Trials Motorcycle - 1st Build. Qs-motor +Votol

[gbeals]

Batteries are in HAND! WOW! Was not expected Batteries to arrive in 2 days. Nothing arrives in two days. Especially not explosives.
Now I feel behind as I haven't even ordered my connectors and still deciding on a Charger. Guess I'll need to speed my research up.

Looks like there is 2lbs of packing and protection in there. TATTU I'm impressed!

 

[gbeals]

CHARGING FORWARD! Heard some pretty good things about this charger, so giving it a whirl. Worse case is my son will get a new RC charger if this doesn't work out. Price was really good in comparison to some others out there. Keep you folks posted as to its quality. Should be here before the end of the month.

[youtube]gSpy8aIEXO0[/youtube]

 

[gbeals]

Low Voltage Alarms - Grabbed me a 10 pack for $20 on Amazon. Not sure if I can post links to products for sale or not. But hey for $20, I'm sure I'll find a use for them.

Amongst various wires/connector/adaptors (small fortune), I did end up picking up one of the parallel balance wires. as suggested.

Figured I'd get the bulk of the bits and pieces ordered, still have some buttons, fuses, and wiring to buy, but the purchasing of the POWER is just about complete.

Some buds and I are taking 1 last trip into the woods on Sunday, then take out the motor and start the fabrication work.

 

[gbeals]

Speed Mode Selector Button I'm not overly thrilled with this purchase but it will do. For now it is functional. I'm not a huge fan of buttons or switches on the bars, but what's one little switch I suppose.

And a gear indicator, Plan to use this for 1,2,3 Power mode display

 

[DanGT86]

Cool to see you moving forward so quickly. I have the same lipo alarms. They are deafeningly loud. I think they are designed to be heard from the ground when you are flying an RC aircraft. Virtually all of the cheap alarm and cell monitor devices on the market tend to drain your cells unevenly. Its not a big deal when they are only plugged in during use but don't leave them plugged into the pack while its in storage.

Keep in mind that since you have enough packs to go 18s 2P you only need balance cables that are a single WYE. Don't accidentally plug cells 1-6 in parallel with cells 7-12 while they are also in series.

The buttons on the bars are annoying depending on your type of riding. I was just looking at a throttle I have with an integrated switch and I know I'm going to destroy my thumb knuckle when riding with it.

One device you might want to consider is a lanyard kill switch for your wrist to the bars. Riding technical trials stuff you run a really good chance of falling with the bike tangled with you. An electric bike wont stall and shut off like a gas bike in gear so you run the risk of laying on a wheel or chain with the throttle jammed on in the dirt. Having the throttle disabled when you fall off completely is a good idea. Not having an audible idle like a gas bike I've experienced several runaway bikes. Normally people accidentally twist the throttle when mounting and dismounting the bike because it does't sound like its ON. Also we have had a runaway bike due to the rubber grip jamming the throttle on and 2 runaways when the throttle ground wire was pulled out of the connector when unloading the bike. As soon as we powered it up it took off across a field by itself and could have really hurt someone.

 

[gbeals]

Decided to take a few steps back in my project. I feel this is a very good thing. I sold my QS Motor/Controller/Speedo/Throttle - the whole kit! Absolutely nothing wrong with it, and QS quality seems to be VERY GOOD. Why the Change then you ask?

I purchased the New QS Motor QS 138 70H V3 with 1:2.35 gear box built in. SPACE SAVER! I was just getting ready to pull the trigger on ordering all my Jackshaft, bearings, sprockets, chains, etc.. When I came across this. I mentioned jokingly "Now I have to sell my new QS motor" and someone bought it. LOL.

I will go with a 12T up front and 42T in Rear with 520 chain. Giving me a 8.2 Gear reduction. Putting me exactly where I want to be.

[youtube]WGrrZTG_Dbc[/youtube]

The reduction in pieces that could break, the upgraded shaft which will accept a 520 chain, makes everything so much easier and cleaner. Not to mention the new space this frees up for batteries. The price was about the same I'd pay for all the bits and pieces. The only down side is I lose the original money I paid for shipping, and I have to wait until early December before my motor arrives.

Here is a mock up in a full size dirt bike. Obviously much bigger than mine, but shows basically my set up.

 

[rynhardt]

Wow, that looks like a righteous unit! :thumb:
I'm going to be very keen to see how this turns out - I might have to upgrade too

 

[gbeals]

Working on my design for battery box while I wait. I figure I can run 6 batteries now, so will go with 18s2p.

I bought a bunch of Series and Parallel connector, wires and various connectors. Here is my mock up on my batteries. 6 Batteries would be on the bottom in Parallel, then put in Series. Is that correct? I don't think it is. I really haven't figured out how to wire this just yet using these connectors.

Do I run in series first? Then add parallel or vice versa?

I pretty much only know that i can take 1 parallel connector and connect two batts. And I can also take 1 Series connector and connect 2 batts. Beyond that, I'm not sure how to connect more together. I'm thinking the top piece I made does series 3 batteries.

Maybe I make two series strips like the top, then parallel them two together?

 

[gbeals]

This is perhaps the correct way? make my 2 series packs then parallel them both?

 

[gbeals]

One device you might want to consider is a lanyard kill switch for your wrist to the bars.

Was on my list from the moment I started the project. But thank you for reminding me to actually purchase it. Grabbed this little guy this evening.

 

[Overclocker]

Decided to take a few steps back in my project. I feel this is a very good thing. I sold my QS Motor/Controller/Speedo/Throttle - the whole kit! Absolutely nothing wrong with it, and QS quality seems to be VERY GOOD. Why the Change then you ask?

i think you made the right decision. that new gearbox motor is super interesting i'm tempted to build a completely new bike :lol:

 

[gbeals]

I read Parallel first, then run in series. Easier to charge, break the series then charge each parallel group.

Maybe this is the right way to wire up my 6 batts? Just 3 in parallel shown below; I'd have to replicate it on the other side of the series connector.

 

[rynhardt]

If you use the balance leads to keep the cells connected in parallel during use, then I don't think it makes much difference how you connect the packs. Either 3 packs in series, and then these 2 in parallel, or 2 packs in parallel and then these 3 in series.

You may want to consider cutting and soldering the XT60 leads to get a more convenient wiring harness once you've decided on a layout. If you want to get fancy you can create a manifold to plug in the main leads and balance leads (and keep them organised), which will also be wired to the low voltage alarm, and then put this into a nice box or something.

 

[DanGT86]

Want you to make sure and get this right because the consequences are pretty bad if you are wrong.

If you go parallel then series than each parallel group is like one giant pack.
So you can treat group:
1-6 A and B as one 6s pack with 2x the capacity
7-12 A and B are also one 6s pack with 2x the capacity
13-18 A and B are also one 6s pack with 2x the capacity

So you basically have 3 double packs in series for 75v total.

You can and should run your balance leads between pack A and B of each numerical group but dont ever cross groups. So NO balance lead will ever go between group 1-6 and group 7-12. At least not when you have the series wires in place.

This is the measured voltage you will get at each point with respect to the master ground. Hopefully this simplifies things for you.


The way you had it in your 2nd picture is effectively 2 independent packs of 18s1P with both independent packs being attached to a single Y adapter. This is fine if you see yourself running one pack while charging the other and only sometimes running them both together. If you go that method then Label all of the packs on one string A and all of the packs in the other string B. In that case you can still connect balance leads between A & B of the same number. So again 1-6 A can be paralleled to 1-6 B but never 1-6A to 7-12 or 13-18.

When in doubt NEVER Parallel cells unless they have the same voltage with respect to the MASTER ground!

 

[gbeals]

Want you to make sure and get this right because the consequences are pretty bad if you are wrong.

If you go parallel then series than each parallel group is like one giant pack.
So you can treat group:
1-6 A and B as one 6s pack with 2x the capacity
7-12 A and B are also one 6s pack with 2x the capacity
13-18 A and B are also one 6s pack with 2x the capacity

So you basically have 3 double packs in series for 75v total.

You can and should run your balance leads between pack A and B of each numerical group but dont ever cross groups. So NO balance lead will ever go between group 1-6 and group 7-12. At least not when you have the series wires in place.

When in doubt NEVER Parallel cells unless they have the same voltage with respect to the MASTER ground!

Once again DanGT - Very helpful. The additional details you added to my photo makes it super clear.

I am of course looking to be as safe as possible, which is why I'm doing a build thread to ensure I gather or discuss some feedback before I actually implement anything. IE: I won't Charge or hook up any batteries until I'm 100% confident I'm good to go; and I'm no where there just yet.

Now to understand Balance cables. Each pack (Pack 1-6 A and B have their own balance cords; I just connect the two together? The cord I have purchased looks to be 6 balance cables that go into one - Not sure that is what I need as you mentioned before, I'm sure I can cut it up and use it though...? Main question is how to I set up the balance between each pack, but not between groups. :wink: Also as mentioned when I add in the LV alarms, how do those get wired in? Seems like I'd need a balance splitter, 1 to balance and 1 to run LVA?

3 Battery pack Option? In my photo mock up I have 6 batteries; would it be fine to just unplug 3 batteries and run as a 18s1p and leave those there for when I want to run all 6? Just an option; I will hopefully be running 6 at all times to reduce the load.

Charging - I have the 4 port charger putting out 400w total. I get that I can plug in 1 battery to each port along with the balance cable. I could charge 4 at 1 time. I also see these parallel boards you can run 6 in parallel at 1 time. Would I just plug that into 1 port and off to the charging races?

Ideally Id want to leave all 6 batteries in the box and build some "patch panel" for ease of connection; well as easy as I can with my setup; but I don't think I'm quite there until I understand the LVA and balance cable set up. Something I'll be googling this evening.

 

[gbeals]

If you want to get fancy you can create a manifold to plug in the main leads and balance leads (and keep them organised), which will also be wired to the low voltage alarm, and then put this into a nice box or something.

I most certainly do want to get fancy with my set up. I think the 3 battery 14Ah is cake at this point. I'd just unplug my series and plug in each to my charger. DONE.

Going for a 6 setup with 28Ah, I think I will need to do something to reduce pulling batteries in and out of the bike so much. Trying to figure out some sort of patch panel allowing me to easily plug or unplug and play with minimal fuss. thinking my batteries are in a patch panel, then my Series/Parallel wire harness would be unplugged to get access to each battery to plug in a different harness to a parallel port board, then to the charger? Or something along those lines. This is all with balance cables aside; so may not work.



I see these but just starting to do my research now; parallel charging board. Not sure if this will help me too much except to charge all may batteries from one port of my charger. My thoughts here were to keep this on the bike, Have a spliced wire from each battery pack go to this board, then when I wanted to charge, I use the 1 wire to my charger? I'm not sure though as I've only thought about this for a few moments now. LOL I'd imagine I'd have to pull my wire P/S wire harness. But need to think this through more.

 

[rynhardt]

If you use 3 x 6s2p (28Ah) in series, then each 6s2p (28Ah) pack is effectively one battery.
So you end up with 3x 28Ah batteries in series again, which you can charge all at the same time (since your charger can handle up to four batteries).
I think once you've paralleled two 6s packs, you probably will never need to disconnect them from each other since they will remain matched up at the cell level.

In the sketch below, you can connect the battery packs to the manifold permanently, and their balance leads also connected permanently. You then make available the (paralleled) main leads (red/black) as well as the (paralleled) balance leads (grey) to which you can then connect the charger, or the bike harness, or disconnect completely.

As has been mentioned, when not using the battery pack, it's best to disconnect the low voltage alarms as well as they do draw a little bit of current which will deplete the battery as well as unbalance the cells.

 

[gbeals]

If you use 3 x 6s2p (28Ah) in series, then each 6s2p (28Ah) pack is effectively one battery.

This is what I was missing and did not understand - thank you for clearing this up.
So YES, I will just leave the two packs together as a parallel for ever. I did not understand that becomes 1 battery.
As stated a 28ah 6s2p x (3)

What are these manifolds you show in your pic? Is that something purchased or made? I only come up with parallel charging boards with my searching; nothing on a "manifold".

If I want to balance two batteries while in use - for a proper discharge; is this what I need? Basically just a splitter?

 

[gbeals]

My favorite photo mock once again.

When in Use:
3 Paralleled X60 connectors + 3 Balance (spliced) connectors (RED Boxes) would be what is exposed in a panel I make.
The Series cable (GREEN Box) I'd use when in use.
The LVA would be used when in use

When Charging:
The Series cable (GREEN Box) would be removed
LVA (x3) would be removed
(3) x60 + (3) spliced balance connectors (exposed in panel to be made) would only need to be plugged direct to my 4 port charger; leaving 1 port open.

When Stored remove LVA, discharge battery using "storage" option on charger.

Is it bad to balance at each charge? Does it just slow things down? Is balance at each charge needed or just frequently?

 

[rynhardt]

Yeah I think you've got it.
Splitters for both the balance leads and the main leads. Your red boxes exposed in a panel. :thumb:

The word "manifold" I used is not the best word. "Patch bay" or "patch panel" would have been better.
Basically a hole cut in a box with your connectors (red boxes) exposed.
If these are not panel mount connectors, you may need to use something like hot glue to fix them mechanically, or 3d print a housing.

Or you could get panel mount connectors and do a bit of soldering.

Once again, I'm not a LiPo expert, but cell-balancing will probably happen by default each time you charge the batteries, i.e. the charger will charge them all to 4.2V, or 4.1V, or 4.0 (or whatever you've set it to). Or when you discharge them on purpose to 3.8V for storage.

They will become slightly unbalanced during use, which is normal.

For example, say you charge the batteries overnight to 4.1V per cell (which takes a few hours). The next morning you disconnect the chargers. At this point the cell voltages are 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, etc.

Then connect the bike harness and the LVA's and go for a 2 hour ride. You get back home and the average cell voltage is now 3.8V per cell. But practically there will be a distribution of voltages around 3.8V, so 3.81V, 3.77V, 3.76V, 3.82V, 3.84V, 3.79V, etc.. which means they are slightly unbalanced.

Then you put them all on the charger again, and after the charge they should all be 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, 4.1V, etc. Which means they are balanced again.

If you don't charge them and you leave them unbalanced near 3.8V, you can just store them like that - being unbalanced is not bad per se, as long as any particular cell is not too flat or too charged when storing.
If they're still pretty highly charged (say above 4.0V), and you want to store the bike for a week or two, it's better practice to discharge the cells to around 3.8V.

Unbalanced cells are just inefficient at the end of the day. If one cell is sitting at 4.0V and another at 3.6V, then you'll only be able to ride until the lowest cell hits say 3.3V if you don't want to damage the cell. Which leaves the other cell at say 3.7V with capacity to do work, but it can't because the low cell would also get drained below the damage voltage.

 

[DanGT86]

My favorite photo mock once again.

When in Use:
3 Paralleled X60 connectors + 3 Balance (spliced) connectors (RED Boxes) would be what is exposed in a panel I make.
The Series cable (GREEN Box) I'd use when in use.
The LVA would be used when in use

When Charging:
The Series cable (GREEN Box) would be removed
LVA (x3) would be removed
(3) x60 + (3) spliced balance connectors (exposed in panel to be made) would only need to be plugged direct to my 4 port charger; leaving 1 port open.

When Stored remove LVA, discharge battery using "storage" option on charger.

Is it bad to balance at each charge? Does it just slow things down? Is balance at each charge needed or just frequently?

Untitled-2.jpg

Looks like you are getting it. I agree that you should think of your paralleled groups each as their own large battery.

Also the parallel balance lead Y adapters you pictured are the correct ones. The one you have with 6 taps into 1 is for balancing 6 packs in parallel. This is something someone would use if they had a cheap balance charger rather than the 4 channel one you have. In your case you can balance your whole pack at once with one of the 4 channels unused.

The parallel charging and balancing boards you guys have been picturing are nice but keep in mind they probably are not rated for the high amp discharges needed to ride the bike through them.

Another thing to watch out for is the wire size connected to the XT60 series adapters. The parallel connectors can use smaller wire like 12g because there are 2 of them. If each battery pack individually is discharging through a 12g wire and and XT60 connector its acceptable because in your case you are pulling only 60 amps from each one. The problem can arise when you have them both connected to a series adapter that is also only 12g wire and XT60 connectors. Now that series wire is pulling double duty by flowing the 120amp total. I don't know what gauge wire your series adapters are from that picture but be aware that you probably want larger than XT60 on the series portion.

Balancing takes a really long time. I would not recommend balancing after every charge. Rewiring everything to go from charge to riding and back takes more time than you will want it to. The balancing portion of the charge cycle can take a few hours by itself not counting the bulk charge time to get them close. Most balance chargers charge by throwing a very small current at the pack and bleeding off voltage to individual cells so the low voltage cells can catch up. This means the charger has to use a very low current to stay within the bleeding off capability of the resistive load in the charger.

I balance my cheap hobbyking lipo every 20 rides and have never had them be significantly imbalanced.

Here is a highly technical diagram about balancing and charging. Lets say you have 3 cells that are out of balance. When you charge the 3 with a bulk charger to 80% full or 12v you have the following voltages shown in green. 4.1 - 3.9 - 4.0 Their total voltage is 12v and none of them are in danger. You could charge to 80% and never noticed they were off balance. Lets say you bulk charged that same pack to their Full Voltage of 4.2v per cell using a bulk charger without balancing. The bulk charger will blindly charge to 12.6v (4.2 x 3). The problem is that to achieve that 12.6v total a cell goes to 4.3v to compensate for the 4.1v cell. The bulk charger doesn't care where the voltage comes from it just looks at the total. This is why you balance. If you balance them to perfection at 4.2v per cell then virtually any voltage less than that total (4.2 x number of cells) or 12.6v in this case, will not run them into territory where they are problematic. In short, balance to 4.2 then bulk charge to slightly less than that and you will have happy cells for months at a time.

 

[gbeals]

Looks like you are getting it.

Only reason I'm getting this, is because you folks took the time to help me. Super awesome!

I'm down to two remaining questions as it relates to my wiring for power.

The Star Bursts represent the area of my questions.



I'd like to have a master power button (I have a magnetic lanyard kill switch for rider ease of use separate from this)
Do I need some sort of fuse or power switch - sorry not sure what they are called. But in my CNC Mill I have these huge switches that "CLICK" on very loud when power is turned on. Rynhardt you mentioned something about a pre-charge? Is that needed for this?

In my simple minded electrical design, If I double up on the balance splitter it will offer me a free port I can leave for ongoing balance needs, allowing me to leave my LVA in. My thought and question is.. Am I able to hook up a power button to the 1 negative in each set to turn off/on the LVA? Or does this even makes sense to do? Looking at those tiny pins an ON/Off situation won't last long.

This "design" allows me to only have to remove the series/parallel harness and plug in my leads to my charger. And Balance leads when needed (every 20ish rides).

 

[rynhardt]

You will need both a fuse and a switch/relay/contactor, rated for the max amperage you expect to draw.

I've got an Allbright SU-2025 48V switch/relay/contactor (blue box) with a 200A fuse (yellow box).
This relay is switched by the magnetic lanyard similar to what you have.
To be more precise, the lanyard kill switch instructs the controller to switch the relay, which it does once the pre-charge has completed. I don't know how many controllers have a pre-charge circuit built in like the OSET.

I also attached the OSET wiring diagram which came off the factory bike, which I think is a good example of best practice wiring.

Allbright contactors are here:
https://www.albrightinternational.com/product_family/low-voltage-stud/

As for the LVA's, I just plug and unplug mine as needed. Not as convenient as a switch, but simple. If you want more convenience then you can always get a full BMS.

 

[DanGT86]

There is a frustrating lack of pre-charge in the electric motor controller world. I wish it was a built in feature across the board.

If you are not clear on the precharge thing its basically a method for keeping the spark down at your connectors or the contacts of your main contactor. The cpntactor is the giant relay that makes the thunk noise in your CNC mill. Controllers have large capacitors in them. When they are discharged like after the controller has been sitting they are basically hungry to fill up. When you make your battery connection to the controller those capacitors act like an open short. So a huge spark will jump across the air gap as you make the connection and it will burn your connectors and ruin them. If you are using a contactor the same thing happens to the contacts of the contactor. So pre-charge is usually a resistor placed in parallel with the contactor. When you make the connection the resistor limits the current that fills the capacitors at a controlled rate so there is no spark. After a few seconds they are full and you can make the main connection with no spark.

There are also anti spark connectors on the market. These have a resistor built in. The tip of the contacts have the resistor so you touch them together and allow a second for pre-charge then you push them the rest of the way in. They would be easier to use without a contactor. Using them with a contactor you would have to touch them together, then switch the contactor on, then push them the rest of the way on. Seems impractical. You could in theory run your setup without a contactor but the lanyard kill switch would have no way to kill all power like it would with the contactor. You could run the safety lanyard with on the throttle wiring or on the brake wiring to kill the throttle but then you are trusting the controller logic in the case of an emergency rather than killing all system power.

https://www.maxamps.com/qs10-anti-spark-male-female-connector-pair
https://www.maxamps.com/xt90-s-anti-spark-female-connector
https://www.amazon.com/Amass-Female-Connector-Battery-Charge/dp/B00RVM93YO

If your pre-charge strategy is a resistor placed across the main power lugs of the contactor you probably want to put a switch in line with the resistor. Reason being if the contactor is turned off (opened) by your safety lanyard while you are on the throttle then the controller will try to draw full current through that resistor and it will likely blow the resistor up. So your start up scheme is the following.

• connect main wiring

• switch precharge circuit on and wait a few seconds

• switch on main contactor

• Turn off precharge switch

I came across this Smart Precharger device on EVwest site a while back. Looks like it would be handy. 71x25x18mm is a bit larger than I would want on a bicycle but on a small motorcycle its not so bad. It does the whole thing for you automatically.

https://www.evwest.com/catalog/product_info.php?products_id=299

If you are asking about leaving the LVC alarms connected and only opening their ground wire to turn them off, I don't know if thats ok. Back in the day there was a similar device called a cell-log8. It hooked to balance leads and had an alarm like these LVC alarms. People found that if you unhooked the ground to turn them off they would still drain the cells unevenly evenly in their off state. You might have to just try it and see if these are the same.

Don't totally discount the idea of a BMS. A lot of times you start out with an ambitious goal of building a complex wiring setup and by the time you buy all the little adapters and connectors you end up at the same dollar amount than if you had just started with a BMS.

Also, what was the cost of that motor/gearbox combo?

 

[gbeals]

Also, what was the cost of that motor/gearbox combo?

The new motor cost was $308 (USD)
The EM150SP Votol Controller was $210 (USD)

I was told that the shaft has also been updated on this motor, and someone stated a 520 sprocket can fit. Time will tell.