[Solved] Source for "button" or "flat" top 18650 Li-Ion

@inq That's funny, I have heard nothing but bad from ebay. In fact I just got some ESP32's that were the wrong number of pins. Any issues I have had with ali have always been resolved, I kept the goods thry refunded me the money. Almost half their website is to do with customer service, fraud protection etc. I have never shipped anything back, Canadian postal rates exceed most ali purchases. If late it's free.

For ebay if I had to ship it back at my shipping cost it would exceed the cost of goods. It used to be possible to ship across the border for a couple bucks, but now they are all the same. If I have to get it from the USA I make sure I use US Postal/Canada Post, the fees are only $10, used to be $5 not long ago, but couriers charge waaaaay more than that just for admin1 or admin2 or admin 3 etc etc. I HATE THEM and forget about shipping anything back.

I just had an item on Amazon I wanted to return, turns out it comes out of China. They don't want it back and offered me 50% off. Now I have 2, one will be up for sale soon, t's one of those USB load testers

Don't want no dog byte!

I just found out I had a login to AliExpress from the days when I owned stock in Alibaba.  It was one of the "sorta" something-better-than amazon ideas I had.

Hmmm, I notice I really did NOT mention more than "project."  The purpose was to power multiple RPi when outside the grid - and soon the Pico and its projects(?) that I hope to soon get working the way I desire.  And, of course, my flashlight that is now serving dual purpose:  Night - light; and Day - electronic toys while being charged by solar or wallWart as available.

Presently I have one of the newer multiStage BatteryTender chargers that can do SLA, AGM, ..., and now IifePO4.  No testing though.

I'll take a look at the device you showed.  If I acquire one, I'll probably PM you when I get into trougle if that works for you?

Geeze, now I am getting to be an "almost" battery expert who is very dangerous due to the low-visibility on the knowledgeHorizon!  "Ok, I promise, no nails!"  See, "I have the first lesson memorized."

The second lesson was, "protected buttonTop ONLY!"

It is a wonder I haven't disintigrated myself ... .

This is the closest to the picture you posted: https://www.amazon.com/Intelligent-Multifunction-Battery-Balance-Charger/dp/B07HNBQKNK/ref=sr_1_6?crid=E36IY0FANOCL&keywords=imax+b6+charger&qid=1651374085&sprefix=imax+b6%2Caps%2C251&sr=8-6

It is priced right.  So, maybe

@darup Amazon links don't work on this forum. just text past them AND wrap them in double quotes, NOT the quote box on the toolbar. Like this

"amazon link here"

One more thing about button tops. ALWAYS insert the positive end first flat on, if you slide it down the end contacts it will short. The case is negative and both touch at once. Ask me how I know!

@darup One more forum note, if you don't click reply at the bottom we don't necessarily know who you are talking to.

Posted by: @zander

who you are talking to

I see ->Reply "Quote thumbUp and Report at the bottom of your message.

At the bottom of "Leave a reply"  I have, in a BLUE rectangle ADD REPLY.  The last time where I became involved in the wrong conversation I did the Reply.  For this reply I am using the ADD REPLY.

The rhyme-and-Reason is a point that I am missing.  Did I do this correctly in replying to your message?

Posted by: @zander

"amazon link here"

Wrap the link in quotes! Got it, I hope!

@darup The procedure is to click the Reply on the message you are replying to. That's the icon beside quote, like, report. 

Then when you finish typing the Add Reply box is the send it command.

@zander 

okay, I used the other "Reply" -- Not the blueBox containing ADD REPLY

Posted by: @zander

Ask me how I know!

If the "reply" I am using is the "correct" reply {{ it put an @zander in the LEAVE REPLY box which the REPLY in the blueRectangle does not}}

Do tell me how you, "Know!"

@darup I think you got it. As to how I knew, because the ADD REPLY isn't visible to me until I hit Reply.

Posted by: @darup

I'll take a look at the device you showed.  If I acquire one, I'll probably PM you when I get into trougle if that works for you?

Links - Most forums just let you add a working link.  This one digs out a picture to show you and hides the link.  I do not know why Bill took that route.  At first, I had a problem with it.  I wanted forum members to get details about the product.  With a picture, if the product name isn't clearly shown, they have no way to research the product.   I've gotten used to the way this forum displays it.  I'm not here to push Amazon, et al on anyone.  It's merely a convenient launch pad.  I assume everyone will make their own decision about where they buy it.  Amazon, ebay, Ali, Walmart, brick and mortar.  To each their own.  I gave my experience.  I did not pass on hearsay - "I read...".  

"The Device" - The LiPro Balancer is an old model and one commonly used in the electric RC models (planes, boats and cars).  It is designed to charge the multi-cell packs.  It is overkill for individual cells.  Packs MUST be balanced and maintained.  I also did not do any research on others devices.  I've never had any trouble with it, but there may be something else newer, better, cheaper out there now.  Do your due diligence.  

To capacity test a cell, the device must discharge all that electricity.  In the case of this device, it just uses a heater and the aluminum case fins dissipates the heat.  It integrates the area under the dissipation curve while it discharges it and gives you an actual Amp-hour capacity that you can compare to the cells "new" capacity.

It can only dissipate so much current, so it is only good up to a certain size cell (18650 is small enough).  It can't "really" be used on the large cells like these.

Lithium Based Batteries - These are large LiFePO4 cells.  They are starting to be used in RVs, boats and house systems.  In their own right they are completely safe (nail test)... but that is completely misleading.  If negligently used, they are very dangerous.  Shorting the terminals with say... a crescent wrench... will pass multiple THOUSANDS of amps through the wrench and near instantly melt it... so fast that it actually splatters molten steel.  

Even though small, the 18650 should be shown the same "respect".  They can easily and instantly melt our hobby level wiring.

Compared to Alkaline or lead-acid, Lithium based batteries are non-trivial to use.  When multiple cells are used together they should be matched and balanced with what's called a top-balance or bottom-balance.  They should be kept balanced by a BMS (battery management system).  BMS's are electronic devices needed to keep them balanced.  If the battery bank is misused or the cells not balanced and matched, they will fail.  The BMS in laptop batteries are a great example of this failure.

I am by no means an expert, but I have read many hundreds of hours of white papers, theoretical and practical papers and a member on a forum dedicated to using these.  (kind of like this forum).  The members range from simple DIY home owners to electrical technicians to PhD theoreticians and I'm not bashful about asking questions or asking for clarifications from them.  It is a very interesting and complex field!

Posted by: @inq

I am by no means an expert

Hey, I am interested.

If I am not sure, I take it under advisement.  I have some lists.  One that is short that worked for me.  Another list worked for others but not me. The last list is of things that are supposed to be the solution that are kept because someday under the proper conditions I might need a "last resort" and it might work!

Compared to what I know, whether you are an expert or not, you certainly have given me a lot of useful input about this subject that is working so far!  It is amazing how something as simple as a battery can have a complex Dr Jeckel/Hide personality.  I have a much greater respect for the 18650 now;  I did not even think/know/consider before.  Said another way, "You teach Good!"

Thanks for sharring. Hope you do not mind as I learn more as I deal with RV, drone, solar, etc. batteries if I check in with questions and concerns?

you and @zander have given me a greater appreciation.

As for small batteries... just ask here.  I'll give it my best shot.

As far as Big Batteries...

Here is the battery build I published on a boat forum I haunt.  I did it as more of a tutorial as all the people there were used to dealing with Lead-Acid.  It goes into the Pros and Cons in nauseating detail... about how I purchased them and the pain and suffering of getting just the cells from China to the final assembly, balancing and capacity testing done by industry standards.  It cross references to extensive links on a couple of other forums, white papers, theoretical doctoral papers.  There is easily several hundred hours worth of reading or skim the pictures in an hour.

Edit - Guess it would actually help if I added the link

https://www.macgregorsailors.com/forum/viewtopic.php?t=28149

@inq 

Keep forgetting which REPLY to use.  Caught it this time.

Got it. Bookmarked the URL/Link.

Duplicated here for my edification: " https://www.macgregorsailors.com/forum/viewtopic.php?t=28149 <"

This also tests my personal reminder to put quotes around an address in this forum so I do NOT get a picture of someSort,

Posted by: @darup

This also tests my personal reminder to put quotes around an address in this forum so I do NOT get a picture of someSort,

Yeah, there's several idiosyncrasies on this forum compared to others I haunt. 

@davee was just cluing me into that...  

He indicated that it was Amazon links that were converted to pictures.  I asked him if he knew if any other sites caused the picture.  So far any links to other forums or our personal websites don't seem to get the pictures... they stay usable links.  Maybe, he'll reply here since using the @ version of someone's handle will notify them you used their name in vein.  

I know the big battery can be rather a daunting undertaking.  How to eat an elephant?  If you have specific questions about it, you can also ask me here.  If a short answer, I'll just do it here.  If I think it's a long topic and I remember writing it somewhere, I'll try to give you a link.

VBR,

Inq

@inq Most of the RV community look to Will Prowse on Youtube. He has tested probably every battery, solar panel, MPPT on the market and takes the batteries apart. Very educational. However, it does tick me off I was born too early, has a nice new house, Tesla etc all from Youtube.

@zander 

Yes, his forum is extensive and where I launched many a discussion and got my cells from one of the "Group Buys".

YouTube - Yeah... they want someone prettier than us old guys!