Samsung 25R/LG 18650HE2/ Sony VTC5 high power 18650 battery

[Nobuo]

Indeed each samsung INR18650 25R is capable of ~35A amps continuously, but in this case the voltage drops ~0.9V respect 1A discharge.

So 120A peaks are completely possible (even till 210A) but not very efficiently of course, heat will be heavily noticeable.

each time you reach 120A discharge, each cell push 20A with a ~0,7V drop. with a considerable amount of heat produced by each cell.

Although the heat generated, this cells are prepared for that, so it will work within you peaks needed

 

[chilau2000]

Indeed each samsung INR18650 25R is capable of ~35A amps continuously, but in this case the voltage drops ~0.9V respect 1A discharge.

So 120A peaks are completely possible (even till 210A) but not very efficiently of course, heat will be heavily noticeable.

each time you reach 120A discharge, each cell push 20A with a ~0,7V drop. with a considerable amount of heat produced by each cell.



Although the heat generated, this cells are prepared for that, so it will work within you peaks needed

Thanks

I've been using a 1.2kwh 18s lipo pack and that capacity seems to be enough for me.

Want to build a similar voltage/capacity pack with 18650 cells.

I may increase to 8p, this will drop peak current to 15a per cell.
The 20s6p config will weigh approx 5kg so will be good to keep the bike light for offroad use.

 

[riba2233]

20A continuos with some kind of cooling

20A peak not for too long (up to 1 minute should be fine, it's not too often) will work without cooling.

 

[scoot-e]

If one were to keep each cell at 3c - 3.5c max continuous for say more than 5 minutes (so approx 7.5a -9a per cell) for a total of 30-35a (5p) are we talking a lot of heat and capacity reduction or is it pretty average/normal would you say?

 

[riba2233]

It shouldn't be a problem, even for prolonged time.

 

[markz]

So the more batteries you put in parallel, the higher the current (Ampere's) will be. And, also the higher the Ah obviously.
Even though the C-rate of the battery itself stays the same.

So if you have a lower C-rate battery, I'd have to google the battery to come up with a acronym the only one comes to mind is 26f and I dont know the specs (I find it hard to find specs on different batteries especially C-rates, and there are so many different types, like the 25r, 26f so on so forth).

Anyway, So if you have a lower C-rate battery....and you want it to OUTPUT the same amps (or more) then a higher C-rate battery, you'd have to put more lower c-rate batteries in parallel to come up with the amps you want for the motor. Whether it be Acont. or Amax on the outgoing conductor (aka wire).

Am I right?

These 25r looks promising as a high discharge battery, I have been eye'ing them for a few days now.

 

[Nobuo]

That's correct. The only thing to aware before purchasing 25R's are if you really need them.

The Amps-hour/cost ratio is not at the level of other NCA cells as 2.9Ah Samsung or Panasonic.

And the most important, if you check carefully several different discharge rate graphs, the efficiency (voltage drop) is extremely similar below 7A as those NCA best Ah/cost ratio. So in some cases it would worth add some parallels and use those other cells

 

[markz]

What are these

NCA cells as 2.9Ah Samsung or Panasonic.

That you speak of?

 

[Nobuo]

Samsung INR18650-29E

Panasonic NCR18650 PF

 

[sn0wchyld]

Indeed each samsung INR18650 25R is capable of ~35A amps continuously, but in this case the voltage drops ~0.9V respect 1A discharge.

So 120A peaks are completely possible (even till 210A) but not very efficiently of course, heat will be heavily noticeable.

each time you reach 120A discharge, each cell push 20A with a ~0,7V drop. with a considerable amount of heat produced by each cell.

Although the heat generated, this cells are prepared for that, so it will work within you peaks needed

20A with a .7 drop is 14W of heat.... per cell. 1.6kw for the pack... not something i'd want to do for very long at all! also means the pack is only 83% efficient (aprox) at that power level (8kw output).
I'd go more in parallel if you can, unless you're talking a few seconds at a time...

 

[spinningmagnets]

For high-drain / high-current, I just found another name, the LG ICR18650-HG2, 3000-mAh, and 20A per cell. I have no experience with these, just vague info from the web.

 

[riba2233]

Same performance at 20A as Samsung 30Q. We are talking about them on forum for a month now :lol: Yeah, those two are the future, we just have to wait for price to drop like it did with lg he2 and samsung 25r:

 

[BoomerChomsi]

I am using 25R for a while now.
I can say: WOOWWW.

Voltages are very stable under load 8)
I was using a 150A bms, but it is not necessary so I have removed the bms.
Voltages drift are almost none 8)

Sometimes I just hook up my Icharger 4010 and and performing a balance charging...

 

[madin88]

Same performance at 20A as Samsung 30Q. We are talking about them on forum for a month now :lol: Yeah, those two are the future, we just have to wait for price to drop like it did with lg he2 and samsung 25r:

tanks for that! i must say wow. they perform really good (if the graphs are true).
do you know if these cells are also NCA?

 

[riba2233]

No reason for graphs not to be real And yes, they are nca, they have to be to get that capacity.

 

[Green Machine]

For high-drain / high-current, I just found another name, the LG ICR18650-HG2, 3000-mAh, and 20A per cell. I have no experience with these, just vague info from the web.

I bought a few extra of these if anyone is interested (a few thousand extra)

I am selling for $4.25 each in quantities of 50. Samsung 25rs for $3.75

 

[sn0wchyld]

For high-drain / high-current, I just found another name, the LG ICR18650-HG2, 3000-mAh, and 20A per cell. I have no experience with these, just vague info from the web.

I bought a few extra of these if anyone is interested (a few thousand extra)

I am selling for $4.25 each in quantities of 50. Samsung 25rs for $3.75

hey mate
can you look at shipping cost for 300 to australia? cheers

 

[Green Machine]

right now i am keeping battery shipments in the united states...maybe later will offer international shipments of batteries.

 

[piwhy]

Hello,
Does someone tested the high power capabilities of these cells in the other way, in charge ? I mean fast, to ultra fast charge ?
The Samsung INR18650 25R can handle 35A continous in discharge, what's it worth in the other way ? What about the LG ICR18650-HG2 or Samsung 30Q ?

 

[riba2233]

Okashira did some quick charge on 30Q cell, you can check it in 30Q topic. I wouldn't recommend it, it shortens cell life, but now and then it's ok.

 

[piwhy]

Okashira did some quick charge on 30Q cell, you can check it in 30Q topic. I wouldn't recommend it, it shortens cell life, but now and then it's ok.

Yes and nothing comparable for example with 26650 A123, which can be easily charged at 6C. There are still not any nmc/nca 18650/26650 cell rated over 200wh/kg capable to face with high power lfp cells ?

 

[riba2233]

Well no, but since they have half the volume and half of C rate, it kind of turn out to be similar, eg. two 25r have same volume as one a123 26650, and together they can output similar current. Still not so high, but it's just matter of choosing what's more important to you.

 

[BoomerChomsi]

Is it bad for my 25R's to charge up to 4V and not using for a few days or week(s)?
Sometimes this happen to me, due time lag to ride my bike to work...

 

[Punx0r]

That should be fine. Storage voltage for a LiCo cell is 3.8V.

 

[riba2233]

I wouldn't use more than 3.9, even 3.8 for optimal storage voltage.