8fun kit performance

[Deleted member 4366]

Looks like it is a 185rpm motor, despite the big green "26" sticker on the hub...

I will drop them an email and see if it can be exchanged for a 201rpm one - fingers crossed!

Pic attached showing the model number.

View attachment 3005

I would've thought 185rpm would be better unless you like to pedal hard. Don't forget that that's the rated speed at 36v. Yours will be about 39v most of the time so about 10% faster, which is approx. 201rpm anyway.

X332race:
Adding solder to the shunt reduces its resistance. The controller figures out the current by checking the difference in voltage each side of the shunt, which depends on its resistance and the current. The lower the voltage difference, the lower the perceived (by the controller) current, so that when it thinks its max current has been reached its actually higher. Therefore you can increase the amount of current that the controller will give, which means more power but not top speed. Ideal current for a 250w Bafang hub-motor IMHO is about 18amps, which gives reasonable climbing power without over-stressing the motor. Naturally, the more amps you use, the less range you get. If you like to pedal hard, 15 amps or less might be better. With 20 amps you can go up very steep hills without pedalling very hard, but it puts more stress on the battery and motor and is noisy. If you need 20 amps or more, the bigger BPM motor is better with a suitable battery.

 

[x332race]

Thanks d8veh.....I can climb all the hills near me fairly easily with not too much trouble so I don't think I need to increase the amps to my motor....however its good to understand what everyone is tackling about just in-case it is relevant!
Regards.

 

[NRG]

Seconded d8veh description. Re the OP, 185rpm is giving you 16mph unloaded on a fully charged battery, this is low, I think this is your problem you need a higher RPM motor plus a bit of shunt soldering...

Thats my photo by the way.

 

[flecc]

Nominally 26" tyres are rather smaller in diameter, typically in the 640/644 mm region, so the 185 rpm only represents about 13.9 mph which roughly matches what you are getting. The 201 rpm represents 15.1 mph.

Getting better current delivery by adding solder to the shunt may lift those very slightly.

 

[jocu3]

Looks like it is a 185rpm motor, despite the big green "26" sticker on the hub...

I will drop them an email and see if it can be exchanged for a 201rpm one - fingers crossed!

Pic attached showing the model number.

View attachment 3005

Hi FJJ, I have exactly the same kit with the same problem. Did you contact the seller and get any answer?

I'm going to replace the 26" rim with 27" one, which matches my original rim size, so I get a small performance boost from that, but I'm still thinking if it would be better to get a motor with higher rpms.

Cheers

 

[Deleted member 4366]

Hi FJJ, I have exactly the same kit with the same problem. Did you contact the seller and get any answer?

I'm going to replace the 26" rim with 27" one, which matches my original rim size, so I get a small performance boost from that, but I'm still thinking if it would be better to get a motor with higher rpms.

Cheers

do you know what the speed is with the wheel off the ground?

 

[FJJ]

Hi FJJ, I have exactly the same kit with the same problem. Did you contact the seller and get any answer?

I'm going to replace the 26" rim with 27" one, which matches my original rim size, so I get a small performance boost from that, but I'm still thinking if it would be better to get a motor with higher rpms.

Cheers

Hi jocu3, It looks like the RPM is correct for a 26" for hill climbing etc. but the seller did say they have limited the controller amps to protect the battery, I guess these bottle batteries don't have too high a C rate. The seller was really helpful and we agreed that I could return the battery and controller, I am going to replace them with a Ping V2.5 36V 15Ah LifePO4 battery and the new KU65 controller from BMS Battery. The BMS stuff which I ordered is due for delivery today (FYI DHL now only charge a £1.25 admin fee for low value imports where the total duty/vat due is < £62.50 or a 2% fee where the value is above), and the Hong Kong Post website shows that the battery was picked up yesterday.

I'll report back once I've tried the new battery and controller combination.

Cheers, FJJ

 

[NRG]

Glad you got to a resolution, however, I'm a little concerned that as the nominal voltage is the same as the original battery the top speed may be similar to what is was before...there again as you are replacing the controller and will be using a better battery the voltage will hold up better under load so the on-road speed hopefully will be greater....hope it goes well.

 

[jocu3]

do you know what the speed is with the wheel off the ground?

Yes, it is 16 mph when I use throttle and lift the front tyre. On the road speed is about 13 mph with throttle and 14-14.5 mph when using pedelec (with high-setting). But it has been snowy and I have studded tire, which may have some impact also.

Otherwise I'm very pleased with the kit. It's silent and I can cycle 6 miles to job without any sweat! Battery lasts at least two days (24 miles), but I normally charge it every evening.

 

[Deleted member 4366]

Yes, it is 16 mph when I use throttle and lift the front tyre. On the road speed is about 13 mph with throttle and 14-14.5 mph when using pedelec (with high-setting). But it has been snowy and I have studded tire, which may have some impact also.

Otherwise I'm very pleased with the kit. It's silent and I can cycle 6 miles to job without any sweat! Battery lasts at least two days (24 miles), but I normally charge it every evening.

If you have the bottle battery, it looks like you're stuck. I've got a feel that the low speed is partly due to the low power. A few more amps might get you up to 15 mph. If you have the 10aH rack battery, then you could either get a 15amp controller or solder the shunt. In my experience, the noise of these motors is proportional to the amps, so you would get a bit more noise under power.

 

[PhilYerBoots]

Hi jocu3, It looks like the RPM is correct for a 26" for hill climbing etc. but the seller did say they have limited the controller amps to protect the battery, I guess these bottle batteries don't have too high a C rate. The seller was really helpful and we agreed that I could return the battery and controller, I am going to replace them with a Ping V2.5 36V 15Ah LifePO4 battery and the new KU65 controller from BMS Battery. The BMS stuff which I ordered is due for delivery today (FYI DHL now only charge a £1.25 admin fee for low value imports where the total duty/vat due is < £62.50 or a 2% fee where the value is above), and the Hong Kong Post website shows that the battery was picked up yesterday.

I'll report back once I've tried the new battery and controller combination.

Cheers, FJJ

I'd be very interested to know how much extra you get charged in total duty/vat and fees on top of BMS and Pings normal prices (oh and postage cost as well..), as I'm looking to get a kit from BMS and the same battery from Ping myself..

 

[Deleted member 4366]

I'd be very interested to know how much extra you get charged in total duty/vat and fees on top of BMS and Pings normal prices (oh and postage cost as well..), as I'm looking to get a kit from BMS and the same battery from Ping myself..

The last couple of times it was £20 to £25. I never had to pay anything for about 10 deliveries before that.

 

[PhilYerBoots]

Thanks Dave.
Just looked up Ping's postage - $95 ouch ! - probably similar for a BMS kit I'd guess. Still the cheapest way to put a decent kit together though and I can see why so many people on here use them.

 

[FJJ]

I'd be very interested to know how much extra you get charged in total duty/vat and fees on top of BMS and Pings normal prices (oh and postage cost as well..), as I'm looking to get a kit from BMS and the same battery from Ping myself..

For BMS I got charged £15.50 on a total order value (incl postage, which you do get charged VAT on) of $109 (shipping was with DHL out of HK even though I had selected CNSFEDEX) which seems about right.

Will let you know re the VAT and Duty on the Ping battery once it arrives, it was also $95 for shipping and it was sent via Hong Kong Post.

 

[FJJ]

I managed to collect my shiny new Ping Battery from the post office today, very well packaged and came with a 2.5A charger. I ordered a 5A charger from BMS too for quick charging. Had a very quick check of it tonight, soldered an HXT-60 connector on and plugged it in to my new KU65 controller - lights came on on the control panel but no motor... Fitted the wheel with the motor and connected the phase wires, and all was good :roll eyes: Seems to only register about 11mph WOT unloaded, but with the limiter wires disconnected its more like 21 At WOT it was pulling about 1.6A on my Turnigy watt meter. Bad news was that it doesn't seem compatible with my current pedelec sensor so it is off with the cranks and BB tomorrow to change it for the BMS one (which has a very short cable that I will have to extend )

 

[Deleted member 4366]

I managed to collect my shiny new Ping Battery from the post office today, very well packaged and came with a 2.5A charger. I ordered a 5A charger from BMS too for quick charging. Had a very quick check of it tonight, soldered an HXT-60 connector on and plugged it in to my new KU65 controller - lights came on on the control panel but no motor... Fitted the wheel with the motor and connected the phase wires, and all was good :roll eyes: Seems to only register about 11mph WOT unloaded, but with the limiter wires disconnected its more like 21 At WOT it was pulling about 1.6A on my Turnigy watt meter. Bad news was that it doesn't seem compatible with my current pedelec sensor so it is off with the cranks and BB tomorrow to change it for the BMS one (which has a very short cable that I will have to extend )

Did you manage to dodge duty on the battery? Just a thought: I seem to remember somebody blowing his BMS by using a higher powered charger. Did you opt for the higher current BMS? In the spec for the battery, it says charging current less than 5A, so it might be best to check with Ping whether that charger's OK before you use it. I think that the BMSbattery one is the same as what Ping supplies. How come you didn't tick the option when ordering from Ping?

 

[FJJ]

Hi d8veh, I'm still waiting on a bill for duty

I didn't get a higher current BMS, but the specs indicated 5A was the max charge current... Ping will supply a 5A charger with it for an extra $44 - do you think that includes an upgraded BMS?

 

[Hurricane]

Hi d8veh, I'm still waiting on a bill for duty

Did you get asked to show proof of payment for ping battery? I had to send mine to fedex and got a bill for £215 for 2x ping 20ah 36v

I was told that C&E do not believe Honk Kong shipper showing value at $80 each and fedex would not deliver till I produced a copy of payment.

Interested to hear how you get on.

 

[FJJ]

It was EMS shipping with parcelforce this end, I wasn't required to fax anything and it was marked as 'power system' rather than battery.

Did you get asked to show proof of payment for ping battery? I had to send mine to fedex and got a bill for £215 for 2x ping 20ah 36v

I was told that C&E do not believe Honk Kong shipper showing value at $80 each and fedex would not deliver till I produced a copy of payment.

Interested to hear how you get on.

 

[Deleted member 4366]

Hi d8veh, I'm still waiting on a bill for duty

I didn't get a higher current BMS, but the specs indicated 5A was the max charge current... Ping will supply a 5A charger with it for an extra $44 - do you think that includes an upgraded BMS?

I think you're in the clear from duty if you haven't yet had a bill.

When I ordered my 36v 20aH, I upgraded to the 5aH charger and a higher rate BMS, which doesn't seem to be an option on yours. My battery can give 40 amps, so I don't think the higher current BMS was for that. I definitely remember, perhaps on ES, that a guy ordered a battery and charger that weren't compatible. My advice would be to e-mail Ping to check before using it. The smaller charger will be OK for now. I guess he'll be on holiday for the Chinese New Year, so you might not get a reply for a bit.