hybridfree/eevblog-posts huggingface dataset:
Recommended (smart?) power meter for home appliances (EU)? - Page 1
Forum section: electronics / general

author: armaguedes
author_rank: Newbie
timestamp: December 22, 2020, 09:17:18 pm
content: Good evening everyone.I'm looking for one of those power meters (V-I-P) for plugged appliances; I neither want nor need fancy functions (wifi, BT, etc). We've all seen MassiveClive.com use his HOPI meter to death, but he himself has stated that it is not very good at the low end of the scale.Now, I'm rather interested in that end of the scale -- from a fraction of a watt, to a few watts -- in order to measure vampire consumption of power bricks, appliances on standby, and somesuch. One such model I've come across repeatedly is the EG-SSM-01 (https://energenie.com/item.aspx?id=9884), of which there seem to be many clones.Any suggestions?Thank you!

author: f4eru
author_rank: Super Contributor
timestamp: December 23, 2020, 07:23:14 am
content: the problem with vampire drain is that it's often really heavily capacitive.adding to that the fact that it is very low values overall, it's really difficult to measure.My advice : take a reasonably cheap meter, like you linked, check that it handles correctly capacitive loads, and then increase its sensitivity 100x by replacing the shunt with a 100x higher one (be sure to put some 4*2 10A diodes in parallel to limit the shunt voltage both directions to 3V when inrushes are present, so to not destroy the meter

author: opampsmoker
author_rank: Regular Contributor
timestamp: December 26, 2020, 09:19:59 pm
content: mains power meters for measuring very low power like standby power can be very inaccurate, due to the fact that they cant handle the burst mode operation of many mains powered devices when in standby.When you go to measure mains smps standby power, you need an expensive power meter for that.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 27, 2020, 12:47:41 am
content: If you're dealing with switching power supplies which is often the case, run them on DC (equal to the peak voltage of the mains AC) and accurately measuring low levels of power would become a lot easier.
Chargehanger now available - Page 1
Forum section: electronics / general

author: f4eru
author_rank: Super Contributor
timestamp: November 29, 2020, 04:06:26 pm
content: Hello all,The product of my pet project, Chargehager, is now finally available to buy after the successful kickstarter campaign:https://www.chargehanger.com/

author: CJay
author_rank: Super Contributor
timestamp: November 29, 2020, 04:08:24 pm
content: I'm not buying it unless it plays Who Made Who when you plug the cable in.

author: f4eru
author_rank: Super Contributor
timestamp: November 30, 2020, 08:11:25 pm
content: Challenge accepted !For 30Euro addition, I'll add a small box to connect to your wallbox which will play ACDC when plugging in...and the sticker is included, of course

author: f4eru
author_rank: Super Contributor
timestamp: December 10, 2020, 07:11:55 pm
content: not interested any more ? addition is too expensive ?
I came across a Tesla Solar Roof install video - Page 1
Forum section: electronics / general

author: Hallcrash
author_rank: Newbie
timestamp: December 09, 2020, 02:36:47 am
content: I was just poking around the youtubes and I managed to come across this guys channel who just documented Teslas "solar roof" install. Tesla also offers regular panels, as well as the solar roof tiles, I found it interesting. I hope he does a long term analysis on the efficiency of those roof tiles.7 to 10 days to install. That's gotta be a lot of labor costs. There are two videos of this install so far.https://youtu.be/qXJ9WUciBVA

author: bdunham7
author_rank: Super Contributor
timestamp: December 09, 2020, 03:21:29 am
content: Check out the first video at 4:10.

author: kripton2035
author_rank: Super Contributor
timestamp: December 09, 2020, 07:58:47 am
content: amazing the number of people working on this roof ! anyway $65k, but almost no electricity bill for 30 years.I did not find how much expected watts this roof outputs ?

author: Marco
author_rank: Super Contributor
timestamp: December 09, 2020, 03:52:47 pm
content: Can you replace a tile without needing to remove a huge triangle section upwards to the top?Also I often see it said the non producing tiles are tempered glass ... yet they cut them to size ...
lithium and polymer lithium batteries store is risk explosion? - Page 1
Forum section: electronics / general

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 24, 2020, 12:50:51 pm
content: If I store a lot of lithium and polymer lithium batteries by placing the battery on top of the other in a bag and in the closet, is there a risk that these batteries will explode or fire even without use?

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 24, 2020, 02:40:16 pm
content: Small but nonzero risk, to further reduce it, put them in a metal cabinet with some automatic fire extinguishers.

author: wraper
author_rank: Unknown
timestamp: November 24, 2020, 02:49:39 pm
content: Do not store them fully charged. Neither good for safety, nor for their lifetime. 40% charge would be about right. As of dodgy batteries such as of unprotected Li poly, it's safer to put them in fire retardant pouches individually, so one battery cannot ignite others. Or metal boxes, with electric insulation between metal and battery of course.

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 25, 2020, 01:25:38 pm
content: my batterys are BP-5L 1800mah and BM20 2000mah, i store charged in 75% this batterys explode and fire stored?

author: wraper
author_rank: Unknown
timestamp: November 25, 2020, 02:42:27 pm
content: BP-5L can be very different, from good batteries with protection circuit to complete trash with fake capacity, no protection, and god only knows their safety. If they are labeled as Nokia, and have dubious authenticity, assume the worst.

author: tszaboo
author_rank: Super Contributor
timestamp: November 25, 2020, 03:15:10 pm
content: Quote from: classicsamus87 on November 25, 2020, 01:25:38 pmFor example, you may only ship some batteries 30% charged by plane.There must be a reason for that.

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 26, 2020, 02:58:46 pm
content: i store in 75% is bad for lonmng term storage bateries and explosion? 50% fast descharge stored

author: tunk
author_rank: Super Contributor
timestamp: November 26, 2020, 03:16:01 pm
content: A bag may not be the best, at least you should cover thepoles with electrical tape. And a solid (cardboard) boxwould be better.

author: classicsamus87
author_rank: Regular Contributor
timestamp: December 08, 2020, 10:37:40 pm
content: What is the charging frequency of the BP-5L and BM20 batteries if I always charge up to 75% and store them?
Reviving the rechargeable batteries? - Page 1
Forum section: electronics / general

author: vinlove
author_rank: Frequent Contributor
timestamp: December 30, 2020, 01:30:41 pm
content: The old AA rechargeable batteries I have are charging, but only lasts for a few minutes, and then loses the charges again.Clearly they have done life? But they have not used that much, kept in the drawers for some years from new.Are there ways to reviving them back to service?

author: opampsmoker
author_rank: Regular Contributor
timestamp: December 30, 2020, 10:04:25 pm
content: what is the cell voltage?If its less than 2.5V then maybe your charger will stop charging it if the volts dont go above 3.1V within a few minshttps://www.youtube.com/watch?app=desktop&v=tbEfhPbqTDE&feature=share...It may be possible to make your own revive charger to persist charging them with limited current until they get a decent voltage.
Any Market for Switchmode Development Kits, Parts? - Page 1
Forum section: electronics / general

author: Optoeng
author_rank: Newbie
timestamp: December 04, 2020, 02:24:06 am
content: I'm retiring from several decades of switchmode power design work. I have loads of ferrite cores, magnet wire, litz wire, EMI/RFI filter components, controller chips, high power rectifiers and MOSFETs, dev kits, etc, etc. I also have a nice coil winding machine. If I found the right destination, I'd consider donating the lot, and I've put out a few feelers. So far, no one near me has made what I consider to be a worthwhile proposal. A lot of this stuff is heavy, so it probably doesn't make sense to ship it any great distance. I'm in the Pacific NW of USA. I'd like to see that someone who is likely to use some of it gets it: no hoarders. Suggestions?

author: jonpaul
author_rank: Super Contributor
timestamp: December 04, 2020, 04:31:12 pm
content: Please contact me via PM, just sent you a note,Jon
Odd NiMH cell behaviour - Page 1
Forum section: electronics / general

author: CJay
author_rank: Super Contributor
timestamp: December 03, 2020, 08:29:07 pm
content: I'm working my way through a pile of NiMH AA cells, I charge them with a Tronic charger, let them rest for an hour or so, measure the terminal voltage then discharge them through a 1R resistor while monitoring the voltage, a very basic test to weed out the useless cells from the possibly useful ones.Most of them are doing reasonably well, there's one or two which are knackered.One of them however is doing something rather odd.I charged it, left it overnight and it checked out at ~.5V this morning, I figured it was stuffed but put it on load anyway. It held up, but, then the voltage started to climb, it's now at 0.9V and it's been on load for 35 minutes.Any ideas what the mechanism is here?
Convert PWM solar charge controller to MPPT Charge controller - Page 1
Forum section: electronics / general

author: inductonator
author_rank: Newbie
timestamp: December 02, 2020, 04:24:42 pm
content: What is the difference between a PWM charge controller and MPPT charge controller apart from Firmware?Can I(in theory) write custom firmware and convert PWM controller to MPPT controller ?What are the things I need to look out for ?

author: krish2487
author_rank: Frequent Contributor
timestamp: December 02, 2020, 05:10:18 pm
content: You said it yourself..The firmware. and that makes all the difference.A big one..Hardware wise, a MPPT charge controller has one additional energy storage element ( usually inductors) that a PWM controller doesnt have.and if you do a bit of googling you can find the difference between a PWM controller and a MPPT controller.and you will pretty soon see, they are apples to oranges.
battery CR2032 leak? - Page 1
Forum section: electronics / general

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 24, 2020, 10:12:04 pm
content: CR2032 battery of Snes cartridge leaks and corrodes the board?

author: james_s
author_rank: Super Contributor
timestamp: November 24, 2020, 10:18:59 pm
content: It's rare, but it can happen. You're talking about a 30 year old battery.

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 24, 2020, 10:22:10 pm
content: I bought a new sd2snes cartridge and it has a cr2032 battery, if i keep this spare cartridge for 30 years will the cr2032 battery leak and corrode?

author: james_s
author_rank: Super Contributor
timestamp: November 24, 2020, 10:25:21 pm
content: It might. It almost certainly will be dead by then. Why would you buy a new cartridge and then put it away for 30 years?

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 25, 2020, 12:04:29 am
content: photo internet

author: helius
author_rank: Super Contributor
timestamp: November 25, 2020, 01:48:29 am
content: That isn't a CR2032 cell. Probably LR2032 alkaline.The liquid inside CR cells is a nonpolar solvent and isn't corrosive, nor does it spread that much.

author: wraper
author_rank: Unknown
timestamp: November 25, 2020, 02:11:02 am
content: Quote from: helius on November 25, 2020, 01:48:29 amThere are no alkaline batteries in such form factor. All of them different types of lithium batteries. Photos of corroded cartridges I googled show battery with CR2032 marking.

author: helius
author_rank: Super Contributor
timestamp: November 25, 2020, 02:21:46 am
content: You're right, an alkaline cell wouldn't supply 3V, either.I think that a source of moisture is needed to react with lithium perchlorate to cause that type of effect. As a perchlorate salt, it is obviously an oxidizer, but needs something to transfer that charge to the metal to corrode it.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 25, 2020, 03:59:52 am
content: I've seen CR2032, 2016, LR/SR44 leak, but they were in the same spot for decades.

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 25, 2020, 01:24:35 pm
content: Do I need to worry about removing all CR2032 from the Snes stored cartridges? is it certain that a moment the CR2032 of the cartridge will leak and corrode the board? the photo I posted is of a person who has a SNes cartridge

author: wraper
author_rank: Unknown
timestamp: November 25, 2020, 03:04:04 pm
content: You need to replace them if you care that cartridges can save game progress. If battery is not dead yet, it will be very soon.

author: classicsamus87
author_rank: Regular Contributor
timestamp: November 27, 2020, 01:05:26 pm
content: I don't know what material is formed in the CR2032 and without corrosive acid when leaking

author: james_s
author_rank: Super Contributor
timestamp: November 27, 2020, 09:36:59 pm
content: It doesn't matter what material is in them, you've seen already that they can leak, and most are only guaranteed to last for 10 years. If you want to store something long term, remove the batteries from it.
Cat walking across solar panels increases output. - Page 1
Forum section: electronics / general

author: DougSpindler
author_rank: Super Contributor
timestamp: November 20, 2020, 05:10:33 am
content: Not sure if this bank of solar panels is putting out much at mid-day. But then the cat waked across is, zoom in to see the cat’s paw prints in the top right. I’m thinking this much have increased the output from the panels, right?

author: f4eru
author_rank: Super Contributor
timestamp: November 20, 2020, 05:07:28 pm
content: why is it that dirty compared to others ?

author: DougSpindler
author_rank: Super Contributor
timestamp: November 21, 2020, 08:51:39 am
content: Maybe the other cats do a better job cleaning the panels? I’m thinking they might roll across them instead of just walking.Seriously I have no idea why this one is so dirty and the others aren’t. There are a lot of panels in this grid which are just as dirty. With the panels this dirty, I’m thinking the output must be next to nothing even at mid-day.

author: srb1954
author_rank: Super Contributor
timestamp: November 21, 2020, 10:35:19 am
content: Quote from: f4eru on November 20, 2020, 05:07:28 pmMaybe it is treated so as to reduce the performance down to the abysmal efficiency of a typical solar roadway.These solar roadway projects seem to easily gain funding from scientifically illiterate governments so maybe the the owners of these panels decided they wanted a slice of that easy funding.

author: DougSpindler
author_rank: Super Contributor
timestamp: November 21, 2020, 01:26:05 pm
content: Quote from: srb1954 on November 21, 2020, 10:35:19 amOur schools, at least in the US, teach students to believe in the impossible. Solar roadways seem impossible. All you have to do believe and they are possible. We don't need no stinking laws of physics.

author: f4eru
author_rank: Super Contributor
timestamp: November 22, 2020, 11:02:30 pm
content: Yeah. It's not impossible.It's worthless, economically hopeless, maintenance nightmare, incredibly low lifetime of a few weeks, and just plain dumb. But not impossible.
CCM boost PFCs in parallel...put inductor in the low side? - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: November 26, 2020, 10:01:18 pm
content: Hi,Do you agree that when paralleling CCM Boost PFCs, the inductor should go in the low side as attached?(EDIT: attachment now removed for editing)Otherwise, the return current of one booster could go through the other ones sense resistor. Only thing is you need isolated power supply for the controllers. But that is OK.

author: TimNJ
author_rank: Super Contributor
timestamp: November 27, 2020, 12:37:16 am
content: Hmm. How about just avoid the whole thing with an interleaved PFC? Often interleaved PFC uses boundary/transition mode (no inductor current sense resistor needed). But if you were to interleave CCM, I think you can do it with just one current sense resistor. Both 1/2’s share the same return path by design.
3 phase system was not balanced - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: November 25, 2020, 05:50:43 pm
content: Hi,Some one showed me the phase current in a mains connected three phase installation.The currents were 100A, 105A and 130A.Is this acceptable?....i dont think so, but he said it was.

author: fcb
author_rank: Super Contributor
timestamp: November 25, 2020, 07:20:30 pm
content: I've seen alot worse. Depends somewhat on the size of the system. The 30A imbalance is small if it is a 400A feed.Pretty common to see if say it's the feed to a block of flats or an office building and perhaps a different phase to each floor, or at least seperate zones.Some industrial metering will penalise for phase imbalance.

author: richard.cs
author_rank: Super Contributor
timestamp: November 26, 2020, 03:27:36 pm
content: I'd say that was pretty good, even unusually well-balanced, assuming it is made up or lots of single-phase loads. Neutral current approximately 30 A*. Obviously if the installation were one 3-phase motor then this would be concerning, but otherwise, all good.* Simplified approximation, subtract the smallest number from the other two, then vector subtract the two resulting numbers.

author: dmills
author_rank: Super Contributor
timestamp: November 26, 2020, 08:05:27 pm
content: Note that you can have perfectly balanced three phase AND have neutral current greater then any one phase current!What you have is at least superficially well balanced, but you really need both the kVAr numbers for each phase and the harmonics to know.I too have seen plenty of 400:350:35 sort of things being indicated on the alternator clocks, not much you can do when 30 seconds later the load is the other way (Except double up the neutral cams and check that the neutral bus temperature is still reasonable).....

author: IanB
author_rank: Super Contributor
timestamp: November 26, 2020, 08:19:03 pm
content: Quote from: opampsmoker on November 25, 2020, 05:50:43 pmIf you consider that the typical mains supply in a residential street or large building in the UK is fed from a 3 phase transformer, with the three phases distributed across the various loads/consumers, then it is pretty much impossible for the three phases to be balanced. Each phase has its own collection of loads which can be turned on or off independently. It would be a miracle if all the loads were somehow the same.
usbanana - magic smoke reduction device - Page 1
Forum section: electronics / general

author: joeyjoejoe
author_rank: Frequent Contributor
timestamp: September 03, 2020, 10:30:58 pm
content: USB is great - endless 5V power supplies to be used on many projects. As a result, I design a lot of things with it, and you might as well.While there are many USB power meters to show current/voltage information, I wanted a way to use the current-limiting features of my power supply when I first plug in a design so nothing goes boom. Assuming that's the case, I can then also see what sort of current draw the device has.The banana spacing is adjustable as well since it would appear the standard for banana plugs is not a standard in some cases. There is a spot for either through-hole or SMT resistors across data lines if your device is smart enough to check for that.

author: joeyjoejoe
author_rank: Frequent Contributor
timestamp: November 19, 2020, 04:09:44 pm
content: It's on github now to make your ownhttps://github.com/gcormier/usbananaHad some eevblog folks reach out and did some tests.. can ship the parts if needed in north america for cheap via lettermail, it seemed to cross the border no problem.
ebike charger cutting off too soon. - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: November 08, 2020, 04:50:16 am
content: Hi all,ive a homebrew ebike,compromising a 1kw controller runing a 2kw hub motor,the battery is homemade,16s/7p,they are new samsung cells with a new bms rated at 35amp,the issue i have is my charger outputs 67.2v which i belive is normal,but my battery charges only to 65.4 volts then the charger cuts off,ie goes from red to green,any idea why this is,i guess it sould realy disconect at 67.2??,cheers paul m3vuv.

author: tom66
author_rank: Super Contributor
timestamp: November 08, 2020, 11:53:55 am
content: When the batteries are charging on the charger, is the output 67.2V?It is normal for Li-Ion batteries to immediately drop in terminal voltage once charged, by about 25-50mV.

author: The Soulman
author_rank: Super Contributor
timestamp: November 08, 2020, 12:44:06 pm
content: I'd say that's a good thing, 67,2V (4,2V/cell) only gives you a few percent more capacity compared to 65,4V (4,09V/cell).With the benefit of increased battery life and a lower chance of setting your house on fire.

author: opampsmoker
author_rank: Regular Contributor
timestamp: November 13, 2020, 11:02:11 am
content: One reason for premature disconnection can be one layer of cells getting out of balance with other layers....eg one layer may reach 4.3V, whilst the others are only 3.9V or whatever, then charging woudl need to stop......a good balancer will stop the rogue layer getting high in voltage and allow the whole pack to charge to higher voltage.
Huge trove of info on all aspects of EVs  - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 08, 2020, 03:19:19 pm
content: Reports on all sorts of interesting stuff - only skimmed it but lots of ares covered, some in very fine detail :https://www.energy.gov/sites/prod/files/2020/06/f76/VTO_2019_APR_ELECTRIFICATION_FINAL_compliant_.pdf

author: nctnico
author_rank: Super Contributor
timestamp: November 08, 2020, 03:26:35 pm
content: These aren't reports, this is just an overview of research projects receiving US government funding for doing research in the next couple of years. It's just a bundle of ideas at this stage.

author: coppice
author_rank: Super Contributor
timestamp: November 08, 2020, 03:39:42 pm
content: I think its just a bundle of the statements of project goals used to get government funding for these research projects. They seem to be funding some interesting projects, but its results that count.

author: f4eru
author_rank: Super Contributor
timestamp: November 09, 2020, 11:18:07 pm
content: Quite some interesting stuff.I love good modern power electronics, and the smell of burning MOSFETS (Magically Obliterated Smoke and Fire Emitting Transistor)Quite interesting how many researchers focus on inductive charging, and impressive efficiency they achieve, but IMHO, we have really better problems to solve....Funny how in 500 pages, only one paper mentions Tesla. (except when speaking about magnetics)
Overload protection is not possible for a Boost PFC control chip? - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: November 26, 2020, 10:55:08 pm
content: Hi,Would you agree that a PFC control chip cannot have overload protection? Ie, that kind of typical overload protection that signals overload if vout is below regulation level for more than say 800ms.This is because PFCs have a slow Vout feedback loop…as such, in cases of sudden no_load_to_full_load switching, the vout may sink below regulation level and stay below regulation level for perhaps a few seconds. This is normal for a Boost PFC and cannot be used as a reason to shut down.As such, all PFC chips should really have a separately implemented overload protection circuit implemented by the user? (and tailored to the application) Would you agree with this?

author: TimNJ
author_rank: Super Contributor
timestamp: November 27, 2020, 12:47:05 am
content: For a regular old boost PFC controller?They almost always have OCP built in, monitoring voltage across current sense resistor, either MOSFET drain current or inductor current, depending on the topology. This is a relatively fast protection, often cycle-by-cycle. Just because the PFC boost voltage droops during load step does not necessarily mean its overloaded.
power supply build - Page 1
Forum section: electronics / general

author: classified
author_rank: Contributor
timestamp: September 12, 2020, 02:07:48 pm
content: hi all i am building my own rov sub but i would like to power it from the sufice i have seen a solution from bue robotics but i find it a little exspensive and was wondering if it is possible to build something simmeler but i am haveing trubble finding any infomation on doing anything simmelerbasicaly you have a surfice unit that produces about 400vdc at 4aand you have a vheical side unit that turns the 400vdc at 4a to about 15v at arond 60a

author: bob91343
author_rank: Super Contributor
timestamp: September 12, 2020, 06:54:58 pm
content: I think you need to repost this. Your message is not clear. It's important to observe rules of grammar and spelling to give your post integrity and enable us to understand it.

author: zenerbjt
author_rank: Regular Contributor
timestamp: September 20, 2020, 09:43:02 pm
content: Sounds like a job for a full bridge with current doubler rectifier output, and synchronous rectifiers.However, you could also do this with Vicor modules.Eg a BCM or two to drop the voltage, then DCM modules to do the regulation to 15V.Whats the spec on the 15v...(+/-)?If you look on the vicorpower website, you'll see all the robot power supplies that they do.For your spec of 400v input and 15v, 60a output...then what about two or three of these in parallel...DCM4623TD2K17E0T00http://www.vicorpower.com/products?productType=cfg&productKey=DCM4623TD2K17E0T00....they have a "droop" output sharing algorithm, so go well in parallel.But check their no load voltage.

author: pwrtrnx
author_rank: Newbie
timestamp: October 25, 2020, 05:37:42 am
content: We have done 800V to 3.7kV on the upper supply side - converted to 350V 40A on the sec side ( ROV applications )it can be done - you just need to know a lot about power electronics to make it quiet and efficient400VDC to 15V 60A is quite doable too - a lot of extant mains power supplies have an internal 400V busSo if you can find some of these say 15V 25A - then 3 of these should do the job ...
Push pull isolated supply needs a filter inductor at input? - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: October 01, 2020, 12:33:35 pm
content: Hello,We need a ~11V, 4mA isolated supply and so are using LT3999 & 78602/1C push pull transformer.(LTspice sim and PDF schem attached.)We have placed the inductor L5 at the input since otherwise its drawing very sharp current spikes from the supply. Why does the datasheet not recommend such an inductor?

author: pwrtrnx
author_rank: Newbie
timestamp: October 25, 2020, 12:44:51 am
content: unfortunately you have put L5 in the worst possible placeit should go just after the input sourcethen the caps on the supply can supply the "current spikes" - have you measured them?Why have they not mentioned it in the data sheet ? that is anyone's guess ...
Lab testing of Tesla 2018 battery chemistry cell cycling performance - Page 1
Forum section: electronics / general

author: trobbins
author_rank: Frequent Contributor
timestamp: October 20, 2020, 02:20:01 am
content: Link to DRES webinar:https://youtu.be/pOQQTwYkg08First presentation is interesting for possible 'after-life' applications of vehicle battery packs.Second relates to 2018 cell chemistry used by Tesla. Nice to see some lab results at 20C showing pretty stable degradation of cell capacity of large cycle numbers, and with different cycle parameters. I doubt real-life detailed capacity degradation data will become available for large in-car battery pack statistics, or storage applications, along with statistical data for many years on service life and failure statistics, as all that is valuable proprietary data that feeds their warranty and marketing, so this may be as close as we get to a practical picture where temperature, encapsulation, vibration, and peak discharge stress would also impose on service life performance.

author: f4eru
author_rank: Super Contributor
timestamp: October 20, 2020, 05:20:46 am
content: 2018 Tesla (company) battery chemistry or 1918 Tesla (man) battery ?

author: trobbins
author_rank: Frequent Contributor
timestamp: October 20, 2020, 07:10:20 am
content: Doh - a centaury behind the times!Yeh, lab testing started in late 2018, so the assumption is they used the cell chemistry that Tesla was using in their cylindrical cells at that time, but packaged the cell in to a small 200mAh format to fit their testing facilities.

author: tom66
author_rank: Super Contributor
timestamp: October 20, 2020, 09:13:44 pm
content: It's worth noting that Jeff Dahn is funded (openly) by Tesla. He's clearly a battery expert, but do consider where his funding is coming from.

author: trobbins
author_rank: Frequent Contributor
timestamp: October 21, 2020, 01:44:02 am
content: For sure this is all funded - its a big job for any lab to set up and maintain that level of long duration cycle testing on a wide array of parameters on just one cell chemistry. It provides one piece of the jigsaw for warranty and servicing and life-cycle battery management, which will grow as a management issue as the number of sold cars increases. Tesla or some after-market third party need to leverage whatever useful capacity remains out of every battery pack, long after any car use has finished.I haven't kept up with the Tesla battery pack replacement/ownership process, and what options are looming, but expect that area of activity will approach much sooner than any Tesla industrial battery situation where battery use may not be as onerous even for daily arbitrage or level shifting.
GM Battery Chemistry "Pending breakthrough" - Page 1
Forum section: electronics / general

author: OldEE
author_rank: Contributor
timestamp: November 20, 2020, 05:14:26 am
content: I was taught that a breakthrough should never go into a project plan because, well, it may not happen so...GM announced that a "pending breakthrough" in battery chemistry will reduce costs, extend range etc. in 5 years.Gave me a good laugh even if it may prove true.https://apnews.com/article/business-chemistry-detroit-electric-vehicles-0928d1d1eda8fd9c6bdccb60dc6d348bLarry

author: Kjelt
author_rank: Super Contributor
timestamp: November 20, 2020, 07:27:49 am
content: Yes always the same.Batteries are hot and investors are willing to pay.So hundreds of R&D startups but also mature companies show off their promising marketing bullshit to get their money.I have been reading it for the last 5 years and still no major breakthrough.Last year: Li based batteries that last a million miles, great but what thry did not say is that it is double the weight and charges at four times slower the speed. And so on.There are marketing wankers that really think the batteries will also follow Moores law, that would be great if it did from the 80s we could now power an EV for 100000 miles on a button cell.
Solar panel lower temp when loaded? - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: October 27, 2020, 05:03:40 am
content: Say we have a typical dark coloured solar panel in full sunshine. It's going to get hot after a while because it's dark colour doesn't reflect as much as a light colour. Then we put an electrical load on it, say 100 watts. This 100 watts gets sent elsewhere, so does that mean the solar panel will now run the equivalent of 100 watts cooler than if there was no electrical load?

author: Berni
author_rank: Super Contributor
timestamp: October 27, 2020, 06:46:34 am
content: Yep because until you connect your load the solar panel itself is the 100W load.You can think of solar panels as having a parasitic zenner diode just like MOSFETs. Once you let the voltage on its terminals raise too high the solar panel starts leaking current between the terminals internally, and just like on a zenner diode this current turns to heat.So to get the most efficiency out of a solar panel you need to strike a balance between having more voltage output and loosing more current internally in the panel.
Vintage Electric Cars - The Briggs and Stratton Hybrid - Page 1
Forum section: electronics / general

author: DougSpindler
author_rank: Super Contributor
timestamp: October 20, 2020, 05:30:37 pm
content: Anyone remember the The Briggs and Stratton Hybrid Electric Car?https://youtu.be/ftMxCehD08U

author: tom66
author_rank: Super Contributor
timestamp: October 20, 2020, 08:19:35 pm
content: Pretty interesting and ahead of its time. I wonder if it had regenerative braking, and how the battery was charged, whether it was by the engine or via a wall outlet or both.I do think the idea of sticking a cca 30hp engine in a car and topping up the acceleration with an electric motor makes a lot of sense.

author: f4eru
author_rank: Super Contributor
timestamp: October 21, 2020, 12:16:51 am
content: itmadea lot of sense, 10 years ago.Now everything with an exhaust pipe is very very close to obsolete.

author: DougSpindler
author_rank: Super Contributor
timestamp: October 21, 2020, 01:13:35 am
content: Quote from: f4eru on October 21, 2020, 12:16:51 amWhat about 35 - 40 years ago when the car was actually built?

author: f4eru
author_rank: Super Contributor
timestamp: October 21, 2020, 01:42:24 pm
content: 40 ears ago it was pretty much ahead of it's time.With lead acid, it was very heavy, but could have been a good option with a halved battery...
Is this the deadliest inverter & transfer switch install of all time? - Page 1
Forum section: electronics / general

author: cpuerror
author_rank: Regular Contributor
timestamp: October 13, 2020, 12:27:45 am
content: (Edit: Sorry linked to the wrong video)It's installed right under a sink in an RV, with green ground wire used for both neutral and line, mains wires soldered together, I could go on but you should watch the video.
How to simulate non-even series parallel battery arrays of LiPO cells? - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: October 09, 2020, 06:56:34 am
content: Hi,LiPO cells in big seires parallel arrays dont share current equally when the array is loaded.....how do you simulate this best?Is the best way just to put different value resistors across each cell?

author: JohnG
author_rank: Frequent Contributor
timestamp: October 09, 2020, 01:19:32 pm
content: Perhaps, though I would also have different resistors in parallel as well, in order to emulate leakage, and include different capacities, as all these play into cell imbalance. I think the best you can hope for is that you will get some idea of possible behavior if you run a bunch of simulations ala Monte Carlo.I once, quite some time ago, developed a quasi-physical/chemical model of a cell to look at cell imbalance effects. The goal was to optimize the size of a cell balancing system for a satellite power systems. All agreed that this was a great idea that would help them nail this problem, but it was a waste of time (except for my education!). The problem was that the the distribution of parameters and the change with cell usage was very expensive to obtain since it amounted to life-testing many more cells than would ever go into space.I would guess that it's cheaper, but still expensive and time-consuming, to do the experiment now, and I'm sure car companies have lots of data on this. I also bet it is highly proprietary and closely guarded data. That's why I think the best you can hope for is to run a few sims with crude models, because it will be difficult to do better without good cell models and the associated parameter data.John
LTC4359 / LTC4367 - Page 1
Forum section: electronics / general

author: zanzeoo
author_rank: Contributor
timestamp: October 04, 2020, 11:16:39 am
content: Hi thereI would like to desing a circuit that can handle multiple 12V battries, the load is not quiet heavy , 4-5 Amps maxthe idea is to use an ideal diode like LTC4359 or LTC4367My needs are :Each circuit would share the load if possible and will have to monitor the battery ( UV lock and reverse battery polarity protection ) and switch of the controller in case of such thing happen.The LTC4367 is interessting but i doubt about using it as an ideal diode ( see page 15 )The LTC4359 would be perfect but no UV . Figure13 page 14 an exemple very interessting for my needs but i dont think the comparator will handle reverse polarityAny ideas ?

author: mairo
author_rank: Unknown
timestamp: October 06, 2020, 04:21:39 am
content: LTC4359 should work for you, see figure 6 on page 10.I have used it in similar - 12VDC automotive design with much higher currents. The UV on that system was done via the shutdown pin of the IC with external circuitry.
Robot power with batteries - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: October 03, 2020, 07:38:20 pm
content: Hi,We are going to power our robot with a 6S/6P array of LiPO cells.Is it best to parallel 6 series strings of 6 cells....Or to have 6 Lipo cells in parallel...and then put six of these in series?

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 04, 2020, 01:57:34 am
content: They're electrically equivalent, but I prefer making series strings and joining them since the balancing links between strings carry little current. So you make the strings and busbars with high current conductors, but the balancing links can use fairly thin wire, most likely 18-22AWG. I suggest a ring topology for the balancing links so a break in one doesn't cause part of the pack to lose balancing.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 04, 2020, 08:36:51 am
content: Always parallel cells. Paralleled cells act as one bigger cell. Then put these paralleled groups in series.Now, if it suits your workflow, you can physically construct series strings first, and if you then connect all the taps together, the results is exactly the same.Do not build series strings to only connect them in parallel at the ends. This requires duplicating BMS for each string, massive complexity increase for nothing.Similarly, never add connectors, relays or whatever for parallel connections. The connections need to be permanent, and reliable. If in-situ paralleling can happen, you need smart isolation switches and DC/DC converters to first balance the cells or strings to be connected to the same State-Of-Charge. This is again so complex that it's not worth doing.
bms and charging - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: October 02, 2020, 05:01:51 pm
content: just something im wondering about,i have a 16s lion pack,can i charge it directly from by battery string minus and the plus of the pack with the b- disconnected from the bms,sort of bulk charging if you like,then switch the b- to the bms for cell balancing,ie does the bms feed the battery thru the power output,or the thin balance wires,or are these just used for balancing?,cheers in advance.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 02, 2020, 05:28:36 pm
content: No one can answer you without knowing what the pack is.Only follow the manual and the documentation by the battery pack manufacturer.

author: m3vuv
author_rank: Super Contributor
timestamp: October 02, 2020, 06:35:37 pm
content: its one im building,16s 10p

author: maginnovision
author_rank: Super Contributor
timestamp: October 02, 2020, 08:44:38 pm
content: Ok what's the bms and how are you constructing/connecting it all? More detail is better if you want an answer.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 03, 2020, 06:21:27 am
content: You need to do enough homework so you can answer your own question.Start by looking at the video posted in the "e-bike Battery Fire" thread and think about if you are ready to start designing lithium ion battery packs. Consider this carefully.
Automotive electric wires/cables/harnesses - Page 1
Forum section: electronics / general

author: bobsaccamano
author_rank: Contributor
timestamp: September 24, 2020, 10:41:57 pm
content: Hi,I'm looking for automotive-grade High Voltage and Low Voltage electric cables for the following situations:1. Connect 48V battery to DC-DC 12V converter. Max. current 12A.2. Connect 12V DC supply to a DC motor (via Delphi connector), max current 12A.3. Low voltage (5V) cables with low current (< 300mA).Where can I find automotive-grade wires especially for 1. and 2. in small quantities? (in Germany/EU)Thanks.

author: Zeyneb
author_rank: Regular Contributor
timestamp: September 25, 2020, 09:47:55 pm
content: Hi,I'm a citizen from the Netherlands. I buy automotive electrical stuff including wires from a small webshop in the Netherlands. It is called:Rick Donkers Auto Electricswww.rdae.nlHis reputation on Google maps is very good. I am also very satisfied with what he can offer. In contrast with many other suppliers he does actually know what he is selling and he adds meaningful comments/instructions on his product pages.He sends to Germany too. If you can bear the dutch language (maybe with some help of google translate) you can add this as an opportunity to be able to buy this stuff for your car.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 26, 2020, 03:10:08 am
content: Quote from: bobsaccamano on September 24, 2020, 10:41:57 pmYour local auto parts store.

author: elektrolitr
author_rank: Contributor
timestamp: September 30, 2020, 08:48:11 am
content: The type used in most automotive wiring is called FLRY. You shall find it easily in both local stores (either electronic and automotive) and on the web.It is available in all reasonable cross-sections and colors.

author: Zeyneb
author_rank: Regular Contributor
timestamp: September 30, 2020, 09:29:58 pm
content: Quote from: elektrolitr on September 30, 2020, 08:48:11 amSo what is a good online store specifically? Even if it is not in English.
Sandy’s Tesla Battery Day Follow-up. Plus More! - Page 1
Forum section: electronics / general

author: DougSpindler
author_rank: Super Contributor
timestamp: September 30, 2020, 02:18:24 am
content: Interesting discussion on the design for cars and efficiency.Is this possible? To have a solar powered mass produced affordable car? (16:40)Anyone have any idea what he's got in the "Dave Box"? He calls it the fountain of youth for EVs. (24:50)

author: Simon
author_rank: Unknown
timestamp: September 30, 2020, 06:54:56 pm
content: Don't double post....
Tesla Powerpack and grid inverter and PV installation - Page 1
Forum section: electronics / general

author: trobbins
author_rank: Frequent Contributor
timestamp: September 28, 2020, 01:26:02 pm
content: Just checking if anyone can confirm that Tesla bi-directional grid inverter connected to a Powerpack and a PV farm would effectively operate as a dc tri-port configuration.As I understand it, the Power pack operates battery pods connecting to a common dc bus. Each pod includes a dc/dc converter to manage the battery voltage. But it also seems that the dc/dc can act with a MPPT function for a dc tri-port configuration where both the PV array DC and the Powerpack DC busses are connected in parallel to the grid inverter. The grid inverter could also act as MPPT control of DC bus if only PV dc was connected (ie. no battery port connected).Subtleties would be to ensure PV power flow was only uni-directional, but the interesting bit would be how they manage the connections of DC buses, especially the PV dc bus in order to provide zero current switching under all PV conditions, and how they would coordinate the MPPT function and if it could actually just be done by the battery dc/dc.
output load resistor in the flyback design - Page 1
Forum section: electronics / general

author: hesam.moshiri
author_rank: Regular Contributor
timestamp: September 12, 2020, 06:16:24 pm
content: in some flyback designs, we can see a resistor at the output that consumes some amount of current, something like a default load, however we can not see this resistor in some other designs.When this resistor is necessary and how it should be calculated?

author: David Hess
author_rank: Super Contributor
timestamp: September 13, 2020, 01:09:15 am
content: I have not noticed that before. Maybe it is there to absorb the leakage inductance spike if the winding is unloaded which would otherwise cause insulation breakdown from excessive voltage.

author: hesam.moshiri
author_rank: Regular Contributor
timestamp: September 13, 2020, 06:35:31 am
content: Quote from: David Hess on September 13, 2020, 01:09:15 ambreakdown of the primary? most of them (with the load resistor) use the RCD clamp to absorb the spikes.

author: David Hess
author_rank: Super Contributor
timestamp: September 13, 2020, 11:10:00 am
content: Quote from: hesam.moshiri on September 13, 2020, 06:35:31 amNo, I was thinking of breakdown of the secondary.

author: rbola35618
author_rank: Frequent Contributor
timestamp: September 14, 2020, 07:15:01 pm
content: Most flyback if left unloaded will peak detect and the voltage will rise to a dangerous level and may damage your load. So you never operate a flyback without a load.

author: zenerbjt
author_rank: Regular Contributor
timestamp: September 16, 2020, 07:36:07 pm
content: ..thats right the leakage inductance ring in the secondary side, breaks over the output diode and charge pumps the output up in voltage above the regulated value, ...if its no-loaded.Also, some old controllers always switch even when there error amp output has gone to its "saturated low" position...so you always get some power throughput, even in no-load...which obviously then needs "drinking off".

author: hesam.moshiri
author_rank: Regular Contributor
timestamp: September 19, 2020, 07:01:04 am
content: Quote from: rbola35618 on September 14, 2020, 07:15:01 pmHow much the current consumption should be?

author: hesam.moshiri
author_rank: Regular Contributor
timestamp: September 19, 2020, 07:51:05 pm
content: Quote from: blueskull on September 19, 2020, 07:27:49 amHow much current the load resistor should consume?

author: Oleander
author_rank: Contributor
timestamp: September 30, 2020, 01:53:36 pm
content: When designing such a flyback, provide a place for a load resistor that can dissipate appr. 0.5% - 2% of nominal output power.Testing it on a bench will tell you what power it should handle. Maybe it will not be necessary at all.
16s lithium ion battery charge voltage - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: September 26, 2020, 10:17:12 am
content: Hi all,i am building a 16s battery pack for an ebike,im using 18650 cells,these are standard cells not the phosphate ones,ie 3.7volt per cell,i have a charger that outputs 67.2 volts,will this work for these type of batterys ?,i just wondered if i need to buy a new charger,i already have the bms.,cheers m3vuv