My first BUDGET e-bike attempt, please help

[Lock]

There is overnight charging facilities at the places where we are staying, the trip should be about 40 miles each day, obviously i wont be using the throttle until im exhausted

Joe... ya might watch Justins video on Google about his trip across Canada by ebike:
[googlevid]7678925878624577581[/googlevid]

Ya can get a sense of the Whs that Justin was carrying for his trip... options for opportunity charging along the way...
Thread on ES also about the trip:
http://endless-sphere.com/forums/viewtopic.php?f=29&t=7134&start=0
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[kfong]

The cogging is from the magnets, Hub motors don't have a freewheel like a geared motor. So you will feel some resistance without power. If you add a little while you ride then it will not be noticeable. With a 10ahr battery you will get a range of 15-20 mile depending on how much effort you can put into it. A rough rule of thumb is an amp a mile without pedaling. So figure half of that distance is covered with the help of the batteries but the other have is having to pedal a bike that is heavier than a regular bike not to mention all your travel gear, add cogging to that and you may find out that you will be working just as hard or harder than your friends. Best thing to do is do some trial runs before the trip so you will know what to expect. You might also want to find a way to secure the packs if you plan to leave the bike unattended. I love my ebike but until I finish my latest ebike, long distances are not practical.

 

[vanilla ice]

One option that hasn't been mentioned in the thread yet is the ebay lipo.. Maybe not as safe or good as the life stuff, but you can get a decent sized pack for $200, and it even works well if you keep the Cmax down! Anyway for anybody looking at $200 packs, one other route to consider.

 

[fifthmass]

Outstanding for your dad buying you the LifePO4 battery!

Now a small thing to consider. The less expensive LifePO4 batteries have a relatively low current rating ('C' rate). A 1.0 to 1.5C rate limit is common for lower priced lithium batteries. Under this standard a 10ah battery would be good to deliver 10 amps at 1.0C and 15 amps at 1.5C. The better ones (Headway, etc) are good for 3-5C and the best (A123 or equal) are good for 10C or more.

What is the amperage rating of your controller? From the Ebay listing it "looks like" a "standard" 20 amp controller. If you run 20 amps (a 2.0C rate) from a 1.0C-1.5C 10ah battery you will shorten the life of the battery and may damage it. Of course if you KNOW that this will be at least a 2.0C rated battery you'll be fine with a 20A controller.

A $50-60 (whatever it is in pounds) watt-meter will be very helpful in monitoring your current usage. Believe me, that 1000 watt motor can draw WAY more than 20amps if there is enough controller capacity to allow it. I have drawn 2.2kw from a 20ah 48 volt battery by my 500 watt nominal motor (Crystaltye 408)

The LifePO4 battery is a tremendous gift from your dad. Be careful not to abuse it with more current than it's rated for. One benefit of SLA's is that they can pass huge current without damage. Ditto for (good quality) NiCads. Be careful with lithium + high C-rates unless you're sure your battery is rated for it. HAVE TONS 'O FUN!!!

regards,
Bill

 

[joeworrall]

Haha yeah it was very nice of him, but he only lent me the money i have to pay him back in march on my 18th birthday.
You made a very good point about the controller that i started another thread on yesterday after i realised my lower amp-hours. You think the controller is 20A? i thought it might be 35 but i havent got the kit delivered yet so im waiting to see.

here are my battery specs:
* Voltage: 48 Volts
* Capacity:10Amp Hours
* Charging Voltage: 60 Volts
* Charging Current: <10 Amps
* Rated Discharging Current: 10 Amps
* Max Continuous Discharging Current: 20Amps
* Max Discharging Current (Peak): 30 Amps 12s

so if the controller is 20amps then brill! If not i'll just modify the shunts until i get the desired maximum

 

[fifthmass]

Haha yeah it was very nice of him, but he only lent me the money i have to pay him back in march on my 18th birthday.
You made a very good point about the controller that i started another thread on yesterday after i realised my lower amp-hours. You think the controller is 20A? i thought it might be 35 but i havent got the kit delivered yet so im waiting to see.

here are my battery specs:
* Voltage: 48 Volts
* Capacity:10Amp Hours
* Charging Voltage: 60 Volts
* Charging Current: <10 Amps
* Rated Discharging Current: 10 Amps
* Max Continuous Discharging Current: 20Amps
* Max Discharging Current (Peak): 30 Amps 12s

so if the controller is 20amps then brill! If not i'll just modify the shunts until i get the desired maximum

OK sounds good if your controller is 20A but if it's 35A you will have to be careful and monitor your current draw with a power meter of some sort. The more expensive cycle analyst from Justin in Vancouver can be programmed for a max current limit. The cheaper WattsUp type meters are not programmable. I have drawn 45A amps through a 40A controller so sometimes controllers don't limit as they should. I have since cultivated a better controlled throttle thumb.

Even with an advertised 2C max continuous I would be careful going much over 15 amps (1.5C) with that battery on a continuous basis. Others here would even argue for 10 amps max(1C).

Have fun & be safe.

regards,
Bill

 

[amberwolf]

There is overnight charging facilities at the places where we are staying, the trip should be about 40 miles each day, obviously i wont be using the throttle until im exhausted

What I would recommend instead that will help both you and your assist system is that you use the assist at appropriate levels at all times to help you, and you just pedal a little faster than it is going. Then you will minimize the power that it is using, and it will minimize the power that you are using.

You'll get longer range out of both you and the system, once you work out what is best for both (takes practice).

 

[dogman dan]

Chances are, the kit has a 20-25 amp controller, since 35 x 48 = 1680 watts. 20 x 48 = 960 watts.

So try to ride as amberwolf described, or better yet ride about 3/4 throttle and pedal briskly. It will still seem easy compared to regular riding. 50k range ought to be possible at 25 kph. For longer distances, you'll just have to make the most of all the downhills and pedal a lot. Some say if you unplug the motor from the controller, the resistance from riding without power gets less.

If you ride too much full throttle with that smaller battery, it will last a lot less cycles. Same thing goes for draining it 100% every ride. The 10 ah battery is best suited for 200-400 watts, not 1000. So cutting your watts by using less throttle will help.

 

[vanilla ice]

Buy a couple of the $25 28v 8s dewalt packs from Phillip, wire them in series, then parallel those to your 48v pack!

 

[Lock]

It will still seem easy compared to regular riding.

Lets hope Joes (non-e)cycling buddies can keep up the pace? It may be diplomatic for Joe to swap bikes with others sometimes...
tks
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[joeworrall]

I've ordered a turnigy watt meter thing, like a cheap cycle analyst just so I can keep a closer eye on the current and stuff. Don't worry about them haha, it's always me at the back on my big heavy bike while they've all got their £700 racing bikes!! I won't go too far ahead either, it's fun to keep as a group, especially to watch my clumsy friend keep falling off hahahah! Half his panniers are filled with bike repair stuff!

If anyone else has got any suggestions they'd be appreciated but for now I think I've got enough info. Thankyou all so much, couldn't do it without you

 

[Lock]

Half his panniers are filled with bike repair stuff!

HAHA! eeeerm.... wait... Half your panniers will be filled with ebike repair stuff, right? Watt will you have in there?
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[joeworrall]

HAHA no i was talking about my friend, he always falls off his bike and breaks it whenever we go on cycling trips so he has to carry a lot of bike repair stuff.. spare inner-tubes, pumps, chains, brake pads, brake levers ect

 

[999zip999]

Love canada It's like turning back the clock, they are more relaxed then the new pilgrims that come to live in So. Cal. let's open a N.Y. deli where the surf spot was. Hay hay it's still a surf spot. Would like to here about your canada ride. They have some good trains too.

 

[Lock]

Hehe... USED to have good (passenger) trains. Bombardier still makes `em but mostly for sale to others (sigh). EVen intercity buses have been disappearing...
LocK

 

[skeetab5780]

joe glad to see you made it to the forums the info here is great.

keep up posted on your budget bike!

 

[DerekG]

Glad you were able to purchase beyond the SLA's... they are a pain

Before I went LifePO4 I had SLA 18aH ones on my rack... I broke two racks that way

Also, while a Cycle Analyst is a good investment, it's all up to what you want to use the bike for. I'm in college right now and use the bike to commute to my classes. I have a 22amp controller right now, however, from a dead stop my CA will read up to 45 amps peak... something to consider. If you can help it don't open the throttle till you are moving at least a few mph... much easier on all the electronics.

Good luck with the bike, I've put over 850 miles on mine in less than 4 months and everything is holding up fine so far.

Oh yea... never leave the battery out overnight even if it doesn't rain / snow/ whatever. The Frost / Dew will wreck havoc on it.

 

[kentlim26]

For information only purpose..

CS3 12v 12hr weight around at least 3.7kg. Each china normal battery = 4.4 kg.

One SLA 18hr of 12v, weight 5.4kg. 3 is still okay 16.2kg.. and 4 sla battery will weight 21.6kg..
when is running with a little bump hit or uneven road hit, the 21.6kg will x 2 = 43kg with force Up and down. it will certainly break any racks.

when the battery is so heavy, it just cannot match with the racks supporting. One of the guys here, have build racks.
he add re-inforcement, the racks break the bicycle frame.

kentlim