Scarfing Power from 5V Pin

@inq do you have an example?

I know Apple is hyper security conscious and also greedy but inder Tim they have started to act a little more human.

@inq It looks like only chrome and derivatives is supported. Back to the closed era again, we know how that works out. Isn't it weird that IBM is gone, but the hardware lives on in the Mac and true Mac is gone, it's all *nix now. 

Hi Ron @zander & @inq,

  Re: your 18650 questions, I am far from qualified in the subject, but offer the following as working hypotheses until something better comes along ... treat with as many pinches of salt as you can find! Inq may wish to comment.

the difference between a 'protected' and 'unprotected' 18650 cell.

A protected cell has a small circuit in series with the 'actual cell' and one of the terminals, probably the positive one, that limits the maximum current flow. It is aimed at reducing the chance of the cell catastrophically destroying itself when shorted, but I, for one, would not wish to be near a charged cell, whilst it is being shorted. I have the impression the circuit is based on a FET, but have never seen a circuit.

BEWARE: I have also never seen a 'technical specification' .. so in some cases, it may be a fraudulent claim or inappropriate/inadequate circuit. Large manufacturers must know what they are making, but they seem to very shy about publishing it.

An unprotected cell has a direct connections between the 'actual cell' and the terminals.

One has flat ends and one has an end with a nipple

As you say, some cells have two flat ends, others 1 flat end and 1 end with a nipple. In marketing terms, there may be a correlation between the physical appearance and whether they are protected or not, but I certainly would not rely on it. Treat protection and shape as two 'independent' factors to consider - do not assume that the shape tells you anything about the internal contents or properties of the cell.

have you seen the 5,000, 9,900, and 19,900 mAh versions of a cell still measuring 18mm x 65mm?

Luckily, I haven't had that much dental surgery 😉 .. (I hope you are feeling better now.)

Cell chemistry and technology is still developing, but the amount of charge a cell of given size can hold is limited by the amount of 'chemical stuff' you can fit unto that volume, and cells, excepting some frauds, are near 100% filled.

Small improvements are usually possible by tricks like reducing the amount of 'structural support', such as insulators, connections, and so on, but these are in the few per cent world, unless serious compromises, usually drastically reducing the charging and discharging rates, are made - and even then, I have the impression, changes are modest.

Doubling, tripling, etc. the capacity requires a rethink of the basic chemistry ... probably not based on lithium-ion.

Anyone can print silly numbers on a plastic sleeve ... unfortunately the cell inside is unable to match them! It is frequently claimed that many cells on the market are 'rejects' from the big manufacturers, with a new sleeve. I cannot verify this claim, but it has a plausible feel, especially with the more extravagant claims.

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As I say above, these comments  are only based on my 'impression' so far ... I accept no responsibility for errors or differences from reality.

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Best wishes and treat all cells with great respect. Dave

@davee Actually that is almost exactly or is exactly what I think. I will post a picture of the so-called 5,000 mAh cells beside the unlabeled cells. Same exact size the unlabeled are I think 2400 or might be legitimately as high as 3400. I need to find out the real numbers today and will post back.

I recently exchanged emails with a local store specializing in the real 18650's so will try to get some answers from them. They did say the 19,900, 9,000 and 5,000 are BS. What I don't know for sure is what is the true highest legitimate number.

I recently accidently (forgot) inserted the negative end first then the end with the nipple. You likely know that is a no no and whaqt happened next. Yes, it shorted since the cell outer covering is at -ve and is very close to the +ve nipple. The big springy contacts made contact with both surfaces and BOOM. The rule is ALWAYS insert +ve nipple end first! I knew that but on that day was sloppy.

Why not use a dedicated 5v supply that is rated for all of the amps required?

And use it for 5v everywhere?

If there is noise on it, use another fully regulated & filtered for the Logic use...  and use the big PS for the other parts.

Just brainstorming...  I'm no expert...

@joelyddon Which project are you referring to? Mine is otdoors so battery operated.

Ron,  I was trying to direct my reply to INQ, the starter of this...

If it's all battery powered,  USB power is battery?

I would think if battery powered, have enough batteries in parallel to supply all of the amps required...  and if that doesn't work, have 2 battery packs... one for the logic ss section and one for the power-hungry section.

As I said, I'm no expert...  just brainstorming...  ideas...

@joelyddon Actually I am not positive what @inq is up to. In my case, a game camera, so power to take a picture is one thing but to send it by WiFi takes a LOT of power and isn'r priority one as the picture is first saved to a TF card. In order to conserve power, I am thinking of using deep sleep and using the RTC to bring the camera out of sleep around dusk. Still in the design stage but it all sounds doable.

Posted by: @joelyddon

Ron,  I was trying to direct my reply to INQ, the starter of this...

If it's all battery powered,  USB power is battery?

I would think if battery powered, have enough batteries in parallel to supply all of the amps required...  and if that doesn't work, have 2 battery packs... one for the logic ss section and one for the power-hungry section.

As I said, I'm no expert...  just brainstorming...  ideas...

 

Yeah... I think I really confused the issue by showing the 18650 battery shield.  😆  The project that I have in mind that prompted the O.P. and @davee and @zander convinced me how to wire it.  I'll do a Frizting later if I proceed, so here's a crude sketch...

• The whole premise is that Lithium based batteries last longer if they aren't charged to 100%.  
• The USB cable is spliced.
• The ground and logic lines continue to the device to charge (cell phone).
• The ground and power are split off to power the WeMos ESP8266.
• The power is also routed through the Relay to be toggled by the WeMos.
• The WeMos will host the web server with web pages.
• The Phone will browse to the web page.
• The web page using Web API to get battery state information will pass that to the server (on the WeMos).
• The WeMos will monitor the battery state and will open the relay when the desired charge is reached, say... 80 or 90%.
• If on the charger continuously... like I tend to do since I use it as a hot spot, I could have the server, kick on the relay at say... 30%.

@inq The oft quoted statement that LI batts should not be charged to 100% is not accurate. The correct statement is to not leave then at 100%. Charge to 100 as long as there is any load that will start bringing them down. I have one program to cycle between 75% and 95% (cuz my programmer won't allow 100%) and as solar increases, the 75% will slowly drop (It's part of the *nix OS that runs the Inverter/Charger) and then next winter slowly increase to about 85%.

Another program I have when power outages seem possible is 'keep at 100%' this is used for short periods until the danger is passed to ensure lot's of power.

Far more PG batteries are ruined by too deeply discharging or over charging than LI by any reason, LI is simply much more robust when they contain a BMS to stop foolish people from trying to ruin them.

Posted by: @zander

Actually I am not positive what @inq is up to.

🤣 😆  No one can ever tell!  Keep 'em guessing.

Posted by: @zander

he oft quoted statement that LI batts should not be charged to 100% is not accurate. The correct statement is to not leave then at 100%.

If you want to make that claim, you'll need to back it up with references.  I could probably find a dozen papers stating what I have written above, but that would force me to dig through my notes.  A simple Internet search gave me this one... (Charging to only 65% SOC gave 4000 cycles versus 100% SOC gave 300-500)

https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

@inq My manufacturer gives me a 10 yr warranty, 3000 cycles to 5000 cycles. No pre-conditions re 100% BUT we know they stick a few extra batteries in the case so I will never reach 100% but I doubt that is the whole story. Much more likely anything negative to do with LI is created and spread by PB agents. Having once worked for a market leader then going into competition I saw first hand how the old king fights. Very nasty.

In any case, I am sure we can agree any battery lasts longer if kept away from max and min.

@inq Just a quick follow up. My batteries were installed almost exactly 2 years ago. My battery monitor reports I have 20 full cycles on them. I can't tell what your chart says about my battery since my per cell full charge voltage is 2.4V.

It sounds like maybe macs and spys if not apples and oranges.

Also it is rumoured they put 105AH in a case labelled and programmed as 100 so we never actually get to 100%, only 95%. All I know is that the VP of technology in more than one open session when asked how to treat the batteries has said 'give em hell'. He backs that up with a 10yr warranty.

Posted by: @zander

My batteries were installed almost exactly 2 years ago. My battery monitor reports I have 20 full cycles on them. I can't tell what your chart says about my battery since my per cell full charge voltage is 2.4V.

Your battery vendor could play a number of games to keep their batteries in the sweet spot and thus successfully promise and deliver 3000-5000 cycles.  As you said... you can't exactly see what's inside... extra cells, BMS configuration that does one thing and reports another up to the end-user.  I recall in one articles of some expert in the field that had seen a number of companies promise those kind of numbers... he stated many of them went out of business, because even they didn't understand how to protect them adequately.  He also mentioned it is less of an issue now as they've learned a great deal about them.  

I'm not sure what 2.4V per cell would be...

Li-Ion - 100% SOC is 4.2 volts

LiFePO4 - 100% SOC 3.65 volts

Maybe it's one of these other chemistries...

https://nordkyndesign.com/lithium-battery-banks-fundamentals/