Hill climbing vs speed - kit options

[banbury frank]

Hi

I see you looked at our site it is new for this years products and is not complete yet

we have the option off a 10 or 15 ah battery also front or rear motor


testing through the winter we no longer sell 36 volt as we found it under powered so a 48 volt 15 AH battery gives you

A massive 750 watt hours the 10 AH still gives you 500 watt hours the controllers are speed limited to 15 MPH

unless you remove a external link for off road use

Thanks for your feed back all helps as develop what you need

Frank

 

[Scottyf]

If your only going to do 3 miles you don't really need a super quick motor and battery combination.

I currently have a 9ah battery and a 250w Bafang motor with a tiny little controller and I compelte 18miles a day and a Marin Kentfield bike fitted with road 35c tires.

I'm usually above assit speed when riding anyway. However I would think that a similar kit with even a smaller battery would be ok for your journey.

You wouldnt really need to load the bike up with a large battery for 6 miles.

Your cheapest route would be to buy a kit and battery of bmsbattery.com
A kit plus even a 10ah battery with delivery will only be about £350.
Smaller battery will limit range and hopefully with a high enough C rating (how much the battery can safely discharge) to hit the amps required at peak.

the 3 speed switches you are after can be brought at a minimal cost (£10 max providing the controller can accept it).

Other options are to buy pre-built bikes but for your journey of 3 miles each way i'd probably look at a MTB for weekend riding with a small 250w Kit.
Keeping it lo weight and drag.

Frank's Kits are really for high pwer applications and 3 miles unless your horribly unfit you should be able to manage unassisted really after a couple of weeks. Espcially if your cycling on the way home quite hard to get a sweat on.

 

[alexk-il]

Hi
I see you looked at our site it is new for this years products and is not complete yet
...
A massive 750 watt hours the 10 AH still gives you 500 watt hours the controllers are speed limited to 15 MPH
...
Thanks for your feed back all helps as develop what you need

Frank

Hi Frank,

Having an option to switch between the road-legal 250Wt to off-road-legal 1001bhp is cool! Too bad for me that your pricing model is off my limits.

Cheers,
Alex

 

[banbury frank]

Hi

Budget kit with UK Support

26" 8Fun Ebike Electric Bike Conversion Kit 36V-8F26F36 | eBay UK


Hope this Helps

can a member who bought one give a report on this kit

Frank

 

[Trevor Holloway]

Its a Sunlova kit, basic but works well, it got me fit over winter and good customer support (I went direct instead of via e-bay).

 

[NRG]

we no longer sell 36 volt as we found it under powered so a 48 volt 15 AH battery gives you

A massive 750 watt hours the 10 AH still gives you 500 watt hours the controllers are speed limited to 15 MPH

Last time I worked out 48v x 15Ah I got 720Wh...

 

[Scottyf]

Indeed I have the Sunlova kit.
Again does the job but if you expect it to take you up hills on throttle only you've got another thing coming.

Weak part on the kit was the controller - Although it works perfectl and never had a problem I think the controller is to low powered.

The Battery can happliy have a max of 18amp's pulled from it but the controller will only draw max 13amp.
(Rated @ 6amp, Peak 13amp, 36v - Max Watt = 468watt Nominal where as the battery could push out 648 watt +38%)

This does prolonge the battery and life (Also range as your forced to pedal) but could provide more torque for up hill climbing.

Other than that, put in battery into the slide rack, lock it ride don't worry about it. Hassle free in the 540 miles I've done on it.

 

[banbury frank]

Hi NRG

16 cells at 3.2 volts = 51.2 volts X 15 AH = 768 Watt hours


I only approximated

Like the Panasonic 26 volt system 18 AH sounds very Big But only 468 Watt hours

Frank

 

[alexk-il]

The only problem that I can see is that most controllers and BMSs have a low voltage cut-off that'll be too low for you, so you need a meter on the handlebars or some other device to tell you when to stop discharging the battery, or you need a custom BMS or a programmable controller, all of which brings more expense.

OK, looks like the 44V option seems to be under the research.
http://www.pedelecs.co.uk/forum/electric-bicycles/8265-my-lipo-trials.html#post103221

I would be glad to see what your findings are .

 

[Scottyf]

Would mean alot of fiddling but those batteries would give a huge c rating and basically great at delivering high current. Small range but alot of power. But no real bms and would require alot of maintence.

 

[flecc]

Like the Panasonic 26 volt system 18 AH sounds very Big But only 468 Watt hours

But all of it usefully used, not much of it wasted by the intrinsic inefficiency that hub motors have!
.

 

[alexk-il]

Would mean alot of fiddling but those batteries would give a huge c rating and basically great at delivering high current. Small range but alot of power. But no real bms and would require alot of maintence.

Can you please proviide more details on "no real bms"? For example this battery has a PCB inside with all the monitoring and protection. However this battery has the same protection level and still shows the red-lettered warnings for using the fire-proof bags while charging.


I am really confused regarding these PCBs and the safety of the LiPo batteries.

Thanks
Alex

 

[NRG]

The BMS in your first link is limited to a max discharge rate of 7amp which is too low. With 15 and 20 amp controllers you need a BMS and battery that has a bit of head room so 30/40amp would be better.

Bare RC packs have no BMS so you need to provide balancing via an RC charger or chargers or by some other means and ideally provide LVC alarms for each cell to prevent cell damage during discharge.

With out a BMS RC cells have no automatic protection from abuse or simple careless use and therefore can be dangerous hence the advice to use fire proof bags when charging.



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[alexk-il]

Thank you for everyone who helped and provided vakuable info.

After reading info on the internet I decided to stay away from DYI batteries, chargers and controllers. Safety should come first.

I guess using a standard 350W hub would be a better idea than over/under-gearing the engine with cheap plastics inside.

Cheers
Alex

 

[Scottyf]

If you wanted a cheap kit think andy is selling a 350watt direct drive for a bargin price. That also has a delta and wye feature for low speed and high speed. If i would have seen it earlier i would have purchased before going down the china route.

 

[alexk-il]

If you wanted a cheap kit think andy is selling a 350watt direct drive for a bargin price. That also has a delta and wye feature for low speed and high speed. If i would have seen it earlier i would have purchased before going down the china route.

Thanks, I'll check it