Why aren't there quick chargers for ebike?

[Oski1997]

Has to do with the charger wattage , amps and battery amps.

Assuming the 500wh battery is 36volts . 500:36= 13.8ah. 13.8ah:4ah(charger amps)= 3.47hours.

If the Grin Satator charger would work on this battery you could have charge at 6.8ah w/o any issues ! Even @8ah the max. rate that the Satiator works.

The reason that charge rate is closer to 4hours and not 3.47h it's due to the slower cycle in the last 25% portion of charging.

It is common in the Ev sector to amplify either the range or the charging times in order to entice customers.

Ebiker01, Yamaha says it takes 2 hours to charge form 75% to 100%. Does that mean that theoretically (using your math) the Yamaha battery should be able to be charged from 0% to 75% in 1.47 hours?

 

[Ebiker01]

Ebiker01, Yamaha says it takes 2 hours to charge form 75% to 100%. Does that mean that theoretically (using your math) the Yamaha battery should be able to be charged from 0% to 75% in 1.47 hours?

Ebiker01, Yamaha says it takes 2 hours to charge form 75% to 100%. Does that mean that theoretically (using your math) the Yamaha battery should be able to be charged from 0% to 75% in 1.47 hours?

My math was wrong b/c i did 13.8:4ah but the charging rate progressively slows down after about 75%.

It would be 0.75x13.8ah(total battery amps) =10.35ah which is 75%.

To charge 10.35ah @4ah/hour rate it takes 2h 35min. 25 seconds time for 0-75%.

Then with the other 2 hours that Yamaha gives from 75%-100% , we get 4h 35min 25sec for a full 100%charge for 500wh pack. If the pack lost some capacity the time is shorter .

But i'm not sure where exactly the charging rate starts to slow down from 4ah to 3.8ah and lower. If it slows down @75,80, 85% ? It should slow down at 75-79%.

Also It takes 15min. to charge 1 amp up to 75% or 80% maybe ? You Could set a timer to charge it based on this numbers.

If you are @30% (4.14ah) set timer 1hour 30min, 6ah IN, battery now has 10.14ah almost 75%.

On my 605wh battery charging @ 6.2amps it slows down to 5ah from 79% then to 4.2 @ 87% and so on....But my battery could have about 10% less amps deterioration by now.

404wh charged in 1hr 24min- That's the advantage of the Grin Satiator charger !

 

[Oski1997]

My math was wrong b/c i did 13.8:4ah but the charging rate progressively slows down after about 75%.

It would be 0.75x13.8ah(total battery amps) =10.35ah which is 75%.

To charge 10.35ah @4ah/hour rate it takes 2h 35min. 25 seconds time for 0-75%.

Then with the other 2 hours that Yamaha gives from 75%-100% , we get 4h 35min 25sec for a full 100%charge for 500wh pack. If the pack lost some capacity the time is shorter .

But i'm not sure where exactly the charging rate starts to slow down from 4ah to 3.8ah and lower. If it slows down @75,80, 85% ? It should slow down at 75-79%.

Also It takes 15min. to charge 1 amp up to 75% or 80% maybe ? You Could set a timer to charge it based on this numbers.

If you are @30% (4.14ah) set timer 1hour 30min, 6ah IN, battery now has 10.14ah almost 75%.

On my 605wh battery charging @ 6.2amps it slows down to 5ah from 79% then to 4.2 @ 87% and so on....But my battery could have about 10% less amps deterioration by now.

404wh charged in 1hr 24min- That's the advantage of the Grin Satiator charger !

I’m going on a ride on Friday. I’ll drain my battery down to 10% and see how long it takes for it to get to 75%. I’ll be in touch

 

[Kayakguy]

If cell phones and laptops had the size of battery pack your eBike does, they wouldn't be a quick charge either. The Tesla charger you refer to is a 220v input charger. Want to carry one of those to the coffee shop?

Although it is slow (about 5 or so hours to charge), the charger than came with my Ariel Rider C class does have the option of 220v input. You just use the right adapter to fit 220 outlet. But this gives no speed-up to the charging rate. I think it may be a feature for using in Europe, Japan, Australia, etc.

 

[Bee Lo on the Go]

I try not to discharge my battery lower than 30% and not higher than 80% bc I want them to last longer (that’s one of the reasons I bought an extra battery to carry on the bike). But I’m wanting to test the charging time from 10% to 70% to see how long it takes. Do you think if I do it just a handful of times in the life of the battery, it’ll still affect the capacity of the battery? I don’t want to injure the capacity just for curiosity’s sake. The reason I’m choosing up to 70% is because I think I remember the charging started to slow down at 70%.

Where did you purchase your extra battery?

 

[Oski1997]

Where did you purchase your extra battery?

I bought it at the bike shop at the same time I bought my Civante for $850 + tax in Irvine, CA.

 

[Bee Lo on the Go]

Thanks

 

[Oski1997]

I’m going on a ride on Friday. I’ll drain my battery down to 10% and see how long it takes for it to get to 75%. I’ll be in touch

My math was wrong b/c i did 13.8:4ah but the charging rate progressively slows down after about 75%.

It would be 0.75x13.8ah(total battery amps) =10.35ah which is 75%.

To charge 10.35ah @4ah/hour rate it takes 2h 35min. 25 seconds time for 0-75%.

Then with the other 2 hours that Yamaha gives from 75%-100% , we get 4h 35min 25sec for a full 100%charge for 500wh pack. If the pack lost some capacity the time is shorter .

But i'm not sure where exactly the charging rate starts to slow down from 4ah to 3.8ah and lower. If it slows down @75,80, 85% ? It should slow down at 75-79%.

Also It takes 15min. to charge 1 amp up to 75% or 80% maybe ? You Could set a timer to charge it based on this numbers.

If you are @30% (4.14ah) set timer 1hour 30min, 6ah IN, battery now has 10.14ah almost 75%.

On my 605wh battery charging @ 6.2amps it slows down to 5ah from 79% then to 4.2 @ 87% and so on....But my battery could have about 10% less amps deterioration by now.

404wh charged in 1hr 24min- That's the advantage of the Grin Satiator charger !

You are correct. This battery is like a clock. I checked the %charge every 10min starting at 5%. Like clock work, it charged in 5% increments every 10min. It took me 2hrs 50min to charge 5%- 90%. The charging rate only slowed down the last 90-100% (It took 60min to charge the last 10%). So, to go from 0-100% it takes me 4hrs.

 

[Ebiker01]

You are correct. This battery is like a clock. I checked the %charge every 10min starting at 5%. Like clock work, it charged in 5% increments every 10min. It took me 2hrs 50min to charge 5%- 90%. The charging rate only slowed down the last 90-100% (It took 60min to charge the last 10%). So, to go from 0-100% it takes me 4hrs.

After the battery losing some capacity I guess you know many charging cycles " the clock" will slightly change

 

[Oski1997]

After the battery losing some capacity I guess you know many charging cycles " the clock" will slightly change

Giant uses a 6v charger which charges their 625w battery from 0-80% in 2.2 hours. Is there a reason why other battery manufacturers don’t use a 6v charger (Which stops at 80% to prevent stressing the cells, of course).

 

[Oski1997]

Thanks for tagging me on this thread.
One of my upcoming research projects for 2020 is to reduce the charging time for next-gen EV batteries. So, I can comment on this.

Quick charging is a hard scientific problem, especially for EVs.

It reminds me of what Guy Kawasaki, one of earliest Apple Investors said... " wireless charging and quick charging are superb ideas and anyone who solves that at commercial scale, would become a billionaire"

Phones can be charged at fast rates because they only offer 1yr warranty and after 500 days/350 cycles, the phone battery capacity sucks but people can afford to replace it.
But, it's quite another thing to replace an EV battery.
It is easy to design batteries that can be charged in 20 mins but the cycle life takes a hit and EV owners don't want that. In an EV, you want very long cycle life.

It is safe to charge at ~ 0.5C and anything more, you would want thermal management and as folks alluded here, weight and cost are limiting factors to implement that on an E-bike. I am sure we will better chargers in the coming years as E-bikes become mainstream.

A large number of 2A and 4A chargers are not built for long-term usage. Among all E-bike chargers, Grin Satiator is one of the very best.

I saw a video that said the new batteries from Panasonic use lithium cobalt manganese cells. The cells have their own temperature gauges, which allows Giant to provide 6a chargers to the bikes that use Panasonics new batteries. Giant says ”this specific type of battery has the lowest discharge rate of all E-Bike batteries, which is an advantage when the bike isn’t being used... there's going to be more charge in it than another battery pack could offer. It also decreases wear and tear on the battery and extends it's charging lifecycle.” Is Giant’s battery the Panasonic/Sanyo NCR18650GA ?? I couldn’t find the cell info.
Ravi, do you know if Yamaha uses lithium cobalt manganese cells? If not, do you know what material they use? I believe Yamaha uses Samsung batteries but I don’t know if they use 35e or 30q. The discharge rate for 35e is 18.9 milliohms and for the 30q it is 12. I also don’t know what those batteries are made of. Does this mean that the Panasonic cobalt manganese cells have to have an internal resistance lower than 12 for Giant’s claim “... has the lowest discharge rate” to be true? And finally, is it generally believed that manganese cells offer THE BEST charge because it offers the lowest discharge rate of any other ebike battery?

 

[Stefan Mikes]

6v

6 A, of course. As I own a Giant e-bike with such a charger, I can tell you Giant batteries (I own two of them) seem to degrade more rapidly than Specialized ones charged at 4 A.

 

[Oski1997]

6 A, of course. As I own a Giant e-bike with such a charger, I can tell you Giant batteries (I own two of them) seem to degrade more rapidly than Specialized ones charged at 4 A.

Do you know if Specialized uses Samsung, LG, Sony, or Panasonic lithium ion batteries? Sony/Murata has a better discharge rate (11.8 milliomps) than Samsung (12 milliomps). LG has a discharge rate of 12.3. They’re all better than the 21.9 milliomps of Panasonic/Sanyo’s NCR1850GA. Since you have first-hand experience with the Panasonic batteries Giant uses, maybe Giant is just marketing their batteries as “the best” without real data??

 

[Stefan Mikes]

Do you know if Specialized uses Samsung, LG, Sony, or Panasonic lithium ion batteries?

No idea...

Since you have first-hand experience with the Panasonic batteries Giant uses, maybe Giant is just marketing their batteries as “the best” without real data??

It's highly probable.