Batteries batteries batteries, one big reason why choose an established ebike brand with good reputation.

[tomjasz]

Any ideas why their battery is so much cheaper? Much cheaper than Luna.

Luna has a higher markup than they admit?

 

[tomjasz]

Fyi not the Sondors battery I was referencing.

Video? Pictures? Citation?

 

[jazz]

Not exactly sure. I know that they purchase in larger volumes so maybe that factors in. They have sold nearly 30,000 e-bikes since 2015 and even with cheap ebikes that is still pretty impressive.

 

[tomjasz]

According to this site; (Link Removed - No Longer Exists)
How is it possible for the range to vary so much in two packs exactly the same size, both containing name brand 18650 cells?

There is a big difference in the performance of different 18650 cells even when they are made by big name makers like Samsung or Panasonic. For example the stock Sondors pack contains this Samsung cell which has very poor energy density 2200mah and also very low price.

The Luna pack uses the Panasonic NCRB cell, which has a very high energy density 3400mah and also a high price.

They also over rate some....if not most. That said NCRB tend to sag more than some newer cells with close Mah ratings. 6P and more makes for a better pack. Some batteries very near the same rating will perform much better. It’s not so simple. In my opinion and FWIW....

 

[tomjasz]

Not exactly sure. I know that they purchase in larger volumes so maybe that factors in. They have sold nearly 30,000 e-bikes since 2015 and even with cheap ebikes that is still pretty impressive.

Yeah the numbers are impressive and Sondors buyer# tend to be very protective and loyal. Even if they spend another $500-$1000 to have a decent bike. <grin>

 

[tomjasz]

Hah! Looking to find info on Sondors battery I ran into a YouTube where the guy is buying $30 packs on eBay and resold for $95 with new connectors. Sheesh!

 

[JRA]

With batteries you get what you pay for and cheap is a caveat emptor situation.

Going forward the new 20/21700 cells are on the horizon and coming soon to a battery you can buy but won't be retrofittable to many of the bikes manufactured today no matter how much you paid for it. It won't be cheap(er) up front but the prospect of 4200-5200mah cells that have a high C rate and 2 thousand charge cycles will make them the long run low price leader as well as have better performance.

 

[tomjasz]

With batteries you get what you pay for and cheap is a caveat emptor situation.

Going forward the new 20/21700 cells are on the horizon and coming soon to a battery you can buy but won't be retrofittable to many of the bikes manufactured today no matter how much you paid for it. It won't be cheap(er) up front but the prospect of a 4200-5200mah cells that have a high C rate and 2 thousand charge cycles will make them the long run low price leader as well as have better performance.

Still seem a way out... Have any insights and source?

 

[Asher]

With batteries you get what you pay for and cheap is a caveat emptor situation.

Going forward the new 20/21700 cells are on the horizon and coming soon to a battery you can buy but won't be retrofittable to many of the bikes manufactured today no matter how much you paid for it. It won't be cheap(er) up front but the prospect of 4200-5200mah cells that have a high C rate and 2 thousand charge cycles will make them the long run low price leader as well as have better performance.

I see a year and a half of press releases, yet nothing more about that.

I also see only one manufacturer (Juiced) doing 52V setups (though the hobby market is another matter).

What gives?

 

[JRA]

"I also see only one manufacturer (Juiced) doing 52V setups (though the hobby market is another matter)."

For that matter there are very few of the international scale manufacturers that even use 48v systems. Considering that the using the same motor @ 20amps, as an example, 36v vs. 48v results in a 240w increase in watts and a 48v vs 52v is 80watts and other than a slight improvement in performance hot off the charge there isn't really a big reason to go to 52v. But the jump from 36 to 48 is substantial enough that a pretty big increase in performance is possible given good cell quality. It's all about how many amps a battery can produce as a 36v battery @ 30amps, entirely possible given that the cells are rated correctly, produces as much as a 52v @ 20a.

Mainly the concern with manufacturers is staying within the regulations for max wattage to maintain a semblance of legality, much of which is based on the EU 250w rating, although there are not many being produced today that adhere to that as per Ohms Law. Here in the states our legal limit of 750w is easy enough for them to adhere to by just upping the amps a bit via the controller and use the same battery voltage it and now has a higher watt capacity to conform and entice sales here.

As for the 20/21700 cells one of the big proponents, along with Tesla, of the larger cells is BMZ a major player in the cell industry with a world wide presence based in Germany. While they are the largest cell producer in the EU they are mainly a technology based company that has the chops to license their technology to other cell producers such as their latest cooperative deal with LG for millions of cells. More info here: http://www.ebikeportal.com/news/future-ebike-batteries-according-germanys-bmz so after reading this you think that those millions of cells are going to be 18650 format you probably would be wrong.

The problem from a manufacturing side is that the cells, although only incrementally larger, are. This precludes their use for retrofitting into existing battery housings and although you can use less cells to achieve the same voltage the increase in battery length creates an engineering problem for the manufacturers getting them to fit in with their existing designs based on the 18650 cells. This will happen gradually as the cells become more readily available but as mentioned before will leave the owners of previous bikes with proprietary systems having to switch bikes to get to the upgrade. As historically the bike industry likes nothing better that to introduce new standards that make this inevitable, headsets, boost etc., I don't think they are too concerned as ultimately it means they sell more bikes. But it also means a stall in their introduction into the e bike market due to this fact IMNSHO.

As usual the "hobby" market is better able to adjust as their more open source based format allows it the freedom to somewhat easily redesign the battery case and still fit existing "hobby" type builds. To me this is a big deal and something that I have always found the most attractive about the "hobby" market as I personally don't have the expendable income to buy a whole new bike every two years as technology advances and even if I did I would probably still gripe about it.

Oh, and that 36v 30a battery I mentioned earlier is made entirely possible using the new cell structure......lighter, stronger and longer lasting than any battery currently in use in only a slightly larger enclosure. Or go with a 20a and get greatly increased range. Sounds good to me! But as the title of this thread suggests, still a good idea to stick with a good brand with some rep when they do start to appear. There is still the possibility of bad cells and sketchy manufacturing by those that are just about staying in line with the trend set by them to be considered.

 

[Asher]

Thank you for the explanation, JRA.

For bikes where the battery, like my Juiced CCS, isn't completely encased in the frame, I don't see why you couldn't design a backwards compatible 21700 battery. It's also already designed to run at 52V.

While I don't have the 52V version, you do notice the power responsiveness dropping from say, 51 to 49V, let alone below. Though first time ebike users will be impressed by virtually any decent ebike.

 

[Alex M]

You are assuming there is no A, B, or C quality parts. I know more about woodworking machinery. Big brand companies have their machinery made in the same factory as the cheap brands. When Delta Machinery was still an American company, they had quality control people on staff in the company. They rejected cast iron castings when it did not meet spec. They didn’t scrap the parts, they were put in the cheap brand machines. No idea if bike companies do the same. I knew executives in woodworking companies, I know no one in the bike companies.

E-parts in A.B, and C are Chinese, both by designer/developer and factory location. US e-bike "brands" didn't develop their controllers, motors, batteries. Maybe they did, long time ago, and then it's been cloned ad infinitum. Like Thomas said, China is a big place - think big Walmart with little factory in the back, thousands of them. Quality mid-low. I'm talking bikes under 2.5K. At best, battery cells in the pack are brand name, and God only knows how they are packed together and what BMS.

You can't compare this to Delta. Hypothetically, they "could" produce if consumer demanded and zillion middlemen on both sides of the border forfeited their profits. I suspect that QA is a big part of the product cost, because this is China, you can't just tell people to do an honest job and expect it to happen. And even at high cost of QA, it's still difficult there.

 

[JRA]

Thank you for the explanation, JRA. You are welcome but it is only an opinion based on the facts as I see them developing.

It's also already designed to run at 52V.

The fact that your bike is set to run at 52v is not going to mean anything as the new cells can be made into any sort of voltage configuration. The issue as stated is the size differential and the ability for your battery type to be adapted to it. Hopefully yes, but even semi integrated batteries will take some creative shoe horning to make them so.

 

[Leandro]

UL lithium ion battery testing

 

[tomjasz]

prevent chance of having short circuit as there are no two cells touching each other.

Brand name batteries are shrink wrapped in materials that will prevent this from happening. Out of the thousands of sales I have been involved with, batteries from reputable builders have never had a short circuit problem related to their wrapping. Yet all batteries should be monitored while charging. I added smoke and heat sensors to my steel cased battery storage/charging cabinet.

 

[Trail Cruiser]

It doesn't matter if it is e-bike or e-scooter, it's wise to purchase from a trusted and reliable source.

 

[tomjasz]

It doesn't matter if it is e-bike or e-scooter, it's wise purchase from a trusted and reliable source.

It's unlikely that was a Li ion fire. More likely, especially given it was not in the USA, a LiPo fire. The only eBike folks using Li Po are the home builders and RC crowd.