 Chicago, 102.1 Milwaukee, 102.3 Waukegan – and local) – the Skywave has no trouble separating these and providing a usable signal for all three.

Shortwave

Seems to do just fine. I have not had any overload issues with my unit and can pull in all as many SW signals and most of my other small portables. The lack of SSB is an inconvenience, I suppose, but I guess you can’t have it all!

NOAA/Weather radio

This band is great to have and is perfectly functional. I will say that this isn’t my most sensitive WB radio, but it’s not deaf by any definition. It’s just a little less sensitive to distant fringe WB stations than some of my other sets. But it does dependably pull in anything within 60 miles, so we’re only talking about ability to pull in distant fringe signals (which can be fun).

Air

I’ve played around with this a little and it definitely works better than expected. O’Hare tower is about 25 miles away and I get it clearly, along with aircraft that are (from what I can tell) basically anywhere within about 60 miles. The ability to scan is very helpful; however, catching a signal when someone is broadcasting is tricky. A little online research into local ATC frequencies goes a long way toward having fun on this band. The Skywave seems to work the Air Band better than the G6 and G3, my only other radios with this band.

So, overall, this radio has been a very pleasant surprise. No disappointments whatsoever. Kudos to C Crane Company for doing such a fine job with yet another radio.

Thanks so much for sharing your thoughts on the CC Skywave, Bob! Like you, I really love this little radio for travel and gave it a favorable review several months ago.

That’s an excellent tip about widening the FM frequency range down to 76 MHz by selecting 9 kHz steps on mediumwave. Brilliant!

Readers should be aware that some Skywave owners have noted a vulnerability to overloading and imaging in urban markets or where blowtorch stations are nearby. If your listening post fits this description, you may want to hold off until C.Crane has addressed the issue.

The CC Skywave can be purchased directly from C. Crane. It is also available at Universal Radio and Amazon.com.

Posted in News, Radios, Reviews, Shortwave Radio, Shortwave Radio Reviews, Travel | Tagged , , , | 2 Comments

Jeff finds a solution for sticky preset buttons on the CC-Radio 2E

CCradio 2e

Jeff, over at the Herculodge blog, recently posted that the preset #2 button on his C.Crane CC-Radio 2E had become so sticky, it was almost to the point of not being functional.

One of his readers suggested that he use Deoxit spray to remedy the sticky button and it worked!

Deoxit is amazing stuff and something I suggest any radio enthusiast keep handy. Years ago, I had an Icom IC-735 I thought needed a new power button;I had to press and hold the button for the power to turn on. I searched for a replacement botton for weeks. When I reached out to a friend who is an electronics technician, he suggested that I open the chassis and try spraying the button with Deoxit.

I did, and it worked beautifully.

Deoxit is not the cheapest contact cleaner around, but it is the brand I trust the most. It comes in both a spray and liquid form.

Posted in How To, News, Radios, Shortwave Radio | Tagged , | Leave a comment

Hot deal: Tecsun PL-380 $24.99 and free shipping

Fullscreen capture 8262015 21204 PMWhile browsing Amazon, I discovered a hot deal: a new Tecsun PL-380 for $24.99 including shipping.  I was very tempted to snatch this one up, but since I already have both a PL-380 and PL-310ET, I’d rather give the opportunity to someone else.

This is not being sold by Amazon directly, rather through one of their sellers. Simply follow this link, then search for for the “1 new from $24.99” to grab the bargain.

There may only be one of these available, so if you’re interested…go, go, go!

Posted in News | Tagged , , | 16 Comments

Tecsun PL-880: Evans notes signal meter and other discrepencies

PL-880 (1)

SWLing Post reader, Evans (in Greece) writes:

I would like your opinion regarding two strange points we noticed in two different Tecsun PL-880 models, which a friend and I have recently purchased. In particular:

  1. The signal meter is supposed to measure up to 99dBu (my Tecsun PL-390 s-meter goes indeed up to 95-97dBu for very strong amateur signals in my area included mine in mw zone). The point is that for both devices (both of which have 8820 firmware) the signal meter does not exceed 85 dBu and in particular my Tecsun PL-880 signal meter does not goes over 70dBu (ie. even lower measurement). Why this behaviour?

  2. Another strange point is that my friend’s Tecsun receiver displays for a “quiet” frequency (mw) a noise level of about 10-12dBu, while my Tecsun device shows only 2-3dBu noise (same frequency in the same spot!). We both tried the threshold muting adjustment (key 9) and this worked a bit but with minor results in sensitivity, especially for my Tecsun PL-880 receiver. Is it possible to adjust the noise level so that it can be 10-12dBu instead of being only 2-3dBu and hence better sensitivity? And is it possible to adjust the maximum signal level (99dBu instead of 85dBu or even worse 70dBu for my device)?

  3. I have noticed that the hidden feature regarding the external mw antenna didn’t work in my case, even though I did resets an tried many times. I pressume, hence, that maybe Tecsun disabled this hidden feature. Is there any modification available to “add something” into the radio hardware in order to be able to listen mw/lw frequences with external antenna and thus, increase sensitivity?

Many thanks for your questions, Evans. Since my PL-880 is a first production run unit, I’m hoping readers who’ve recently purchased the Tecsun PL-880 might comment.

I suspect Tecsun engineers give little thought to calibrating the S meters. I’m very curious if there is a hidden feature to do this, but I’m guessing this is limited only to those who can program the DSP functionality of the chip inside.

Posted in Mediumwave, News, Portable Radio, Radios, Shortwave Radio | Tagged , , , | 4 Comments