Ebike charging using Street EV chargers for electric cars

[vulcanears]

MJ1 for one pack and 35E for the other.
BMS is a 30A Bluetooth BMS. Don't remember what the balancing current is, but I've checked the cell-voltages dozens of times and there were always perfectly balanced.

 

[vulcanears]

Oh, in case anyone is interested: I also charge laptop, drone batteries and Photo/Film equipment with my battery packs, using a 36V to 13.8V DC/DC converter and then using car chargers to charge my electronics. If you ever try to do this, do NOT buy a 36V to 12V DC/DC converter. Many "12V" car chargers for drones, etc have a low voltage cutoff of 13V so that they don't suck the car battery empty.

 

[WheezyRider]

MJ1 for one pack and 35E for the other.
BMS is a 30A Bluetooth BMS. Don't remember what the balancing current is, but I've checked the cell-voltages dozens of times and there were always perfectly balanced.

Which are your favourite, the 35E or the MJ1? How much did you pay per cell?

On the BMS with Bluetooth, does it show you the bank to bank voltage on your phone?

 

[vulcanears]

Which are your favourite, the 35E or the MJ1? How much did you pay per cell?

On the BMS with Bluetooth, does it show you the bank to bank voltage on your phone?

I can't really tell the difference between the two battery packs in real world use and I don't pay much attention. Both are fine. Will be interesting to see the remaining capacity after a year. Got them from nkon.nl - don't remember the price.

Yes, the smartphone app for the Bluetooth BMS shows the 10 individual cell voltages of the 10s pack. That's really useful for making sure that the BMS works correctly.

 

[Nealh]

Over time all being equal the MJ's should be better but unless one see's about 700 complete cycles on both then he will never know.

 

[WheezyRider]

I can't really tell the difference between the two battery packs in real world use and I don't pay much attention. Both are fine. Will be interesting to see the remaining capacity after a year. Got them from nkon.nl - don't remember the price.

Yes, the smartphone app for the Bluetooth BMS shows the 10 individual cell voltages of the 10s pack. That's really useful for making sure that the BMS works correctly.

Nice so with about 60Ah of capacity on your bike, what sort of range do you get? Can you do 200 miles on a charge?

 

[WheezyRider]

Over time all being equal the MJ's should be better but unless one see's about 700 complete cycles on both then he will never know.

I had a look at the reviews on Lygte-info.dk and although the MJ1 has a better max current, at a 1A draw, it gives 3.2Ah, while the 35E gives 3.35Ah at 1A. Not a lot in it, but the 35E are cheaper and if only using a low current draw, it looks like they might be a good option. It'll be interesting to see the residual cpacity of the two packs after a few hundred cycles.

 

[Nealh]

On ES user docware put a few well known top cells to cycle life testing with 4.1v - 3.3v charge /discharge and 2.5a/1a charge/ discharge regime all eventually reached 700 cycle over nine months of constant cycling.
The pannies/sanyo's performed worse of all as did the power tool 30Q cell.
The 29e also showed what an under rated epic cell it is.

This is the final graph.

 

[vulcanears]

THANK YOU, Nealh, that's incredibly helpful! Have been looking for a test like this for ages.
Do you still have the link to the original thread? Would love a similar graph with capacity in Wh on the y-axis.


Also: Am I assuming correctly that they charged with 1A and discharged with 2.5A?

 

[WheezyRider]

On ES user docware put a few well known top cells to cycle life testing with 4.1v - 3.3v charge /discharge and 2.5a/1a charge/ discharge regime all eventually reached 700 cycle over nine months of constant cycling.
The pannies/sanyo's performed worse of all as did the power tool 30Q cell.
The 29e also showed what an under rated epic cell it is.

This is the final graph.
View attachment 36697

Very interesting plot Nealh. The 35e drops quite a lot, but it still ends up with a higher capacity after 700 cycles than a new 29e, which is important for this application where you want high capacity in a small volume/weight. The LG cells look good, although some of the reviews I've seen say the cell to cell internal resistance is quite variable, which is not good for pack building.

The 50e is interesting too. A physically bigger cell, but the capacity/weight ratio is similar to the high capacity 18650 cells. Having fewer cells in a pack may have advantages.

I'm quite surprised that they have such a high capacity after 700 cycles!

If you have the original link Nealh, I'd like to see it too.

 

[Nealh]

Very interesting plot Nealh. The 35e drops quite a lot, but it still ends up with a higher capacity after 700 cycles than a new 29e, which is important for this application where you want high capacity in a small volume/weight. The LG cells look good, although some of the reviews I've seen say the cell to cell internal resistance is quite variable, which is not good for pack building.

The 50e is interesting too. A physically bigger cell, but the capacity/weight ratio is similar to the high capacity 18650 cells. Having fewer cells in a pack may have advantages.

I'm quite surprised that they have such a high capacity after 700 cycles!

If you have the original link Nealh, I'd like to see it too.

29E after 700c is 5% better then 35e, however 5% is small as is most of the other %'s.
The PF's fall off the cliff, I will have to wait and see if that happens to mine as have three packs with PF. What I can say is they pack a good punch at lower voltage using pas 4 or 5 on 6/7% inclines at 1.5 - 2km in distance.

 

[Nealh]

Li-ion cells cycle ageing

This topic arise from the Pajda´s idea in another thread : https://endless-sphere.com/forums/viewtopic.php?f=14&t=102387&p=1507776#p1507776 Frustrated and tired by never ending unfruitful debate about cycle life of various Li-ion cells, I finaly decided to start some long term cycling to see...

endless-sphere.com

 

[vulcanears]

Thank you very much, Nealh! Great find!

Which one of the cells (preferably 18650) would you pick for a 250W 10s9p system that's optimised for capacity and cycle life? I would have picked the MJ1 again, but WheezyRider's comment regarding internal resitace made me a little nervous.

 

[Nealh]

Been following the thread from day 1, no where else have I seen any comparison like it.
Best bang for buck is the 29e esp in 9p but depends on the current required.

 

[Nealh]

I have not seen any discussion about cell/cell variable internal resistance for MJ1, typically 37 - 40mohms is the IR.

 

[WheezyRider]

Thank you very much, Nealh! Great find!

Which one of the cells (preferably 18650) would you pick for a 250W 10s9p system that's optimised for capacity and cycle life? I would have picked the MJ1 again, but WheezyRider's comment regarding internal resitace made me a little nervous.

I was looking at the nkon.nl site where you got yours from and some reviews are not very positive for the MJ1 cells. Only one mentioned about variability of internal resistance though. It could be significant, or it could be someone who doesn't know what they're talking about who's made an incorrect measurement. I've tried looking around to see if anyone else has had this problem, but most reviews only look at one or two cells and different people measure internal resistance in different ways, so it's hard to compare like with like. Probably not worth losing sleep over.

The MJ1 datasheet does say to only use cells from the same batch in a pack (probably true for all types of cell though ). I don't know if you order from Nkon if you can specify that you want them all from the same batch.

 

[Majority]

Very interesting topic, but in the end of the day we all will need to recharge our batteries at some point on our long ebike journey, it doesn't matter if the battery is big or advanced, at some point we will need to recharge them, and the fastest way so far is an AC wall socket or a EV charging stations.
The best thing we could do right now is to make a p2p shared charging point map (from public places to private houses that accept to recharge ebikes for free or paid) like an app.

 

[flecc]

Very interesting topic, but in the end of the day we all will need to recharge our batteries at some point on our long ebike journey, it doesn't matter if the battery is big or advanced, at some point we will need to recharge them, and the fastest way so far is an AC wall socket or a EV charging stations.
The best thing we could do right now is to make a p2p shared charging point map (from public places to private houses that accept to recharge ebikes for free or paid) like an app.

Way back in 2011 two of our members started to set up a new scheme called Cyclecharge, registered the company and with the help and donations from members started to set up charge points based on various commercial premises like cafe's, pubs etc making available 13 amp sockets for e-bikers own chargers. Each had a window sticker or the like advertising the facility and they would benefit from added custom.

With low demand it never really succeeded and four years later in 2015 the company was wound up and website closed.

There's a large number of Cyclecharge post links available through this site's Search facility, explaining much of the detail.

Personally I still feel the demand will be too low to build an adequate network since only a very small minority long distance e-bike and our total e-biking is low compared with such as The Netherlands and Germany.
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[WheezyRider]

Way back in 2011 two of our members started to set up a new scheme called Cyclecharge, registered the company and with the help and donations from members started to set up charge points based on various commercial premises like cafe's, pubs etc making available 13 amp sockets for e-bikers own chargers. Each had a window sticker or the like advertising the facility and they would benefit from added custom.

With low demand it never really succeeded and four years later in 2015 the company was wound up and website closed.

There's a large number of Cyclecharge post links available through this site's Search facility, explaining much of the detail.

Personally I still feel the demand will be too low to build an adequate network since only a very small minority long distance e-bike and our total e-biking is low compared with such as The Netherlands and Germany.
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The idea was ahead of its time, but it wasn't a bad one. It's time will come, maybe sooner than we might think, what with people being poorer and needing cheaper transport post Covid.

These guys are putting together cycle friendly route planners. They might be interested in adding an e-bike charging point map to one of their layers:

https://www.cyclestreets.org/

 

[flecc]

The idea was ahead of its time, but it wasn't a bad one. It's time will come, maybe sooner than we might think, what with people being poorer and needing cheaper transport post Covid.

These guys are putting together cycle friendly route planners. They might be interested in adding an e-bike charging point map to one of their layers:

https://www.cyclestreets.org/

I think the problem is one of frequency of use. It's one thing to set it up with a pub or cafe, but if they then don't see anyone coming in to charge or that happening so infrequently they think it a dud scheme and take down the sign.

It really needs the sort of strong backing that the huge car charging network has now, but with no money to be made that isn't likely.
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