Greenway Cross City

[anotherkiwi]

My feeling is never ask more than 1C from a battery. My 10.4 Ah Li-ion worked OK with the Mxus hub motor because I wasn't asking it for more than 11 Amps most of the time. As soon as it was used with the GSM it started sagging badly but if I only ask 10 Amps or less it plugs along giving about 8 Ah from a full charge.

A couple of 10.4 Ah batteries in parallel is another solution.

 

[Ultrafunkula]

your motor is stamped 350W, it will pull more current than the 250W version.
I think you will need a better battery on the long term.

Is this a case of battery size 10.6 / motor current 14a slightly imbalanced as in unable to cope with discharge demand for working hard , but suited to flat terrain, e.g. Holland and the fens, and fact that motor is in effect sited for 350w and tuned down Woosh?
A 36v 15 to 20ah would be able to cope with demand not suffer the rapid drop in V due to capacity/size, and remain legal?

 

[anotherkiwi]

Answer to both: Yes. China is pretty flat in the cities too.

The first time I rode with my 20 Ah LiPo I was blown away, 0.6V sag in assistance level 5 of 5 on 15% climbs is something you can only love! Even using just the 10 Ah of LiPo is better because it is capable of supplying 15 Amps continuous, it will sag over 1 Volt though. A Watt meter between the battery and the controller will tell you max Amps and max Volts.

 

[Woosh]

UF,
I can't advise you because I don't have access to one of those motors. My evaluation bikes are still in Shanghai.
We know the cell pack is made with Samsung but you need to weigh the battery to determine the cell type. Typically, 10.4AH packs are made with 10S4P, 40 x ICR18650-26F cells and should weigh 40 x 50g + 500g for the wires and casing, about 2.5kg.
The cells inside should be pink. http://www.batteryspace.com/prod-specs/ICR18650-26F.pdf

Those cells have an internal resistance that goes up with discharge, 18milliOhms when you are at the bottom of the hill, 33milliOhms when you are half way up.
A 350W Bafang will pull 18A climbing hills if Bafang specify the Max Drive the same way as with their BBS01 motor. That will give a voltage sag of 18A * 0.033 Ohms * 10 / 4 = 1.49V sag. You freshly charged battery would show 39.5V or two or three bars instead of 4 when climbing hard. Less if the battery is a bit depleted.

Edit: sorry for the mistake.

 

[redcup1999]

I went out for another ride this evening.

Much better.

I'm still waiting for the replacement disc to arrive, so didn't go hell for leather.

I did keep the assist level on 3 and used a gear or two lower than I would normally use up the hills. Sag was not noticeable through my legs, but the level on the display dropped by 3 bars towards the top of the hill, before recovering (I think the display is far too sensitive with regards to changes in voltage). At the end of the 6.2 mile ride, the battery level on the display had recovered to showing a full 10 bars.

Unfortunately I messed up the strava recording, so am unable to provide a direct comparison with the Crossfire and Tornado, although it did "feel" a bit faster, albeit with more frantic spinning of the legs.

 

[anotherkiwi]

I went out for another ride this evening.

Much better.

I'm still waiting for the replacement disc to arrive, so didn't go hell for leather.

I did keep the assist level on 3 and used a gear or two lower than I would normally use up the hills. Sag was not noticeable through my legs, but the level on the display dropped by 3 bars towards the top of the hill, before recovering (I think the display is far too sensitive with regards to changes in voltage). At the end of the 6.2 mile ride, the battery level on the display had recovered to showing a full 10 bars.

Unfortunately I messed up the strava recording, so am unable to provide a direct comparison with the Crossfire and Tornado, although it did "feel" a bit faster, albeit with more frantic spinning of the legs.

I went for a ride too, chilly 9-12°C but dry and sunny. I don't look at the bars any more, I look at the voltage reading. I left home with 38.4 V and after about 28 km came home at 37.4. I experienced the usual 0.6 V sag so at times the voltage reading was 36.7 V. There is about another 20 km of less hilly riding left in the battery.

I am a bit fitter having been out the last two weeks so am back to spinning at my normal cadence of 60 to 70. I tried the 32 tooth front chainwheel again and found the right gearing to climb the steep hill at 25 km/h!

 

[redcup1999]

New disc received in the post today at no charge - good service from Greenway

 

[Recy]

Buddy recently had cause to contact them with a small issue, they responded at once to sort it out. Will keep posted, but so far so good. Reassuring

 

[Ultrafunkula]

Just been onto his Greenway site on eBay ,the commuter version with mudguards ,rack etc, but with cable disc brakes, is doing well 5 sold and almost gone . 4 sold and almost gone are the Cross version, other sellers have them listed though so he may have sold some to other local dealers, when he first got them, but are a fair bit dearer on price.

 

[brightonebikes]

I'm pretty sure the cells inside are Samsung pinkies, ICR-26F, poss. ICR-26H.

Sent using this crappy tapatalk app. that has such poor functionality I can't even click 'like'!

 

[Ultrafunkula]

A quick update regarding battery sag that we've been seeing on our bikes, I have purchased a controller lead and programming software, my bike has the amps set to 20a it's a 25amp 36v nominal volts controller ,so stamped on motor casing to 14a 250w 36v,is incorrect regarding the amps . motor casing ID stamp g33 350 so confirming it's a 350w unit only held back by manual speed setting in display, and that battery cannot cope with the discharge rate, I'm going to save a few pennies up and purchase a 17ah 48v battery for the old girl.

 

[redcup1999]

A quick update regarding battery sag that we've been seeing on our bikes, I have purchased a controller lead and programming software,

Interesting. I've got the lead, but not done anything with it yet - do you have to take the motor casing off to plug it in, or is there somewhere you can plug in closer to the display unit? (I've been too busy to look yet!).

The controller may be a 20amp controller, but is that full 20amps being used on assist level 5? I guess it depends on other settings? But I think that may explain the hideous sag and also my findings that it seems to perform better up hills on assist level 3 rather than level 5.

I'm hoping to order a new battery in the next few days - it's looking like I will go for 15Ah 36V with Samsung 30Q cells to try and ensure the pack can supply enough current to unleash the motor.

 

[brightonebikes]

The cable plugs into the green Higo connector where the display currently does, no need to remove anything to do that.
Totally agree that the battery performance is underwhelming. I don't think I'll go up to 48V, but will spec. something up to 36V approx. 15Ah with continuous discharge rating of 25A and max of 30A.
With a view of using the bike in places where the full potential of the motor can be unleashed without contravening any laws power allowance wise, including upping the max assist speed limit, it definitely needs an uprated battery to do so.
As it stands it's perfectly usable if you don't wish to rinse the thing for everything it's got to offer
Moving forward with throttle fitting too, but will update on that at a latter time

 

[Ultrafunkula]

Interesting. I've got the lead, but not done anything with it yet - do you have to take the motor casing off to plug it in, or is there somewhere you can plug in closer to the display unit? (I've been too busy to look yet!).

The controller may be a 20amp controller, but is that full 20amps being used on assist level 5? I guess it depends on other settings? But I think that may explain the hideous sag and also my findings that it seems to perform better up hills on assist level 3 rather than level 5.

I'm hoping to order a new battery in the next few days - it's looking like I will go for 15Ah 36V with Samsung 30Q cells to try and ensure the pack can supply enough current to unleash the motor.

Lead plugs in at top of the down tube by headstock, just pull the display lead and you will see the connector come out from behind the Ill fitting grommet, pop it apart, disconnect battery, plug the lead in and have a mooch around.
I've upped my assist keep current from a lowly 30% to 60, gonna give it a whirl in the morning. And in throttle section it has max speed at 34kmh so I've set that to as designated by display.

 

[redcup1999]

Thanks both.

I've plugged in and read all the data from the controller.

I'm attaching screen grabs here in the unadulterated state for future reference.

The only change I've made so far is to drop the Current Limit from 20Amps down to 11Amps to try and help preserve the integrity of the battery. I'm tempted to up the keep current as well though.

 

[Ultrafunkula]

Thanks both.

I've plugged in and read all the data from the controller.

I'm attaching screen grabs here in the unadulterated state for future reference.

The only change I've made so far is to drop the Max Current from 20Amps down to 11Amps to try and help preserve the integrity of the battery. I'm tempted to up the keep current as well though.

View attachment 17803 View attachment 17804 View attachment 17805

Wheel diameter to 700c instead of 26 red

 

[redcup1999]

Wheel diameter to 700c instead of 26 red

Ha - just spotted that. I would assume that the display value overides that, but will change it anyway.

 

[brightonebikes]

Thanks both.

I've plugged in and read all the data from the controller.

I'm attaching screen grabs here in the unadulterated state for future reference.

The only change I've made so far is to drop the Current Limit from 20Amps down to 11Amps to try and help preserve the integrity of the battery. I'm tempted to up the keep current as well though.

View attachment 17803 View attachment 17804 View attachment 17805

The throttle tab has not bearing on anything at present.
11A could be a little too low to appreciate the motor, especially with keep current at 30%.
Perhaps try 14-15A and keep current around 40%. That should give a nice balance of sufficient power when needed but maintain decent range.
Shouldn't create any bad sag effect either.
It's all about finding a good balance for how and where you ride.


Sent using this crappy tapatalk app. that has such poor functionality I can't even click 'like'!

 

[redcup1999]

The throttle tab has not bearing on anything at present.
11A could be a little too low to appreciate the motor, especially with keep current at 30%.
Perhaps try 14-15A and keep current around 40%. That should give a nice balance of sufficient power when needed but maintain decent range.
Shouldn't create any bad sag effect either.
It's all about finding a good balance for how and where you ride.


Sent using this crappy tapatalk app. that has such poor functionality I can't even click 'like'!

Agreed - after a bit more reading, I'm upping Keep Current to 70% and going with a current limit of 13A. This should keep me within the limits of the battery once going and provide me with the welly I want when going up hill.

Alas I won't have time to test tomorrow, but will be doing my "usual" Sunday morning route so will see if that brings performance up to where I want it to be.

 

[brightonebikes]

Agreed - after a bit more reading, I'm upping Keep Current to 70% and going with a current limit of 13A. This should keep me within the limits of the battery once going and provide me with the welly I want when going up hill.

Alas I won't have time to test tomorrow, but will be doing my "usual" Sunday morning route so will see if that brings performance up to where I want it to be.

I find it great fun making little tweaks and improving the performance to suit your needs. It's not all about raising the power to go like a bat out of hell, finding a happy medium that provides a balance of power and range is the go!
Once familiar with programming techniques, it;s easy to store a few 'maps' to use depending what sort of days riding you have planned.
The biggest thing to remember is to make small incremental changes at a time and test, not going from one end of the scale to the other. Enjoy. Hope you have a great Sunday ride out