Can you make your own lithium batteries?

[Gypsy Freedom]

on the goal zero yeti. if the specs of all the parts work for a particular persons need, then they might not be that bad. but if someone is using the full power of the battery each day they will have a hard time charging it back up with the included charge controller. if it is not a good prepackaged fit, it is often more cost effective to build your own system

be wary of the open box discounts, no return options and only half the warranty. full price for a new one of what was mentioned is closer to $1000 and still only comes with 1 year warranty.

do the research and match up what it can do to what you want it to do. then decide

 

[IGBT]

It is true the open box only has a 6 month warranty but people on this thread were talking about used cells and those probably have zero warranty.

 

[Travelmonkey]

I agree one should be cautious re: open box products. One good rule is to buy from mfg (via their ebay or amazon store).

 

[justawfulgamer]

If someone ends up buying batteries lmk your source.

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[XERTYX]

I have considered building a small 4S4P project based on what I have learned in this thread IF the drill motor BMS/charger I linked works without a charge controller with the junk batteries I mentioned. So I started looking on amazon. I searched 18650 battery i believe. 

The first 3 results or so was a package deal for $17.99 with 6 18650 9800mah batteries, a dual wall charger, and a tac light @ over 1000 lumens. 1200 perhaps. 

That seems like a good deal on batteries and youd have a free flashlight and wall charger for the flashlight. I didnt look any further for them there are probably better deals out there. But for tinkering under $20 for 6 batteries and a tac light and charger that's where I would start

 

[geogentry]

The first 3 results or so was a package deal for $17.99 with 6 18650 9800mah batteries

After you sure about that mah rating? 18650 are usually somewhere between 2500 and 3000 mah.

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[XERTYX]

That's what the amazon page said.
For a more serious build maybe this would be better.
100X 5000mah 18650 batteries according to the description $67.95
https://www.ebay.com/itm/Lot-Garber...hargeable-Battery-For-Flashlight/202503866315

 

[XERTYX]

After you sure about that mah rating? 18650 are usually somewhere between 2500 and 3000 mah.

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LED 1600 Lumen 18650 Flashlight with 6PCS 3.7V 9900mAh Rechargeable Battery and Charger,Ultra Bright Adjustable Focus and 5 Modes https://www.amazon.com/dp/B07QTZV32V

 

[geogentry]

The Eilong battery is made by:
Changzhou Yufeng vehicle company
Changzhou, Jiangsu, China
Factory claims they are only 2600 mah.
The real ones are blue.
The ones on Amazon are yellow and claim 9600 mah. Wild guess is they are fake.




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[geogentry]

Those batteries on Ebay claim to be 5000mah. According to Sara Yan, portable power supply solution advisor at Li- ion batteries the maximum mah that has been achieved in the laboratory, for 18650 batteries, is 3500mah and it is not stable.

I can find no source of manufacturer for that brand name of battery. But the claim of 5000 mah 18650 battery would make me say fake.

Sorry for delay in response took a while to do the research.

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[Wabbit]

...Wild guess is they are fake...

What was the giveaway?

 

[geogentry]

Take your time when buying 18650 batteries. Do enough research to know they are real. Amazon and Ebay can not possibly verify or police the sellers of millions of products. Find out the reputable names and try to stick to those brands.

And to build the setup that you talked about would have required you spend more than $20.

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[geogentry]

What was the giveaway?

mah. But I didn't just want to throw out an opinion without some kinda facts. Facts are solid, opinions are like noses most everyone has one.

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[justawfulgamer]

Those batteries on Ebay claim to be 5000mah. According to Sara Yan, portable power supply solution advisor at Li- ion batteries the maximum mah that has been achieved in the laboratory, for 18650 batteries, is 3500mah and it is not stable.

I can find no source of manufacturer for that brand name of battery. But the claim of 5000 mah 18650 battery would make me say fake.

Sorry for delay in response took a while to do the research.

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Agreed. Those are fake.

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[XERTYX]

That's unfortunate that amazon allows sellers to make impossible claims. I know that they cant possibly police the whole market but seems as though they'd have a bigger net than that. Maybe I've finally found the platform to sell my get rich quick scheme. Dehydrated water.

Yes I know my project would have cost more than $20 but if someone just wanted to tinker with them I was saying $20 gets you in the door. Worst case scenario you have a $20 flashlight.

 

[B and C]

Or a $2 flashlight that cost $20. Could be worth it for the experience though. I would not keep them anywhere near something combustible though. If the cheap BMS goes???

Edit to add: Remember those Samsung phones that burst into flames on their own without being plugged in? I really think it was because people were rooting them and removing some of the BMS software when they didn't know what they were doing.

 

[XERTYX]

So assuming the Ebay lot are 2600mah and were actually safe to use that means you could have 25 parallel sets in 4S configuration. That would be a 65Ah battery for roughly the price of a 29DC walmart battery. Still might be worthwhile for someone. Less than 68 cents a cell is tempting.

 

[XERTYX]

Or a $2 flashlight that cost $20.  Could be worth it for the experience though.  I would not keep them anywhere near something combustible though.  If the cheap BMS goes???

Edit to add:  Remember those Samsung phones that burst into flames on their own without being plugged in?  I really think it was because people were rooting them and removing some of the BMS software when they didn't know what they were doing.

True enough. But I'd give $17.99 for a bright flashlight. I live in the woods I can never have too many flashlights. Haha.

IDK if the BMS is controlled by the software or not. I've rooted dozens of phones and devices. Never had one catch fire. In fact I actually fixed a few that WERE over charging and undercharging by rooting and removing batterystats.xml from it so that it had to recalibrate and build a new xml file.

 

[B and C]

Never rooted a device. I just live with the space that the bloatware takes up and if running, doing a force stop on it.

So there has to be software somewhere controlling the charging to build an xml file. The battery didn't do it on its' own.

 

[XERTYX]

You're absolutely right. There is software that manages the charging. Its built into android itself. Now I dont put it past samsung to have built into their kernel a proprietary set of parameters that were lost when you flashed a new ROM onto it post root.

Like I say though. I have had 3 or 4 phones that would have been garbage if I hadnt rooted them. The xml file cant be removed otherwise and so eventually the battery would have been toast and throw the phone away. But whatevs. I havent rooted this one. Yet. And it's a samsung. It claimed to have hotspot on its And does. But the service provider locked the apn settings. A little root magic fixes that. But oh well.

Anyway I dont know enough about lithium to speculate.