GCinDC's Giant DH Comp

[Cresh]

some scenes from the am, which is always more fun for some reason..
[youtube]zMp5DMTv048[/youtube]

Ha! I know that honk too. It's like a cowbell, he wants you to go faster!

 

[dan974]

ghost rider back on tracks love it !

 

[dnmun]

way cool. really like the histogram of the cell voltages. 20mV is about normal imo.

is there a place for you to plug in and charge in the garage where you pack the bike?

this is the kinda monitoring you needed to charge without fear when you are not present to watch it.

i don't think you need worry about a fire now that it has this kinda supervision.

i think this is the key to lipo safety. a good BMS to monitor and protect it. except the risk of shorts is still there so you might wanna think big fuse. 80A fuse, 100A fuse. or breaker.

 

[rodgah]

Yeah that could potentially cause issues. I'd sort that out. If the battery has some stronger cells than others (which it most likely will) the weaker parallelled cells will try to compensate for voltage sag to equalize through only the balance taps. It's probably not such an issue now when the pack is new but as it gets cycles on it this will become more pronounced and it could result in significant heating of your wiring, or worse case, the dreaded balance tap melt and sparkle.

To visualise it another way, it's sort of like how normal RC balance chargers work.
They bulk charge through the main pack wires at say 5 amps and try to correct imbalances in cell voltage by bleeding the high ones down at maybe 5% of that power. Trying to balance like this is like pissing on a roaring fire. This is vaguely comparable to your set up is now, because you're bulk discharging current though the main wires and then the cells are trying to self balance through their paralleled balance taps.

I had a bit of a discussion about this in my thread....sn0wchyld made a little simulation of what would happen if paralleled cells became unbalanced for whatever reason....not as bad as you would think.

its in here if your interested
http://endless-sphere.com/forums/viewtopic.php?f=6&t=36682&start=42

so are you saying jay that you make your packs like the right not the left? obviously with the balance tabs paralleled

I had mine wired like the right at first. But after thinking about it for a while that logic would also make you scared to parallel 6s packs instead of 2x3s .... get what I mean? I guess the way I look at it is if hobby king sold 12s or 24s packs would you be scared to parallel them? I am still forced to parallel at the 12s level as I am using a hyperion to charge, but with good bullets and sound building and monitoring of the individual cells groups I see no need to stress too much.

Interesting that the turigy cells (i assume are the 4 ones on the far right of the graph) standing tall next to the zippys. I dont think I have seen a side by side test result that looks like that before.

 

[GCinDC]

I had a bit of a discussion about this in my thread....sn0wchyld made a little simulation of what would happen if paralleled cells became unbalanced for whatever reason....not as bad as you would think.

sounds like great vacation reading. i can't wait. huge presentation today, then a million things before noon tomorrow then a 16 hour drive with 3 kids, wife and mother in law to unwind...

I had mine wired like the right at first. But after thinking about it for a while that logic would also make you scared to parallel 6s packs instead of 2x3s .... get what I mean? I guess the way I look at it is if hobby king sold 12s or 24s packs would you be scared to parallel them? I am still forced to parallel at the 12s level as I am using a hyperion to charge, but with good bullets and sound building and monitoring of the individual cells groups I see no need to stress too much.

i'm not sure why you'd be scared to parallel them once you checked to see that all the cells were balanced at the same voltage. before that, yeah, i'd be scared..

paralleling at the 12s level doesn't offer much cell level protection! so you discharge at 24s2p and charge at 12s4p or something? i'll have to read up on your thread.

i LOVE your hand drawn diag, and you point out exactly my question. however i was inspired to do my own because what's deceptive about yours is you make it look like 4 cells when it's really 24... and the only place i'd have to parallel the subpacks is between the 8s packs and 4s packs...

...because in my case, it's 20 cells. each 4s pair is paralleled on bms board. the curved line connecting the subpacks is the 10g wire/5.5mm bullets:

the vertical lines between the cells represents each factory soldered tab on lipo pcb.

 

[rodgah]

i'm not sure why you'd be scared to parallel them once you checked to see that all the cells were balanced at the same voltage. before that, yeah, i'd be scared..

sorry I wrote that a bit wrong, what I meant was (on my diagram) the right method is over the top. If you were scared of bad things happening if wiring on the left method you would then have to break it down further and get scared of paralleling big packs (6s or 8s)and instead use little ones (3s 2s etc)....see where I am going?

In both cases(left or right) I would be far more inclined to believe a solder joint would go bad inside of one of the packs long before a 5mm bullet would come undone, so either situation is not going to help the pack it is in paralleled to.

paralleling at the 12s level doesn't offer much cell level protection! so you discharge at 24s2p and charge at 12s4p or something? i'll have to read up on your thread.

since you like the diagrams ill do another one lol.....
I charge the pack in 2 halfs (12s2P via 2 x db25 connectors) nothing is unplugged.... the charger accepts 12cells(pack balance tabs are paralleled... see the horizontal lines) and a main discharge + and -. I just charge one lot up till 95% let it balance, then unplug and move to the other db25 and repeat. The only real problem I could have would be charging one half and forgetting the other.

what's deceptive about yours is you make it look like 4 cells when it's really 24.

like my point earlier....4s 20s 24s it doesn't matter :lol: there is always a bunch of cells in series before the main discharge leads make a parallel, so if we are scared of going more than 6 or 8s in series why arent we scared of 6s packs and use 3s packs instead :lol: :lol: :lol: ?

In a perfect world we wouldnt parallel cells at all, in fact I have a DH comp same as yours that I am going to hubify, and I am tossing up the same pack as what I have now in the bighit or using the 8AH turnigy packs in a 24s1P so there will be no issues with this....and a super easy build .

Take it easy man, the roads no place for fatigued drivers.

 

[Hyena]

Man, screw you guys and your bloody napkin drawings :lol:
This is what I'm talking about. I parallel my packs as closely as possible so each parallel bank essentially comes one big 6S (or what ever) battery.
Then just series them as you normally would

 

[MattyCiii]

Man, screw you guys and your bloody napkin drawings :lol:
This is what I'm talking about. I parallel my packs as closely as possible so each parallel bank essentially comes one big 6S (or what ever) battery.
Then just series them as you normally would

Woah, is that a PVC box (beam?) around your packs?

 

[GCinDC]

got it. thanks, hyena. in my case i was very tempted to use 4s extensions so as to ensure there's not physical pressure on the bms boards, and make sure they've got room to breath (but they're situated fine and not routinely hot. just at the top of the charge for 1/2hr..)

SO, i opened it up a bit more down the hill near home... i'm almost at a very big number... and i thought 50 was huge.. (forgot to take a proper photo)

may only be 56 or 57mph as i haven't sorted out my wheel ratio...

ps. andrey told me if i selected kph instead of mph, all the temps would switch to Celsius... someone's thinking!

some of today's highlights: hitting 59mph or whatever, then waiting behind the officer. charging in the batcave. return commute with a sweet move at 2:20, and then some characters at dupont.
[youtube]toEA9e54rrw[/youtube]

now i must do something about the noises on the bike. they're freaking me out. i think it's mostly chain slap, but the suspension's like a 1980 station wagon. i've not installed the chainguard... amazing how the chain stays in place thos when you don't pedal!

 

[Trackman417]

I have always thought about carrying around my bulk charger but thought all the rattling would drive something loose. Guess this is not the case, since you ride your bike 10X more aggressively than ever would .
What was that at 1:28?

 

[GCinDC]

What was that at 1:28?

crappy edit. since i've got dual go pros, i occasionally show forward the cut to the reverse, but i removed the transitions on that i couldn't get the timing right so i guess it looks like a mistake...

 

[speedmd]

That controller is a lot of bang for the buck . Why are there only 4 or 5 people on the forums that are using this full time?

I am giving it a close look and comparing to the others. Not ready for it just yet, but like what I am seeing so far.

 

[GCinDC]

left at 3pm. stopped for dinner. arrived at 7am.

boat involved in accident two summers ago is now for sale because it's uninsurable..

rode around the lake today. tops out at 51mph on the flat:

going to do some good range tests while here. need a better usb cable cause the computer isn't recognizing the gopro.

 

[GCinDC]

[youtube]lYufEqazKHE[/youtube]

 

[kfong]

Crap Greg, get yourself on some real single track riding. Here is some in your state.
http://www.singletracks.com/mountain-bike/map-list.php?state_id=401

 

[dbaker]

Thanks, Kfong I can use those maps. FYI Greg is on vacation in Wisconsin

 

[pchen92]

Wow I'm so happy that you are back on the road
This controller looks really high end and reliable :wink:
Your video are always so good. Do you have pics of your mount on the frame and fork ? What mount do you use ?

 

[GCinDC]

Crap Greg, get yourself on some real single track riding.

lol. anywhere to ride for me is a great place to ride. the track you're commenting on is an overgrown snowmobile trail i found, and a narly section of it at that. the wooded area is actually really cool. i'm sorry the vid doesn't capture it. feels like a skatepark with hills. it's a nice place to get away to in any case. after a rain, the bridge was pretty slippery:
[youtube]FXcIRpcKU4M[/youtube]

Your video are always so good. Do you have pics of your mount on the frame and fork ?

thanks! i just moved the fork mounted hero 3. now it's sticking off the frame more, but less bouncy cause i'm using the motorsports suction mount attached to frame w/ worm clamp:

whatever works...

bottom bracket/suspension mount is using gopro sticky mount that i strengthened w/ worm clamp once, and now can't remove - it's been there since before the fire:

 

[flyinmonkie]

Glad you're having fun in WI Greg. I'll be in that neck of the woods permanently just in time for winter. I'll have a new bike or 2 made up by next summer though.

Clay

 

[kfong]

Greg definitely check out some of those single track places listed. It's all I ride these days. Even upgraded my front shocks to Fox float 32, have to install it this week. Never thought I would go to that extent on an ebike, or even on a normal mountain bike. Bike is easily over 3K now. It's very similar to tree skiing out west for me. If we only had mountains in Michigan At least I'm not paying over 100$ in lift tickets every time I head out, and it gets my adrenalin fix until ski and snowboard season comes around or when we get the winds needed to windsurf or kiteboard.

Crap Greg, get yourself on some real single track riding.

lol. anywhere to ride for me is a great place to ride. the track you're commenting on is an overgrown snowmobile trail i found, and a narly section of it at that. the wooded area is actually really cool. i'm sorry the vid doesn't capture it. feels like a skatepark with hills. it's a nice place to get away to in any case. after a rain, the bridge was pretty slippery:
[youtube]FXcIRpcKU4M[/youtube]

Your video are always so good. Do you have pics of your mount on the frame and fork ?

thanks! i just moved the fork mounted hero 3. now it's sticking off the frame more, but less bouncy cause i'm using the motorsports suction mount attached to frame w/ worm clamp:

whatever works...

bottom bracket/suspension mount is using gopro sticky mount that i strengthened w/ worm clamp once, and now can't remove - it's been there since before the fire:

 

[pchen92]

Thanks Greg

 

[GCinDC]

Greg definitely check out some of those single track places listed.

thanks, i found a trail 45 min away that looks cool! and here's someone's vid of it:
[youtube]6MDdFz9nIRI[/youtube]
now if it only stops raining....

coldest days on record by 10 degreess someone said.

 

[kfong]

It was cold a overcast here as well. Tried to kiteboard but it was a bust, winds were just too light. Every now and then a squall would form, making me stay a little longer only to be rained on

The trail on that vid should be fun. http://trails.mtbr.com/ is a good source for how they are rated. Be sure to wear a helmet, I usually carry a phone and some tools as well as things to fix a flat and enough water for the ride. In the car, I bring the bike tool box and charger setup if I plan to go to one of the bigger, more challenging rides. Nothing worse than not being able to do a quick fix, but not having the tools to do it. I have a charge setup that can charge from my car if I'm willing to wait an hour, useful for fully exploring a new site to see if you want to come back.

 

[GCinDC]

The trail on that vid should be fun.

It was! i chickened out on the jump tho. wet trail, hookworms. plenty of excuses, but it were it not for the tree at the bottom it was one of my dream jumps..

bummer i left the dirt tire back home.

 

[speedmd]

Hi Greg

Any updated feelings/ observations on the adaptto display- controller. Seriously looking for something like this.