Sparkbikes - SPARK 350W, 48V 13Ah, 26"x2.1" tires

[HKPolice]

Thank you for the info. I looked it up and by my reckoning, when new, that cell is preferable to Samsung 35E !
However, that doesn't say anything about aging.
The report suggests uneven quality control, but it is a Korean cell. Perhaps when sold from China in packs they did poor welding and such?
(Link Removed - No Longer Exists)

https://www.imrbatteries.com/content/samsung_35E.pdf

Here's a more in-depth review of some parameters https://www.candlepowerforums.com/v...-Test-review-of-LG-18650-M26-2600mAh-(Purple)

The 35E is a much better cell for this use case because of its higher capacity. When these battery packs are limited to ~30A output by the internal fuse and maybe 20-25A max from the speed controller, there is no need for high output cells.

Remember, there are 4-5 sets of cells in parallel so each set only needs to output 7.5A max before the fuse blows, and in practice the speed controller's amperage limit means each set only needs to output ~6A.

 

[Handlebars]

The 35E is a much better cell for this use case because of its higher capacity. When these battery packs are limited to ~30A output by the internal fuse and maybe 20-25A max from the speed controller, there is no need for high output cells.

Remember, there are 4-5 sets of cells in parallel so each set only needs to output 7.5A max before the fuse blows, and in practice the speed controller's amperage limit means each set only needs to output ~6A.

OK from that angle, but from what I gather, the lower capacity cells are generally better for longevity.
What benefit do you understand exists for higher capacity vs lower capacity?
Noted also that the LG cutoff is 2.75V.

 

[HKPolice]

OK from that angle, but from what I gather, the lower capacity cells are generally better for longevity.
What benefit do you understand exists for higher capacity vs lower capacity?
Noted also that the LG cutoff is 2.75V.

Cell capacity plays a very minor role in longevity. The build quality is most important, next is how it was used. For example, Tesla Model S uses Panasonic NCR18650B cells which are rated for 3200mah and there are tons of cars with over 85% capacity after over 200K mileage.

The M26's poor longevity has been reported in the Xiaomi M365 electric scooter as well. LG cells overall are cheaper than Samsung & Panasonic cells of the same capacity, so you get what you pay for.

I just found out that the 17AH Spark bike battery pack uses LG F1L cells which has a rated capacity of 3350mah. Technically speaking, the pack should be labelled as 16.75AH (3.35AH*5).

Realistically though, the battery pack is more like 15AH because the cells only offer around 3166mah capacity when discharged @ 2A (roughly 500w output). This makes the pack effectively 3.16ah*5=15.8AH but since the battery cut off voltage of the controller is a lot higher than 2.5v, actual usable capacity is around 15AH or less. Here's a website comparing the F1L to Panasonic's equivalent: https://www.thunderheartreviews.com/2018/10/lg-f1l-vs-panasonic-ncr18650b-capacity.html

While low discharge rates are identical, at 5A the F1L struggles and that's reflected in the price. $3.9 for Panasonic & $2.6 for the LG.

I was hoping that these 17AH battery packs had LG M1J cells which are rated for 3400mah and perform much better than the F1L under all discharge rates, but I guess 99% of users won't care about the cells used, only about the rated capacity.

Here's a review of the LG M1J cell vs comparable cells from other top manufacturers and the LG ranked last: https://www.thunderheartreviews.com/2018/08/3500mah-18650-li-ion-cells-discharge.html

 

[HKPolice]

I have owned my 2018 Spark for 1.5 years (which is 2 full riding season). The battery is fine. In fact, I haven’t noticed any degradation. Mine is the upgraded 48V x13AH (not 10.4AH). I keep my bike indoors, so never subjected to any extreme heat or cold. I charge my battery once or twice during the winter off-season to maintain around a 60-70% charge.

Spark’s latest 2019 model is now on “Black Friday” sale for CAD$1,199 (~US$906!), now with free shipping. Not sure if it is available in the US yet.

Not only is the price now less than mine (my old price was CAD$1,249 + $99 shipping), it is now better equipped!

500W motor (vs 350W on mine)
48x13Ah battery (vs 10.4Ah standard on mine)
Front and Rear fenders (vs none on mine)
Rear Rack (vs none on mine)
Integrated front and rear lights (vs none on mine)
27.5“ wheel (vs 26” on mine)

Also, you can now upgrade to a 17Ah WITH hydraulic brakes for CAD$300 more (not available to me in 2018).

How much mileage do you have on the bike? After doing some research, I think most 13AH LG reention dorado battery packs also use the M26 cell because 2600mah*5 = 13AH. The battery casing can be used in 4P or 5P configurations. 10.4AH = 4P config.

 

[Handlebars]

Cell capacity plays a very minor role in longevity. The build quality is most important, next is how it was used. For example, Tesla Model S uses Panasonic NCR18650B cells which are rated for 3200mah and there are tons of cars with over 85% capacity after over 200K mileage.

The M26's poor longevity has been reported in the Xiaomi M365 electric scooter as well. LG cells overall are cheaper than Samsung & Panasonic cells of the same capacity, so you get what you pay for.

I just found out that the 17AH Spark bike battery pack uses LG F1L cells which has a rated capacity of 3350mah. Technically speaking, the pack should be labelled as 16.75AH (3.35AH*5).

Realistically though, the battery pack is more like 15AH because the cells only offer around 3166mah capacity when discharged @ 2A (roughly 500w output). This makes the pack effectively 3.16ah*5=15.8AH but since the battery cut off voltage of the controller is a lot higher than 2.5v, actual usable capacity is around 15AH or less. Here's a website comparing the F1L to Panasonic's equivalent: https://www.thunderheartreviews.com/2018/10/lg-f1l-vs-panasonic-ncr18650b-capacity.html

While low discharge rates are identical, at 5A the F1L struggles and that's reflected in the price. $3.9 for Panasonic & $2.6 for the LG.

I was hoping that these 17AH battery packs had LG M1J cells which are rated for 3400mah and perform much better than the F1L under all discharge rates, but I guess 99% of users won't care about the cells used, only about the rated capacity.

Here's a review of the LG M1J cell vs comparable cells from other top manufacturers and the LG ranked last: https://www.thunderheartreviews.com/2018/08/3500mah-18650-li-ion-cells-discharge.html

Thank you for the great findings and explanations!

 

[Handlebars]

Cell capacity plays a very minor role in longevity. The build quality is most important, next is how it was used. For example, Tesla Model S uses Panasonic NCR18650B cells which are rated for 3200mah and there are tons of cars with over 85% capacity after over 200K mileage.

While those may play a more major role, I was thinking more generally, that is, everything else being equal. When it's already indicated as being affected by say, build quality, then it's tempting to relegate the question to what matters here. But that doesn't answer the question of capacity vs longevity all other things being the same - so the more general question. But I would have to agree in this case especially, quality might be the most important factor to consider.

The M26's poor longevity has been reported in the Xiaomi M365 electric scooter as well. LG cells overall are cheaper than Samsung & Panasonic cells of the same capacity, so you get what you pay for.

Or even less :I

I just found out that the 17AH Spark bike battery pack uses LG F1L cells which has a rated capacity of 3350mah. Technically speaking, the pack should be labelled as 16.75AH (3.35AH*5).

Thank you!

Realistically though, the battery pack is more like 15AH because the cells only offer around 3166mah capacity when discharged @ 2A (roughly 500w output). This makes the pack effectively 3.16ah*5=15.8AH but since the battery cut off voltage of the controller is a lot higher than 2.5v, actual usable capacity is around 15AH or less.

Yes, makes sense.

Here's a website comparing the F1L to Panasonic's equivalent: https://www.thunderheartreviews.com/2018/10/lg-f1l-vs-panasonic-ncr18650b-capacity.html

While low discharge rates are identical, at 5A the F1L struggles and that's reflected in the price. $3.9 for Panasonic & $2.6 for the LG.

So a heavy person with backpack and panniers might overly tax this battery.

I have no other ebikes so far to compare to but it's quick enough for me and top speed allowed is 32 km/hr anyway. It does that for me all the time. I notice much faster battery drain when I go uphill.

I was hoping that these 17AH battery packs had LG M1J cells which are rated for 3400mah and perform much better than the F1L under all discharge rates, but I guess 99% of users won't care about the cells used, only about the rated capacity.

I thought the MJ1 were too much to hope for seeing as the cell type was not mentioned. Normally I would expect the bike seller to make a small brag if it was MJ1. I guessed at the F1L in fact from a bike battery seller website I had studied which was offering a good selection of cases and cells and voltage etc in the battery builds. I hadn't been interested in that cell though, seeing the cheaper price. I just knew it as the one of the cheapest cell offerings that was listed by type.

If it lasts me a couple of years without incident I'll be OK with the deal.

 

[HKPolice]

Thank you for the great findings and explanations!

To further complicate things, Lithium cells are also graded as well since there will always be manufacturing tolerances so the best cells go to the highest bidder.

You can see the grade "B3" listed on boxes of F1L cells here:

The grade is never printed on the cells themselves though. I'm betting most consumer electronics including ebikes do not contain Grade A cells, which are reserved for commercial/industrial use.