NURDRAGE's Tritium Nuclear Battery - Page 1
Forum section: electronics / general

author: RandomTask
author_rank: Contributor
timestamp: November 30, 2016, 11:33:35 pm
content: Maybe should've posted to Renewables sub-forum. Maybe mods can move/change

author: timb
author_rank: Super Contributor
timestamp: December 01, 2016, 12:46:30 am
content: Wow, that's really cool and gives me some ideas! I think I'll build one and try it out with an energy harvesting circuit I've got...

author: RandomTask
author_rank: Contributor
timestamp: December 01, 2016, 12:54:06 am
content: Yeah - one of NurdRage's best vids to date. Maybe he can get a case 3D printed for the device.

author: EEVblog
author_rank: Unknown
timestamp: December 01, 2016, 03:18:02 am
content: Yup, VERY cool!Might have to make one...Although, a CR2032 battery delivering 1uW would give about 600000 hours of operation, or 68 years. So the shelf life of the battery, so probably around 10 years.

author: NurdRage
author_rank: Contributor
timestamp: December 01, 2016, 03:43:12 am
content: Quote from: EEVblog on December 01, 2016, 03:18:02 amI replied to your youtube comment already but i'll say again here to make sure you get it: Would you like to get my battery? I don't know how to build anything useful but i would love to send it to someone who can and present a video on it.

author: Falcon69
author_rank: Super Contributor
timestamp: December 01, 2016, 03:56:58 am
content: hmm, very cool.Interesting what NurdRage said about the single panel actually producing more because the foil was reflecting the light.That brings up an idea. What if you encased all this into a single enclosed case with mirrors, and formed the tritium in such a way that you create an infinite mirror pattern. I wonder how well those panels will produce power then.

author: EEVblog
author_rank: Unknown
timestamp: December 01, 2016, 04:06:06 am
content: Quote from: NurdRage on December 01, 2016, 03:43:12 amThat would be cool, thanks. Should be able to run a low power ARM processor and LCD with a uWIIRC I think green light around 500nm would give the best efficiency with amorphous silicon, so other colours may not work as well.

author: Falcon69
author_rank: Super Contributor
timestamp: December 01, 2016, 04:09:17 am
content: Filmed at 11:00....Dave Jones makes first homemade nuclear digital LCD Clock. He'll die before IT quits telling time.

author: NurdRage
author_rank: Contributor
timestamp: December 01, 2016, 04:13:58 am
content: Quote from: EEVblog on December 01, 2016, 04:06:06 amAwesome, i'll package and send it off in the next few days. Hopefully it'll arrive before Christmas. Although i'm guessing with the holiday season the mail system will be busy.Just a note: i still haven't found a good case for it so i'll just send the bare battery. You'll need to put it into a dark container (like aluminum foil) for accurate power measurements without external light.Thanks for the info on the green phosphors! I'll keep in mind if i test other colors.

author: coppice
author_rank: Super Contributor
timestamp: December 01, 2016, 04:16:46 am
content: Quote from: EEVblog on December 01, 2016, 03:18:02 amIn 10 years most CR2032 cells will loose quite a lot in self discharge, but you can still get enough power over that time to run an RTC. If you want 15 year life you usually need something bigger, just so that all the extra initial energy can be lost to self leakage and leave enough for your RTC. Much beyond 15 years these simple lithium cells can't be relied on not to break down with corrosion. If you want 20 years or more you need to look at more expensive battery types, from people like Tadiran.

author: EEVblog
author_rank: Unknown
timestamp: December 01, 2016, 05:48:35 am
content: Quote from: coppice on December 01, 2016, 04:16:46 am1% per year according to Energiser datasheet for a CR2032

author: eripaha
author_rank: Contributor
timestamp: December 01, 2016, 06:19:46 am
content: Quote from: NurdRage on December 01, 2016, 04:13:58 amWhen i read your text i hear the distorted voice you have on your youtube videos, i find this hilarious.

author: coppice
author_rank: Super Contributor
timestamp: December 01, 2016, 06:26:08 am
content: Quote from: EEVblog on December 01, 2016, 05:48:35 amGreat. So their battery will take 100 years to die.Try a data sheet that gives you more of a realistic picture. The data sheets which quote a simple self-discharge percentage (typically 1% to 2%) are talking about storage performance for the early life of the battery, under cool conditions - basically what happens between manufacture and the start of use. Data sheets which give longer term information, including the effects of higher temperatures, show far higher losses to self discharge over a realistic 10 year operational life.

author: NurdRage
author_rank: Contributor
timestamp: December 01, 2016, 07:07:29 am
content: Quote from: eripaha on December 01, 2016, 06:19:46 amI have made a machine that let's you read my comments in my voice.

author: EEVblog
author_rank: Unknown
timestamp: December 01, 2016, 10:35:10 am
content: Quote from: coppice on December 01, 2016, 06:26:08 amSure conditions matter. Got a quantifiable figure for that?http://www.varta-microbattery.com/applications/mb_data/documents/sales_literature_varta/HANDBOOK_Primary_Lithium_Cells_en.pdf

author: timb
author_rank: Super Contributor
timestamp: December 01, 2016, 11:00:28 am
content: Quote from: Falcon69 on December 01, 2016, 04:09:17 amTechnically, based on the half-life of Tritium, you wouldn't have much useable power after about 20 years...

author: tszaboo
author_rank: Super Contributor
timestamp: December 01, 2016, 11:24:31 am
content: Quote from: EEVblog on December 01, 2016, 10:35:10 amhttp://industrial.panasonic.com/cdbs/www-data/pdf/AAA4000/AAA4000PE12.pdfPanasonic also claims that:"Since the substance that is chemically very stable isused for plus terminal as an active material (BR series:Poly-carbonmonofluoride, CR series:Manganese dioxide),ifpreservation conditions are proper, 90% of capacityremains even after ten years storage."In any case, if I wanted to operate something for more than 10 years, I would use lithium thionyl chloride battery from Tadiran. They are proven for 30 years operation, they claim that 40 years is possible. Something like a 2450 cell gives 0.5Ah, plenty of power to throw around.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 01, 2016, 11:54:23 am
content: Interesting application, but we minor peasants will never have any material to build any sizable battery.I had to download the video and play it back at 1.14x speed as his voice sound too vomitus for long play.

author: timb
author_rank: Super Contributor
timestamp: December 01, 2016, 01:00:26 pm
content: Quote from: Quarlo Klobrigney on December 01, 2016, 11:54:23 amWhy not? A battery that size would be very useful for a wireless sensor node.You simply use an energy harvesting IC to charge a supercapacitor up between transmit pulses.

author: Kevman
author_rank: Regular Contributor
timestamp: December 01, 2016, 03:10:50 pm
content: You know, I recently pulled and replaced something like 8 CR2032s in my SNES carts, and measured their voltages as I pulled them. Thelowestvoltage one was 2.85v, from Donkey Kong Country 2.The F-Zero and SMW battery (1991-1993) both measured over 3.1v!So yeah, CR2032s can last a while.

author: NurdRage
author_rank: Contributor
timestamp: December 01, 2016, 04:38:57 pm
content: Quote from: Quarlo Klobrigney on December 01, 2016, 11:54:23 amSorry about my voice. I've paid to have proper subtitles made in all my videos. You can turn off the sound and turn on the subtitles in the youtube player.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 01, 2016, 05:55:36 pm
content: I have an idea.... parts ordered....

author: Gyro
author_rank: Super Contributor
timestamp: December 01, 2016, 06:44:36 pm
content: We used to use Tritium backlights in military radio gear, decent quality ones, borosilicate glass etc. They're actually fairly short lived, 10 years and they'd start looking pretty miserable (we had various aged ones kicking around the lab). It's not just the half-life of the Tritium, it's the degredation of the phosphor from bombardment too.Don't give up on the Lithium just yet.

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: December 02, 2016, 11:40:29 am
content: Quote from: NurdRage on December 01, 2016, 04:38:57 pmSorry, no offence was intended against you personally. It just that your voice sounds much like Lionel Fanthorpe to whom I do take offence to. I will continue to listen to more of your videos in the future when you deem to make public.

author: RandomTask
author_rank: Contributor
timestamp: December 02, 2016, 01:44:05 pm
content: How about wrapping each vial with flexible photovoltaic film? Feasible, or risible?

author: @rt
author_rank: Super Contributor
timestamp: December 02, 2016, 03:23:35 pm
content: Funny that turned up in suggested videos and I watched it tonight.I wondered if the cell itself was phosphor coated, and maybemonocrystaline, how much better it might be.. so long as there wasa safe way to handle and encapsulate the tritium as well.

author: NurdRage
author_rank: Contributor
timestamp: December 02, 2016, 06:51:29 pm
content: Quote from: EEVblog on December 01, 2016, 04:06:06 amI've sent off the battery by airmail this morning. They said it should get to you in about 3 weeks, and should arrive before Christmas. You'll recognize the box by the green "NurdRage" logo card i taped to the side.I'm really looking forward to whatever you do with it.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: December 02, 2016, 07:06:19 pm
content: I wonder what the expression would be when it gets checked in customs and they find out it has radiation irradiating from it, addressed to That Crazy Aussie Bloke from a guy calling himself NurdRage.

author: Falcon69
author_rank: Super Contributor
timestamp: December 03, 2016, 04:54:26 am
content: Chances are, your cell phone puts out more radiation then a few of these will. But would be interesting to know for sure. I could see it throwing up some possible red flags to if it puts out alot.

author: timb
author_rank: Super Contributor
timestamp: December 03, 2016, 06:13:06 am
content: Quote from: Falcon69 on December 03, 2016, 04:54:26 amThe vials that the tritium is encased in is leaded glass, so it it puts out minuscule amounts of radiation.So little, in fact, that some people implant them under their skin to create a "firefly" tattoo. (Obviously they double insulate them with leaded vial inside of a borosilicate glass vial, as you wouldn't want lead leaching out...)

author: Gyro
author_rank: Super Contributor
timestamp: December 03, 2016, 09:24:52 am
content: Actually they don't go to the extra bother of leaded glass, the Tritium emission is only low energy electrons (beta particles, hence the original trade name of betalights), borosilicate glass blocks them just fine.

author: VK3DRB
author_rank: Super Contributor
timestamp: December 03, 2016, 10:55:00 am
content: The speaker talked non stop for 25 minutes, never missing a beat. He would even win against Scott Morrison in the motor mouth competition. Besides the usefulness of learning the science, I cannot see any useful value in this cell that a simple primary battery cannot achieve.In any case, I did learn that sulphuric acid dissolves silicone rubber.

author: timb
author_rank: Super Contributor
timestamp: December 03, 2016, 12:04:21 pm
content: Quote from: Gyro on December 03, 2016, 09:24:52 amSorry, the implantable ones are borosilicate glass that contains the tritium, then that's encapsulated in leaded glass (to reduce emissions) which is then encapsulated again in biosafe borosilicate glass.

author: timb
author_rank: Super Contributor
timestamp: December 03, 2016, 12:12:55 pm
content: Quote from: VK3DRB on December 03, 2016, 10:55:00 amPrimary cells are temperature sensitive, a nuclear battery like this is much less so...A company sells commercial nuclear batteries in DIP24 packages for thousands of dollars that only put out 500nA, so they're obviously useful for something, even if you can't see it.

author: RandomTask
author_rank: Contributor
timestamp: December 03, 2016, 02:15:29 pm
content: Quote from: VK3DRB on December 03, 2016, 10:55:00 amApplications where battery replacement is not feasible?

author: NurdRage
author_rank: Contributor
timestamp: December 03, 2016, 03:55:52 pm
content: Quote from: VK3DRB on December 03, 2016, 10:55:00 amI'm not really talking non-stop. It's just editing. I find people don't like pauses where i say nothing. If that's an issue, you can always pause the video yourself. It's easier to pause a continuous video than to skip over the boring parts of a discontinuous video.As for value. I say straight out at the beginning that this video is to explore the science. We do a lot of things to explore science. The innumerable number of "potato battery" kits you can buy online proves that something need not be useful to be educational.But commercial versions do exist, and there is a market for them despite only being in microamp or less range. The reason is Nuclear batteries are more reliable and predictable than primary batteries.After 20 years at weak current draw you may have 90% of your primary batteries still operating. But if your application demands 99.99% reliability then a 10% failure rate is a non-starter. The good thing about a nuclear battery is that despite its severe power shortcomings it's extremely predictable. You can plot the decay rates for all the components (the tritium, the phosphor, and solar cell) and they will keep that decay rate well into the future. You can thus predict to within a few percent what the power output will be many years in the future. You just have to ensure you have enough spare capacity installed that at your desired End-Of-Life enough decayed capacity will remain.To put this into perspective, the Voyager space craft launched almost 40 years ago are still operating and still transmitting.A primary battery unfortunately has variable decay that's extremely hard to predict. Even different batches of the same batteries will have different impurities that alter the decay rates so the self-discharge is different. The decay data you obtain for one battery can be different from another. If your application demands ultra-high reliability this is not acceptable.The biggest market for these batteries is remote sensors. Existing energy harvesting solutions work well for most remote sensors but there are a few edge cases where that's not enough. In that case, if the value of the data is more than the few thousand dollars, then nuclear battery is used.Another area is hardware security modules. These self-contained modules have cryptographic processors for handling secure transactions in an otherwise untrusted network and physical environment. The battery is not accessible because that's a possible attack vector. So for absolute security the modules are sealed with no battery access. But if you expect your module to be in operation for 10+ years then a chemical battery is not viable. And again, predictability is paramount when your handling multimillion dollar transactions or highly secure data. Throwing a few tens of thousands of dollars at a system that has ultra high reliability is a bargain.

author: tszaboo
author_rank: Super Contributor
timestamp: December 03, 2016, 04:13:34 pm
content: Quote from: timb on December 03, 2016, 12:12:55 pmActually the solar panels used are very temperature sensitive.

author: SeanB
author_rank: Super Contributor
timestamp: December 04, 2016, 01:19:33 pm
content: Quote from: NANDBlog on December 03, 2016, 04:13:34 pmYes, but they will still generate power when at liquid helium temperatures, where a conventional primary cell will be doing a very good emulation of a glass block.

author: TheAmmoniacal
author_rank: Unknown
timestamp: December 04, 2016, 03:48:34 pm
content: Unrelated question, but I went looking for your video on the Mg/KOH reduction in mineral oil (with tert-amyl alcohol or tert-butanol), but I can't find it? Did you delete it? Any reason why?

author: stj
author_rank: Super Contributor
timestamp: December 04, 2016, 10:07:10 pm
content: Quote from: NurdRage on December 03, 2016, 03:55:52 pmyes it is, i have secure modules that still run after 20years+search "sega fd1094"

author: timb
author_rank: Super Contributor
timestamp: December 04, 2016, 10:34:22 pm
content: Quote from: stj on December 04, 2016, 10:07:10 pmI've seen coin cell backup batteries last 5 years and I've seen them last 25 years. It depends on a lot of factors and can't be reliably determined.With a Nuclear power source, you can guarantee a certain runtime based on the halflife of the element.

author: Artlav
author_rank: Frequent Contributor
timestamp: December 04, 2016, 10:42:50 pm
content: Hm, how would such a nuclear battery work at cryogenic temperatures?It would be interesting to try putting it into liquid nitrogen.Best done outside, naturally, since the glass on the vials might break...

author: NurdRage
author_rank: Contributor
timestamp: December 04, 2016, 11:19:39 pm
content: Quote from: stj on December 04, 2016, 10:07:10 pmWhy are you selectively quoting that statement, but intentionally ignoring my thorough explanation of chemical battery reliability (and address your specific situation) before that?Search "Quoting out of context"

author: stj
author_rank: Super Contributor
timestamp: December 05, 2016, 12:51:03 am
content: i didnt feel it was out of context, chemical battery's are often used in potted devices with a long expected lifespan.infact a chemical battery may have a better thermal range that a tritium vial with a reactive coating on the glass.

author: NurdRage
author_rank: Contributor
timestamp: December 05, 2016, 01:09:54 am
content: Quote from: stj on December 05, 2016, 12:51:03 amIt was out of context, because you completely ignored this earlier statement:Quote from: NurdRage on December 03, 2016, 03:55:52 pmIf you don't demand absolute reliability then use all the chemical batteries you want. Heck chemical batteries are used in 99.9% of the security modules out there. If they do fail then they are simply replaced because whatever data they are processing is not considered that valuable. This is the case for most of the market. And certainly the case for a video game console where the company actually benefits if you have to buy another one.But there is that 0.1% edge case where the data IS that valuable so they throw nuclear batteries at it.You're right that chemical batteries can be used for long life devices. But you rebutting my statement where i said they are not viable is out of context because i was saying it in the context of high reliability applications.Quote from: stj on December 05, 2016, 12:51:03 amThey don't. the chemicals in the coating have a greater thermal range than chemical batteries.

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2016, 11:30:42 am
content: Curious that with all the advances in phosphor technology, white LED advances (yes I know it's a different phosphor!) etc. Betalight still only spec 15 years (131000 hours) maximum.http://www.betalight.nl/I realize that Tritium has a half life, but I would have expected them to have been able to maintain useful light output for longer than that (ie. phosphor that 'saturates' initially to delay the onset of light output reduction. The ones I had kicking around were effectively 'dead' at 20yrs.Interesting that they do an IR source one thoughhttp://www.betalight.nl/en/light-source/ir-betalight.htmlMaybe that would be a better spectral match for a silicon cell if you could get hold of the bare tubes.

author: NurdRage
author_rank: Contributor
timestamp: December 05, 2016, 04:45:19 pm
content: Quote from: Gyro on December 05, 2016, 11:30:42 amOdd. I've seen one that was incredibly weak, but still going after 20 years.Keep in mind, an expiry date doesn't necessarily mean total failure. They might have just put that there to indicate it would be too weak for most purposes. If they *didn't* put an expiry date, then people would complain their lights were shit at 15+ years and demand a refund. I've had products in my lab last 9 years despite being labelled with a 5 *month* expiry date.Was yours actually dead? or just really weak to be "effectively" dead? Where there any measurements taken?After 20 years only 32% of the tritium should remain active. Now I don't know what the phosphor decay rate is but if its equal to the tritium then at 32% phosphor remaining there would be ~10% light output.The thing with exponential decay is that its not linear. its not like the loss goes down smoothly to zero. It asymptotically approaches zero.

author: edavid
author_rank: Super Contributor
timestamp: December 05, 2016, 05:34:05 pm
content: Quote from: timb on December 04, 2016, 10:34:22 pmThe degradation of the phosphor and photovoltaic cell also depends on a lot of factors. It seems like a real challenge to make a nuclear PV source with guaranteed life greater than that of say a Tadiran battery.

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2016, 07:39:04 pm
content: Quote from: NurdRage on December 05, 2016, 04:45:19 pmNope, dead as in not visible in the dark, admittedly without particularly dark adapted eyes. I had a few of them (still have I think), a couple of flat ones about 50mm x 5mm and some button ones about 10mm diameter. A fair number used to get 'borrowed' from the lab for personal keyfob lights, house numbers (7 segment) etc. They were quite a novelty at the time, but used to worry postmen after it was explained how they worked! Maybe phosphor technologyhasimproved a bit over the years, although I guess the half-life would still be an issue.It's a shame a slightly more long lasting isotope can't be used. Americium (as used in smoke detectors) comes to mind, but is unfortunately an Alpha emitter rather than Beta. Of course the old favorite was Radium - the scary thing was that it would burn out the Zinc Sulphide it was mixed with after a few years so that it was no longer luminous. Quite scary to see old 1930s watches and alarm clocks which no longer glow but have brown burn marks on the paper dials where the hands have been stopped. The other problem being that it emits a bit of everything!

author: Howardlong
author_rank: Super Contributor
timestamp: December 05, 2016, 10:57:04 pm
content: Quote from: EEVblog on December 01, 2016, 04:06:06 amIndeed, you might end up debunking a bunch of nanowatt microcontroller marketing nonsense in the process! I do however applaud such an effort, quite an engineering challenge, and certainly it would make a good experiment as well as being very educational, not just from a technical perspective.

author: NurdRage
author_rank: Contributor
timestamp: December 06, 2016, 04:02:37 am
content: Quote from: Gyro on December 05, 2016, 07:39:04 pmInteresting. It's true that the 20 year old one i was looking at was VERY dim and i could only see it after i let my eyes adjust for awhile. I think i might do a long term experiment to measure the decay rate of the tritium vials. That is if Dave can send back my battery after he's doneAs for longer life isotopes. Actually other isotopes are used... they're just not available to the public for obvious safety reasons. They're solids with high biological retention time. Tritium is a weak emitter and biologically cycled out quite quickly so its a much lower hazard. Its short half-life is actually an advantage for safety as it won't linger too long in the environment. "Just" a century or so.Betavoltaic cells do away with the phosphor decay problem altogether by using betavoltaic cells. This is indeed the better option for long life applications and while betavoltaic cells do decay themselves from radiation exposure, the decay is less and more manageable than phosphors. There are also versions that use non-tritium isotopes. Promethium and Nickel are the most common. Their radiation isn't as damaging as radium and thus they can give power for many decades.Alternative phosphors are available. Due to extensive research in display technology (Everything from CRT, to plasma, to OLED) there are literally tens of thousands of phosphor compositions known to science. It is possible that a survey could find longer lasting ones. Such research isn't done though because as said before betavoltaic cells already exist and eliminate phosphors as an issue. Money is better spent making the betavoltaic cells themselves better.Ultimately I don't actually expect anyone to use my device for commercial projects. It's more of a fun hack and curiosity, like getting a Tesla coil to play music.Interestingly enough when i was researching the concept for the video. I did come across a lot of recently declassifiedmilitaryresearch into phosphor based indirect conversion technologies. Apparently at the power levels they need, around 100-1000 microwatts, the phosphor based system is more cost effective and they deal with the decay by just packing a huge amount of extra capacity at the beginning. Size and weight isn't an issue for their applications so a giant stack of tritium vials is acceptable. Economies of scale let them create an exceptionally cost effect unit versus using betavoltaic devices.