(Beginner) Long-term battery quality: EM3EV, Grin, EBike.CA, Luna

[999zip999]

Cyc as from the factory. As they admitted to me the 855 Bluetooth bricks up and cannot be used they have a new controller called an X6 in-house programmed and it's 60 amps. They're going to send me that controller for the upgrade fee of $60 plus $30 shipping because of the BAC 855 Bluetooth controller never worked and they know it they just lied to mee for about a year and a half acting like it did and give me different downloads and different this and and how to pin out the wires for the controller so I can use the controller via my phone and Bluetooth never worked lied to again. I talked to another person that had the same controller and he's the one you told me it's bricked up and it won't work.Cyc bought it from Canada they try to program it on their own and they failed failed and failed. Never again will I buy from those scumbags as they lied lied knew it wouldn't work and lied me again for a year and a half. Then they agreed to give me a 20% discount on $240 controller then they offered me a 30% discount to get the X6 controller I just kept at them and they decide to give me the controller for 60 bucks instead of $200 plus shipping of $30.
This is after I paid $1,200 for this kit 2 years ago because it took two and a half months for them to ship it to me.
Yes I thought it was my dream mid-drive but dreams get crushed.
Bike still in the garage waiting for the new controller I hope it works this time and those knuckleheads might be able to help me. Shame on you Cyc lie lie lie. So that's what happened to me with that company good luck to you if you go that route I will contact you when the controller gets here and we'll talk about it then.
Sent talk to text words can be asked.

 

[nicobie]

That's just bad. Be sure to let us know how it turns out.

 

[999zip999]

Jil em3ev has always been good for many years. Paul has always experiment ed with some of the best concepts long time ago he used A123 a rock solid cell. Long ago but now that cell is too big and too heavy even back then it was too big and too heavy for an e-bike.
Plus they stand behind their product when they have to. Meaning his batteries are pretty Rock solid. Plus he doesn't like to sell things that can easily break. Like he stopped selling his version of the 9C motor because was too easy to melt hot rodded that was a direct drive hub.

 

[999zip999]

Fuzzy wuzzy ( isn't that fun to say )
Those are all good manufacturers suppliers. E-bikes.ca and em3ev a point above. Luna experiments more and has an issue or two but if you live in LA and you have a problem you can go punch him in the nose you can't punch some Alibaba supplier in the nose or even return the battery the motor or anything because of shipping cost.
Fuzzy wuzzy what part of this world do you live in it makes a big difference and how much you want to spend ? All we know is that you're looking at a mid drive and a battery.
Maybe you could tell us your plans like how do you want to use it off-road commute to work do you have to have hills is it flat those type of things. Some people want to stealth an electric motorcycle. Which I have to do because I live in Southern California 72 volt 45 mph heavy bike. Yeah it's a hell of a lot of fun but I make it look homeless and no one steals it. As I live near the beach in southern California. And people when they come to the beach sometimes they could take things from the beach back home with them and I don't mean just seashells.

 

[nicobie]

As I live near the beach in southern California. And people when they come to the beach sometimes they could take things from the beach back home with them and I don't mean just seashells.

Ain't that the truth. At times it seem that the rest of the US is dumping all it's trash on us. Things have changed in the last few years.

 

[999zip999]

In the old days you could take a surf pole dig up some sand crabs for bait or some other living thing on the coast and go fishing and catch something. From the beach there was life. We need to get the worms and the sand crabs back in the tide zone. They had to shut down Laguna Beach because there's so much poaching going on people just fill up buckets of sea life and walk home with it to let them die How many times can that happen in a week on a reef.
And what do they leave behind in piles.

 

[nicobie]

At my fishing spot (Surf,CA) My dad and I used to get Halibut pole fishing. Perch were an easy catch until the boat people figured out that a very cheap onshore licence enabled them to catch a almost unlimited quantity of almost any species. That was the end of the perch. God forbid if the homeless get as resourceful.

 

[sysrq]

Jil em3ev has always been good for many years. Paul has always experiment ed with some of the best concepts long time ago he used A123 a rock solid cell. Long ago but now that cell is too big and too heavy even back then it was too big and too heavy for an e-bike.
Plus they stand behind their product when they have to. Meaning his batteries are pretty Rock solid. Plus he doesn't like to sell things that can easily break. Like he stopped selling his version of the 9C motor because was too easy to melt hot rodded that was a direct drive hub.

EM3EV 20Ah 52V 35E (rated at 31A continuous) battery seems to drain faster than noname Chinese battery with 28A BBSHD. Shame it's hard to confirm exactly due to unpredictable conditions.

 

[999zip999]

The BMS has something to do with that how high is HVC
and low is LVC set at ? How old were the cells when bought how old is the battery pack ?

 

[neptronix]

EM3EV 20Ah 52V 35E (rated at 31A continuous) battery seems to drain faster than noname Chinese battery with 28A BBSHD. Shame it's hard to confirm exactly due to unpredictable conditions.

35E is a very high energy, low power cell that's best at 1C or below, like most cells in it's class.

it would be no surprise if you got less capacity out of the em3ev unit due to higher voltage drop versus a less energy dense, but more powerful cell of the same advertised capacity. Some cells' power ratings go up to the point where they're throwing out up to 15% of their energy to heat due to voltage sag. If you do not conservatively spec cells for your application then you can expect the battery to fall short of expectations due to that.

 

[sysrq]

35E is a very high energy, low power cell that's best at 1C or below, like most cells in it's class.

it would be no surprise if you got less capacity out of the em3ev unit due to higher voltage drop versus a less energy dense, but more powerful cell of the same advertised capacity. Some cells' power ratings go up to the point where they're throwing out up to 15% of their energy to heat due to voltage sag. If you do not conservatively spec cells for your application then you can expect the battery to fall short of expectations due to that.

Theoretical max current for 14S6P 35e battery is 48A. 31A continuous current and 40A burst current (as specified by EM3EV) should be more than enough with 28A controller. EM3EV keeps recommending discharging the battery completely and then charging it to the full so that the smart BMS can calculate correct battery health. Currently after one registered charge cycle it sits at 98% health.

 

[neptronix]

Yeah, theoretical is 48a, but that's hella saggy and you would never want to use this cell at that rate ( ~7A per cell )

If you're running 28A continuously then you're running about 1.4C. So let's do some comparison to how the cell performs in the spec sheet.

Per: Test of Samsung INR18650-35E 3500mAh (Pink)

I've drawn a simulated line to show how much sag you have a 28 amps ( ~1.4C ). In this condition, you may be getting just 3.3ah out of the cells, instead of the maximum of 3.4ah.



This is at room temperature though... IE in perfect conditions.

You don't have your location set, so i don't know what the weather is like where you're at. But if you're in freezing weather, that virtual green line now looks like the purple 15A lines, because freezing weather triples the internal resistance of a cell. In that condition, you're only getting 3ah per cell and you now have an effective ~17ah pack

So.. seasonal sag happening? its January after all..

A non-balanced pack ( can happen after a long time of sitting, which would happen at their warehouse ) can be another reason you aren't getting the stated capacity. This would add to the any seasonal sag factor and make it worse.

But i would say at 1.4C-ish, because this is a very high energy cell, you'll always be an amp hour or two short of full capacity unless you run 1C or less. Another thing about these '35' cells from all makes, is that they're all 3.4ah in reality.

 

[sysrq]

Yeah, theoretical is 48a, but that's hella saggy and you would never want to use this cell at that rate ( ~7A per cell )

If you're running 28A continuously then you're running about 1.4C. So let's do some comparison to how the cell performs in the spec sheet.

Per: Test of Samsung INR18650-35E 3500mAh (Pink)

I've drawn a simulated line to show how much sag you have a 28 amps ( ~1.4C ). In this condition, you may be getting just 3.3ah out of the cells, instead of the maximum of 3.4ah.

View attachment 345057

This is at room temperature though... IE in perfect conditions.

You don't have your location set, so i don't know what the weather is like where you're at. But if you're in freezing weather, that virtual green line now looks like the purple 15A lines, because freezing weather triples the internal resistance of a cell. In that condition, you're only getting 3ah per cell and you now have an effective ~17ah pack

So.. seasonal sag happening? its January after all..

A non-balanced pack ( can happen after a long time of sitting, which would happen at their warehouse ) can be another reason you aren't getting the stated capacity. This would add to the any seasonal sag factor and make it worse.

But i would say at 1.4C-ish, because this is a very high energy cell, you'll always be an amp hour or two short of full capacity unless you run 1C or less. Another thing about these '35' cells from all makes, is that they're all 3.4ah in reality.

The last time battery was used 6 months ago in the summer at around 20°C with average current around 7-8A and short spike around 25A for half an hour resulting in 70-75% remaining charge.

 

[neptronix]

That battery looks impeccably balanced.. if that data is true, we can rule out a balance problem.

 

[sysrq]

That battery looks impeccably balanced.. if that data is true, we can rule out a balance problem.

According to rumours below: "The 2021 test of the 35E indicated Samsung improved this cells performance over time"

Caltech/NASA 18650 performance test

Great find! Lots of data to look at in that paper. This test by NASA focuses on long term performance. Generally in this community we have only had access to test results of brand new cells, thanks to the efforts of HKJ, Mooch, and sometimes a few others. Focusing on different criteria yielded...

budgetlightforum.com

So it's impossible to know when the Samsung 35e cells in EM3EV battery pack were manufactured.

 

[sysrq]

That battery looks impeccably balanced.. if that data is true, we can rule out a balance problem.

Another battery with GA cells from different user seems to be even more impeccably balanced except for one cell. Battery health also shows no degradation (100%) after 5 cycles compared to mine with 98% after just one cycle (charged 3 times in total: from 50% to 100%, 75% to 100% and from 90% to 100%).

 

[sysrq]

Accidentally found that Samsung 35e is said to be slightly improved after 2021.

Test of Samsung INR18650-35E 3500mAh (Pink) 3

Will see if EM3EV is able to provide the cell manufacturing date.