Charging to 80% without a Satiator

The part where it says Chances of explosion, lipos are safe from explosion. Ask the many people who burnt there garages and cars down if lipos don't explode from overcharging.

That's because there are lots of STUPID people in this world who use LiPo's without any BMS and overcharge and burn their house. There are millions of phones, cameras, other toys with LiPos and they don't burn down the house because they have some sort of BMS that prevents overcharging. When you use a battery cell without any BMS and do stupid stuff, it should burn down their house. More proof for Darwin theory. We need to get rid of those stupid people. Even 18650 will catch fire. Any battery can catch fire if treated poorly or punctured. I used the schematic to show the difference in structure and little bit of functionality.

Please stop spreading wrong information saying all Li-ions are Lipo family. It creates a lot of confusion and spreads wrong information.

Please include references of vetted scientific articles as references. Don't just say I am the distributor of a LiPo that was shipped from elsewhere.

Lipo is not a different chemistry. What do you think is in your bike pack?
You can believe what you want, but that chart is very wrong.

This kind of comments lead to lot of confusion and mistrust. People are always suspicious of internet information because they know it is not properly vetted and verified.
What is normally considered as LiPo in the scientific world is different from regular 18650 cells. The chemistry and packaging can be different. and Graphene is just a marketing term.

Let's not try to do chest bumping with macho-masculinity about who is right. This is not personal and we should spread scientifically true information and credit those who did the work.

The Li-ion battery technology is a culmination of decades of research by thousands of people. The real heroes of people like John Goodenough, who is considered the father of Li-ion battery, it is him who discovered the Cobalt based cathode that was commercialized by Sony in the 1990's and led to the growth of li-ion technology.


Here he is receiving the highest honor from President Obama.


If you are interested in knowing the science behind using polymer electrolytes in the LiPo battery, I have attached vetted scientific article [PDF files below]. This can be beneficial to understand the nuances.
Lipo battery.gif
 

Attachments

  • Polymer electrolytes for LiPo battery.pdf
    1.8 MB · Views: 849
This is getting totally overplayed. Perhaps Felix can square us away?
3.6-4.1v per cell and it’s as good as it gets, conserving battery life, with the current run of 18650 batteries. Go for a ride, start a savings can in the garage. Everytime you ride, stuff at least a Buck away. Chances are you’ll have enough to nearly replace, come the day.

And for anyone thinking LiPo isn’t popular, check out endless_sphere. That lot was riding on LiPo before this lot knew about eBikes. No I’m no expert. Hundreds of sales, a dozen builds, and I learn something daily. There a propensity on forums, with nom de plumes especially, to to from zero to expert in 60 minutes of googling.


And George, I’m beginning to see your point.

I'm Feliz not Felix, I hope the information you're spreading is more accurate than your ability to spell a name correctly.
 
Thank You Ravi for your #37 write-up! You have cleared up some of my misconception.
The information you've provided a clear explanation on the density differences between Lipo(lithium Polymer) and Li-Ion 18650 batteries!


One reason for some of the ongoing confusion in this blog is due to messages that are incomplete in the way data is being interpreted and written.

We have a need to clarify references to data with specifics as best as can be stated. If we are going to refer to a previous post, make sure to reference the post number!

Mark, I believe the information you have been presenting has been unintentionally confusing.
Understanding basic Lithium battery densities -as clarified by Ravi's write-up made that clear.
 
I had to double-check - we are in the Juiced Bikes Forum, and the juicedbikes website states:
"Uses the latest in Lithium-Ion battery cell technology" for their battery packs.

So is the chart I created, that uses 42.1v as 20% and 51.5v as 80% correct? It sure seems so based on the low voltage cutoff Juiced recommends and the max charge voltage also given.
Surfstar: Please be sure it is understood which battery pack capacity values you are referring to so that we blog readers understand that you are referring to a specific size of a battery, whether 36, 48, or 52 volts etc. For instance, I can only surmise that the values you list "42.1v as 20% and 51.5v as 80% correct" are for a 48 volt battery.
 
Surfstar: Please be sure it is understood which battery pack capacity values you are referring to so that we blog readers understand that you are referring to a specific size of a battery, whether 36, 48, or 52 volts etc. For instance, I can only surmise that the values you list "42.1v as 20% and 51.5v as 80% correct" are for a 48 volt battery.

Correct. I made the chart for my CCS which is now shipping with a 48v 12.8Ah battery.
 
This thread got out of hand and I apologize for being part of it. The initial question is about voltage percentage. If you want to run your pack down to say 25%, on a 48 volt or 13s battery, your resting voltage after you turn your bike off, should be 13x 3.75 = 48.75. Or close to that. When you ride your bike, your cell voltage will sag down while your are using your power, when you stop using your power, your voltage will rise back up. Your BMS has a Low voltage cutoff or LVC. This cutoff is probably unknown to us but, what it does is use a set number, say 42 volts, when your battery sags down to 42 volts, your BMS should cut power. When it cuts power, your voltage should rise back up to 48 volts. Now this is just an example of how you can use the charts. This is also where you can make sure your only using say 75% of your battery or whatever percentage you want to use. The chart I posted is correct for resting voltage. The juice chart is correct for when you should cut power while your battery is under a load. So I believe the juice chart numbers refer to a recommended LVC and not your resting voltage. The only way your going to know how much of your battery you're using is if you use the chart I posted as a reference for resting voltage. I hope this makes sense and let me know if you guys have any questions on this topic.
Ravi
li-ion is term used for a hard metal case battery. Lipo is short for ( li-ion pouch ). The 2 can share the same chemistry or not. It depends on the market they want to target. But today's 18650 cells, the good ones anyway, use a Cobalt manganese formula. The lipos I sell, also use a cobalt manganese formula. Cobalt is the stronger of the 5 types and why they use it for markets that have a higher power requirement. The main difference between the two is only the casing. And yes there are 5 types of li-ion.
.http://synergyfiles.com/2015/09/5-types-of-lithium-ion-batteries/ This is the last i'm going to say on the subject of li-ion and lipo.
 
All I can say is thank God for the ignore button. Ravi as usual is a breath of fresh air and an expert.
 
This is where it gets interesting. It turns out that what marketing departments are calling “Lithium-polymer batteries” are actually “Lithium-ion polymer” batteries.

What the heck does that mean?

In short, it means that so-called “lithium-polymer” batteries are almost exactly the same as lithium-ion batteries, but they are instead contained in a flexible polymer casing. It’s basically just a repackaged lithium-ion battery... Sorry, I'm with Mark F on this one
 
It turns out that what marketing departments are calling “Lithium-polymer batteries” are actually “Lithium-ion polymer” batteries

This is where Chinese marketing companies falter. They mislabel things and exaggerate the C-ratings.

Most established companies like Samsung, Sony, LG Chem etc, label Li-ion or Li-polymer depending on what it is and have detailed spec sheet, C-rating sheet to go with.
Since most of the cells are made in Asia, many small vendors just slap labels that are most appealing. It is true that Li-ion cells can made to look just like LiPo packs but these are 2 different things.

It is widely known that many Chinese-made cells post exaggerated values for energy density, C-ratings, lifecycle. There are 100's of threads on this on Endless Sphere forum.
There is a whole forum dedicated to discussing this: https://endless-sphere.com/forums/viewforum.php?f=14

In actuality, every chemistry has its own plus and downsides.
 
Mark had the correct chart and the one I always use. I can't address the chemistry issue, I just get upset over all the conflicting, confusing and false information. I'm in Canada and a 52V/ 21AH battery is nearly $2000,
someone giving bad advice or circulating incorrect charts just isn't right.
 
Mark posted the correct chart. We aren't discussing C-ratings, cycle life or false advertising. we're talking voltage. The voltage values/state of charge for Lipo and Li-ion are the same
 
This is where Chinese marketing companies falter. They mislabel things and exaggerate the C-ratings.

Most established companies like Samsung, Sony, LG Chem etc, label Li-ion or Li-polymer depending on what it is and have detailed spec sheet, C-rating sheet to go with.
Since most of the cells are made in Asia, many small vendors just slap labels that are most appealing. It is true that Li-ion cells can made to look just like LiPo packs but these are 2 different things.

It is widely known that many Chinese-made cells post exaggerated values for energy density, C-ratings, lifecycle. There are 100's of threads on this on Endless Sphere forum.
There is a whole forum dedicated to discussing this: https://endless-sphere.com/forums/viewforum.php?f=14

In actuality, every chemistry has its own plus and downsides.


I have a lot of experience using lipo cells flying RC machines and know first hand of the hazards of false claims/labels especially the propensity to overstate C ratings.
 
Mark posted the correct chart. We aren't discussing C-ratings, cycle life or false advertising. we're talking voltage. The voltage values/state of charge for Lipo and Li-ion are the same

Right, I don't think that was ever in question.
 
Mark posted the correct chart. We aren't discussing C-ratings, cycle life or false advertising. we're talking voltage. The voltage values/state of charge for Lipo and Li-ion are the same

As Feliz said, voltages are not the problem.
4.2V is a standard upper limit for most 18650 and LiPo's. 99% of the cells and chemistries have 4.2V/cell as the upper limit. This way, the internal impedance of the cell is kept low and get more lifecycles.
So, most charts are based on 4.2V/cell reading.

The basic fact is both (Li-ion 18650's and LiPO's) are different things in construction and contents like electrolyte.
None of the mainstream ebikes use LiPo pack. They all use 18650 pack, not LiPo. Calling all of this as LiPo is completely false peddling of information.
 
Lithium polymer is the same as lithium-ion, just in different packaging. This is why full state of charge voltage is 4.2 volts per cell for each and going below 3.6 volts RESTING VOLTAGE per cell will reduce cycle life for each. There are varying degrees of quality with both and the low impedance/resistance cells will always perform better. This is a silly argument
 
Last edited:
Back