rolls
10 mW
Hi, can anyone tell me a definitive C rate for INR18650-29E cells? I have read 1.5C, 3C, 6C, 8C. Which one?
Samsung INR18650-29E C rate
- Thread starter rolls
- Start date
rolls
10 mW
That's why I asked. Else where on cell_mans site they are rated 3C max, another site rates them at 3C continuous.
rolls said:
Are you sure? I think you might be mixing them up with the NCM cells.
Edit: I'm going through his batteries now and can only find max 2C rating. He recommends a 40 amp controller on the 25 amp hour pack 1.6 C. On another battery he recommends 1.5 C but the max rating is still 2C.
I'd go with a max of 1.5 C. If they are even remotely close to the Tesla Panasonic batteries they should last two decades or so if you are careful with them.
Russell
1 MW
From what I've read they are 3C max. In any event you really don't want to run them at that level for very long because the voltage sags significantly under load. For example I have a downtube type battery that is made up of the cells in a 4Px13S arrangement (11Ah) and the voltage will sag 4.5V under a 25A (about 2.3C) load.
There's a test of the cells here:
http://www.candlepowerforums.com/vb/showthread.php?384132-Test-Review-of-Samsung-INR18650-29E-2900mAh-(Blue)
-R
There's a test of the cells here:
http://www.candlepowerforums.com/vb/showthread.php?384132-Test-Review-of-Samsung-INR18650-29E-2900mAh-(Blue)
-R
rolls
10 mW
From the em3ev site "These new cell types are the High Energy INR18650-29E (NCA Cell, 3C Max rated cell, with approx 2.8Ah nominal Capacity)", but on the same page (small triangle bat) it states "The 29E cell is 2C rated and we recommend a Max of closer to 1.5C.".
As I said previously another site had rated them at 3C continuous, so who is right?
As I said previously another site had rated them at 3C continuous, so who is right?
1C continuous max
3C Max short bursts
The C max and continuous C rate all depends on blah blah blah. How long can the burst last? The best thing to go off of is IR when selecting a cell than then determine how long you can burst for by keeping track of cell temps in use. The temp probe needs to be connected to metal not the plastic casing. If the cells are getting too hot at full throttle (for however long your needs are) you selected the wrong cell or didn't make you pack big enough (just add more cells in parallel to distribute the load). If your cells don't every get even warm your pack is heavier than it needs to be and you should have selected a higher energy cell rather than a higher power cell, but at least you can always fix that problem with a bigger motor/controller
Be aware a battery has a lot of thermal mass and peak temp has a delay
What we really need is a third input for battery temps on our controllers or cycle analyst.
7.4 Initial internal impedance
Initial internal impedance measured at AC 1kHz after Standard charge.
Initial internal impedance ≤ 45mΩ
SAMSUNG SDI Confidential Proprietary
Spec. No. INR18650-29E Version No. 1.1
1. Scope
This product specification has been prepared to specify the rechargeable lithium-ion cell
('cell') to be supplied to the customer by Samsung SDI Co., Ltd.
2. Description and Model
2.1 Description Cell (lithium-ion rechargeable cell)
2.2 Model INR18650-29E
3. Nominal Specifications
Item Specification
3.1. Nominal Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.1. Typical Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.2. Minimum Capacity 2,750mAh (0.2C, 2.50V discharge)
3.2. Charging Voltage 4.20 ± 0.05 V
3.3. Nominal Voltage 3.65V (0.2C discharge)
3.4. Charging Method CC-CV
(constant voltage with limited current)
3.5. Charging Current Standard charge: 1,375mA
3.6. Charging Time Standard charge: 3hours
3.7. Max. Charge Current 2750mA (not for cyclelife)
3.8. Max. Discharge Current 2,750mAh (continuous discharge)
8250mAh (not for continuous discharge)
3.9. Discharge Cut-off Voltage 2.50V
3.10. Cell Weight (max. (g)) 48g
3.11. Cell Dimension Diameter(max.) : 18.40 mm
Height(max) : 65.00 mm
3.12. Operating Temperature
(Cell Surface Temperature)
Charge: 0 to 45°C
Discharge: -20 to 60°C
3.13. Storage Temperature
1 year : -20~25°C (1*)
3 months : -20~45°C (1*)
1 month : -20~60°C (1*)
Note (1): If the cell is kept as ex-factory status (50% of charge),
The capacity recovery rate is more than 80%.
note after storing them at 45C for 3 months at half charge they only guarantee 80% of initial capacity
3C Max short bursts
The C max and continuous C rate all depends on blah blah blah. How long can the burst last? The best thing to go off of is IR when selecting a cell than then determine how long you can burst for by keeping track of cell temps in use. The temp probe needs to be connected to metal not the plastic casing. If the cells are getting too hot at full throttle (for however long your needs are) you selected the wrong cell or didn't make you pack big enough (just add more cells in parallel to distribute the load). If your cells don't every get even warm your pack is heavier than it needs to be and you should have selected a higher energy cell rather than a higher power cell, but at least you can always fix that problem with a bigger motor/controller
Be aware a battery has a lot of thermal mass and peak temp has a delay
What we really need is a third input for battery temps on our controllers or cycle analyst.
7.4 Initial internal impedance
Initial internal impedance measured at AC 1kHz after Standard charge.
Initial internal impedance ≤ 45mΩ
SAMSUNG SDI Confidential Proprietary
Spec. No. INR18650-29E Version No. 1.1
1. Scope
This product specification has been prepared to specify the rechargeable lithium-ion cell
('cell') to be supplied to the customer by Samsung SDI Co., Ltd.
2. Description and Model
2.1 Description Cell (lithium-ion rechargeable cell)
2.2 Model INR18650-29E
3. Nominal Specifications
Item Specification
3.1. Nominal Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.1. Typical Capacity 2,850mAh (0.2C, 2.50V discharge)
3.1.2. Minimum Capacity 2,750mAh (0.2C, 2.50V discharge)
3.2. Charging Voltage 4.20 ± 0.05 V
3.3. Nominal Voltage 3.65V (0.2C discharge)
3.4. Charging Method CC-CV
(constant voltage with limited current)
3.5. Charging Current Standard charge: 1,375mA
3.6. Charging Time Standard charge: 3hours
3.7. Max. Charge Current 2750mA (not for cyclelife)
3.8. Max. Discharge Current 2,750mAh (continuous discharge)
8250mAh (not for continuous discharge)
3.9. Discharge Cut-off Voltage 2.50V
3.10. Cell Weight (max. (g)) 48g
3.11. Cell Dimension Diameter(max.) : 18.40 mm
Height(max) : 65.00 mm
3.12. Operating Temperature
(Cell Surface Temperature)
Charge: 0 to 45°C
Discharge: -20 to 60°C
3.13. Storage Temperature
1 year : -20~25°C (1*)
3 months : -20~45°C (1*)
1 month : -20~60°C (1*)
Note (1): If the cell is kept as ex-factory status (50% of charge),
The capacity recovery rate is more than 80%.
note after storing them at 45C for 3 months at half charge they only guarantee 80% of initial capacity
rolls said:
Ah ha, I was wondering which page it was on. Yeah, I'd be pretty confident that is a mistake and he meant 2C max. The 1.5C is what I would go with regardless. The specs that the manufacturer give are often optimistic.
999zip999
100 TW
Just be kind. I run a A123 20ah pack at 30 a. But 40 would fine.
melodious
100 kW
What motor & controller will these cells be used on? At what speeds?
Terrain type & topography?
Style of bike (i.e. MTN, bent)?
Will you be carrying loads of gear?
The first year I ran my 50v 25ah 29E's @18-25amps continuous with some off the line spurts & small hills closer to 30-40amps. Still too soon in my battery's lifespan if I have degraded them, but highly highly doubt it. I'm still getting the same resting voltages after a full charge. And the small 3-4 volt sag has always been present since purchase. The sag resolves itself once the load is off.
Terrain type & topography?
Style of bike (i.e. MTN, bent)?
Will you be carrying loads of gear?
The first year I ran my 50v 25ah 29E's @18-25amps continuous with some off the line spurts & small hills closer to 30-40amps. Still too soon in my battery's lifespan if I have degraded them, but highly highly doubt it. I'm still getting the same resting voltages after a full charge. And the small 3-4 volt sag has always been present since purchase. The sag resolves itself once the load is off.
LikeToRideMyBike
100 W
- Joined
- Jan 9, 2016
- Messages
- 151
So what is the continuous c rating for a 52v14.5ah Samsung 29e pack with a 30a bms; using a motor with a 25amp controller? And how did you come up with this figure? I'm sorry for interrupting this discussion with this question... I'm getting so frustrate because for days I've been trying to figure out the equation for how to get the continuous c rating of any given battery pack... I'm a bit lost. 
But I know I need to run these Samsung 29e cells between 1 and 2c. I've learned that much from this discussion.
thanks
But I know I need to run these Samsung 29e cells between 1 and 2c. I've learned that much from this discussion.
thanks
wesnewell
100 GW
Samsung rates the 29E cells at 2.75A continuous and 8.25A burst. That equates to 0.95C continuous and 2.85C burst using the rated capacity of 2.9ah. Anything else is just BS someone has made up. I wouldn't run them over 1C for any length of time if you want them to last.
wesnewell
100 GW
There may not be any noticeable physical problem, but you can be sure there is an internal problem. Eventually he will notice a decreased capacity and premature failure compared to cells that are run within the specs. To me, that's a problem.
www.recumbents.com
10 kW
Like2ridemybike - If you want to play it safe and run at 1C, this means you should run at 1x your pack's ah rating of 14.5 ah, or about 15 amps continuous. 2C would be 2 X 14.5 = 29A.
Warren
Warren
999zip999
100 TW
There's a lot better cells out there get a 10amp cell or better.
DrkAngel
1 GW
INR18650-29E spec sheet - from Samsung
≤.5C charge
1C maximum charge (with severe cycle life deterioration!)
≤1C continuous discharge
≤3C brief surge
≤.5C charge
1C maximum charge (with severe cycle life deterioration!)
≤1C continuous discharge
≤3C brief surge
Perth_ebiker
100 mW
2 decades ???Joseph C. said:
I cycle my batteries (30q cells daily) and expect around 700-1000 cycles. I got 4 years out of my last pack but that was before I rode everyday. I only charge to 4.1v
How many cycles would you guys expect out of cells these days ?
Pajda
10 kW
Perth_ebiker said:
It depends mainly on average DoD. Generally from my tests I can say that after 1000 cycles at 50% DoD with 0,5C-1C rate almost all modern 18650 cells still have more than 90% of their initial capacity. If I have a look at currently running test of Samsung INR18650-29E so it have 96,5% of initial capacity after finished 250 cycles.
Hello guys. Admiration for the knowedge of this board. Apologize for my bad english. I need little help.
I bought Razor E300 scooter. It is with 250W 24V motor and old heavy 2 pcs 12v 7Ah batteries.
I plan to upgrade it with 18650 batteries from this site: https://eu.nkon.nl
- Samsung INR18650-29E 2900mAh E7 - 8.25A
or
Panasonic NCR18650PF 2900mAh - 10A
I will write you my plan and questions, hoping someone to help little
So for 24V motor i need ~ 7 x 3,6V batteries. 7P
For max Ah i will put 8 or 9 in a row so i can get for example 8 x 2900mAh ~ 23Ah 8S
My worries are:
1. How can i measure what is the peak consumption of the motor?
2. When i put more batteries in a row, how to calculate the maximum drawing current?
with this example 7p8s
I think if the motor draws /just a assumption/ 20A, devide it to the count of cell in a parallel so 20A/7= less than 3A
So these batteries INR18650-29E 2900mAh E7 - 8.25A will be ok? Or should i buy batteries with more drawing current 10A, 15A?
Thanks in advance!
I bought Razor E300 scooter. It is with 250W 24V motor and old heavy 2 pcs 12v 7Ah batteries.
I plan to upgrade it with 18650 batteries from this site: https://eu.nkon.nl
- Samsung INR18650-29E 2900mAh E7 - 8.25A
or
Panasonic NCR18650PF 2900mAh - 10A
I will write you my plan and questions, hoping someone to help little
So for 24V motor i need ~ 7 x 3,6V batteries. 7P
For max Ah i will put 8 or 9 in a row so i can get for example 8 x 2900mAh ~ 23Ah 8S
My worries are:
1. How can i measure what is the peak consumption of the motor?
2. When i put more batteries in a row, how to calculate the maximum drawing current?
with this example 7p8s
I think if the motor draws /just a assumption/ 20A, devide it to the count of cell in a parallel so 20A/7= less than 3A
So these batteries INR18650-29E 2900mAh E7 - 8.25A will be ok? Or should i buy batteries with more drawing current 10A, 15A?
Thanks in advance!