Ebike "The Resurrection"

[GMUseless]

Looks pretty good...but Ive got a few things to think about.

Generally, all the items on a Hobby King must come from the same warehouse. In the US, it's much cheaper and quicker to select batteries available in the US warehouse. And, most of the accesories aren't usually stocked in the US....so once you add your batteries, you won't be able to add the other items. In that case, it's cheaper and easier to deal with someone else. We use Hobby King for cheap / huge selection of LiPo. They aren't known for great customer service.

Make sure to order extra packs to allocate for duds. Many report between 10-15% bad quality rates with HK. But still cheaper despite this.

I don't think the bullet conectors are right. You want 4mm bullets to match to those on your batteries, and I prefer them in pairs...not in three's. Not sure what your plan was there but, but threes aren't what you want for battery connections. Definately order something like 2x extra connectors and wire...you'll always want / need more.

10 awg is good for the main battery leads to the controller, but overkill for the connections in the harness. Plus, 10awg might be tough to fit into the bullet housings. I've used 12awg or 14awg for individual branches on my harnesses. Also, when I make harnesses, I usually add a couple of extra P taps for expansion.

If you use heat shrink, you'll need many sizes..get an assortment.There's always some connector or orther thing larger than your wire you're trying to wrap..so it's good to have all sorts of sizes.

I also like the Celllogs. I got mine from EP buddy...they've also got lots of the wiring accessories you might want.

Just make sure you have some way to meaure your LiPo the day it arrives. Hobby King's return policy is 24 hours from delivery to file a warranty claim.

[doc007]

UPDATE

Stainless steel arrived about a month back from Onlinemetals.com. It has been going into surgery since its arrival:


(Onlinemetals review: Would have been nice if they blew off the shavings with some compressed air before shipping. Overall, I was pretty happy with the speed of transport, price, and quality assurance. I would use their service again, if need be.)

After a bunch of this (including test fitting and measuring):


We finally got to this:


And eventually ended up with this (comparison to original dropouts located below and to the left, respectively):



Fits like a glove:



Dropouts done!! Big thanks to the good friends that helped make this turn from a chunky block of stainless steel to a piece of art. Your expertise in machining and CAD were vital to the successful completion of this operation!

[doc007]

While on the topic of surgery. The baby also got circumcised upon arrival:


Ouch! Had to do it though. Needed to figure out the wiring combo:



That's what I call a birds-nest. Hopefully, the battery pack doesn't suffer the same fate. The wiring above resulted in full-throttle (no pun intended, although I'm sure he would be proud). We believe that the combination of wires, at least for the halls, were correct since the motor didn't stutter during the full second we kept it hooked up (didn't want to blow the motor just yet). We suspect the resulting full throttle was due to a defective twist throttle. Time will tell. Replacement thumb throttle is on its way.

Big thanks to a fellow ES pal for helping me out with this part. Your experience was very helpful in making the diagnosis.

More to come! Stay tuned...

[doc007]

Discovered a little rubbing sound when I initially got the motor. When spinning the motor by hand you can hear a rubbing noise when the wheel reaches a certain section during rotation. I was worried it might be a wire rubbing.



Decided it would be best to pop it open before running power to it:


Interesting markings "8x7 +2" (I was told I was getting a 9x7 winding! ) I wonder how this motors performance will compare to a real 9x7 winding. I wonder if this is why Jason changed his mind about allowing me to open the motor at the last minute (http://www.endless-sphere.com/forums/vi ... =3&t=42569). Anyway, here is a pic:


Here is some close-up pics to show the build quality:

(Some wire is exposed from the black wire sheathing on the center hall. The middle bare wire on the center hall looks a little kinked.)


(Some of the plating wasn't stuck together, but this is not where the noise it coming from)


(The culprit of the noise left its mark on the side plate. You can see the marking doesn't make a full circle. That explains the noise only when the wheel reaches a certain point in its rotation)


(The culprit was the white insulation covers. Their ends directly coincided with the location of the mark on the side plate. I wasn't worried about it since no real wire was rubbing. I figure the insulation will conform to a less resistant shape after some motor use.)

[doc007]

Can someone please confirm if the discharge wiring below is correct?

[sn0wchyld]

Can someone please confirm if the discharge wiring below is correct?

looks good to me mate.

[doc007]

Great, thanks for checking it over. Any ideas on how I can wire it up differently to clean it up? I plan on having 5 packs on each side of the bike mounted on this:

[sn0wchyld]

Great, thanks for checking it over. Any ideas on how I can wire it up differently to clean it up? I plan on having 5 packs on each side of the bike mounted on this:

one thing you can do is wire each individual pack in series, so you have two 20s 5ah packs, then parrallell these via the balance leads for easy balancing. that way you can plug pack 1's +ve directly into pack 2's -ve... pack 2's +ve to pack 3's -ve etc etc. saving yourself some wire, connectors and soldering. Not so great if you need to reconfigure the pack to charge though, and you really need to have your wits about you when you're connecting up the balance leads - as its easy to mess up and parallel the leads from pack two to pack one etc etc. but if you've got a 20s charging solution (bulk charger or a couple of 10s chargers in series) so you dont have to change your pack to charge then it works quite well... and saves you allot of time and space.

word of warning though... be very carefull if you wire it this way... as it's much easier to make a mistake than normal wiring, given it ends up looking very atypical with each pack plugged directly into the next.

[doc007]

Ok, cool so this is the same pack configuration as the previous diagram as above. Please confirm if the discharge wiring is correct here:



As an ALTERNATIVE:
So snowchyld, you were saying that maybe I can series up the left side and series up the right side. And then parallel them? This way I can keep all the wires in the same position even when I bulk charge? ..Let me know if I got this correct.

I can see how this can be messed up since this isnt the normal routine of plugging in the connectors. I wonder if I can make a bullet & wire housing of some sort, maybe something out of wood, so all I have to do is connect blocks together (one side has the bullets, other side has the loops of wires set up in series) on each side of the bike. Anyone have any experience with this?

[sn0wchyld]

Ok, cool so this is the same pack configuration as the previous diagram as above. Please confirm if the discharge wiring is correct here:



As an ALTERNATIVE:
So snowchyld, you were saying to maybe I can series up the left side and series up the right side. And then parallel them? This way I can keep all the wires in the same position even when I bulk charge? ..Let me know if I got this correct.

I can see how this can be messed up since this isnt the normal routine of plugging in the connectors. I wonder if I can make a bullet & wire housing of some sort, maybe something out of wood, so all I have to do is connect blocks together (one side has the bullets, other side has the loops of wires set up in series) on each side of the bike. Anyone have any experience with this?

yep, that's the same as you posted before.

here's what I was talking about...

20s series packs.jpg (64 KiB) Viewed 554 times

the blue wires represent the balance wires
as you can see, by plugging the +ve of one directly into the -ve of the next, you save yourself a considerable amount of wire and connections - just 3 connectors are required (2 for the packs, 1 to go to your controller) vs the 16 needed for your setup. It also means less resistance in your lines, so less voltage sag too, which translates to greater efficiency!

You do however, need to be VERY careful when wiring it all up, as the potential exists to short out packs. So take your time, triple check everything, and triple check your triple check! Also, dont bother with this unless you intend to bulk charge!

[doc007]

Snowchyld, thanks for the info!! It's a lot clearer now. I think I will use your method of wiring since I do intend to bulk charge. Also, there is less of a wiring mess.

Questions:
1) When I wire up the batteries like you have in your drawing, do I need to worry about the order in which I connect them? I was thinking of making a block of bullet connectors that plug into each side of the pack(20s1p) at the same time.
2) Also, do you think I will have to worry about a spark when plugging them into the controller or the charger?

Thanks a bunch for all the help!

[sn0wchyld]

Snowchyld, thanks for the info!! It's a lot clearer now. I think I will use your method of wiring since I do intend to bulk charge. Also, there is less of a wiring mess.

Questions:
1) When I wire up the batteries like you have in your drawing, do I need to worry about the order in which I connect them? I was thinking of making a block of bullet connectors that plug into each side of the pack(20s1p) at the same time.
2) Also, do you think I will have to worry about a spark when plugging them into the controller or the charger?

Thanks a bunch for all the help!

1.
if you mean what wires go where, then absolutely. yes.
the actual order in which you connect the main packs by their discharge leads doesn't really matter much (more at the end), but once this is done, you need to be extremely careful when connecting each individual pack's balance wires from one 20s 5ah string to its 'sister' pack in the other string of 20s5ah. if for example you connect pack 1's balance leads in string 1 to pack 3's balance leads in string 2, then you'll get a nice big flash, and you wont have any more balance leads on pack 3. There's a number of other dangers that exist, but rather than list them all, I'll simply say this...

Once you have each separate 20s 5ah 'subpack' wired up in series (via the main discharge leads) go through and label with a bit of masking tape or something, each packs #, counting up from the most -ve pack in each subpack. that way, when it comes to parallel the 2 sub packs via the balance leads, if the #'s dont match up, you know you're doing something wrong.

If you're still unsure of yourself, use a thin peice of wire (like, as thin as your hair) to test the connection before you actually connect it with the normal plugs. if somethings wrong, the thin wire will vaporise/spark but your packs and their leads will be unharmed.

2.
are you using bullet connectors? (ie 4mm?) if yes, I wouldn't worry too much. bullet connectors manage that spark pretty well, since it'll be right on the tip of the connector, and the main current path is through the sides. Still, if you have the time its worth it, its better for the controller's internals and means you're connectors will last longer... a 100-500 ohm 3 or 5w resistor should be enough.

as to the packs order again...
ideally, you want to measure the capacity and internal resistance of each individual pack in your collection (any decent lipo charger should be able to do this). then match them up as best you can weakest with the strongest, and working in form there. that way, you end up with a pack consisting of cells that are all, on average, fairly equal. this step isn't totally necessary, just helpful for getting the most out of your pack, and reducing the frequency of balancing.

[renago]

I'm doing something similar , but don't have any pic at the moment.
one thing that is not clear is about the balancing wires :
here we have 10 battery packs , but only 5 exit for balancing ?
how can this be ?

when you want to recharge all packs , you must break up the wiring and ri fix them later .
is there no way to to bulk charge them all together .

ps I am using LIPO 6s 5ah

Renago

[sn0wchyld]

I'm doing something similar , but don't have any pic at the moment.
one thing that is not clear is about the balancing wires :
here we have 10 battery packs , but only 5 exit for balancing ?
how can this be ?

when you want to recharge all packs , you must break up the wiring and ri fix them later .
is there no way to to bulk charge them all together .

ps I am using LIPO 6s 5ah

Renago

10 packs, arranged 5 in series, 2 in parallel. thus there are 5 pairs who have their balance leads connected to each other, hence why there's only 5 sets of balance leads.

[iovaykind]

Doc.. the last wiring diagram looks good.. you can series before parallel, just make sure that cell 1 of "pack 1" matches up with cell 1 of "pack 2". The only thing you can't do (well.. there's much you can't do, but anyway..) is have cell 1 from pack 2 paired with cell 2,3.. etc. The first cell.. most "positive" have to match up with the other pack's most positive cell as well.

[doc007]

Ok this wiring has been haunting me. It's gonna be too messy for me. I want something neat and clean. Not a bunch of connectors all over the place.
This is the pack in its metal housing. With the pack oriented like this (wires coming out from the middle rather than from the sides) I get some space to add padding.

--Positioning--
Space for padding on each end (GOOD):


No space for padding, tight fit (BAD):



--Wiring?--
I am FINALLY considering permanently paralleling each pair of packs to cut down on the amount of connections and clean-up the wiring. This also negates me from having to worry about internal resistance and all that if I were to go series to parallel.

The discharge diagram of the entire pack should look something like this, definitely cleaner than before:


Bulk charging set-up should look like this (right? ):



Questions:
1) What are the pro's and con's of permanently paralleling? Anything I need to worry about? Anything I'm missing?
2) Essentially I will have to join two wires together and make it lead to one. What's a good way to parallel each pair of packs for a good/clean/strong/reliable connection?

[Ykick]

You seem to understand about using the balance connectors to balance bricks while connected in series groups. As long as you realize permanent connections would make it much harder to remove the brick and place on a conventional RC Balance charger I see no major drawback from permanent connections. In fact, fewer connections usually better for any high power circuit.

It's been well over a year since I've broken series groups up and all my power connections are pretty much locked together. I've brought up a few low cells over that time but just by using the balance connector and charging 1S directly to the low SOC cell.

[izeman]

Questions:
1) What are the pro's and con's of permanently paralleling? Anything I need to worry about? Anything I'm missing?
2) Essentially I will have to join two wires together and make it lead to one. What's a good way to parallel each pair of packs for a good/clean/strong/reliable connection?

1)

pro: no connectors, easy, no chance to connect them reversed
contra: if one of the paralleled cells is damaged, you won't realise that, or better said: as soon as you realise the broken cell could have damaged the good one as well

2)

solder two 14awg wires directly to the connector. or open the insulation of one wire at a length of 1cm, then remove 1cm of insulation of the second wire, put this wire next to the now clean wire, and wrap some centimeters of single wire (eg. cat5 cable) around the two wires. that way they won't move when you solder them together. then put some heat shrink over the wire for insulation.

rem: use the BIGGEST soldering iron you can find. 80w+ is good. the longer you put heat on the connection the worse. if you put too much heat into it, solder win run inside the cable and make it stiff.

[iovaykind]

I think the issue you have is that you have 5 packs on each side of the bike, making wires going over the top tube look really bad.

My best advice is to do the following:
1. Connect each of the 5 packs in series. Use one of them and cycle a few times, check for duds. Do the same with the other.
2. After weeding out duds, if there aren't any, charge them both up and then permanently series/parallel the groups.

It's a method which will allow you to still enjoy your bike while you test and build your pack. I did it for mine, and after finding out I didn't have duds, I went ahead and created the final battery pack.

For me though, it was 4 packs on each side, so it was easy to parallel. If you want less wire mess on top of the top tube, you're going to parallel groups that are next to each other, and the 5th pack on each side will have balance wires going over the top tube.. that's as clean as its going to get. aka one set of 4s parallel going over the top tube, and one set of power wires.

Let me know if it becomes too much to handle.. when I get into medical school I'll be much more free to help

edit:
the method i'm talking about allows you to have only 5 jst plugs to read from instead of 10. in fact, with 20s we can make 5s groups so you only have to read cells 4 times.

[doc007]

You seem to understand about using the balance connectors to balance bricks while connected in series groups. [dont be so sure lol ive never played with RC stuff before so this is all new territory for me] As long as you realize permanent connections would make it much harder to remove the brick and place on a conventional RC Balance charger I see no major drawback from permanent connections. In fact, fewer connections usually better for any high power circuit.

It's been well over a year since I've broken series groups up and all my power connections are pretty much locked together. I've brought up a few low cells over that time but just by using the balance connector and charging 1S directly to the low SOC cell.

So essentially what your trying to say in laymen terms is:

A) that I will be able to bring up low 1S cells individually via the balance connector while the pack is hooked up parallel to series?

Like so:


AND

B) that I will not be able to use the balance charger on a single 4s 5Ah pack since my batts paralleled? But I could use it on every paralleled pack (4s 10Ah) and even my entire pack as long as I remove all series connections?

Like so:



Are these diagrams right? Correct me if I'm wrong. Feel free to edit the pics, if you like. (Pics usually help me understand better and faster)

Also, where were you getting your 4V source from? and how were you monitoring it to make sure you didn't over charge?

[doc007]

[b]
1)
pro: no connectors, easy, no chance to connect them reversed
contra: if one of the paralleled cells is damaged, you won't realise that, or better said: as soon as you realise the broken cell could have damaged the good one as well

2)
solder two 14awg wires directly to the connector. or open the insulation of one wire at a length of 1cm, then remove 1cm of insulation of the second wire, put this wire next to the now clean wire, and wrap some centimeters of single wire (eg. cat5 cable) around the two wires. that way they won't move when you solder them together. then put some heat shrink over the wire for insulation.

rem: use the BIGGEST soldering iron you can find. 80w+ is good. the longer you put heat on the connection the worse. if you put too much heat into it, solder win run inside the cable and make it stiff.

1) interesting point. So does this mean that 2 lipo cell logs for each parallel pack will not work as intended (to monitor the individual cell voltage for each pack) bc the two packs are in parallel? Thus I would be getting an average reading of cell 1 in pack 1 and cell 1 in pack 2?? I was under the assumption that you would only get an average reading if the balance leads were in parallel (not the main terminals). im such a newb! lol let me know if this is right or wrong.

2) thanks for that tip:!:

[doc007]

Let me know if it becomes too much to handle.. when I get into medical school I'll be much more free to help

Get in already!! Let me know if you hear anything positive! I'm rooting for you!

--yeah you pretty much hit the nail on the head, i dont want to have many (if any) wires going over the top tube for aesthetics and safety (dont want to accidentally cut a flimsy balance wire going over the top tube if/when i take a fall)

--i definitely need to start cycling my packs to check for duds AND i definitely want to get the bike rolling. If you have an extra wiring harness that I can borrow until im done cycling these pack that would be awesome!

[rui_fujino]

This maybe little off topic but i'll put some input from my experience with bulk charging and balancing.

Im currently running 20s2p (8x5s). I've created 4 of 5s2p and hooked those in series to make the 20s2p.
the bulk charger is just the fast way of charging upto 83.5v and I'm using 4 battery medic(balancer) to keep individual cells from going over 4.2v.
However. Once in about 6month I take all the batteries out of bike and balance charge them with my slow 200w RC charger to make sure all the batteries are perfectly balanced.

it is important that you balance charge and make sure all the cells are within 0.1v difference BUT i would say once you start cycling the battery packs, they will act predictably.

(the reason why you want to parallel packs before series is when two or more packs are in parallel, they balance individual cells* with each other and you can avoid once cell discharging too fast)
*given the fact balance leads are parallel connected with each packs while draining.

[Ykick]

Like so:


AND

Also, where were you getting your 4V source from? and how were you monitoring it to make sure you didn't over charge?

That's the general idea and obviously need to guesstimate a bit on how much SOC to add to a single cell. I usually bulk series charge the whole pack and then rig 1S connection from RC Charger to top off low cell. No need to break any connections and this also works with parallel group balance connectors.

I've used cell phone wall warts too in a pinch but the float voltage worries me on most of those so I turn to the RC charger which will offer much improved control for this type work. Another plus with the RC charger is that you can use discharge mode to drain off excess SOC if you add a little too much.

[doc007]

Cleaning up the mess:

So in hopes to help clean up the wiring mess, I've come up with modified bullet connector design to support paralleling packs. This is the result I am going for:


What do you guys think is the best way of making something like this?

I'm thinking of modifying the bullets as follows:



In order to make this part, some ideas I've considered are:
1) soldering horizontal 10awg wires and then crimping vertically,
2) soldering horizontal 10awg wires and then wrapping copper wire vertically, then solder again, or
3) soldering horizontal solid copper wires and then wrapping copper wire vertically, then solder again,
Lastly, cover the wiring with some heat shrink.

what might be the easiest (most durable) way to put something like this together?