here is some info on 20v yardworks lithium ion

Don't know if this is a silly question but I'll ask anyway...Do the led battery gauge lights work when you have them hooked up and riding the bike ??? Have you had a chance to look before powering the bike off with the battery bag open.I'm curious.

Yep 65 pounds of lead on a bike is crazy heavy.

Thanks
Eric
 
Naw,I was talking about these led's on the batterys...

YardWorks-04 (Small).jpg

It's a Kinda stupid question but I was just curious if they were lit before you powered the bike down and opened the battery bag.

How warm do the batteries get after a good hard ride and how many ah did you use after the 34.5km ride.

I have to agree that throttle/headlamp battery meters are sorta useless once you've used a ca or watts up meter,I use a watts up.

On a side note... When we got the Canadian Tire flyer with Friday's paper I was kinda hoping to see these Yardworks Batteries in there and on sale,no such luck though...

Thanks
Eric
 
Hello there nusandvolts,I was wondering if you had tweaked the shunt wires of your new controller to accomodate the bms of the Y .W. batteries.You could even temporarily reinstall your older 15amp (?) controller to see if it resolves the issue.If it does then adjust the shunt of your clyte brushed controller?

Eric
 
Thats cool,Yep when you get a taste of more power it's hard to go back,sorta like having high speed internet service and considering going back to dialup.Another way to increase the torque/acceleration is to mount the motor in a smaller wheel.Then again that's more money spent and you've already spent a tidy sum on these Yardworks Batteries and chargers.

I'm currently using my 25 amp controller and it peaks out at
26amps/900watts on steep hills (20inch brushed clyte rear hub) and I usually crest the hill at ~20km/h with pedaling of course.Speed isn't an issue with me,I'm getting older and I'm quite happy cruising along at 32 to 34 km/h on the flats.It looks as though these Yardworks Batts may work out for me.Too bad they don't have the 6ah batt spec sheet on their web page.I guess I better start saving my money so I can get some in the fall.

Thanks and keep the updates coming!
Eric
 
Hi nutsandvolts , i love to read your reports on your set up, good to know that you are getting more range with 2s 3p than 3s 2p it does not surprise me, could it because it is more tempting to go faster :wink: lol ...anyway you are saying in a previous post that you had to run to a couple of C. Tire to get some packs ...you should be happy to know that the one at 181 principale in aylmer they have over 10 packs :lol: from what i read you could go and get them with your bike
 
I have a c lyte 5304 on a rocky mountain bike, and for batt. i have a 36 volts 15 ah nimh and 48 volts 6.9 ah a123 ...so you live in chelsea and moving to ottawa ... yes i know a little about evco but never been there but i did go to juergen place if you know him. if you don t know him he is a guy that sells ebikes in ottawa.
yes it would be nice to go for a ride .
 
yes that is the same juergen i tried one of his homemade recumbent it is a nice ride, EVCO looks interesting i should go there to see what it is one of these day ...i think it is on mondays is it?
 
nutsandvolts said:
This ebike stuff is addictive, both the building and riding. It is driving me absolutely crazy that I can't use my bike today.
Click to expand...
Getting in the gasser feels like punishment, filling-up feels like robbery. :evil:
 
Hi there Nuts&Vs

Very interesting thread indeed, but I have one request if you could check it out: I would like to have some voltage sag measurements done at a couple different load currents? Do you have some appropriate load resistors to check this out? This would be great to know, since it would help us compare these packs to other ones (I'll be measuring the same thing when I get my new Ping pack and I'll post the results).

I think it would be best to do tests at three different load currents (two would be the minimum, but three would give us a better idea of the cell's characteristics).
Also, I was thinking these voltage measurements under load could be done at two different states of charge: Once when the pack is close to full charge (after removing the first bit of energy to get a fairly stable voltage), and then additionnaly when the pack has maybe a quarter or so its charge left. I'm thinking this would be usefull info for the EV community because some people report packs that work well (low sag) at high states of charge, but that the sag gets bad as the battery looses charge. Of course this is normal battery behavior, but I'm quite sure some display this weakness much less than others.

If you do this, make sure the voltage readings are done right at the pack's output (as I'm quite sure you know, Ns&Vs - this is mostly for others that might want to do this too to add to our knowledge base).
Thanks for all your posts, man! I just wish these packs were on special sometimes, but somehow I don't think this will happen. :roll:
Pat
 
nutsandvolts said:
Yeah Juergen let me try his 500W bionx xtracycle and the smaller bionx, bikes with WE and clyte 4 series, and yuba mundo cargo bike. It was after trying his bionx xtracycle that I decided I needed a longtail bike like that. He is a dealer for xtracycle and yuba, wilderness, bionx, and clyte. He also has some really cool custom bikes, several recumbents, and one that was made from parts of a glider. EVCO is interesting, they do a lot of education, and they have a grant to setup a course on electric vehicle conversion.
Click to expand...

Does Jeurgen have a store? It would be nice to drop in if I'm ever in the area.
 
Do you have two large resistors lying around, or that you could scavenge from some dead electronic stuff? Since your packs are about 20V-6Ah, approx 1C discharge would happen with a 3 Ohm resistor. It's no big deal what exact resistor or resistor assembly you use to test the pack, because you need a current meter to measure the exact current draw anyways.

For our purposes, load tests done between 1C and 3C would be most usefull. Of course these packs have a BMS limiting current to 5C, so if possible it would be great to see results from just bellow this limit too. This would require about a 0.66ohms resistor, but only trying it will tell you what will be OK with the BMS. Also, it's not important what exact current you get with any setup (doesn't have to be C multiples), because we are reading the exact current we are draining anyways.

The setup would be: Volt meter connected directly across the pack under test. Load resistor(s) connected through an amp-meter, this series connection set up to be able to quickly connect and disconnect it from the battery pack (or cell) under test. Make sure any surface charge has been bled off by a bit of discharging before taking any readings.

When ready to test:
Connect the resistor+amp meter string to battery, read voltage and current fairly quickly (specially if using low wattage resistors!), then disconnect. Change the resistor(s) to your next desired value. Repeat readings. etc.
You could do this set of measurements at any state of charge of the pack (or cell) that would be significant to us, like full charge(after removing surface charge), maybe half full, then maybe when you have about 1/4 or so charge left. Make sure you use the same pack for all tests so we are comparing the same thing.
May the swartz be with you!
 
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