GCinDC's Giant DH Comp

[dnmun]

no, you don't have to disconnect anything. use a second set of terminals with the wires soldered onto each end of the battery packs that are now connected in series. no need to change anything on the adapto BMS, it will just sit there and balance any cell that climbs over the 4.2V level.

 

[dbaker]

They won't let him bring the bike up to his cube

 

[Cresh]

xxxx

 

[dbaker]

I have been tracking low temps trying to anticipate ice. No ice found yet on the CC trail. Sorry to hear about your crash

 

[GCinDC]

yeah, cresh, that's a nasty bummer about the wipe. i'm going to dash over to your thread to see if you at least got vid.

 

[GCinDC]

happy new year, folks.

so i'm 8 weeks out of surgery and the shoulder is getting better, and well enough to ride.

if you recall, i moved offices and no longer can charge where i park the bike. and the 4s subpack (2x 5800mah for 11.6Ah) was starting to die, leaving me with nowhere near the capacity i'd need to commute to work and back, esp at high amps w/ the maxe.

so i decided to make a new detachable pack that i could bring to my desk and charge w/ the bulk charger. and i could balance charge at home w/ the coil. seems reasonable, right? i'm not terribly psyched about having to unscrew the BMS connector from the controller each time, but if it goes well, i could cut the BMS cable near the pack and use andersons, since it's only 4 wires.

rather than buy 2 new 4s zippy 5800 packs, i decided to use the 6s packs that have been in storage in the garage for a couple years (waiting on the thudbike). cause since i was changing the config, why not jump up from 20s to 22s?

so i first made the balance wire harness for 3x6s and 1x4s:

i attached the maxe to the downtube and started planning the battery pack layout:

two 6s packs are about 4" wide so the steel frame wasn't going to work, and i decided to finally try out molding the kydex around a form i tacked together:

and made 3.5" + 3/4" for 4.25":

then the layout and forming:

i formed some of the excess around the top and seat tubes to see how well it 'snapped on':

then i started to attach my balance harness but wasn't paying attention and put it backwards, and shorted a wire, which i replaced easy enough:

to get the pack in and out easily, i cut off the top (and plan on adding a second piece top). i reconfigured the BMS for 22s and started charging/balancing:

even after balance charging all the cells to 3.86 before attaching/paralleling them, i found they were way out of balance.

i'd also upped my bulk charger voltage to 92V btw, but saw the top cells rise over 4.2V so unplugged it and let them balance for hours and hours but not long enough to balance them.

today was my first day back so i taped the loose bits together and rode it in, but was very disappointed to get a LowBatt error only halfway in, pulling 80A mind you, but still. so i switched to eco and pedalled the rest of the way to work.

so now i have to decide how to replace the bad cells/packs... when i first checked them, all the 6s packs seemed reasonably balanced for having sat in the garage for 2+ years. all except one which had a cell with reversed polarity. so maybe they're not worth the effort after all.

if i'm going to buy a replacement or two, i might as well spend a bit more to get new zippy compact 5800mah cells, so at least i'll have the extra capacity to add to the 4x8s packs that i've been using and know are pretty good... especially if i want to enjoy the maxe a bit more. 22s is pretty sweet.

 

[fechter]

The Kydex stuff looks great. How do you bond the edges? Is there a glue that works on it?

 

[dnmun]

you can balance the pack by using some power resistors on the high cells. since they have the JST plugs you can insert the resistor lead into the JST plug spot for the high cell and drain them that way.

if you have two or three high ones adjacent each other then you can put the resistor across all 3 and triple the drain rate.

drain them all down to about the same level as the low ones in voltage and then recharge to full charge and see if the adapto BMS will balance them but it uses really small balancing shunt resistors so it will take a long time if you cannot drain the high ones down first.

this is always a problem when putting a new pack together. i doubt if you have individual cells that are much different from the others.

balance is not voltage. balance is charge stored so you need to do discharge tests into a dummy load to see how close they are in voltage at the end, not the point close to full charge.

 

[Ohbse]

Kydex is a great idea, looks very cool. You will no doubt the able to get the battery to balance a bit better than .126v but I suspect you're going to struggle with ongoing imbalance due to the age/difference between packs - especially bulk charging off the bike.

Time for a new pack perhaps? Given your constraints and need for a bit more range and probably less risk (if you're no longer charging in an all concrete carpark) perhaps it's worth jumping to 18650's? Seems to be working out very well for everyone that's tried it. If you can track down somebody with a suitable spot welder it's not too difficult to assemble. You'll be able to jam in more Wh and won't be short on power either. Also makes it possible to have super tidy wiring for power and BMS.

Somebody pointed out that my first attempt at a lipo pack resembled some sort of IED - my next couple have ended up much tidier.

 

[GCinDC]

took about 6 days but finally balanced...

the reason for the imbalance - the 5th cell charger on my OLD bc168 (the charger that likely caused my fire) was 1.1V OUT from the others!

time to throw that in the trash!

before the cells balanced, i'd lost hope and ordered 2 zippy 6s 5.8Ah packs, and think i'll probably just go ahead and run a 22s 11.6ah zippy pack. here's a pic of fooling around w/ layouts, but i decided to stack them all cleanly, and back in the steel/cordura case, my old standby, lol! :lol:

in order to detach, i'll remove the worm clamps and sew on some velcro straps.

i added a connector near the BMS to make it easier to detach. don't want to have to keep unscrewing it at the controller:

i slipped a strip of kydex under the shrink tube to make the connectors easier to handle w/o risking the soldered connections.

in past years, in this weather, i'd have been so psyched to go ebiking, but not this year. maybe it's just too risky for my shoulder. but it's also the absolute disgust i've developed for the effect of salt on the bike, and it's nowhere near waterproof.

and i took apart, greased and reassembled the rear shock/suspension because i could not figure out where this mysterious creaking was coming from and it was driving me nuts:
[youtube]2nZaAMaOmWY[/youtube]

anyway, for nostalgia, here are a couple fun vids of my braver, more able self from late last year:
[youtube]F6Fr8bmcuwM[/youtube]

[youtube]jjtEeOofoTc[/youtube]

[youtube]yIrutg3TT5Y[/youtube]

 

[Lenk42602]

....... but it's also the absolute disgust i've developed for the effect of salt on the bike.....

corrosion. never. sleeps.

The bane of east coast two wheeling commuters in ice melt (salt), rust belt wintry months.

Every night when I get home the bike gets rinsed off. Immediately. Only real solution.

 

[xenodius]

....... but it's also the absolute disgust i've developed for the effect of salt on the bike.....

corrosion. never. sleeps.

The bane of east coast two wheeling commuters in ice melt (salt), rust belt wintry months.

Every night when I get home the bike gets rinsed off. Immediately. Only real solution.

You could also go with a full fairing Not suitable or appropriate for offroading, though.

I've decided living in the rainy Northwest that in order to commute by ebike without making any lifestyle compromises, I need a fairing. It's less maintenance, requires less planning for inclement weather, increases comfort... and you'll save time when you don't have to bundle up just to go a couple miles down the road when it's freezing.

I think a Bafang+Fatbike would be a reasonable, low-maintenance winter compromise, but waterproofing is really hard especially with heat-cycling.

I still fight rust up here and they don't even use salt.

 

[dbaker]

Good to hear you got them balanced. I trashed a BC168 as well. The challenge for me this past week was the changing low temperatures that made layering choices tough. layers of gloves, jerseys, tights, caps, and jackets The CC trail was plowed all the way I have been running a 18650 pack I made from tool packs. Range anxiety getting home

 

[broke]

I was thinking of building a raptor what do think about that frame kinda expensive for me? Also my friend has some used internal a2b batteries 18650 for 100 bucks each 36 12 ah. With charger there pretty used but still work what do you think? Used 18650 cells? Thanks gcindc

 

[crezzy2k1]

Regarding the creaky suspension. I got some bushings from this guy http://www.ebay.com/itm/Shock-Bush-Removal-Tool-DU-Bushes-for-Fox-Manitou-X-Fusion-5th-Element-/121544121278?pt=UK_sportsleisure_cycling_bikeparts_SR&var=&hash=item1c4c981bbe

It has stopped the creaking i was having on my DH Comp which from your vid sounds the same.

 

[GCinDC]

Regarding the creaky suspension. I got some bushings from this guy

thx, i replaced the bearings on my black dh comp after the fire, but the the threads that are stripped on one of the linkages are actually part of the frame. i replaced the bolt i'm using instead and lubed the bushings and it's been fine since then.

running the 22s zippy pack now. feels a lot better. here were stats for return uphill commute. not too efficient, but i love that burst of power!

oh, and my h4080 got up to 375F on the hill before power cut out.

 

[70ivi452]

thx, i replaced the bearings on my black dh comp after the fire, but the the threads that are stripped on one of the linkages are actually part of the frame. i replaced the bolt i'm using instead and lubed the bushings and it's been fine since then.

When thread is damaged you can fix it with helicoils or keenserts.

 

[Ohbse]

oh, and my h4080 got up to 375F on the hill before power cut out.

Solid effort! Power is intoxicating isn't it... You're definitely pushing the limits on that motor

Thought about buying a Cromotor or something similar? Buying from the original manufacturer ends up being pretty affordable. As well as running a lot cooler, you're also going to get a good amount more thrust at the same controller settings for a small increase in weight. Did you have a 135mm swing arm?

 

[ridethelightning]

hey obse, where is the best place to get a cro at a good price these days?

 

[Ohbse]

hey obse, where is the best place to get a cro at a good price these days?

http://endless-sphere.com/forums/viewtopic.php?f=31&t=65972&p=992467&hilit=quanshun#p992467

Quanshun is the actual manufacturer of the Cromotor. I'm all in favor of supporting people like zombiess and accountant who are creating products and distributing them for a reasonable price, but if they don't have stock what can you do.

 

[GCinDC]

so damn busy lately. some updates.

- 2 weeks ago: riding 20mph next to cab who slammed on the brakes and turned right into me to pick up customer, but i somehow managed to skid/lean/stop to avoid collision. shoulder was not happy about it.
- last week: jumped the light at the circle when i saw it turning yellow for crossing traffic and saw person in lane stopping, but hadn't noticed car in further lane speeding up! thank god they saw me and braked, and that i was able to skid/slide out of the way and only get tapped and knocked over in the middle of the intersection but landed on my feet. maybe time to finally stick some mounts on the blue bike to start running the gopro more regularly - woulda been a good one.
- tossed on the studded wheel, so riding in all weather, getting salt bath. alas
- HS40 can't handle 12kW for long, esp uphill! having to really manage the throttle on the way home, even in freezing temps, otherwise the motor cooks on my long hill
- routine PT for shoulder, now 13 weeks out, but it's frozen; haven't been able to improve range of motion much. stuck at 45 degrees external rotation and 120deg flexion; seeing the doc next week - who likely will suggest a cortisone shot in the shoulder capsule or they put me under again and 'manipulate' it to unfreeze.

now the real reason i'm posting today, to share this awesome vid i found - amazing traction/driving w/ skinny wheels!
[youtube]nq2jY1trxqg[/youtube]

 

[dnmun]

interesting that the BC168 was off by 1.1V. i would never have expected that. in analyzing your fire i assumed the BC168 was able to maintain control over balancing voltage so if it was off by 1.1V and got up to 5.3V overnight that would have been enuff to send it into thermal runaway. the Boeing 787 lipo pack test was only 4.50V for 24 hours.

so now i can discount my theory that it was from heat generated in the JST/sense wire plug connection.

glad your shoulder is healing up too.

 

[Cresh]

haven't been able to improve range of motion much. stuck at 45 degrees external rotation and 120deg flexion; seeing the doc next week - who likely will suggest a cortisone shot in the shoulder capsule or they put me under again and 'manipulate' it to unfreeze.

Wow, I don't think my shoulder injury is as bad as yours, and I'm too scared to get back on the bike. My shoulder is a little frozen and doing PT also, hope you get better soon...

 

[GCinDC]

haven't been able to improve range of motion much. stuck at 45 degrees external rotation and 120deg flexion; seeing the doc next week - who likely will suggest a cortisone shot in the shoulder capsule or they put me under again and 'manipulate' it to unfreeze.

Wow, I don't think my shoulder injury is as bad as yours, and I'm too scared to get back on the bike. My shoulder is a little frozen and doing PT also, hope you get better soon...

i'd be a bit traumatized as you if it black ice too, but what are you doing instead - metro?

my commute is only 6mi, so i could go 15mph all the way with a hand tied behind my back and still get there sooner than by pubic [sic] transport.

you suing the city? i'd bet you weren't the only one that bought it that day.

 

[Cresh]

haven't been able to improve range of motion much. stuck at 45 degrees external rotation and 120deg flexion; seeing the doc next week - who likely will suggest a cortisone shot in the shoulder capsule or they put me under again and 'manipulate' it to unfreeze.

Wow, I don't think my shoulder injury is as bad as yours, and I'm too scared to get back on the bike. My shoulder is a little frozen and doing PT also, hope you get better soon...

i'd be a bit traumatized as you if it black ice too, but what are you doing instead - metro?

my commute is only 6mi, so i could go 15mph all the way with a hand tied behind my back and still get there sooner than by pubic [sic] transport.

you suing the city? i'd bet you weren't the only one that bought it that day.

It happened outside of the city, in Arlington. But I did wonder why they didn't say anything about me riding in traffic on a motorized bike. I was cruising with traffic, real lucky a car didn't run me over... Now I realize it was not my fault - it was a clear day and no rain recently. The black ice was caused by underground water leak. If it was raining I wouldn't have been going as fast, or probably wouldn't have been on the road. They are lucky I didn't sue.

By the way, been taking metro. It stinks, literally :-(