17ah Samsung 35E at 30A

Batteries, Chargers, and Battery Management Systems.
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Em3ev battery with Samsung 35E vs. UnitPackPower battery with Sanyo GA

Post by Pizzabroodje » Nov 26 2018 12:10am

I want to purchase a battery pack for my BBSHD.
I'm looking at two options but can't decide which one is best.

Option number one is a 52v 17.5ah shark pack with Sanyo NCR18650-GA from UnitPackPower: https://www.aliexpress.com/item/Free-Ta ... 57877.html

Option number two is a 52v 17ah Jumbo Shark pack with Samsung INR18650-35E from Em3ev: https://em3ev.com/shop/em3ev-52v-14s5p- ... e-battery/

The main thing that speaks to me about the Em3ev one is that it has a smart BMS which balances the cells while charging and at >50% charge. It does come at the expense of Sanyo cells though.

The main thing I'm looking for is cycle life. I already bought a Luna smart charger for adjustable speed and a 80%-90%-100% switch. (Will probably charge at 2A and till 80% most of the time, maybe from time to time faster or more).

I will probably be going 25mph+ most of the time (no hills), and will be using throttle most of the time.

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Re: Em3ev battery with Samsung 35E vs. UnitPackPower battery with Sanyo GA

Post by Tommm » Nov 26 2018 12:55am

Worth giving up the GA for the far superior build quality. It will likely cost a bit more too, as it doesn't have tax and shipping included.

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Re: Em3ev battery with Samsung 35E vs. UnitPackPower battery with Sanyo GA

Post by Pizzabroodje » Nov 26 2018 8:13am

Okay thanks.
So according to you the one from Em3ev would probably get more cycles?


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17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 08 2018 2:05pm

I want to buy a 17ah jumbo shark from Em3ev with Samsung 35E cells. They recommend using it at 25a continuous, but I want to use it at 30A continuous.
Would that decrease the cycle life a lot (also compared to a 17ah pack with Sanyo GA cells from Unit Pack Power)?

Thanks!
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Re: 17ah Samsung 35E at 30A

Post by neptronix » Dec 08 2018 2:44pm

Go look at the datasheet for the cells. It wastes a good amount of energy even at 1C and you want to push almost double that. The most ideal discharge rate, if you want it to last, give very close to full capacity, etc is 1C or 17.5A.

Check out the triangle packs. They have more cells in series and a 20-30ah pack of these would be more ideal for 30a. Or a pack made up of more powerful cells. Samsung 30q would be good for 2C in a 17.5a size
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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 08 2018 7:05pm

Thanks,

I looked at a datasheet before but it just said 8A max continuous discharge. I looked at another one today and indeed it says 1c discharge for cycle life.

The Samsung has about 2700mah left after 500 cycles with 1c discharge so 17A with a 17ah pack.
Sanyo GA about 2100-2200 with 6A discharge per cell so ~1,76c so 30A with a 17ah pack.

Which one would be better at 30A?

The thing is, I have to leave my bike in a big city, and I don't think a triangle bag is secure enough. A diy triangle case would be too much of a hassle I think.

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Re: 17ah Samsung 35E at 30A

Post by Joachim » Dec 09 2018 3:53pm

samsung 30Q 3000mah 15A discharge.
backpack battery a option?
Voor 550 E heb je zoiets al op maat gemaakt in NL :bigthumb:

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Re: 17ah Samsung 35E at 30A

Post by 999zip999 » Dec 09 2018 8:28pm

I believe the Samsung 30q would have less stress.

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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 09 2018 10:19pm

Joachim wrote:
Dec 09 2018 3:53pm
samsung 30Q 3000mah 15A discharge.
backpack battery a option?
Voor 550 E heb je zoiets al op maat gemaakt in NL :bigthumb:
I don't want to carry the battery everywhere. I want to be able to securely leave it on the bike.
999zip999 wrote:
Dec 09 2018 8:28pm
I believe the Samsung 30q would have less stress.
Yes but a 70 cell pack (the max amount for a frame mounted hard case as far as I know) with Samsung 30q would give me just 15ah tho instead of 17ah. Or is that difference neglectable also considering the better cycle life?

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Re: 17ah Samsung 35E at 30A

Post by izeman » Dec 10 2018 5:14am

I would prefer the 30Q 15Ah over the 35E 17Ah. Your 17Ah pack will suffer much more under high load, and will age much faster. And it won't take long until you are below 15Ah. So better start with stronger cells from the start. My 2c.

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Re: 17ah Samsung 35E at 30A

Post by docware » Dec 10 2018 6:03am

"25 mph+ most of the time, using throttle."

What distance, travelling every day ? Really mph ?

Why do you assume 30 A continuous ?

Can you describe your gears ?

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Re: 17ah Samsung 35E at 30A

Post by izeman » Dec 10 2018 8:48am

saybot wrote:
Dec 10 2018 8:17am
definitively choose INR18650-35E.
If you looking for the same battery (same protection) as em3ev in Europe fell free to ask.
Definitely NOT 35E if you're asking 2C load. These are high capacity cells, not high load cells like 25R. 30Q is in between.

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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 10 2018 9:04am

saybot wrote:
Dec 10 2018 8:17am
definitively choose INR18650-35E.
If you looking for the same battery (same protection) as em3ev in Europe fell free to ask.
Why the 35E's? That's the opposite of what the rest is recommending (or do you mean in comparison with UPP Sanyo GA)? Em3ev also has 30q's for example.
docware wrote:
Dec 10 2018 6:03am
"25 mph+ most of the time, using throttle."

What distance, travelling every day ? Really mph ?

Why do you assume 30 A continuous ?

Can you describe your gears ?
The distance will vary a lot. Anywhere from 15km to about 40km. Yes mph (atleast I'm planning on going that fast). Most likely even 30mph+ if possible.
30A continuous because I will be using full throttle most of the time, with the controller set to 30A.
I will put a 52t chainring in front, and a 9-speed 11-36t cassette in the back.

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Re: 17ah Samsung 35E at 30A

Post by docware » Dec 10 2018 9:37am

You wrote at the beginning : „The main thing I'm looking for is cycle life. I already bought a Luna smart charger for adjustable speed and a 80%-90%-100% switch. (Will probably charge at 2A and till 80% most of the time, maybe from time to time faster or more).“

That is in direct opposite of your current requirement. For example 30Q is 3000 mAh cell. But in reality there is cca 2100 mAh in the range 4,1 – 3,2 V at 3 A for 30Q. For 5p battery it is 10 Ah, 20 minutes ride. And at 6A/cell the capacity is definitely lower.

The cells will be dead in less than one year.

Full throttle means speed about 45 - 50 km/h, or more !

35E cells are definitely unsuitable.

Frankly speaking your expectation is unrealistic for 15 Ah or 17 Ah battery. At such load you need completely different battery.
For good life expectancy you need at least 10p battery with Samsung 30Q for 30 A continuous. Or rather Lipo battery, 25 - 30 Ah.

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Re: 17ah Samsung 35E at 30A

Post by saybot » Dec 10 2018 10:26am

Pizzabroodje wrote:
Dec 10 2018 9:04am

Why the 35E's? That's the opposite of what the rest is recommending (or do you mean in comparison with UPP Sanyo GA)? Em3ev also has 30q's for example.
yes i mean 35E with comparisson with UPP Sanyo not in general.
This cell got similar spec but the price is different.

If you want to have 30A continous you should calculate around 50-60% of max continous current from datasheet for cell. So for 35E in 5P you can ride around 25A max continous.
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Re: 17ah Samsung 35E at 30A

Post by docware » Dec 10 2018 10:39am

On the other hand, from my calculation you probably don´t need more than 20 A (cca 1 000 W) for your required speed cca 45 km/h. Assuming really flat Netherland terrain, headwind max 10 km/h. But again, 15 Ah battery is in reality cca 10 Ah. After 30 minutes of such ride is battery nearly empty.

Please be carefull at such high speed. Or rather, ride slower and your battery will be happy. :-)
At cca 10 A you can go about 35 km/h.

I am really sorry, but you can be absolutely sure that Samsung 35E cells will be dead very soon at 5 A. No way. Such advertisement is incompetent.

By the way, in fact, balancing modern cells is not so important. Definitely is not needed to do every charge. New original cells in properly built battery really keep stability without balancing. I personally measured my 10s5p Sanyo GA pack during this summer. The whole battery is still within 3 mV without balancing. I usually charge to cca 40 – 41V, so BMS have no chance to start balance.


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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 10 2018 9:40pm

docware wrote:
Dec 10 2018 9:37am
You wrote at the beginning : „The main thing I'm looking for is cycle life. I already bought a Luna smart charger for adjustable speed and a 80%-90%-100% switch. (Will probably charge at 2A and till 80% most of the time, maybe from time to time faster or more).“

That is in direct opposite of your current requirement. For example 30Q is 3000 mAh cell. But in reality there is cca 2100 mAh in the range 4,1 – 3,2 V at 3 A for 30Q. For 5p battery it is 10 Ah, 20 minutes ride. And at 6A/cell the capacity is definitely lower.

The cells will be dead in less than one year.

Full throttle means speed about 45 - 50 km/h, or more !

35E cells are definitely unsuitable.

Frankly speaking your expectation is unrealistic for 15 Ah or 17 Ah battery. At such load you need completely different battery.
For good life expectancy you need at least 10p battery with Samsung 30Q for 30 A continuous. Or rather Lipo battery, 25 - 30 Ah.
I want long range, high power and cycle life. But apparently that's pretty much impossible with a 14s5p pack.

I know it's 45-50kmh. That's the least I want to go as I want to use it as a scooter.
saybot wrote:
Dec 10 2018 10:26am
Pizzabroodje wrote:
Dec 10 2018 9:04am

Why the 35E's? That's the opposite of what the rest is recommending (or do you mean in comparison with UPP Sanyo GA)? Em3ev also has 30q's for example.
yes i mean 35E with comparisson with UPP Sanyo not in general.
This cell got similar spec but the price is different.

If you want to have 30A continous you should calculate around 50-60% of max continous current from datasheet for cell. So for 35E in 5P you can ride around 25A max continous.
Including shipment it will be the same price (€6 difference) between the 35E pack from Em3ev and the GA pack from UPP. The GA is rated at 10A and the 35E at 8A. So according to you the GA can handle 25-30A and the 35E 20-24A. Wouldn't the GA be the better option?
docware wrote:
Dec 10 2018 10:39am
On the other hand, from my calculation you probably don´t need more than 20 A (cca 1 000 W) for your required speed cca 45 km/h. Assuming really flat Netherland terrain, headwind max 10 km/h. But again, 15 Ah battery is in reality cca 10 Ah. After 30 minutes of such ride is battery nearly empty.

Please be carefull at such high speed. Or rather, ride slower and your battery will be happy. :-)
At cca 10 A you can go about 35 km/h.

I am really sorry, but you can be absolutely sure that Samsung 35E cells will be dead very soon at 5 A. No way. Such advertisement is incompetent.

By the way, in fact, balancing modern cells is not so important. Definitely is not needed to do every charge. New original cells in properly built battery really keep stability without balancing. I personally measured my 10s5p Sanyo GA pack during this summer. The whole battery is still within 3 mV without balancing. I usually charge to cca 40 – 41V, so BMS have no chance to start balance.
As I just said, I want to use it basically like a scooter, so the faster the better. What's your recommendation on a 14s5p Sanyo GA pack at 30A?

I could also get a 14s8p 28ah triangle pack from UPP with 35E's. Is mounting it with some kind of metal cable ties / hose clamps possible, safe and secure?
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Re: 17ah Samsung 35E at 30A

Post by docware » Dec 11 2018 2:02am

I understand of using BBSHD as a scooter. In fact, thanks to its internal reduction ratio it is only effective solution for such motor. You need to keep high rotation speed to have good effectivity of the motor. For BBSHD it is in the range 120 – 150 rpm, so definitely not for pedaling.

Just hope your bike, tyres and you are ready for high speed.

14s8p sounds better, but it is still compromise if you want long range, high power and good cycle life. 5p - no way. Calculation is still the same. The required power is going up with the cube of the velocity.

You should set current limit 20 A in the BBSHD program.

By the way, do you want to ride in the winter also ? What temperatures are common in your area ?

Regarding the metal clamps, it can harm the plastic case of the triangle pack.

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Re: 17ah Samsung 35E at 30A

Post by fechter » Dec 11 2018 9:36am

How far is the commute? The other thing is you will likely run less than 30A at cruising speed. The bike simulator can give you a good idea of power consumption for a given speed.

On one of my bikes I replaced the velcro straps with some gigantic zip ties. They make some really hefty ones.
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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 11 2018 10:41am

docware wrote:
Dec 11 2018 2:02am
I understand of using BBSHD as a scooter. In fact, thanks to its internal reduction ratio it is only effective solution for such motor. You need to keep high rotation speed to have good effectivity of the motor. For BBSHD it is in the range 120 – 150 rpm, so definitely not for pedaling.

Just hope your bike, tyres and you are ready for high speed.

14s8p sounds better, but it is still compromise if you want long range, high power and good cycle life. 5p - no way. Calculation is still the same. The required power is going up with the cube of the velocity.

You should set current limit 20 A in the BBSHD program.

By the way, do you want to ride in the winter also ? What temperatures are common in your area ?

Regarding the metal clamps, it can harm the plastic case of the triangle pack.
The bike, tires and me are ready for that speed, don't sorry about that.
I will ride in the winter too yes. The lowest temperature in the Netherlands is about -5°C and it will most of the time be about 0-6°C.

What about plastic coated metal cable ties? And if that's not enough with a heat shrink tube e.g. wrapped around?

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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 11 2018 11:02am

fechter wrote:
Dec 11 2018 9:36am
How far is the commute? The other thing is you will likely run less than 30A at cruising speed. The bike simulator can give you a good idea of power consumption for a given speed.

On one of my bikes I replaced the velcro straps with some gigantic zip ties. They make some really hefty ones.
My smallest commute is about 15km in total, and regularly more, up to about 40km.
The thing is I want to go as fast as possible pretty much, and the BBSHD can do 30A without upgrading the controller.

What do you think about plastic coated metal cable ties? If not soft enough by itself with a heat shrink e.g. wrapped around?

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Re: 17ah Samsung 35E at 30A

Post by docware » Dec 11 2018 11:25am

Obviously you are able to find the way how to fix the triangle pack without damage.

The capacity of Li-ion battery is going down with temperature. For example, look at the Sanyo GA cell diagram for various temperatures at 4 A discharge from 4,2 V. There is capacity 2320 mAh at 3,3 V level and 25 °C. At 0 °C capacity is decreased to 1730 mAh. Difference 590 mAh means 25 % capacity down.

But much worse is higher degradation of cells during low temperature discharging. That means worse lifecycle of the battery.

Solution is …. A) thermal isolation of the battery B) LiFePo cells. C) Acceptance of shorter battery lifetime.

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Re: 17ah Samsung 35E at 30A

Post by Pizzabroodje » Dec 11 2018 11:45am

docware wrote:
Dec 11 2018 11:25am
Obviously you are able to find the way how to fix the triangle pack without damage.

The capacity of Li-ion battery is going down with temperature. For example, look at the Sanyo GA cell diagram for various temperatures at 4 A discharge from 4,2 V. There is capacity 2320 mAh at 3,3 V level and 25 °C. At 0 °C capacity is decreased to 1730 mAh. Difference 590 mAh means 25 % capacity down.

But much worse is higher degradation of cells during low temperature discharging. That means worse lifecycle of the battery.

Solution is …. A) thermal isolation of the battery B) LiFePo cells. C) Acceptance of shorter battery lifetime.
So you think the plastic covered metal cable ties with optional heat shrink is a viable solution?

I know cold affects the battery, but that won't be too big of an issue for me also because our temperatures aren't too extreme.

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