here is some info on 20v yardworks lithium ion

[Anonymous]

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[wasp]

r u still sliding the batteries onto the chargers?
i have my bats in the orig box from schwinn and want to just hook up jumpers
to charge the bats...i just checked while the bats are out and to charge
its on the c for the ground...

thx wasp

 

[Anonymous]

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[wasp]

so the last bit tells me your only using + and - for both charge and discharge...thx
i have no fuse wired in but tried my 2 bats out
at full charge 21 volts each i got 13km of 25-30 kmh and a bunch of stop and full
power runs untill it tripped
reset my power and was good to go
checked voltage on bats were 16.84 and 17.01
on charger now exactly 4.5 hours charge time
this was my maiden trip with these bats and i'm a happy guy
btw the bats are listed at 2.76 pounds each?
the best is the way my bike now feels...24lbs lighter

thx wasp

 

[Anonymous]

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[wasp]

Yours are actually taking 4.5 hours to charge? Mine never take that long, usually 3 hours, sometimes less.

ya thats charging them off the charger using c
tomorrow i will wire up my bats and forget about using the c
it's working for you and worst case senario they fry(not fuse protected)
and i use my 1 year warrenty...

thx for the input
wasp

 

[mikereidis]

Yours are actually taking 4.5 hours to charge? Mine never take that long, usually 3 hours, sometimes less.

Mine take 3 1/2 hours to go green, after I discharge them to LVC 15v.

I keep them on hours longer though and the voltage goes up from 20.81 to 20.95 most recently.

The extra terminal on the battery is just another negative connection. No additional positive, so what's the use, and I guess the main contacts handle 31a anyway.

I've crimped some blue connectors to wires that hang from my chargers. I sometimes connect one wire from each charger ( + from 1 and - from 2) to connect to my batts "center tap". Then the other leads go the the right batt terminals. No problem two at a time, neither lead is grounded or anything. Disconnect controller or any other load.

I haven't opened up my batts or charger yet. No need until I work on the better charging solution. And I don't want to mess with the batts such that I can't return them if they fail.

I tested 4s range this morning, 20-25 KMH maximum, except some hills and a few runs to 32 KMH. Surprise, surprise, I got the same range as my 1s test yesterday: 44 KM from 4 batts. But today I did virtually no pedalling. This is wonderful !

So if I go light on the throttle, I'm not sure I see much reason for anything less than 4s. Efficiency may actually be a bit better, and I was able to do 20 KMH easily (and 30+ KMH at full throttle) up the worst 10% hills. I look at simulator graphs for 1s versus 4s and full throttle on the 1s versus 20% throttle on 4s and power output and efficiency are the same.

 

[Anonymous]

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[mikereidis]

I tested 4s range this morning, 20-25 KMH maximum

4S? That would be 74V nominal (the batteries are labelled as 18.5V inside).
You ran 74V at speeds of only 20-25kph?

Yep ! 80v fully charged and under load, dropping to 60v or so at full discharge / LVC about 50 metres before my house at 44 KM mark.

Yes, the throttle was very "twitchy" at low speeds. At first I thought I had a loose batt connection, but it's just the "twitchiness" of the throttle at very low settings. I'm planning to add a potentiometer, with a "reduced power" switch to reduce the throttle range (maybe to 30-50% of full) and see if that eliminates the low end sensitivity.

To navigate tight turns at 5-10 KMH I generally let throttle return to 0, and occasionally modulate the brake.

I'm taking the trailer and kids out today. Will see how 340 pounds reduces the range from 240 pounds and 9 WH / KM. Should be a bit less twitchy with the added weight.

I'm realizing now the batts are the most expensive (and important, performance/range wise) part of my conversion.

Batts: $680, chargers: $70, motor/hub: $270, controller: $145, 2 throttles: $30, wires/connectors/etc: $100. (taxes and shipping not included).

Total: $1295. Batts are 52.5% of the pre-tax and shipping total.

Taxes: $133.
Shipping: $40.

Grand total: $1468. With taxes, batts are 52.3% of grand total.

 

[wasp]

here is my 2 bat set up

 

[Anonymous]

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[Anonymous]

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[mikereidis]

80v fully charged and under load

You didn't get the magic smoke that I did, lucky you. What controller is that? And you didn't mention top end speed running 80V. How fast? I am also wondering what the range would be running full throttle on 80V, or maybe you don't want to run it that way?

I made a dumb mistake a while ago and killed a battery (actually probably just the bms), took it back
and they exchanged it no questions asked, not even a discussion about warranty.

If I did, I'd send the smoke and controller back to ebikes, under 1 year warranty:

Ctrlr is http://www.ebikes.ca/store/photos/C7220PF.jpg

Ebikes/Crystalyte C7220PF 24-72V 20A pedal first controller, IRFB4110 mosfets 0.69 kg (1.52 lbs) $145.00 Sold out

From http://www.ebikes.ca/store/
The controllers are guaranteed against failure for 1 year when used in the following setups:
...
72V controller with IRF4110 mosfets: All motor and battery combinations up to 84V .

I've never yet seen these batts fully charged over 20.98 volts, even after several days on charger. So 4s is at most 83.92 volts, just under the warranty threshold. I beleive caps etc. are 100v.


Just how did you kill that battery, BTW ? I figure short circuits don't do it, so other than really high voltages, perhaps 100v reversed, these batts are almost electrically bullet-proof (for average stupid Joe CdnTire consumer warranty cost reduction.) I figure Joe might drop a tool or iron filings into the batt terminals, but he'd have to go out of his way to connect the batt to 120 vac.


Top speed, in theory, after a long period of acceleration on flat grade, is about 40 MPH or 65 KMH. At http://www.ebikes.ca/simulator/ I plugin:

404
19.1" wheel
80v (fully charged and under loads of 2-10 amps or so; maybe I should lower this for 20a operation)
batt resistance: 0.2 ohms
controller: 20a
ctrlr resistance: 0.01 ohms (4110s on 20a ctrlr ? I dunno. 14 gauge power wires.)

Peak motor power output I see is in the 1300 watt range. At 40 MPH it's about 1280 it look like.

Figures from that now defunct calculator indicate for 160 lb rider (I'm 174 clothed/equipped), 80 lb bike (Currently 72 for mine) and "road racer on drops" profile (Maybe roughly equivalent to my laid back recumbent profile ?) that about 1144 watts are needed at 0% slope. 1% slope is 1388 watts.

On my best battery I got 100 WH and 5.5AH running a nominal 14.35a load. At 20 amps, If I assume I get 5 AH then my 4s pack would be good for 15 minutes, or 10 miles / 16 kilometres. Using my assumed 100 WH per batt that's 40 WH / mile or 25 WH per km.

I could then run my aux 2s pack at full throttle at 30 MPH, 48 KMH for the same 15 minutes (note 20a controller plus 5 AH batteries at 20a, in series config with no parallel, will always give 15 minutes at constant full throttle, assuming you can always force the controller and motor to consume the full 20 amps.)

So I'd go 7.5 miles or 12 km on the 2s pack, about 27 WH / mile or 17 WH / km. I'd have to pedal the last 4 km home. Need 4s x 2...

All rather academic unless you have a long, straight, level test track and no wind issues etc.

I had thought I would be comfortable at 50 KMH and could push it to 60. 40 KMH is the fastest I've gone a few times, the first time on maiden test run, and it was easy and quick to get than on 2s with a 2-3% downhill. I'm more comfortable limiting myself to 30 at most, with 20-25 being average.

If I had some proper safety equipment for elbows and knees etc. and a good, clear, straight, reasonably safe place to try (probably a good road, like Gatineau roads when closed and without lots of people like Alcatel Sundays or whatever), I'd be willing to see how well 50 - 60 look. For a while at least.

Also need better brakes, and perhaps tires. I'm still averaging one wipeout per 44 KM, easy Ottawa River run trip. Today some guy came into my lane on a corner, and my brakes are marginal, and I jack-knifed the kid trailer. Only injury was a minor scratch on my leg from the under seat steering.


Some pics and a bit more info on my latest mods and Ottawa River Run with 350 lbs of bike, kids, etc .: http://endless-sphere.com/forums/viewtopic.php?f=3&t=5749&st=0&sk=t&sd=a&start=30#p88977

 

[Anonymous]

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[chessir]

So how can us USA ebikers get a hold of these yardworks batteries? Canada Tire will not ship to US. Is there a comparable battery available here?

 

[pwbset]

Is there a comparable battery available here?

Do a search on Milwaukee packs. A lot of people here are using them very successfully. They are 28v and about 2.6ah useable per pack and run about $97 with free shipping from toolup.com (they used to be $80 and a few people are waiting to see if the price goes back down with less demand, but I doubt it will in this economy). The actual model number (which you can search with google) is 48-11-2830. They have a multi-year, multi-thousand charge warranty.

The Bosch 36v, Makita 18v, Rigids and other tool packs are also likely being used in their native packaging by others.

 

[mikereidis]

So how can us USA ebikers get a hold of these yardworks batteries? Canada Tire will not ship to US. Is there a comparable battery available here?

AFAIK, you'd have to get someone in Canada to buy and ship, or if your close to border, come here for a visit. Too bad the Canadian $ isn't 63 cents US like it was 6 years ago. Now 95 cents I think.

I had though that CTire had a few stores in northern US states in the past perhaps, but I don't see any US listings on Ctire website store finder. Perhaps I'm thinking of that other Canadian institution: Tim Hortons (coffee and donuts. Cdn KrispyCreme)

So now you're looking for some LiMn batts, in general. Having used these LiMn batts I don't think I'd want to go to ping packs or other LiFePo batts. If I recall correctly, LiFePo needs parallel connections for decent current. These can do 30-31 amps with no parallel.

Other LiMn options may not have a BMS built in. I REALLY like the BMS helping protect me from silly mistakes. I also really like being able to return these batts under warranty to store for 1 year, perhaps 2 if I remember my Visa buyer product protection warranty properly. I also like dealing with 6 packaged batteries, rather than 30 individual cells.

I think what are referred to as EMoli batts are pretty much equivalent to these. Main EMoli source I've heard people use is Milwaukee tool batts. I think I checked the prices on these at one point and found it was cheaper and/or easier to go with YardWorks. Maybe price was similar. Do a google search on EMoli or manufacturer name listed earlier in this thread and you may come up with possible products.

 

[wasp]

i run around nicely at 30-40 kmh i can push to 45kmh thats with 2 bats at 42volts
my bike ways 76.5 lbs i way 220 my bike is a schwinn izip/mongoose clone
this bike only has a 250 watt motor and is tough
i have no cooling mods so i don't hold it pinned for more than 3-4 km
i have more than 3000km on this bike since april
as for getting yardworks bats in the us...the tech i spoke with is based in us
i love these little bats and tough little bms's unlike dewalts...haven't read up on
the milwalki bms's yet
if these bats are run 2+2 for 42 volts @ 12 ah is there anything to look out for?
i want 2 more but need to work on better connections
as for accidents...i had one the first day out
hit a truck that...cut in front of me

thx wasp

 

[Anonymous]

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[mikereidis]

I also have diodes across the pos/neg terminals of each battery to protect the BMS, using SBR30100 super barrier diodes (I don't know if this is actually required for these batteries, was using the experience that others had with dewalt as a guide, the diodes ensure batteries cannot see more than their own voltage level if BMS fails).

i want 2 more but need to work on better connections

Most people are obviously fans of anderson power poles, but I find them difficult to work with, not very tight, and the contacts are small. I am using alternator harness connectors from canadian tire, the contacts are huge relative to andersons, so far they are working excellent but are not cheap, around $4 for a set of male/female.

So far I'm relying on the CTire warranty for unexplained trimmer accidents, instead of diodes to protect against reverse voltage. I've had at least 10 LVC cutouts in series configs from 2s to 4s, and nothing bad has happened yet.

With 4S, I guess you could have reverse 60 volts on the tripped battery, although it's more likely to happen at 45-50 volts or so if all the batts are getting low. Early 31a BMS current cuttof could do -60 - -63v though.

I suspect if we got more info on the battery BMS we'd find there is some protection. But I don't see where they'd need it for garden tools that only have a single battery.


I don't know if wasp was referring to battery side connections. I had some issues with 10 gauge solid cables that would pop out when wires were bent. I used yellow female connectors crimped to the 10 gauge, and taped down the 10 gauge somewhat. Yes, I just jammed those connectors in there; may have widened them a bit, but I want a solid connection.

So now the only 10 gauge I have is a few inches from the batteries. Those are taped down hard so the don't wiggle and stranded 14 gauge is tied to those.


Now my charger side slide connections: at least I have them now, but it would be REALLY nice to have an easier to use plug and socket

 

[Anonymous]

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[wasp]

I would like to have one circular, waterproof, dustproof, locking 12-conductor plug for the charger connection. Such things are available at digikey but they are expensive, in the range of $30-$40 not even including the crimp parts that go inside them. Maybe some day ....

i was thinking gm weatherpak from the junkyard...

wasp

 

[mikereidis]

Just re-checked Canadian Tire shipping policy. Canada only it appears, but may include the far north, for our Eskimo/Inuit e-bikers. Or e-sledders ?

Perhaps some enterprising Canuck should consider reselling these on EBay. No PST and GST should be refundable, so basically $105 US + shipping and profit/handling fee at current exchange ? IMO, these are compelling in that price area, even with US available batteries.

Also noticed they show a pole saw for $80, no batt or charger included. Seems only the grass trimmer/edger has them included.

So thats 5 products now: grass trimmer/edger, hedge trimmer, leaf blower, chainsaw and pole saw. Get the whole collection for $470 with 1 batt and charger... No stock locally on the blower, chainsaw or polesaw.

On to Battery charging options: where N is number of "20v 6ah" batteries...

 

[mikereidis]

Battery charging options: where B is number of "20v 6ah" batteries...
where Y is number of Yardworks chargers...
where P is number of Yardworks chargers in parallel

For examples, B = 6, Y = 2, P = 3

#1: Use 1 - B Yardworks chargers at $30 + tax each currently.
Cost: Y * $30
example: $60
Connectors: From B+1 (series, sharing connections) to B*2 (seperated)
example: 7 to 12
Time: B/Y * 3.5 hours at 2 amps (0.33c)
example: 6/2 * 3.5 = 10.5 hours

#2: Use P - B * P Yardworks chargers in parallel.
Question: Could this work ? If each provided 2a of constant current, could parallel provide 4a ?
Cost: Y * P * 30
example: $120
Time: B/(Y*P) * 3.5 hours at 2*P amps (0.33*P c)
example: 6/(2*2) * 3.5 = 5.25 hours

#3: Adapt/use commercial Li-Ion charger
Cost: yes
?

#4: Build own charger

I'm having visions of building a "cheap ass" controller that would charge faster and be dangerous. I.E. no isolation transformer, therefore potentially rather dangerous voltages on bike with respect to ground. I think a locking and enclosed container for the bike could actually be cheaper than fancy isolation transformers. That's my excuse, don't try this at home, I'm technically a professional with electrons... (albeit rusty).

I figure if you don't mind wasting a bunch of power in a big resistor (I.E. a 120vac, 12.5a, 1500w old style heater), then it's easier to provide something close to a constant current.

I've been poking inside the YW charger and it seems to just be a typical CC (2A, 0.33c) and CV (4.2v ?) charger that switches to CV mode at 20.81v or so (when the green light comes on to indicate "full charge".) I think "full charge" is really just the CV phase and batt voltage can slowly rise to 20.98v or so. I don't think CV phase ever ends, it just tails off to 5 milli-amps or so, which I guess keeps the batt fresh, although LiMn really doesn't need freshening much.

So I'm thinking for the CC phase, I could get away with a heater(ie cheap 9.5 ohm 1500w power resistor), a full wave bridge rectifier good for 15amps at 120v, a capacitor, a timer to turn it off after T minutes, meters to watch current and voltage, and a fully charged fire extinguisher, good for electrical fires.

Capacitor needed because I think these batts might have logic inside them that requires lower levels of ripple than naked cells would.

Calcs indicate this could charge a single 1S in 40 minutes at 10.8 - 10.2 amps or about 1.75c. Stuff I've read elsewhere indicate 2c is fine for LiMn. I think CTire went conservative with 0.33c, and to decrease cost of charger. Perhaps 10c would be possible, but 60 A is a LOT of charging current and lifetime would be affected.

A 2s would charge in 49 min, a 3s in 63 minutes and a 4s in 88 minutes. Hmmm...


I've also read that LiMn can be charged in parallel, but ONLY if battery connections are solid, and pretty much equal. I'm not sure I want to take that chance, unless BMSs help.

 

[Anonymous]

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