Throttle wiring questions...

[Neophyte]

I recently purchased a Bafang BPM 48V500W Rear motor kit. Inclusive of the thumb throttle seen here…

http://www.bmsbattery.com/ebike-parts/54-thumb-level-throttle-with-battery-meter-and-a-switch.html

And as you might guess the actual unit wiring differs from the stated specs which are as follows…

Thumb Level Throttle with a Battery Meter and a Switch.

1. Yellow --- Brown: Round Red Switch.
2. Green: Battery(+) for Battery Meter LED Display.
3. Throttle: Red --- +5V, Black --- GND, White --- Signal.

As it turns out it's the green and brown wires that are soldered together while the yellow is an unterminated single wire. And, so, am I correct in assuming that it's the yellow wire that connects to Battery(+)? And, if so, what do the soldered green and brown wires connect to? Seemingly these wires activate the switch which I assume turns On/Off the controller.

Also, on the power front there are the expected black and red battery wires from the controller and also a thin red wire that, as I understand it, connects also to Battery(+).

Do I have this right?

[ Please forgive my ignorance. Still learning. ]

Thanks for any/all assistance.

 

[sangesf]

Ok.. Will try to help here..
Strarting with the easiest first...

Power side of things:
Red (thick) and Black (thick) are main power wires to battery
THIN red wire is used for a "key switch" type setup... (more on that, a little later)
If the thin red wire is not connected to main power, controller will not work..
Usually the wire is connected to a switch to turn the controller on/off..
I believe with their controllers, IF you connect both the red wires at the same time to power, the controller won't "turn on".. You would need to connect main red first and THEN connect thin red wire. (I think it's some kind of "safety feature")..


The throttle connections will need the use of a Volt meter if you want to make sure of the connections..
With the volt meter connected to Brown and Yellow wires and in "continuity test" you should see continuity when you push in the button. If that's the case, then you're good to go..
Here is the (more on that, later) part..
If that's the case, then you would hook up yellow to main power and hook up the thin red wire to the green/brown connection. Why?
Here it goes.. Yellow is hooked up to main power.. When you hit the button on the thumb throttle, power is supplied to the brown wire (and green and red thin wire)...
Now why is that good?
First, with (main power) already hooked up to controller, it's all ready to be "started"..
(remembers above when I said if you hooked up the thin red wire at the same time controller wouldn't "start"? - you'll see in a second..)
When (switch is pushed) power is supplied to green wire, it lights up the LEDs on "fuel gauge" of the throttle..
At the same time, you are connecting the ("starting") thin red wire to the controller and everything should work!
So basically, with the throttle switch in the "off" position, the LEDs are not lit and power to the thin red wire is also off.. (This is how you tell if the bike is "on" or "off")
With it in the "on" position, you can then go!
Now realize, even though the controller is "off" it may be drawing minimal amps. (usually about .02a - so if you're not going to be riding the bike for a week or so, just disconnect the battery, so you don't drain it.)

If anyone sees an error in my post, let me know.. But I doubt it.

P.S. That's the simplest hookup of all the wires, as you could also setup a seperate toggle switch for the thin red wire as a "non starting of motor" as opposed to the throttle switch.. Especially if you have another use for it.

Any questions, comments, queries, are welcomed.

 

[Neophyte]

Very impressive.

Greatly appreciated.

The time and trouble you took going into such great detail. The obvious level of involved expertise. An obvious rare gift for clear and lucid explanation.

Thanks kindly.

I wasn't looking forward to a 'trial and error' installation. The prospect of possibly damaging the kit components and/or far worse.

And one question if you don't mind:

When you write...

"you would hook up yellow to main power"

...do you mean to Battery(+)?

 

[sangesf]

Yes, Battery Pack Positive (+) is what you would hook up to the yellow wire.

Warning... Make SURE that the yellow wire (and the brown/green wire combo) is what is hooked up to that switch... There is a good reason why I say this, as explained below.

(General throttle information)

Basically most (LED and non-LED) throttles work this way....

1.) Controller* (NOT battery) supplies 5v to a (normally) Red (+) and Black (-) wire going to throttle.
(*Important to note "controller supplies the 5V".. Yep, you guessed it.. "more on that later".)

2.) Coming "out" of the throttle is a third wire (of indeterminate color) that (usually) supplies from .8v - 4.2v back TO the controller. (On your throttle it's the white wire...)
As you push the throttle, the voltage starts to increase (or decrease) as you push down (or release) the throttle.) This is normally called the "variable line", as the voltage varies as stated above. (or in your case, they call it a "signal line").
(.8v is low end or no motor movement and as you start throttling, the voltage rises and that "signals" the motor to start moving, until you've throttled all the way up to 4.2v which is motor movIng at highest speed.. - Often referred to as WOT or "Wide Open Throttle".)


Now, throttles that have LEDs on them (like yours) have a 4th wire (of indeterminate color - but on yours it's green) that just lights up the LEDs to show generic voltage levels (full, low, empty).. There is only one wire, because the "ground" on most controllers are common ground, which means most components connected to the controller all use the same ground.
Now mind you, that the (green) wire leading to the LEDs uses the full battery voltage and NOT 5v.

Now, here comes (again), the "more on that later" part...
Remember, the red and black wires on throttle use 5v (from controller*) and the "signal/variable line" varies that voltage as explained above.. IF for some reason, you hook up FULL battery voltage to either the red or white (signal) wire (on the throttle), you WILL "kill" the throttle.

Now YOUR throttle ALSO has a switch.. Those are the yellow and brown wires on yours.
Hope that all made sense.. LOL

Let me know, if you have any other questions, comments or queries?

 

[Neophyte]

Excellent once again.

The level of detail you provide is greatly appreciated. Goes a long way toward furthering my understanding in general. Being of great import to me.

I purchased an eZee kit, locally, some months back and the installation of same was as straightforward as one could ask for. The kit I purchased from BMSBattery, on the other hand, is a very different story. Inclusive of the three speed switch seen here...

http://www.bmsbattery.com/ebike-parts/53-three-speed-switch-kit.html

Don't know its purpose and unlike what's pictured on the website it arrived complete with bare wires. No termination of any sort.

The one very positive I do have to say about the company has to do with the battery I purchased as seen here...

http://www.bmsbattery.com/48v/249-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

Turned out to be high quality. Completely reliable and very close to the rated 20Ah capacity (in the 19.6Ah area). The unit enclosed in heavy duty shrink wrap complete with an underlayer of padding all around. As for dimension and weight specs? The website isn't accurate...

Dimensions: 2.5" x 7" x 11"
Weight: 7 kg.

Fits perfectly in either of the following bags...

http://ca.itselectric.ca/Crystalyte_Key_Switch_Bag_p/bag_crystalyte_key_switch_bag.htm

http://neptronix.org/forumpics/falconevbag.jpg

The latter bag I purchased from Patrick Winston of San Diego Electric Bike...

http://sdelectricbike.com/Cases_Bags_Racks.html

[ Scroll down to see the bag. ]

Carrying one battery on a rear rack and the other in the front triangle is a world of improvement in balance and handling vs. both batteries at the rear or one at the rear and the other at the front.

And please forgive the late reply. The internet went down in my area in the wee hours. Came back up just now.

And thanks again.

 

[sangesf]

The three speed switch is to limit (or pass the limit) of the controller...
When connected to the three wires on the controller...

Center position is "off" or normal amps. (I think 30a max)

Left position is limit amps.
(Have no clue what amperage that is, but prolly 15a max)

Right position is prolly 45amps draw.

But don't quote me on that (in terms of amp draw), I'm just "guesstimating".
But that's generally what that switch is used for.

If you feel so inclined, and you don't think you're gonna use it....
I could use it as a replacement to my broken one.

(I use it for my directionals as seen below)...
[youtube]iX1lwRFUTkQ[/youtube]

 

[Neophyte]

Thanks once again.

And quite the machine. An awesome setup for sure. Nice job.

And probably not the question you were expecting, but…

From where did you source the seat?

As for the switch?

Send me the mailing details and it's yours.

 

[sangesf]

Thanks once again.

And quite the machine. An awesome setup for sure. Nice job.

And probably not the question you were expecting, but…

From where did you source the seat?

As for the switch?

Send me the mailing details and it's yours.

It's a standard Schwinn OCC Chopper bicycle (banana style) seat..
(You can always find 'em on eBay.. If you watch, you can usually get one for $20, but people normally sell them for about $40, however the seat post is NOT a Standard seat post, it's larger in diameter and one entire piece and specifically made for that seat.. )

PM'd ya my info..

Also, here's my craiglist ad, I've just posted, for my other (old) OCC chopper..
(P.S. That was the second (of FIVE), I've had so far)

http://miami.craigslist.org/pbc/bik/2755507291.html

 

[Neophyte]

Thanks.

And five?

You're hooked, are you?



Definitely a solid e-bike platform.

And the switch has launched.

Airmail.

[ Friends in high places. ]

 

[sangesf]

Hope you live in the USA...
Don't want you spending a lot on postage.

 

[Neophyte]

In sub-zero Vancouver, B.C.

Rather be where you are.



And no worries. Connections make it cost-free for me.

And if you don't mind I'd like to ask you a question about batteries.

My primary battery at the moment is the one I earlier referenced...

http://www.bmsbattery.com/48v/249-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

My idea is to purchase one of the 10 Ah versions as seen here...

http://www.bmsbattery.com/48v/166-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

Placing the two packs in discharge parallel using the harness seen here...

http://ca.itselectric.ca/product_p/eparts-parallel-wire.htm

[ Complete with 40A blade fuses. ]

The question being is it safe to so parallel?

The packs will be fully charged at hookup and will be charged separately as called for.

Or is it best to parallel packs of equal capacity? As identical as possible?

Thanks.

 

[sangesf]

It's safe to parallel those two... BUT!!! only for the first 20AH worth (10Ah each), then you would be close to having the 10Ah empty..

See this thread for more information...
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=34618
I have a few posts, on there, that should help...

After reading it, if you have any questions.. Just ask.

 

[Neophyte]

Thanks once again.

And an interesting discussion.

I'm going to make things simple by placing a custom order for a 30 Ah pack. The dimensions of which will be 16.7" x 5.75" x 2.5" and will fit nicely in the battery bag I intend to buy. The [ Large ] version ...

https://www.revelatedesigns.com/index.cfm?fuseaction=store.catalog&CategoryID=1&ProductID=5

The bag, in turn, fitting nicely in the front triangle of the Electra Townie 21D that I'll be buying tomorrow...

http://www.electrabike.com/Bikes/townie-original21d-bikes-mens-181213

A few extra lengths of Velcro will see the installation done right.

I test rode the Townie today and really liked it. Comfortable to say the least.

And can't go wrong for $660.00.

 

[sangesf]

Update on your purchase(s)?

P.S. Just came home and there was a nice little package waiting for me in my mailbox.

Thank you a bunch!

I'll replace my broken one tomorrow!
(before, the right side was broken.. Three days ago, the left side stopped working..)
Now that I have the replacement, it'll be nice to have my directionals functioning again!

 

[Rassy]

Sangesf wrote:

It's safe to parallel those two... BUT!!! only for the first 20AH worth (10Ah each), then you would be close to having the 10Ah empty..

I don't know whether or not it is safe to parallel these two, but assuming it is I think the above answer is wrong.

Since these batteries are the same chemistry, and this chemistry slowly loses voltage as it discharges (I have the 48V 20AH LI-ion (NiCoMn) from BMS Battery also), both batteries should maintain equal voltages as they discharge. Therefore they will both reach empty at the same time.

The above quote would have been true if these two batteries were hooked together in series, which would then give about 100V for 10AH worth of discharge.

 

[Neophyte]

sangesf…

You're very welcome.

Was the least I could do considering the time and trouble you went to to provide me with a welcome degree of peace of mind.

And if yourself and Rassy would be so kind I'd like to ask for your collective insight in the following matter...

Soon, I'll have two fully operational e-bikes, one of which will be carrying two identical 48V20Ah battery packs purchased from BMSBattery.

The plan is to parallel connect the two for discharging purposes but if such is not safely doable then it will be a matter of running them separately.

And on the subject of that parallel connection I received the following reply from Ken Cheung of [ http://www.powerinmotion.ca ] ...

The problem with diodes is heat. When you running two batteries that are identical, you don't need diodes. The diodes create heat and waste your energy. However, if you are running two differ size or chemical battery, a diodes does help to block the stronger current going over to the weak battery. But again, it added heat and resistance just to do its job. It is much simple to change out one battery when the first battery is run out of energy. diodes waste energy.

[ When you running two batteries that are identical, you don't need diodes ]

From Annie Lei of [ http://www.ecitypower.com ] I received the following reply…

You mean you will put the two battery packs connecting in parallel so that the capacity would be larger? In this case, why don't you purchase one battery 48V40AH? If you connect the two battery in parallel, you need another BMS to protect the battery packs.

[ If you connect the two battery in parallel, you need another BMS to protect the battery packs. ]

And I tried to get clarification of the BMS requirement but failed due, seemingly, to language issues. My understanding being that an additional BMS would be required were I to charge the two packs in parallel but no such requirement for discharging purposes.

How right/wrong am I?

Thanks in advance.

P.S.,

Rassy…

You wrote the following in an earlier reply to me…

Originally I had to unplug battery 1 and plug in battery 2, but now I have a battery selection switch wired in so I can just switch off the power to the controller, flip the selector switch to the alternate battery, and switch on the power to the controller.

And I just might try implementing such a switch if the parallel route proves not safely doable.

Thanks.

 

[Rassy]

First, I was tired last night when I wrote the previous, and left out a couple of things. First, I don't believe it's wise to combine two batteries in any way unless they are the same chemistry and rating, unless you are really knowledgeable and have adequate monitoring capabilities. Even then, some bms's don't like being combined without proper diodes being added, etc. Since I don't know or understand all the electronic stuff, I just avoid the problem by not doing it.

I currently have two batteries on my trike that are different chemistry and different capacities. Using just one at a time eliminates all worry of compatability. The downsides include more voltage sag (from using just one at a time), and a possible shorter battery life from being used harder.

It sounds like you are on the right track. Unless you need lots of amps, such as a max greater than about 30, one of those 20AH batteries should be sufficient. I normally pull under 10 amps, but occassionally pull a little over 20 with just moderate voltage sag, about 3 volts.

Good luck with your projects.

 

[SamTexas]

... the following reply from Ken Cheung of [ http://www.powerinmotion.ca ] ...

The problem with diodes is heat. When you running two batteries that are identical, you don't need diodes. The diodes create heat and waste your energy. However, if you are running two differ size or chemical battery, a diodes does help to block the stronger current going over to the weak battery. But again, it added heat and resistance just to do its job. It is much simple to change out one battery when the first battery is run out of energy. diodes waste energy.

The above underlined portion is not accurate. It implies that current would flow from the battery with the higher capacity to the lower one, which is not true. Current only flows from one battery to the other when there's a voltage difference. So if a 1Ah battery with a voltage of 48.0V is paralleled to a 100Ah battery with voltage of 47.9V, there will be a current flow from the smaller (1Ah) battery to the larger one.

It's never a good idea to parallel two different chemistry batteries together because of different voltage-state of charge (SOC) relations.

 

[sangesf]

That's basically what I was saying....
Forget about diodes and BMS' for a second..

Let's say you have two batteries... One is 5Ah and the other is 20Ah...
According to the people here, they're saying that you should get 25Ah total...

Just not gonna happen... 
As a matter of fact, if you pull 25a, and the battery's have the same c-rate (re: "group resistance") your gonna pull 1.25C from the 20Ah and 5C from the 5Ah, you will kill off that 5Ah battery MUCH quicker.. 
It's not going to magically pull, let's say, 20A from the 20Ah battery and 5A from the 5Ah battery, it's basic physics and electronics...

NOW, if you have a BMS attached to these batteries that limit amp draw of 20a and 5a respectively, AND you were pulling 25a constantantly, THEN it would work. (and adding a diode would be imperative too)

It's a huge amount of complexity to add batteries/cells of different sizes..
Why do you think battery makers don't make a battery with let's say, 5 2ah cells and a 10Ah cell in a parallel grouping within a 20Ah battery? Think about it. 

It's not gonna work like this.....
Battery A = 20Ah
Battery B = 5Ah
Your riding with a constant pull of 25A..
9.5Ah in, Battery A is at 39.6v (4.75Ah used) and Battery B is at 36v (also 4.75ah used) (actually combined voltage will show 37.8v) and you accelerate at 30A.    Battery A gives you 15A and Battery B gives you 15A..  Battery A doesn't magically throw 15A into Battery B to save it from dropping below 36v, just because they are in parallel..
I just don't see it..

Maybe I'm completely wrong, too.. But I don't see largely different AH'd batteries throwing alot of current at each other..  Although they DO throw current, it's just not enough to compensate for the Amp pull of our bikes.

If you were pulling only 2A constantly, THEN it might work..

P.S. I tried an experiment such as the above with a 35Ah SLA and 7Ah SLA batteries connected in parallel which, I believe, proves my original guess.

 

[Neophyte]

Thanks for the replies.

On the subject of parallel connecting two identical 48V20Ah battery packs, for discharge purposes, I contacted Adam at [ http://www.ebikes.ca ].

The battery packs seen here…

http://www.bmsbattery.com/48v/249-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html

And Adam's reply to my query…

Hi Gary,

You only need diodes if the batteries are different chemistries or if you are connecting them in series.

DualBattCable (the $20 parallel harness) is what you need.

Thanks,

Adam

The referenced harness seen here…

http://ebikes.ca/store/photos/DualBattCable.jpg

And taking all into account I purchased the harness and put it to use without issue. Both packs were fully charged at hookup and after use are being charged separately after disconnecting the harness.

Thanks again to all.