2WD Semi-Recumbent Recycled-Parts Cargo eBike: "CrazyBike2"

[amberwolf]

Been using the EIG 14s1p pack from this on SB Cruiser since getting it operational again, as the A123 pack is insufficient to run SBC due to some odd behavior in the righthand motor controller of SBC cutting out at too high a voltage (which it didnt' used to).

But anyway, today I did some testing with a freshly-built (out of old cells but used a lot less than the original pack) 14s2p EIG NMC pack, vs the original 14s1p, just a couple of quick runs from 0-20MPH on each one.

Test done with each pack in turn, packed into the toolbox rather than working into the frame like normal (is a PITA). Each started out at 58v. Note that the 14s2p weighs twice the 1p, so the 2p's runs have that added maybe 20-ish pounds. (less than 10% of bike weight, probably around 6-7% total with me on there)



The 14s2p EIG did better than the 14s1p, but is fairly close for this kind of short run at full charge. Probably see much more difference over a work commute, for instance. Took about 3-3.5 seconds 0-20MPH; distance in the street from the corner of my front yard to the side gate start. Run back was the same. Less sag than the other.
57.7 vrest
54.2Vmin
0.141Ah
8.2480wh
79.54Amax
0.071mi

The 14s1P EIG took about 4-4.5 seconds, going all the way past the side gate. Run back about the the same, maybe a hair more time and distance.
56.9 vrest
48.9Vmin
0.148Ah
8.1310wh
79.01Amax
0.081mi

 

[amberwolf]

For a while, CB2 is going to just be FWD, with the rear wheel/motor/controller, and just have a regular bike wheel in back, becuase I needed to move ti's motor/wheel over to SB Cruiser's left wheel, due to a problem with the 9C's axle on the hollow (inboard, wire) side.

See the SB Cruiser thread, past couple days' of posts, for more details on that.

 

[amberwolf]

So CB2 has been down essentially since the above. Well, it was functional minus the rear motor for a bit, but then I took the front forks off of it to swap with SB Cruiser and haven't gotten round to putting the SBC fork onto CB2. I keep intending to go back and fix it up so it can be my backup in case SBC is down, but whenever there's time either the weather hasnt' allowed it or else I wasnt' phsyically able to do it, and whenever I could've done it there's been no time. :/

However, I really came back to the thread to post this, that I found while I was looking at streetviews for something else (stupid traffic stuff in my area), for a post here:
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&p=1316753#p1316753

I found a perfect side view of CB2 in traffic, probably on my way to work, here:
https://www.google.com/maps/@33.5815784,-112.1221558,3a,75y,92.38h,98.71t/data=!3m6!1e1!3m4!1saki8ghw-VnDjrkshpLUv5w!2e0!7i13312!8i6656
dated September 2016, one year ago this month.

Click image thumbnails for full size image

 

[amberwolf]

While posting something else, I had a thought take over about making an SB Cruiser-like box frame for CB2, to improve it's cargo carrying ability, and it would end up something like this:



where teh boxes at the rear are replaced with framed-in ones that are part of a seatbox like SB Cruiser's, though I'd still use the suspended-mesh seat CB2 presently uses, just bolted to the top of the seatbox instead. LIke SBC, the whole seatbox top and seat would fold forward to access teh inside of the box.

Teh steering and front fork would be the same, as well as handlebars, etc. I havent' finished the front triangle section but it'd be setup to hold the battery in it sort of like now, except not in an ammocan, but rather as sets of 4 to 6 cells as "book" blocks between cover panels.

The seatbox would not be as tall as SB Cruiser's, probably only a little mor than half as tall, but the rear boxes would remain the same size as the present ones, though shaped a bit differently at the bottom--instead of a regular box, they would have the outer bottom edge "bevelled" inward so tighter turns can be made (more lean before box strike on pavement would occur). I'd probably extend the seatbox downward with teh same bevelled area at it's outer ends, too (not shown in drawing yet). Would add a significant, if small, amount of storage space by doing this.

Not shown is triangulation beams; just to make the shapes clearer.

The whole frame should be stiffer than CB2's is presently, so I could probably revisit a middrive like the powerchair motors I used to mount under the frame by the cranks. I only abandoned that approach when hubmotors became an option for me, and I'd had so many derailments and parts destroyed.

If I used thin light wood to cover/fill the framespaces like i did on SB Cruiser, I might not need the triangulation of the boxes, as the wood would stiffen them being inside the frame itself.



I dunno that I'll ever build this, as the trike has more uses and I havent' even ridden teh bike in...a really long time (more than a year? two?). But I had the idea so I posted it so I won't forget / lose it, in case I do ever decide to revamp the bike and ride it again. Might be worth a complete rebuild, if so.

 

[amberwolf]

got a question via pm, but the answers could be useful to others, so:

I'm wandering if you might be able to tell me about the EIG cells you used on your crazy bike. Me and a friend just acquired 150 of the same cells. I don't suppose you could tell me what sort of performance you could get from them? Mainly I just want to know if they will deliver 150 amps at 1p for short bursts?

they're rated at 5c (100a for 1p) continuous, and 10c (200a for 1p) for 10 seconds.

as long as you're within those limits, you're within the specs for the cells when they were brand new.

if yours are old (but unused) or old and used, they'll be less capable by some margin, which you'd have to test for if you want to know exactly what that is. you can compare to the spec sheet for voltage sag under various loads to get an idea whether yours are working as they should.

mine are several years old, and used, and are still working pretty well, but the ones presently on the trike do sag a fair bit under loads above 2-3c or so. they're still only around 38mohm for the entire 14s pack (vs what can be 400-500mohm for equivalent 14s 18650 packs).

I intend to replace an ageing 72v 20s15p li-ion 38ah pack.

if you're replacing a pack of that size (2700wh), then to get an equivalent capacity (range) you'll need 20s2p eig cells, which will be about 2900wh, 72v 40ah. (which also gives you 200a continuous, 400a burst)

if you don't need the range, just the performance, then 20s1p will work, but it only gives you about half the range you used to have.

So any pearls of wisdom on those EIG cells would be great.

assuming you have them in their black plastic holders (with aluminum plate on one side):

use brass busbars to connect the cells; i'd go with 5mm thick stuff. copper works too.

i think jonescg and jimbob01 here on es have patterns for them available in their threads about those cells, they'd be easy to have waterjet or maybe laser cut, or you could even bandsaw them by hand if you needed to.

a piece of clear lexan or similar, with ends bent so they reach the top-pack-ends bolt holes (see below) and are secured by them, so nothing can end up landing across the busbars and shorting them out. (i just used clear packing tape on one, and gorilla tape on another, to secure the lexan...but if i had had bigger lexan pieces i'd've bent them as described).

use some long bolts thru the top corners of the cells, to secure them together; i'd add end plates of something hard to protect the flat pouch side that's exposed on one end (really i'd put one on each end, since that aluminum plate .

then a sheet of aluminum or similar with holes that match those in the bases of the cells at the bottom edge, to secure that end of them all.

if you don't know what i mean, i can post pics.

 

[Johnuhtron20]

HI Amberwolf

Can you just elaborate a bit more on the EIG cells, how much sag were you experiencing before and after putting (how many cycles??) lots of cycles on the batteries, and under which amount of load?.

Just so it gives me a rough idea of how much the stated discharge rates are conservative or possibly exaggerated?

Thanks

John

 

[amberwolf]

Can you just elaborate a bit more on the EIG cells, how much sag were you experiencing before and after putting (how many cycles??) lots of cycles on the batteries, and under which amount of load?.

mine were already well-used when i got them, so i don't know what they're like new, other than the datasheet info.

right now, on my sb cruiser trike, my several-year-old 14s2p pack sags from around 52v to around 49v under max startup load of about 80a, when it's about half full (50% discharged). afaicr that's about the same as when i started using it on teh trike, but you'd have to find and check the ca data in the sb cruiser thread to be sure.

i don't know how many cycles it's been thru for me (and no idea how many before i got the cells, but afaicr they were all used hard in a racing motorcycle before i got them); typically i charge it back up after i've run it down a little more than halfway (so i can always be sure of having at least 10-15 miles of range at any particular time). takes about 3-4 days to run it down, so that means i'm probably recharging it a hundred times a year. it's been running the trike at least a couple years, probably mroe than three (you'd have to dig up when it was installed over in teh sb cruiser thread), so it's seen perhaps 200-300 cycles like that, and some cycles of complete rundown before i established the present routine.


i don't remember the info from the 14s1p pack used on the bike this thread is about, you'd have to look thru the posts in this thread for the cycle analyst (ca) wattmeter data for the vmin, amax, vstart, etc. whcih will tell you the voltage sag at the highest current on a particular ride. (there is also data like taht over in teh sb cruiser thread, both for the 14s1p pack from this bike, and for the current 14s2p pack, which is made of a differetn set of cells than the still-existing but not in-use 14s1p pack. ) .

Just so it gives me a rough idea of how much the stated discharge rates are conservative or possibly exaggerated?

the datasheet info is going to be exactly what they're like when new, neither conservative nor exaggerated, when used under the same conditions stated on the datasheet. so it has a discharge curve showing the voltage at a few different currents, thru the recommended range of state of charge.

what yours are like you will have to test if they are not brand new (in both time since manufacture and in usage), to find out what they're actually capable of.

 

[Johnuhtron20]

Thanks for the reply Amberwolf. I really appreciate it. Seem like pretty good cells to me, from what your saying, especially when bearing in mind they were thrashed cells to begin with.

Thanks again.

John.

 

[amberwolf]

Just a bit of followup on the above:

Some days ago I had need of a 14s test pack and didn't want to lug the twice-as-heavy spare 14s2p pack for SB Cruiser from the shed to the house, so I grabbed CB2's old 14s1p pack in the ammocan and carried it in, hooked it up and found significantly lower voltage than I expected, by about a couple of volts. Since I had 3 balance taps on it externally accessible as two 6s and one 2s, I hooked up three cellogs to it and immediately got alarm on the middle one that the last cell (number 12 of 14, with 1 being the most negative) had dropped to 2.6v. The rest of the cells were between 3.5 and 3.6v.

I'd left it at about 3.7v/cell for storage, about 52v, since that's less degrading than leaving it stored full. I don't remmeber for sure but it's probably been at least a couple years since it was used, though I did check it's balance sometime the year before last along with anything else I had stored at the time, and it was within a couple hundredths of a volt on each cell, or better. I think the last time it was used was to run SB Cruiser itself before I got and started using the newer cells in the 14s2p packs.

I opened the ammocan and could smell the solvent of a leaking cell immediately. Pulling hte pack out of the can I could clearly see the swollen cell #12 had forced a gap on either side of it. Not much of one, but there. I unbolted the bottom plate at that end, and the busbars off the top of the cells connecting to #12, and pulled off the end three cells and separated out the failed #12 cell.

The cells had marked on their edges their numbers, and on this cell I had actualy replaced it several years ago (2012, IIRC; have to go look at the markings again) because I had a low cell then, too; I think that one had high internal resistance and was internally leaky, it's back in this thread somewhere--it was causing excessive voltage sag.

This one was discolored at both bottom corners (but not *all* along the bottom edge), where the pouch itself had failed somehow. There's no sign of physical damage, deformation, corrosion, etc., that could have eaten into the pouch or punctured it, etc. I don't know what caused the failure.

I did dig out a spare cell and physically swapped it out, but it's at a higher charge state so I need to drain it down to match, or just charge the rest of the pack up to be close to it and then balance them all up manually. Started the draindown process with a 50ohm 50w resistor on that cell, but even though the resistor was quite hot when the breeze wasn't blowing, even after three hours (while I was fixing dinner and doing stuff with the dogs, etc) the cell didnt' even drop a hundredth of a volt.

I guess it's not taht big a shock really, since at 50 ohms, starting at IIRC 3.9v, taht's only 78mA, which is insignificant compared to the 20Ah cell capacity (perhaps 60-70% full at that voltage?). Also, at that voltage and current, it's only a third of a watt...so it was surprising that a third of a watt make a finger-sized metal-encased resistor hot enough to be touchable but not be holdable in my hand. (when the breeze had been blowing it was just uncomfortably warm).


After that time I was too wiped out to continue so I disconnected that and put it all away for later "someday" continuation.


But it was interesting that one of the cells should fail just sitting like that. Disappointing, too, but those particular cells *were* pretty old and well-used, probably up to a few years older than the ones I'm using in SB Cruiser, and likely used harder than SBC's before I got them, as well as after.

 

[amberwolf]

I'm resurrecting the CB2; it'll be sufficiently different that I'm going to rename it to the Cloudwalker Cargo Bike, and give it a new thread over here:

https://www.endless-sphere.com/forums/viewtopic.php?f=6&t=111081

 

[gman1971]

impressive!

 

[amberwolf]

Thanks--you'd probably like the sb cruiser better; it's over here;

The SB Cruiser : Amberwolf's 2WD Heavy Cargo Trike & Dog Carrier

This thing replaces Delta Tipper...er, Tripper v1.0, whcih was cannibalized to build it. https://endless-sphere.com/forums/viewtopic.php?f=2&t=22720 It's mostly Dogman's fault ;) ...er, inspiration, as he suggested it as a joint build for his trip out here this year. Tiny and Yogi discuss...

endless-sphere.com

and the new version is still in design over here

Amberwolf's Schwinn Trike Rebuild / Conversion to Heavy Cargo Hauler

From here: https://endless-sphere.com/sphere/threads/the-sb-cruiser-amberwolfs-2wd-heavy-cargo-trike-dog-carrier.67833/post-1827806 I got an old Schwinn Tri-Wheeler Town and Country (probably the 1971 or 75 or 78 model, based on info from bikehistory.org) from someone I knew from the...

endless-sphere.com

i don't think i'm ever going to get to rebuild crazybike2 into the cloudwalker like i wanted to, though.