Schwinn I-zip?

[AndrewFleming]

Still hunting out bikes over in Canada. Do you reckon the specs below sound realistic (flat conditions, low wind most of the time). It won't do the long journey I was hoping for but I've concluded no bike is likely to do that. It looks like it would cover shorter trips (15k) is the range is honest and that it may by cyclable when the battery is flat

Schwinn I-zip
* 24V portable lead acid battery pack easily recharges through any household power outlet
* Travels at a speed of up to 24 km/hr and up to 40km on a single charge
* Power on/off switch and twist throttle
* Charger LED indicates when the battery is fully charged, throttle LED indicates when power is low
* Steel comfort frame with suspension fork, seven-speed twist shifter with Shimano rear derailleur and 26" heavy duty alloy rims with comfort tires

Prince is cheap 600 Can + tax (16%) which would be a little over 300 STR This sounds too good to be true so I suspect it is.

 

[Baboonking]

specs don't sound very realistic, of course it depends how much you pedal and whether the bike has a pedelec mode. also depends on how big that lead battery is. If its 10ah expect about 10 miles full throttle. If its 15AH then expect about 16 miles (peukurt effect gives u a bit more for a larger battery). looks like a fun bike though.

nice and easy bike to modify. you could of course fit a nimh battery and for the same weight get 3 times the range . With lead acid the most you'll likely see in an electric vehicle applicaton is 20 watthours per kilo, nickle metal hydride will give about 60 watt hours per kilo) lots of good ebike kit and parts suppliers in candada. See www.ebikes ca.

 

[AndrewFleming]

If its 10ah expect about 10 miles full throttle.

I suspect its using this
http://www.amazon.com/Currie-Schwinn-Mongoose-Scooters-Battery/dp/B000NNBB1Q

Which is 10a so only 10 miles / 16k

From what you say above could I replace the battery with
the 24V 18Ah Nexcell NiMH
(3rd item down at http://www.ebikes.ca/store/)

which weighs 50% more and so expect 16 (for extra AMP) * 3 (weight diff) *1.5 (50% heavier battery) = 72km

 

[coops]

Hi Andrew

It actually looks identical to the men's version of
the "Currie Izip" available here in the UK, which has been mentioned here in some detail recently.

15-20 miles (~25-33km) range with normal pedalling is given on the above site, and I'd guess thats on level terrain, so probably lower if used on hills. Also remember that the range will decrease over time (for NiMH at least, not sure about SLA?). How far is the long journey you hoped to do Andrew? Some successfully carry a spare battery for such trips without problems.

It's been said here that its likely to be on the heavy side (since its a steel frame) at probably around 35-38kg including battery, but power output should be quite good - for more details search here for "izip" .

NiMH would be lighter Ah for Ah than SLA, and should have a longer life, but I guess if you want to use the same battery case/holder, you'd have to work out if the NiMH batteries would fit... .

There's a video of another bike with a Currie motor at the bottom of that webpage link.

Currie motors I think can be differently configured (internal gearing & power rating) and are also available separately in the UK with NiMH battery options.

P.S. If you switch from SLA to NiMH I think you may need a different charger too? Check this if you're considering that .

Stuart.

 

[Baboonking]

i think there's a mistake in the weight. of the schwinn battery which is messing up the maths my guess from the specs is a weight 6.8kg (240 watt hours / 35 watt hours per kilo (the 20 hour rating for lead batteries).

Basically. You can work out how much energy is in the battery either by wieght of battery or the specificaton.

I'll try working it out by specification.

So for nexcell nimh.

18 AH * 24 volts = 432 Watt hous of energy.

For Schwinn

10 AH * 24 volts = 240 watt hours, but due to peukurt effect on lead acid we only 60 %
of that energy. (the 60% figure is a guess, it could be higher or lower depending on how fast the battery is discharged, if you want to look it up PowerStream Power Supplies and Chargers for OEMs in a Hurry has accurate figures for b&B lead acid batteries)


240 watt hours * 0.6 = 144 watt hours of energy.


so the nexcell pack has roughly 3 times the energy.

 

[electric.mike]

hi Andrew i cant help you with the theoretical maths only experience of riding heavy electric bikes, the 15km range you are asking for unless you weigh well over 12 stone, should be achieved with care on the izip.one of the most important things to remember with the throttle only system is don't touch the throttle until you are already moving,if you can propel yourself upto about 3to4mph you will save an awful lot of battery.
i am now finding my powabyke which has two power modes but both are via throttle is very easy to save power on because not being just pedalec the battery is only used when i really need it.
and remember about theory, the bumble bee cant fly because its wing area to weight ratio is wrong but so long as we don't tell it will carry on flying.

mike

 

[coops]

so the nexcell pack has roughly 3 times the energy.

... & should then (with pedalling & on the flat, low wind) give around 3 times the range of a 10Ah 24V SLA i.e. ~50km/30miles?

Sounds do-able, even conservative, & in flat terrain & at a "cruising" speed you'd probably get more, but that 24V 18Ah battery is heavy - 7.02kg! ~1.5 times the SLA weight...! And would put the total bike weight near to ~40kg if not more!

I'm sure it is a fun bike, till you have to pick it up .

And would it fit the SLA battery case?

I think if you really want a bike for long range flat-terrain trips, either a very economical bike (possibly lower-powered/higher-geared &/or more pedal-assisted, or just go easy on the throttle as Mike said) or two batteries might be more practical?

I've forgotten, Is the Canadian speed limit for ebikes higher than the current 25km/h (motor only) limit in th U.K. Andrew?

Stuart.

 

[Baboonking]

i think the nimh pack and sla pack are the same weight.

 

[coops]

i think the nimh pack and sla pack are the same weight.

My mistake, I missed what you said about the weight error on that 10Ah 24V SLA battery link. Still, ~7kg for a battery is pretty heavy in my book! - but then I'm more familiar with NiMH - even 36V 9Ah NiMH is around 5kg max, and has more useable energy too .

P.S. Mike - I think Andrew means 15km each way so 30km total range ~18miles. Is that what you meant?

 

[Baboonking]

when i first tried nimh, it was like another world of electric biking, no more worries about batteries running down, nice and light etc.

That said I've recently got a couple of powabykes from Nigel on this forum. They weigh a whoping 40KG each but are still fun and practical bikes . They have quite large lead battery packs so the range is still good, so far as i've tested them very good, especially in pedelec mode.

 

[coops]

I feel like I've missed a trick here: buy a bike built for SLA battery size & weight, then refit with similar weight NiMH for significantly longer range than you'd get even with a 36V 9Ah battery (maybe 1/4 to 1/3 more?).

I don't suppose there's any really noticeable difference when riding a heavier bike, and unless you have to carry the bike a distance, that shouldn't be any problem.

I've been trying to decide the best way to fit batteries to a standard aluminium mountain bike as part of a hub motor kit "fit": I wanted to avoid heavy batteries on the pannier/rear rack & currently my best option seems to be a "water bottle fixing" type case like the Bionx (only a bit bigger & a bit less stylish) but I'm concerned about the stress on the down tube of fixing 5kg+ like that, so having a bike frame which is designed to hold heavy batteries seems a distinct advantage, and with more budget ebikes available now like the izip, its an option really worth considering .

Hmmmm... thats got me thinking now! Maybe I'll rethink my conversion plan.

Do you think the "Schwinn" izip has the same frame as the Currie izip at 50cycles? I'll have to do a search to find out more about the range .

Also, has anyone tried refitting SLA cases like this one with NiMH packs? I think there was a brief reference to it on this forum quite recently, so I'll do a search for that too.

 

[flecc]

A popular method of mounting SLA batteries in the USA has been in a bag strapped under the crossbar, so that seems strong enough. I agree that the downtube alone is a poor option.
.

 

[electric.mike]

P.S. Mike - I think Andrew means 15km each way so 30km total range ~18miles. Is that what you meant?

coops
if that is the case then a change from sla or a spare would be needed i can get 18miles from our sakuras in pedalec with new batteries and they are 36v7ah sla but 6 months down the road it may only be 15miles whilst after 15months i could still get 10miles.

mike

 

[coops]

Ok, here's some more info & ideas for the izip, see what you think:

First, bike seems to be same as a 2006 model Currie Mongoose CB24V450W (CB=comfort bike I think) weight given variously as 41kg (Currie) & 37kg (2 retailers) (also available with Aluminium frame, much lighter @ ~30kg or less), listed here, more info & useful reviews here motor specs (unite MY1018 24V 450W peak output , 250W rated) here & the blog of the guy who's video is on the 50cycles site is here (more info & images) also another UK retailer here.

Gearing on the bike looks useful: motor geared to 15mph max, drivetrain looks to be ~42T front & shimano 7-speed derailleur freewheel block 28-13T low/high (13T high @ rear would be enough to pedal to ~18mph cadednce ~72rpm, 28T low ok for starts & up to ~6-7mph, but not very low for slower)

Any (future) upgrade to NiMH while retaining the battery case seems complicated (to me) by its dimensions : approx 9-10cm square by 30+cm - I can't work out how to (easily - without custom built) fit any size of D-cellpack to a capacity of more than 24V 12Ah - ~300Wh, and thats if such D-cells (3/2 D or F ?) are easily available.

So what about using "sub-C" 12V packs like these? : around 3.7-4.3Ah at 0.2C 0.74A (max 30A) only ~700g & under £25 each, case could easily fit 6 or 8 (in 24V pairs) giving 24V 288-360Wh & only 4.2-5.6kg. Flexible too - if 6 used, could be rearranged to give 36V 7-8Ah if needed?


[current draw from each battery < 0.2C 0.74A @ ~0.31A for 8 pack of 24V 14.8Ah or ~0.416A for 6 pack of 24V 11.1Ah? ] - EDIT: I think this bit is wrong - see below

I've heard of C or sub-C being used for ebikes with lower "voltage sag" than D-cells, so could this be a viable future upgrade to the izip? I'm a bit concerned that the peak Currie current 25A is close to the 30A limit on the batteries - I can't remember my electronics, how would the arrangement work & handle charging/discharging? Is it effectively 3 or 4 24V cellpacks in parallel, so the total current is divided over each 24V cellpack : so max current draw would be 6.5-8.3A per cellpack/cell (for 3 or 4 x 24V packs)? is the current divided over all the batteries or supplied by each battery?

If it could work, even a ~360Wh 24V NiMH pack @ 5.6kg would reduce the bike's weight by a few kg to ~35kg (if the 37kg SLA weight is correct) with a range of up to ~30miles+/50km+ ! 4.2kg 288Wh 24V pack would be ~1.5 kg lighter - 4.2kg so bike weight ~33.5kg & range ~22.5 miles+/37.5km+ .

I know the ezee Liv has lighter alloy frame (29.2kg total), has 324Wh NiMH already and the motor is just as powerful, but the izip has (I think) better pedalability when unpowered especially at higher speeds (~15mph & above) due to better range of gears for pedalling on the Izip - 7 gears (derailleur) compared to Liv's mere 3, (albeit hub gear & roller brake? Still seems more of an electric bike with pedals than a motor-assisted bike), better freewheel motor separation from the wheelhub, the frame + motor may be heavier but not by a huge margin (~5.5kg?) and its likely very strong, and the izip could be bought & fitted with NiMH (& still have SLA as 2nd battery) as above for total cost little more than the cost of the Liv...

[Izip drawbacks are no lock/security of battery case to frame... - does the Liv's?]

Izip does have ignition key for on/off power

What do you think? Possible upgrade?

 

[Baboonking]

sub c cells are apparently pretty good. 30 amp discharge from a 3.5ah! I think you can get 4.2AH sub c now. you'll have to charge each series string seperatley but discharge is ok in parallel. If 25 amp is the peak discharge rate then you'd also be ok with good quality 30 amp d cells. If you look on the ebikes.ca site you can get very high discharge rate d cells aswell so, as usual, more than enough options, which of course can make it harder to narrow down

 

[coops]

Thanks Baboonking - I was counting on your input since you've already trodden this parallel battery ground . I forgot you have a Currie setup too - how's the bike these days? Still have the 2 parallel 24V 13Ah packs? also do you think the Izip's weight is ok - I reckon about 29-30kg minus batteries, so possibly only 35kg or less with, depending on battery choice?

My aim is twofold: to fit a good capacity 24V NiMH cellpack with adequate high drain characteristics (~25A peak, unless overvolted a bit...) in to the Izip's SLA case (approx. dimensions in my previous post), such that it can be easily charged - preferably with one charger only...

Sounds like it'd be fiddly then to have lots parallel/series cellpacks like I describe? If I'd need to charge them as 12V series strings & then connect them in parallel for discharge, that's either an extra step or extra charger I need each recharge... I'd prefer it simpler really Also keeping the parallel cellpacks in "balance" could be tedious...

So maybe I'll stick with the best fit non-parallel solution which seems to be a single custom-made 24V ~12-13Ah 3/2 D or F series cellpack, for ~312Wh & 25-30 mile range.

Where did you get yours, and were they "standard" or "custom fitted" cellpacks & how's the quality?

Else, the standard D cells would be awkward shape & only one 20 battery 24V cellpack at ~216Wh would fit unless you really worked to custom-fit them in somehow...

I may start a new thread on this, rather than hijack this one further, but the idea seemed relevant to Andrew's original post re: range & Izip, & was sparked by the discussion.

Stuart.

 

[Baboonking]

Actually I've no idea what my bike actually weigh - much lighter the bike I had before If I could take it down to the bicyle weighing station I would. I can carry it up the a flight of steps and onto a train, just.

I'm not sure what the izip wiegh I doubt the curry motor and drive sytem weighs much so its down to the battereis and the bike. Looks like quite a fun bike, lots of easy mods like overvolting and using different unite motors which seem fairly available.

I now run my bike at 48 volts which works really well. Its nice to have the options to switch down to 24 volts if i'm running out of energy. The packs actually give out more than 13AH in parallel.

I got my batteries from china, quite cheap but a little scary as I wasn't sure if I'd get ripped off. In the end it all turned out well. I've put about 100 cyles on them now with no loss of performance. They sag a little. About 7 volts at 30 amps. At lower discharge rates the sag isn't noticable.

damn I must go to bed its 3am! flippin internet!

 

[coops]

I've no idea what my bike actually weigh - much lighter the bike I had before If I could take it down to the bicyle weighing station I would. I can carry it up the a flight of steps and onto a train, just.

Thats probably just about the same as I could manage with the Izip

I'm not sure what the izip wiegh I doubt the curry motor and drive sytem weighs much so its down to the battereis and the bike. Looks like quite a fun bike, lots of easy mods like overvolting and using different unite motors which seem fairly available.

Yes, I think so too & I hope if I opt for one to have some fun!

I now run my bike at 48 volts which works really well. Its nice to have the options to switch down to 24 volts if i'm running out of energy. The packs actually give out more than 13AH in parallel.

Is the motor in your Currie a "standard" i.e. like the Izip's? I assume you are overvolting, but is that from 36-48V or 24-48V? don't know if I'd try that!

I got my batteries from china, quite cheap but a little scary as I wasn't sure if I'd get ripped off. In the end it all turned out well. I've put about 100 cyles on them now with no loss of performance.

Thats good to know I'll shop around & see what I can find...

They sag a little. About 7 volts at 30 amps. At lower discharge rates the sag isn't noticable.

Well, just so long as they don't fall off the bike... hehehe!

damn I must go to bed its 3am! flippin internet!

Yes, me too! All this battery-case geometry is twisting my brain! Thanks for your input, most useful

Stuart.

 

[Baboonking]

Is the motor in your Currie a "standard" i.e. like the Izip's? I assume you are overvolting, but is that from 36-48V or 24-48V? don't know if I'd try that!

currie have made lots of motors, so its hard to say whats standard and whats not. The old currie motors were brushless and I have a few of these. The one I'm running at the moment has the old controller removed. Instead I'm using a crystalyte controller, the motor was designed for 24 volt so its running at double the rpm. Its currently a little too fast (30mph) so I'm going to hear it down again to 22 mph or so but keep the voltage at 48 volts. This should give me any amount of torque I need which will be useful for towing stuff when,and also let the motor run efficiently when I'm not, well, thats the idea anyway.

The newer curry motors are brushed, so its more important to pay attention to cooling/current limiting if overvolting.

 

[coops]

ok, one last thing (hopefully!) to sort out: how well do currie's in general, but the Izip motor in particular, freewheel when not operating?

Its an easily overlooked issue for ebike newbies like myself, who might assume all bikes freewheel equally easily, but a very important issue to me for a satisfying pedal/electric "hybrid" experience especially since recently touching on the issue of hub motor "freewheelability" on this forum and finding some (most) become relatively hard to pedal at higher speed due to the geared reduction in the hub not being isolated by a freewheel...

I'm deciding between the Liv & the Izip, but I feel this issue may clinch it: I can overlook other potential shortcomings of the Izip (weight, SLA battery, noise etc.) if it is better in this area...

So any idea how the Izip does/may fair in this respect?

P.S. I'm no mechanic expert as I said before, but if I look for info on the motor, might that tell me what I need? Anything I should look for? Else I'll call 50cycles on Monday to find out... was a bit late phoning today

Stuart.