Panasonic NCR18650GA disclosed specs, and 30Q Samsung cells

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Mar 29, 2016
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383
Hi,
I am considering this battery:
http://www.ebikes.ca/shop/electric-bicycle-parts/batteries/b5216-lim-dt.html

I wanted to find more detailed specs about those cells, but the official ones are very, very shallow.
For example, it writes only "standard" charge rate at 0.5C, and I am interested in:
1. The maximum continuously allowed charge rate.
2. The maximum peak charge rate. (Regen peak currents)

I rely heavily on regen on all my E-bikes in the hilly city I live, and I can reach braking powers in the order of 1000W for the small-powered bike, to above 2000W on the "armed to the teeth" one.
My current batteries are A123 20Ah prismatic cells, which are perfect for regen (up to 4C continuous), but sucks at mechanical properties like vibration-tolerance, their weight and volume.
Do anyone know where to find detailed specs about the NCR18650GA like A123 provides?

I also consider the 30Q cells by Samsung, which em3ev sells. Their packs are also cheaper, too.
Searching for information about them here vs the other 18650's gives you a jungle of information, with overwhelming page results which I have no time to read... (especially that most topics go off-topics eventually!) Also, none which I found talks about what I asked.
So I thought to ask here, if you recommend the Panasonic NCR18650GA ones, or the 30Q by Samsung?
My 1st priority is the ability to consume large regen currents, 2nd is the life cycle count.
 
keep in mind that the higher rate you charge cells at, the harder it is on them. since regen braking is only momentary, rather than continuous, in most applications other htan long hills, that might not matter to the cells.

however, it might matter to the bms on the cells--it has to be designed to handle the currents and the heat produced by them in the charge/discharge fets.

you also have to make sure the pack you get has a bms that charges and discharges thru the same port, or else the bms cannot control the pack under regen, and the potential for damage exists, especially when the pack is full or near full, when high charging currents are not normally desirable.


there's some cell info in these posts
https://endless-sphere.com/forums/search.php?keywords=Panasonic+NCR18650GA&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
but i don't know if it's what you're after.
 
amberwolf said:
keep in mind that the higher rate you charge cells at, the harder it is on them.

I know that, but that doesn't really answer my question... :|
Most cells have standard charge rate and fast charge rate recommended by the manufacturer. I understand that for those Panasonic cells, the only guaranteed charge rate to achieve the life-cycle count graphs is 0.4C? (1475mA)
For example, I would like to know if I can safely charge the 52V 16Ah battery using 2 Satiators in parallel, with 16A combined current. (Without causing long term damage to the cells). This is a 1C rate, which is fine on most Li-Ions, but no charging documentation on the specs for those Panasonic cells...

amberwolf said:
since regen braking is only momentary, rather than continuous, in most applications other htan long hills, that might not matter to the cells.
I see. I thought that such surge charge current, even brief one, will cause accumulating damage.

amberwolf said:
however, it might matter to the bms on the cells--it has to be designed to handle the currents and the heat produced by them in the charge/discharge fets.

you also have to make sure the pack you get has a bms that charges and discharges thru the same port, or else the bms cannot control the pack under regen, and the potential for damage exists, especially when the pack is full or near full, when high charging currents are not normally desirable.

Regarding the BMS, this is what Justin told me about the Hailong battery with the Panasonic cells:
"There is no cutoff or protection of regen current via the discharge port. So from the BMS side things should be fine."

amberwolf said:
there's some cell info in these posts
https://endless-sphere.com/forums/search.php?keywords=Panasonic+NCR18650GA&terms=all&author=&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
but i don't know if it's what you're after.

You tell me to go into the jungle again? I didn't find the answers I look for and this is why I started a new thread, but I could look more into it. Someone must create an organized Wiki of all the information we collect here! :D
 
There is a wiki, linked in the stickies at the top of every forum, but most poeple just post in threads rather that doing as one of those stickies suggests.

You are always welcome to write wiki articles or edit what's there. :)

I do the search-suggestion links whenever I don't know an answer myself, but have seen it out there in a thread (or what I think is the answer, but can't know if it is the one somoene is looking for). I don't have the time to dig out every answer for every person, so that's usually the best I can do--sometimes if I don't answer, no one does, and at least if i post the search suggestions the questioner gets a direction to go in, rather than no answer at all.
 
But you know the answer to your question ?
The manufacturer said more 0.4C charge will reduce the cycle life....and you want to charge at 1C.
So you can expect reduced cycle life....It wont destroy them, just reduce cycle life.
..But how important to you is a reduction in cycle life, compared to longer charge times and reduced regen rate ?
Everything is a compromise....there is no free lunch in this game. :cry:
 
Hillhater said:
But you know the answer to your question ?
The manufacturer said more 0.4C charge will reduce the cycle life....and you want to charge at 1C.
So you can expect reduced cycle life....It wont destroy them, just reduce cycle life.
..But how important to you is a reduction in cycle life, compared to longer charge times and reduced regen rate ?
Everything is a compromise....there is no free lunch in this game. :cry:

I was thinking that Panasonic just omitted the "fast charge" figure, as part of their "Chinisification", and so there was more work required to fine the missing specs. 8)
So you say that if they show just standard charge of 0.4C, then it's the fastest charge rate regarding the cell's life?
It seems really strange, because I heard that Tesla use those cells (correct me if I am wrong here!), and for car charging you really don't want to wait 270minutes, as the spec sheet say.....
 
thunderstorm80 said:
..... I heard that Tesla use those cells (correct me if I am wrong here!), and for car charging you really don't want to wait 270minutes, as the spec sheet say.....
Tesla do not use the GA cell, they use their own spec version of Panasonic cells,..very similar to the BE or Pf commercial cell.
search / read around the forums, there is much info on it...also on GA cell life.
eg..
https://endless-sphere.com/forums/viewtopic.php?f=14&t=85113&p=1244507&hilit=sanyo+18650GA+cycle+life#p1244507
https://endless-sphere.com/forums/viewtopic.php?f=14&t=91821
 
Passon GAandconsider 30q, abettercell likely with longer life. Following Em3ev’ lead is a smart move. Better builds too! Paul is conservative in rating.
 
Just looked there are some really goo$ prices from em3 in the sale section. Gonna grab one too!
 
tomjasz said:
Just looked there are some really goo$ prices from em3 in the sale section. Gonna grab one too!

I know em3ev, and they definitely have good prices and nice packs.
I wanted to make an order, but it seems they don't ship their product to Israel. (You can't get shipping quote option to Israel)
If someone from Israel reads this, I am curious if were able to order anything from them lately?
 
Get with Micah Toll and Elhaanan on ES FB. I think Elhaanan went to building because of the lack of acesss.
 
thunderstorm80 said:
tomjasz said:
Just looked there are some really goo$ prices from em3 in the sale section. Gonna grab one too!

I know em3ev, and they definitely have good prices and nice packs.
I wanted to make an order, but it seems they don't ship their product to Israel. (You can't get shipping quote option to Israel)
If someone from Israel reads this, I am curious if were able to order anything from them lately?
 

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thunderstorm80 said:
I wanted to find more detailed specs about those cells, but the official ones are very, very shallow.
For example, it writes only "standard" charge rate at 0.5C, and I am interested in:
1. The maximum continuously allowed charge rate.
2. The maximum peak charge rate. (Regen peak currents)

All(!) 3500mAh 18650 cells include Si in the anode, this seems to reduce cycle life significantly and especially reduces charge rates.

Samsung updated their 35E datasheets from 0,5C charging to 1A max charging for cycle life.

So imho(!) those 3500mAh are not a good idea for a system with recuperation.
 
Cephalotus said:
All(!) 3500mAh 18650 cells include Si in the anode, this seems to reduce cycle life significantly and especially reduces charge rates.

Samsung updated their 35E datasheets from 0,5C charging to 1A max charging for cycle life.

So imho(!) those 3500mAh are not a good idea for a system with recuperation.

Any changes in the GA specs? Interesting that more and more are reporting shorter life with GA.
 
Cephalotus said:
thunderstorm80 said:
I wanted to find more detailed specs about those cells, but the official ones are very, very shallow.
For example, it writes only "standard" charge rate at 0.5C, and I am interested in:
1. The maximum continuously allowed charge rate.
2. The maximum peak charge rate. (Regen peak currents)

All(!) 3500mAh 18650 cells include Si in the anode, this seems to reduce cycle life significantly and especially reduces charge rates.

Samsung updated their 35E datasheets from 0,5C charging to 1A max charging for cycle life.

So imho(!) those 3500mAh are not a good idea for a system with recuperation.

This is why it's so hard for me to think of moving away from A123 batteries, which I have.
I rely strongly on recuperation/regen, and rather powerful ones in the hilly terrain I live.
A123 cells have no recuperation limits, no need for any sort of current limit (discharge or charge), and their life-cycle count is huge and more than compensates their initial higher cost. (and it isn't being shortened by fast charge/discharge rates)
Their only con is weight, which again is compensated after two years or so when a parallel aged Li-Ion chemistry is losing it's capacity due to aging/life-cycles and from that point the weight becomes an advantage.
 
thunderstorm80 said:
This is why it's so hard for me to think of moving away from A123 batteries, which I have.
I rely strongly on recuperation/regen, and rather powerful ones in the hilly terrain I live.
A123 cells have no recuperation limits, no need for any sort of current limit (discharge or charge), and their life-cycle count is huge and more than compensates their initial higher cost. (and it isn't being shortened by fast charge/discharge rates)
Their only con is weight, which again is compensated after two years or so when a parallel aged Li-Ion chemistry is losing it's capacity due to aging/life-cycles and from that point the weight becomes an advantage.

LG HG2 can be charged at 4A (continous) per 18650 cell and will last for many hundred cycles under that conditions. (datasheet performance, not my own experience)) If you use it within a reduced SOC window it will last for thousands of cycles.

Even after those many cycles with reduced SOC window and many years energy desnity of that 3Ah cell will still by higher compared to new A123 cells.

NCA cells usually also have better calandar life compared to LFP.

If you want ultra quick charg times LTO is the way to go, but I doubt that you need that for ebikes.

I have tried recuperation up to around 50C and 12A and with a normal bike, normal bike tires and wet tarmac this is around the useful limit just for friction between tire and road (at the rear tire obviously)...

Propably this is higher with electric motorcycles.
 
Cephalotus said:
LG HG2 can be charged at 4A (continous) per 18650 cell and will last for many hundred cycles under that conditions. (datasheet performance, not my own experience)) If you use it within a reduced SOC window it will last for thousands of cycles.

I can confirm that with my own measurement.

100% DoD cycling (4.2V@100mAh cut-off - 2.5V) LG HG2 can do:

0.5C charge - 1C discharge: 1000cycles to 70% nominal capacity (but immediately after that quick death occurs)
1C charge - 1C discharge: 800cycles to 70% nominal capacity (then quck death occurs)

50% DoD cycling (4.2V@100mAh cut-off - 3.6V) LG HG2 can do:

0.5C charge - 1C discharge: 1000cycles to 90% nominal capacity
1C charge - 1C discharge: 1000cycles to 90% nominal capacity
 
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