40 mile round trip commute - 20mph - help please :)

[LeighPing]

I don't have to cycle every day since I have a car and 200cc scooter. But I would like to do it at least twice per week

Ah.. not too bad then. My commute is 18 miles each way. 5 miles countryside, 13 miles urban. If it were the other way round, I'd probably park the car up and do the last 10 on the bike. I've thought about it often. Maybe one day.

 

[emjay]

I'm going to be putting together a fast commuter kit very similar to the one you're proposing (same motor, similar battery/controller), hopefully very soon - the bits are currently sitting in cardboard boxes in my shed - so I'll try to write up my experience and drop a link here in case it's useful.

 

[Forge Custom]

Re controllers, can anyone explain what a MOSFET is in simple terms a technical lightweight like myself might understand please?!

Cheers

 

[LeighPing]

Re controllers, can anyone explain what a MOSFET is in simple terms a technical lightweight like myself might understand please?!

Cheers

https://en.wikipedia.org/wiki/MOSFET

 

[Forge Custom]

https://en.wikipedia.org/wiki/MOSFET

Yes - I've seen that but what does it mean in controller terms?! For example.
36V/48V 350W 6Mosfets 17A Brushless DC Sine Wave Controller

 

[D8ve]

Yes - I've seen that but what does it mean in controller terms?! For example.
36V/48V 350W 6Mosfets 17A Brushless DC Sine Wave Controller

A MOSFET is like a carburettor, it allows power to energy into the engine.
More is better if you need high power. 6 is about the minimum and 12 is common but not nessiasry for a 350 watt bike.

 

[Wicky]

http://www.50cycles.com/electric-bikes/e-motorcycles/ts1200r.html

;-)

 

[Forge Custom]

A MOSFET is like a carburettor, it allows power to energy into the engine.
More is better if you need high power. 6 is about the minimum and 12 is common but not nessiasry for a 350 watt bike.

Got it. Thanks D8ve!

 

[Forge Custom]

Thanks d8veh,

I know that I shouldn't be spoon fed but I really don't wish to mess this up.

Is this all ok before I purchase? Any issues with this battery suggestion? And also, does anybody know which charger would be suitable as I believe a slow charger which can be stopped at 90% is a worthwhile investment (and I will ideally want two if I plan to charge both ways).

From BMS:

Q128C Rear 36V 201RPM
https://bmsbattery.com/ebike-kit/768-q128c-135mm-500w-rear-driving-ebike-hub-motor-ebike-kit.html#/213-rpm-201/42-voltage-36v

48V14.5Ah Case-08 Bottle Panasonic Battery Pack No Controller with a USB Charger
https://bmsbattery.com/ebike-battery/819-48v116ah-case-08-bottle-panasonic-battery-pack-battery.html#/27-ac_voltage-200264vac

From PSWPower:

36V/48V 350W 6Mosfets 17A Brushless DC Sine Wave Controller
http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-39N8.50CQE
+
KT-LCD6 display
Lamp & Switch ($6 so why not)
Left Throttle (may not install)
Wuxing Brake (don't think I will purchase given that PAS sensor will solve that issue)
Speed Sensor
Dual Hall PAS Sensor

I don't know if this is correct but that controller is listed for a 350W motor. The Q128C is listed as 500W. So would this 20a controller be better? Anybody know?
http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

 

[Steve A]

Just here to trump SW's photo.View attachment 21197

God i love these comparisons, not! I know its only a bit of fun, but please i thought i left strava etc behind grrr.

As someone who was a bit obsessed with PR's, KOMS etc i soon realised you can't compare..

bike i.e weight, tyres size, wheel size, crank etc etc etc
weather conditions
is person just saving themselves for that ride , KOM
are they riding in a group
The list goes on. I can show you an average on over 25mph, but guess what it proves nothing.

Getting off my soap box now.

 

[anotherkiwi]

I don't know if this is correct but that controller is listed for a 350W motor. The Q128C is listed as 500W. So would this 20a controller be better? Anybody know?
http://www.pswpower.com/peng/iview.asp?KeyID=dtpic-2016-3F-33C0.50CGS

The 17 A controller will give you 816 W peak with a 48 V battery. The 500 W motor rating is the power at which the motor will run at for 1 hour without heating, just like the 250 W rating of legal motors. A 22 A controller is going to give 500 W constant and 1 kW peak, I think that they have one of those.

 

[Deleted member 4366]

Here's an explanation about what the controller's mosfets do. In the controller, they work as electronic switches, like relays, except that they can open and shut very quickly and at a high frequency. They're gates. The battery is connected directly to the motor, but it's blocked by the closed mosfets. When you switch on the controller, it's CPU will open and close the mosfets at the right time and frequency to regulate the motor's power. There's normally 6 or multiples of 6 because there's a pair on each of the three motor phase wires. One of the pair is connected to the + and - battery wires, so when it's open it makes the coil pull the magnet; the other is wired the other way round to the - and + battery wires, so it pushes the magnet. As each magnet comes to each coil, a mosfet opens to pull it, then it closes and the other one opens to push it on. The controller's cpu has to look after the timing. When it gets it wrong, you get that fierce mechanical grinding from the motor or the motor won't start. the same thing happens when a mosfet blows because the coil is stuck pushing or pulling the magnet all the time instead of at the right time, or it's stuck closed, so can't give any power on that phase, which throws everything out.

 

[R0881E]

Finally chosen my donor... A 2011 specialized secteur elite. I am currently living down under and it cost me 212 dollars.. So about £140. Bargain.

 

[R0881E]

Ok, I have now confused myself with the battery options and my head is in a large mess.

As per my original spec, I would love a battery that will do the full commute (20miles each way) since it is less hassle and the battery will be cycled half as often (Hopefully better battery life).
On the flip side, that brings extra weight and I am unsure what range I will end up with. It would be a bad outcome if I went all out on a large, expensive battery only to find that it cannot quite complete the round trip and I am instead still charging each way.

I want to cycle hard at the same time (fitness is the primary motivator).

Option A (Luna Mighty Mini) 300whrs.
Pro: I could fit this in a saddle bag and it would be light and stealthy.
Con: Would I find myself having to be too conservative with the power. It would only get me one way, if that.

Option B (Example Dolphin Style High Energy-33G 46.8V 12.4Ah 580Whrs).
https://em3ev.com/shop/preditor-l-47v-8-4ah-11-8ah-frame-battery/

Choosing the 33G as it fulfills my 17A current requirement and provides more capacity than 30Q etc at a lower price.
Pro: Case looks tidy and waterproofed. Would easily cover one way, maybe both if I had it turned down.
Con: The battery pack is pretty obvious. It may not get me both ways.

Option C (Dolphin style with integrated controller).
https://bmsbattery.com/ebike-battery/774-48v116ah-case-08-bottle-panasonic-battery-pack-battery.html?search_query=bottle+battery+48v&results=291

Pro: Self contained controller etc makes for a tidy build. Can buy together with Q128C from BMSBattery and save on shipping etc.
Con: Panasonic battery, unsure whether 18A sinewave controller is as good as from PSWPower, all eggs in one basket if something fails, won't make return trip.

Option D. (EM3EV Triangle battery (937whrs)
https://em3ev.com/shop/50v-14s6p-small-triangle-pack/

Pro: Should easily allow me to complete a return trip, even cranking up the power, trusted seller. Would also theoretically extend the life of the battery.
Ambivalent: Triangle pack may look stealthy but also have to fit in controller etc.
Con: Significantly more than BMSBattery as would require dual postage with hub. If battery fails early then it was an expensive mistake. Still unsure whether this is less / more stealthy than a dolphin style battery since I have to also fit the controller in which means either 1 big bag or 2 bags with this setup.

As a noob, I cannot determine my accurate range though I have read a few threads advising how efficient a road bike is with a small hub.
I want something that will put together fairly simply with less risk of me ballsing it up or having to try mix and match and hack cables and plugs from different suppliers.

Does anybody have any suggestions? I was leaning towards option D but I would prefer advise before I buy the expensive option which may turn out to be an expensive mistake.

Thanks to anybody who can help

 

[Deleted member 4366]

The capacity is more complicated than the number written on the cells because with the lower powered cells, the capacity goes down as the power goes up. If you look at the actual discharge curves on any of the 18650 test websites, you can see the graphs, so have a look at the actual capacity on the 5A and 10A graphs.

The Mighty mini will be too small for what you need. We got about 10 miles out of one averaging 20 mph using a Bafang BBSHD, and it got pretty warm, which is not good for a battery. That was with token pedalling.

Eclipse Bikes have nice batteries in the UK.

You can buy the BMSB integrated 20A sine-wave controller separately (as a kit with LCD, PAS, etc.). Remove the battery connector, blank off the hole and mount it wherever you want with whatever battery you want. When you buy it integrated in the battery, all the wires are too long, so you have to find a way to lose the extra, which spoils the nearness unles you cut and solder them.

 

[R0881E]

The capacity is more complicated than the number written on the cells because with the lower powered cells, the capacity goes down as the power goes up. If you look at the actual discharge curves on any of the 18650 test websites, you can see the graphs, so have a look at the actual capacity on the 5A and 10A graphs.

The Mighty mini will be too small for what you need. We got about 10 miles out of one averaging 20 mph using a Bafang BBSHD, and it got pretty warm, which is not good for a battery. That was with token pedalling.

Eclipse Bikes have nice batteries in the UK.

You can buy the BMSB integrated 20A sine-wave controller separately (as a kit with LCD, PAS, etc.). Remove the battery connector, blank off the hole and mount it wherever you want with whatever battery you want. When you buy it integrated in the battery, all the wires are too long, so you have to find a way to lose the extra, which spoils the nearness unles you cut and solder them.

Thanks d8veh,

As I mentioned earlier (and should update my sig) , I am currently living in Australia which means that I can buy from around the world with no customs / duty charges provided the total is below $1000 AUD (600 quid).

I did look at eclipse before.

Is the BMS controller as good as the PSWPower variant that you usually suggest? Or should I stick with that?
The BMSB kit is this I presume? Would that fulfill my requirements once I add a battery and the Q128C?
https://bmsbattery.com/controller/698-sine-wave-controller-for-09-case-controller.html

I had read up on capacity and em3ev provide the figures for the triangular packs which is handy. I am torn between saving a bit of cash and buying a smaller battery vs buying the larger one at more expense but only requiring charging once per day and therefore only one charger too.

I spend so much time analysing and then feel confident to purchase, only to stumble on a different thread which sends me down a different path. My scooter broke down so now is a good time to actually commit to something

 

[Steve A]

I don't know of any motor / battery combo at a reasonable price that would give you 20mph / 40 mile round trip. I think this is a bit of a holly grail. The only option is to carry 2 batteries. The best I've had is about 22/23mph over an hour and battery dead.

 

[R0881E]

I don't know of any motor / battery combo at a reasonable price that would give you 20mph / 40 mile round trip. I think this is a bit of a holly grail. The only option is to carry 2 batteries. The best I've had is about 22/23mph over an hour and battery dead.

I averaged 17mph without any assistance when I cycled in one day this week. I am thinking that 200w assistance for an hour each way should help me reach my target speed and fall within this capacity.

I want it as an assist, not as a lazy pedaller.. But I am fairly ignorant so wished to check first


Still searching for 18650 graphs for 33g as per d8veh suggestion btw

 

[Benjahmin]

Don't know if this helps, but it has been oft said that a rider consumes 10 - 20w/h per miles. Obviously the stronger the rider the lower the consumption, but the higher the speed the higher the consumption. So 40 miles @ 20w/h per mile would mean 800w/h. Looks like the triangle battery would give you some headroom even on a 'It's Monday and I feel like ****' kind of day.

BTW Bravo for even considering 40 miles a day AND working.

 

[anotherkiwi]

You should be able to just do it with 500 Wh, when I started with the first bike I was using 7.5 Wh/km = 482.7 Wh for 64.36 km and averaging 26.7 km/h (16.6 mph) you are younger and fitter than me.