12v batteries in series with two motors

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jyracing
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Re: 12v batteries in series with two motors

Here is the controllers and throttle I want to use, I haven't purchased them yet.

NEW 24V Controller CT-201C6 for Razor Scooters (replaces the earlier CT-201).
Rated Voltage: 24 Volts
Maximum Current: 29 Amps
Rated Current: 10.5 Amps
Usable Motor: 140 to 350 Watts
Under Voltage Protection: 20.5 Volts
CT-201C6motorcontroller.gifSuitable for Electric Charger ≤ 3.0 Amps

NEW Thumb Throttle Cable (Hall Effect) with 24 Volt LED Meter
Throttle has 3 LED indicator lights. One LED is for power status and two LEDs are for battery status.

Throttle Controller Description

Red connects to Red Voltage 4.3 to 5.0 Volts

Black connects to Black or Yellow Ground

Green connects to Green, Blue or White Speed Adjusting Signal (0 to 5 Volts)

Yellow* connects to Orange or Yellow LED Power and Battery Status

Thumbthrottle4wire.jpg

Since I can just use one throttle then a twist throttle (same connectors as thumb throttle) may be easier over a long haul because I can adapt a mototcycle cruise control to it easily.
twistthrottle4wire.jpg

With these controllers it looks like the red and green are the switchable wires, like you said. But, I am not understanding exactly where the switch connects to. The red provides +4.3 volts to the throttle and the green on the throttle sends the signal back to the controller to adjust the power that is sent to the motor? So at no throttle zero volts are sent back to the controller from the throttle. If that is the case then dont I just break the circut. Like this?
dual_controllersoneon1.gif

What happens to the RED in your drawing? Can you show me your drawing with one switch off and one on and tell me which one is on and which one is off please?
dual_controllers.gif

Frxdy
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Re: 12v batteries in series with two motors

Thanks for the dual wiring. Perhaps I'll give the change a try. Of course it will disrupt the equallity of the vortex flow so near to Shamu, but I think his great strength can handle the pressure.

Shamu is my horn! Stomp him with a fist & he gives a scream like a cat with tail under a rocking chair.

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Re: 12v batteries in series with two motors

jyrascing,

Please don't take the the wrong way but the diagram you built will NOT work!!!!!

Two reasons;

1. You can NOT connect the positive wires together. This could cause component failure in one or both of the controllers.

2. You can NOT leave the green wire disconnect. This could allow the controller to intermittently apply power to the motor. The green wire, in our example, is the control wire and tells the controller what to do. If the wire is left disconnected, stray signals can cause all kinds of strange things to happen at the output of the controller. When the switch in your diagram is open it is the same as disconnecting the wire and letting it hang.

I am not sure what the gray wire is, but I would guess it is battery plus. By connecting them together the batteries are now in parallel using a very small wire that may get very hot and release the magic smoke, not a good thing. If this is the battery plus wire you could use both throttles on the handlebar and only connect the gray wire and the ground wire (normally black) to the inside throttle so you could monitor the battery pack for that motor. Connect the remaining wires to the other throttle so you can control both motors with one throttle and the indicator lights on that throttle will allow you to monitor the other battery pack.

Grandpa Chas S.

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Re: 12v batteries in series with two motors

Not taking it the wrong way at all Chas. I just wanted to show you what I was thinking. Wrong as usual. But I am learning, thanks to you.

1. I understand. I wont do that. Magic smoke, BAD!

2. Oh, okay, I think I understand now. The green wire is the control out of the throttle going back into the controller. So, when I want to disconnect one motor I connect the green wire that comes out of motor control one to the red wire that also comes out of the motor control one, so the red wire loops with the green wire on controller one? Like this..
dual_controllersOneOff_1.gif
Is the correct? Specifically, Are my arrows showing the correct direction of power flow through the green and red wires or does the power flow (arrows) go the other way?

The grey wire is for the "pretty little LED lights" on the throttle that tell you when the power is on and at what level the voltage of the batteries are at. Seller's words, "Throttle has 3 LED indicator lights. One LED is for power status and two LEDs are for battery status."

There is only one battery pack, so on motor controller one I dont use the grey wire.

Thanks Mr. Chas

JY

ps Cool aerodynamic horn Frxdy. Where can I get one? Sea World? Does it scare the neighborhood cats and drive the dogs crazy? :)

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Re: 12v batteries in series with two motors

JY,

I found the data sheet for your controller. Here it is.

If I were doing what you wish to do I would not put in "switch one" on my diagram I would just connect the green wires together and use a different set of wires to disable the controllers.

You said you like control and I noticed you tried to find a way to disable which ever controller you wanted. So if you look at the data sheet there is a way to disable the controller provided for you. It is the Brake Connector. If you place a switch across the brake connector when it is closed the controller is disabled. You could then have 2 switches one controlling each controller.

There, that should be clear as mud,

Grandpa Chas S.

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Re: 12v batteries in series with two motors

Damn, Grandpa!
Brillant minds think alike. Okay, one brillant mind (yours) and one vivid imagination (mine) think alike sometimes.

I thought of that too. The brake switch! I already have that TNC schematic. I copied and pasted parts of it in the drawings. But thank you for finding it.

I didn't want to bother you with my brake switch idea until we worked out the single throttle control idea.

Chris at TNC Scooters is a nice guy and very honest. TNC Scooters is who I have bought the 55 tooth sprockets, lots of #25 chain and masterlinks from so far. Getting the controllers and throttle(s) from him soon too. Once I figure out which controller and how many throttles. You might notice that the schematic says max watts is 250. This will be a problem with my 350 watt motors. I just emailed Chris about it.

If it turns out to be only 250 watt max then I am back to square one on which controller to use. But I think a controller with a brake switch is the way to go to disable one side .

You said...
"I would just connect the green wires together and use a different set of wires to disable the controllers" ... You said you like control and I noticed you tried to find a way to disable which ever controller you wanted. So if you look at the data sheet there is a way to disable the controller provided for you. It is the Brake Connector. If you place a switch across the brake connector when it is closed the controller is disabled. You could then have 2 switches one controlling each controller."

That's something like I was trying to say in a previous thread but I couldn't say or draw it right.

Clear as mud? No, I understand it clearly.
But what is muddy is that still leaves the ONE or TWO throttle delenma: If I splice the two red wires together I will get magic smoke, right? So, I have to use only one red wire from only one controller to the throttle. With the brake switch activated that is connected to the one controller that is providing the 4.3 volts to the throttle, will the other controller still work? In other words, I want to be able to shut either motor off. And I'm afraid that activating the brake switch on the controller with the red wire connected to the throttle will shut the other running motor off. The $64,000 question?

Okay, so it should look like this with one red wire not being used?
dual_controllersOneOff22.gif

Just a yes or no, or go away will suffice :)
Thanks,

JY

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Re: 12v batteries in series with two motors

JY,

Just a yes or a no? Thats a tough one. OK ... YES!

Sorry I just have one more thing.

Question; If you do use the brake switch then will you also have a switch on the brake to disable the motors when braking?

Grandpa Chas S.

BTW what program are you using to edit the diagrams?

Frxdy
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Re: 12v batteries in series with two motors

A cute little program for making diagrams & such is "Inkscape".

Http://www.inkscape.org/

It's totally free, no strings attached.

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Re: 12v batteries in series with two motors

It will? Are you kidding me? Just when I was ready to give up on the one throttle idea?Are you saying that the $64000 question is answered too? It's okay to just cut off the red and grey wires on one controller? Really? Why does that seem too easy after all that we have been through? Okay, thank you. I'm going to buy two controllers anyway. One for a back up.

At least you didn't say, "Go away" ... yet

Braking? We dont need no stinkin' brakes! Flick, flick on the two switches and drag my feet like I did back in Junior High? Back pedal on my unicycle front wheel to slow it down? Throw the motors in reverse? Aim for the nearest Mercedes? Actually, it will be "flick, flick" on the two brake switches and then apply the brake lever that controls the front manual pad brakes I am going to adapt to the unicycle 16" front wheel. I didn't tell you that I have three arms (and a third leg).

I'm kinda embare assed to admit it but I use plain old MS Windows Paint 5.1 2001. Probably the worst program for editing and a PITA, but I like it. My vivid imagination compensates for lack of Paint's ability. You otta see the bodies that I can put under Jennifer Aniston's head with Paint. Wait a minute, maybe you shouldn't? Why do you ask? That bad huh?

The motor controller may change to a 36 volter because now I am obsessing on overvolting my little $15, 350 watt, 24 volt motors. Since I am going to upgrade to 36 volt motors soon anyway, I might as well start with the 36 volt motor controllers and 36 volt throttles now and overvolt these bad boyz. I have read several articles about current multiplication, overheating and heat losses, heatsinking motors, and overvolting while undercurrenting. If I only increase it 12 volts it may work. What's one more 85 pound, group 27, deep cycle, marine batery at this point? Hmmm... 50% more distance? Any comments or suggestions on the subject? Can you say Magic Smoke? I knew you could.

My next thread? Hmmm?

Overvolting a 24 volt dual motor, dual controller, single throttle, 600 pound, 2 seater, 3 wheeled unicycle?

I will be awaiting your responses to that thread with bated breath Chas.
I sincerely thank you for all your help Sir Chas!

JY

I should change my ID to Magic Smoker? I love triple entendres :)

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Re: 12v batteries in series with two motors

Short answer: NO. That won't work.

Grandpa Chas S.

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Re: 12v batteries in series with two motors

LMAO
That was the wrong thing to tell me Dad.
Now I have to do it.

Signed,
The Magic Smoking Rebel

ps I bet it will work great for 10 minutes
pps I just finished drilling, grinding, painting, bolting and mounting the rear suspension. When you gonna come over and wire this thing up for me? The motors arrived yesterday.

Reply:
Short answer, I aint

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Re: 12v batteries in series with two motors

Smokin,

You will be surprised at how long the 24-volt motors will last. The only thing I think you should know is, if you use a 24-volt battery pack and a 36-volt controller the controller may never come on because the 24-volts is lower than the low voltage cutout of the controller.

I myself am running a 36-volt controller on a bike with a 24-volt 240-watt motor. I have a little over 300 miles on the bike in this configuration. The controller I use is 36-volts @ 25-amps which is 900-watts. Yes I am pushing 900-watts in that little motor and it climbs hills right now!

Grandpa Chas S.

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Re: 12v batteries in series with two motors

I concur. I have (I think) the exact same motor. I strapped it to a skateboard once, and ran 36V through it for quite some time. Still works fine.

Aww, you beat me to the "just cut off the second controller's wires" solution ;).

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

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Re: 12v batteries in series with two motors

Cutting off the second (red +-5 volt throttle and grey LED battery level) controller wires is definately what I am goig to try, thanks to Sir Chas (meant respectfully).

Okay, wait just a minute. Overvolting... First you (Chas) say "NO. That won't work." and then you say that you are doing it yourself, "I myself am running a 36-volt controller on a bike with a 24-volt 240-watt motor. I have a little over 300 miles on the bike in this configuration. The controller I use is 36-volts @ 25-amps which is 900-watts. Yes I am pushing 900-watts in that little motor and it climbs hills right now!"

I'm so confused. But 900 watts on a 24 volt motor, I like it!

I am going to add the third 12 volt battery so I have 36 volts in series going to the 36 volt controller supplying the two 24 volt motors. Hence my comment "What's one more 85 pound, group 27, deep cycle, marine batery at this point?"

I completely agree that putting a 36 volt controller with builtin ~30.5 under volt protection on two 12 volt batteries in series wont work. But to add a caveat to this. There are controllers out there like the 36 volt controller at http://www.tncscooters.com/YK42-3.php that dont have under voltage protection built into them. Simple, yet gets the job done. Occam's razor...
YK42-3jpg.jpg
And it allows for two controllers and one throttle, but not the power cutoff during braking switches.

Here's another Pandoras Box... Match volting batteries and motors with an overvolted controller that doesn't have undervolting protection. From what I have read, it heats up faster if the motor's optimum performance level is not acheived or is surpassed.

Overvolting (36 volt batteries and 36 volt controller) with a 24 volt motor will overheat, if the rpms are taken past the optimum performance level (OPL) or the OPL. In larger, heavier motors they can act like a heat sink to assist in dissipating that extra heat caused by lugging the motor or by the additional rpms. In theory, it's seems like the same as IC engines.

Man, have they come out with water cooled electric scooter motors yet? Since the real problem with overvolting is heat and friction, the trade off between the added water cooling drag and substantially reducing heat, seems well worth trade? I am going to add a ram air cooling duct to each motor. Like they do on NASCAR brakes.

Serious question...
I am not seeing the problem clearly where undervolting for short periods of time (to limp home) with cause serious damage to the motor if I am careful? In fact, if I am 10 miles from home and my battery level drops below ~20.5 or ~30.5, whichever setup is the case, I would be willing to fry a cheap $15 motor to get home at a reduced speed without peddling a 500 pound trike 10 miles. So, I am leaning towards a 36 volt controller that doesn't have undervolt protection, like the YK42-3 but I want the power cutoff during braking too for the switches.

Here's the serious question...
If I get 36 volt controllers with all those bells and whistles, 7+ connectors (lock ignition, UVP, OVP, OSP while charging, battery indicator, etc.), do I have to use them or shunt them somehow? Or, are they open circuts that dont activate until the loop is closed. Like the brake switch shuts power off to the motors when the circut is closed?

I almost bought 24 volt controllers today, but now, I'm glad I didn't.

One more question...
The YK42-3 connects the positive wire directly to the motor and uses the ground wire to control the amount of power the motor gets? Is this a good thing or bad thing?

JY

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Re: 12v batteries in series with two motors

OK, I have to go to work right now but I have a solution you may like. Don't buy anything today. I have just what you need it will take some time to get all the drawings made and to find the links to the parts. I'll have the answer tonight.

Grandpa Chas S.

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Re: 12v batteries in series with two motors

Okay, I will wait.

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Re: 12v batteries in series with two motors

Jy,

Sorry it took so long, here is a diagram of the controller I have been using with great success. I have relabeled the connectors with the way I would connect the unit. As you can see I am using the key (Lock Connector) as the disable switch and if you are using a key switch you can place the key and disable switches for each controller in series so they both still work. This leaves the brake switch (Brake Connector)free to use on the brakes. I also took the Battery Indicator Connector an used it to run a 36-volt tail light and a battery meter if you want them. The Tail Light Connector on this controller is really a Brake Light. Very useful, I think, I use it just for fun. Of course if you plan to use two (2) controllers then you still need to connect the black and green throttle wires together. BTW this is a very good controller I have put mine through it's paces without one glitch.

Grandpa Chas S.

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Re: 12v batteries in series with two motors

No problem. You didn't take too long. I am not in a hurry. I want to get this right the first time. With one caveat, I am going to start with the two new 24 volt/350 watt/22 amp Currie motors that I already have. An ongoing experiment.

Great idea! We are thinking alike again.
I had been looking at the JC-116-3. According to Clifford at TNC, "-2" means 24 volts, "-3" means 36 volts, and so forth. I'm leaning towards the more powerful CT-660B9 http://www.tncscooters.com/CT-660B9.php at TNC. As well as liking the simplicity and power of the YK-42-3.

I like the JC, but I am also trying to look forward in time and predict the inevitable future upgrades. After all, my trike will weigh as much as 700 pounds or more with 3 heavy 12 volt batteries, two adults, frame, suspension, wheels, etc. I weigh 225 pounds. Two little 24 volt/350 watt/22 amps motors, even overvolted and overamped are going to struggle with 700+ pounds. If they will move the trike at all. At best, they shouldn't last very long pushing all that weight, even on flat ground and me peddle starting the trike. Murphy's Law?

I am predicting and fully accept catastrophic motor failure. But, I want the electrical system (controllers, batteries, circuts, switches, etc.) to survive the motors frying. I will fuse them all so I can protect them. And, I want the sustem to already be upgraded for two larger motors of 750 watt/27 amps, or even 1000 watt/35 amp motors.

Back to the 8 connector JC-116-3 controllers...
They are rated to only 500 watts/30 amps. Whereas the 7 connector CT-660B9 controllers are rated to 1000 watts/40 amps. The CT is only missing the brake light connector. Unfortunately, both the JC and CT have that damn undervolt protection. I want to be able to limp home even if I may fry the motors by undervolting them or shorten the life of the batteries by deep discharging them.

And now I am back to the YK42-3 controllers. 800 watts and simple, no undervoltage protection and only one connector for the throttle. So I can upgrade to 750 watt motors. What else do I really need?

This brings me back to the CT660B9 controller.
Okay, a brake lever that when squeezed not only applies the brakes but cuts off the motors would be nice. Both the JC and CT have that. They both have a tail light that would be nice at night too. I can just switch the Lock connectors in series with a toggle switch to be a main switch. They both have a charger connector that might be nice if I decide to trickle charge the batteries at <= 3 amps through the controllers with two chargers.

The JC-166-3 does however have the brake light connector that the CT doesn't have. A nice accessory to help prevent getting rear ended.

But again, the YK doesn't have that damn built-in undervolt protection and I see no way around it with the JC or CT. Since it is built in, I cant shunt it, switch it, or cut it off. I can only make sure I keep the batteries at ~30.5 volts or above, even in the middle of nowhere. Otherwise, I'm peddling.

I have a bit of a conundrum.

What do you think Chas?

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Re: 12v batteries in series with two motors

IF the batteries go undervoltage and you want to suck them dry.... can you add a couple of toggle switches and have them disconnect the controller and connect the batteries direct to the motors?

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Re: 12v batteries in series with two motors

Jy,

First JC-116-3 is rated as you say at 500 watts however if you look at the facts 36-volts at 30-amps equals 1080 watts, so as you can see this controller can put out much more than 500 watts.

As for the 350 watt motors moving a 700 pound bike it will roll right along. You will be surprised at the power of these little motors. I have a Miami Sun (Adult Style Three Wheeler) with a single 350 watt motor running 36-volts. This trike weighs about 200 pounds and with my 220 pounds on the bike it will run 14 MPH and climb just about any hill I want. I have it geared a little low as the trike was built for my 72 year old mother to use. So if one (1) 350 watt motor can drag my bulk up hills Two (2) should move your trike just fine.

I still recommend the JC-116-3 controller it can take a pounding and keep on putting out the power, and it has the best set of options. The under voltage protection is there to keep you from destroying you batteries. If you drain them even once, the damage to lead acid batteries is tremendous. I have found this out the hard way. I also know if you are getting near the low on battery and you start peddling to help the motor you can go 3 to 4 times as far with very little effort. I once went 32 mile with my Merida and peddled most of the time with the motor and only used 3 AH of battery, which gives me an effective range of 64 miles using all 6 AH available. On the motor alone it's range is 23 miles. BTW the Merida is the bike I have the JC-116-3 controller in.

I am predicting and fully accept catastrophic motor failure.

It will not happen, unless you plan to go to 48-volts.

Maybe I am not sure what your intent for this vehicle is. I use mine as a grocery getter. I see no reason to go to 750 -watt motors. My EZ-3 currently uses a single 500-watt does about 30 MPH carries 36-volt 24-AH worth of lead. My upgrade plans for this trike have changed 6 times in the past year. To tell you the truth I don't even know why I want to upgrade it it is a very good ride I think I only need to put Lithium batteries on it and leave it at that. But I digress.

Please do as you want, I can only give you advice from my experience. I would advise, if you want a larger controller DO NOT use the YK-42-3. You really need the low voltage protection and at least the CT-660B9 will give you that.

Grandpa Chas S.

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Re: 12v batteries in series with two motors

Good idea Frxdy. I didn't think of an emergency bypass switch. That will solve the limp home problem. Thank you. But Chas has me scared about undervolting now.

So undervolting may kill the batteries Chas? Ouch, my batteries are 100 bucks each. Peddling is not really a option. Remember, the peddles are part of the 16" unicycle front wheel. At about 5 mph I cant keep my feet on the peddles anymore. But if I was dead in the water I would have too. Or call AAA. ;)

That's amazing Chas. I would be happy with 14 mph. These two little dinky motors will both fit into a 1 pound coffee can. I tried to do the speed calcs on my setup and theoretically, with my motor at 2400 rpms, 11 tooth motor sprocket, 55 tooth rear sprocket, and my 48" wheel circumference I come up with 21.81 MPH. That is, if I did the calcs right. I doubt I will see anywhere near 20 mph.

Watts have been puzzling me... rated watts versus maximum watts. Does that mean that the JC 116-3 is rated at a continuous 500 watts but has a very short surge capabilty of 1080 watts?

This battery AH rating has me puzzeled too. If a motor is rated at 20 amps does that mean it will draw 20 amps in an hour? I just went out and checked my new batteries and they are 125 AH. That doesn't seem like very much as compared to the T-105 6 volt battery's 225. So, in theory my 125 AH could discharge 20 amps an hour for 6.25 hours? Do I double the AH if running two of my batteries? So with one 22 amp motor and 250 AH total battery, does that mean I can go for 11.36 hours. With two 22 amp motors I can go 5.6 hours? That doesn't seem right.

Okay, you have convinced me. Low voltage protection it is. The YK42-3 is out. I am going with all those damn protections and all those damn connectors. But, I must admit I was thinking about using one JC-116-3 and one YK42-3 together. All the connectors on one side and limp home capability the other.

In fact, check this out. On ebay I just now bought a new Electric Scooter Brake Handle with Motor Kill Switch for 49 cents. A new 24 volt CT302S9 controller for 5 bucks. And, a new 36V CT-660B9 40A controller for 15 bucks. $27.54 for all three includng shipping. Great deals huh? They were too cheap to pass up. Dont worry, I am not going to try to hook them both up at the same time. I wont even ask how to do it. :)

But I'd like to ask you, if I run one 24 volt/350 watt/22 amp motor on a 24 volt/250 watt/30 amp controller for a while, what will happen?

I am going to buy one more 36 volt CT-660B9 controller. It just seems like the controllers should be matched. Or should I get one JC 116-3?

Not really sure what the purpose of my trike is for. It was just an idea, then it became an experiment, then a hobby, and now an obsession. A $1000, 2000 pleasurable labor hour meaning for life. I like trying to reinvent the wheel and I love building things with my own two hands... My house on 4 acres, my race cars, a 45' triple axel 3 car trailer, A side by side two seater 10 speed trike, just to name a few. And now, the Electric Love Buggy. Probably will be used to go on picnics with my lady. A grocery getter sounds good too.

Well, I'm off to lengthen the axel by 4 inches and permanantly mount it.

I really appreciate you sharing your knowledge and experience with me Chas. When I get my trike on the road, my 78 year old mom can race your mom. :-)

JY

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Re: 12v batteries in series with two motors

Well, lead acid batteries certainly don't like going below 10 volts. It may not kill them right then, but certainly it will shorten their life big time. Also, if below 10 volts, you might have to trickle charge them for a few days to get them to come back up. Dead dead dead batteries don't like to accept a charge.
I'm still wrapping my brain around the amps and watts thing myself. I'm sure Chas can explain it better, but you're almost on the right track... a 12V 20 amp batter will in theory put out 20 amps for an hour, BUT, that's at 12V. When you put two 12V, 20 amp batteries in series to get 24 volts, you now have a 24V 20 amp battery. Drawing 20 amps at 24 volts, they will go an hour, BUT.... if you draw 40 amps, they will not go 1/2 hour. It would be quite a bit less. Also, that's by doing the math, in reality you have to remember that you're not going to use more than 80% of the battery.

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Re: 12v batteries in series with two motors

"That's amazing Chas. I would be happy with 14 mph. These two little dinky motors will both fit into a 1 pound coffee can. I tried to do the speed calcs on my setup and theoretically, with my motor at 2400 rpms, 11 tooth motor sprocket, 55 tooth rear sprocket, and my 48" wheel circumference I come up with 21.81 MPH. That is, if I did the calcs right. I doubt I will see anywhere near 20 mph."

I might gear it a little lower if I were you. Maybe like 15-17mph or so. Having a few sprockets on hand is handy, too.

"Watts have been puzzling me... rated watts versus maximum watts. Does that mean that the JC 116-3 is rated at a continuous 500 watts but has a very short surge capabilty of 1080 watts?"

Something like that. Basically a controller has a voltage and current limit. You multiply these togeter to get the max power it can pass. It's also given a watt rating, but I have no idea how they come up with it. Probably measuring temperature rise and such. Most controllers will allow their max ratings for any length of time, unless a thermister cuts them out or they explode :P.

"This battery AH rating has me puzzeled too. If a motor is rated at 20 amps does that mean it will draw 20 amps in an hour? I just went out and checked my new batteries and they are 125 AH. That doesn't seem like very much as compared to the T-105 6 volt battery's 225. So, in theory my 125 AH could discharge 20 amps an hour for 6.25 hours? Do I double the AH if running two of my batteries? So with one 22 amp motor and 250 AH total battery, does that mean I can go for 11.36 hours. With two 22 amp motors I can go 5.6 hours? That doesn't seem right."

Whoa, whoa, whoa. You're running a 125Ah pack? WTF? I think you have the most usable Ah capacity of anybody on here ('cept maybe for the Vectrix guys ;)).

In theory, a 125Ah pack could give off 125A for an hour. It could also give off 1A for 125 hours. Or 25A for five hours. Get the idea?

In actuality, however, you will usually see about 60% of that, due to Peukert losses and not discharging them too deeply. You might actually see around 80% just because you will be draining them at the 5 hour rate with a 25A controller. Basically, you can get more energy out of the lead-acids if you discharge them slower.

Paralleling them up will double the Ah rating, but keep the voltage the same. Putting them in series will double the voltage, but keep the Ah rating the same.

An any case, you'll get a lot of runtime with that setup. Even with the controller sending it's max amp limit to the motor, you should see about 4 hours of runtime with two batteries in series O_o. Two motors at max will see 2 hours of runtime. I wouldn't be surprised to see the thing last three hours or more in the real world with batteries that size.

"But I'd like to ask you, if I run one 24 volt/350 watt/22 amp motor on a 24 volt/250 watt/30 amp controller for a while, what will happen?"

You'd have a bit more torque to get you moving. That's about it. Unless the 250W controller fries, but I doubt it would.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

jyracing
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Re: 12v batteries in series with two motors

Hi Frxdy and Link,
Thanks for sharing your knowledge with me too. Poor Chas has been tutoring me through 1st grade on this stuff. So far, I think I'm failing 1st grade. Chas has probably forgotten more electrical info than I will ever learn.

Okay Frxdy and Link, I get it finally. Parallel increases AH, in-series increases volts. Since my batteries will be in-series, the AH doesn't go up. So with 125 AH, I can theoretically draw 25 amps for 5 hours. But using only 60% of the battery's available AH I actually only have 75 AH available? With two 22 amp motors... 75AH / 44A = 1.7 hours of travel time? Or with an average speed of say 20 mph I can go 34 miles. That sucks!
At 80%, 100AH / 44A = 2.2 hours of travel time, or 45 miles at 20 mph. A little better.

Whoa, whoa, whoa. You're running a 125Ah pack? WTF? I think you have the most
usable Ah capacity of anybody on here

That's what it states on the battery. Bare in mind that these are not scooter batteries. They are big, boat batteries: 50+ pounds and they measure 13x7x10 inches. Probably not the best battery to use, but they are comparatively cheap and available at Walmart for $75 plus core. Do you know of a better battery that I can use in this price range with more AH?

I might gear it a little lower if I were you. Maybe like 15-17mph or so.

Why? To reduce the speed for safety? To reduce the amp draw due to the extra torque required for those low end sluggish hi speed #25 55 tooth gears? Or will I gain substantial travel distance since you said...

Basically, you can get more energy out of the lead-acids if you discharge them slower.

So, the slower I go, the further my batteries will take me indistance. I like that.

I have calced a few of the rear sprockets that are available: 65 tooth (18.46 mph), a 68 tooth (17.64 mph,) and the 80 tooth (15.00 mph). The motor gear can only be 11 tooth because I cant find any other #25 motor gears that mount to my 5/16" round shaft shear pin motor.

Having a few sprockets on hand is handy, too

I would need to have two of each, but they are 10 bucks each. So, it would be about 100 bucks with shipping to have all 4 (8 total) of them sitting around to experiment with. I am trying to keep on some kind of imaginary budget. There is no money amount limit, but when I can save money and not sacrifice, I want to. Like the deals on ebay I just got. The more powerful 36V CT-660B9 controller for half the price of the less powerful JC 116-3. Also, I bought the 55 tooth because that keeps me close to the max speed allowed under California's electric bicycle/trike law of 20 mph and under with assisted peddling.

Okay, so the batteries shouldn't go below 10 volts and I shouldn't use more than 80% (preferrably 60%) of my batteries available power. The controllers shut down at ~10.5 volts so the low voltage problem is covered. And the controllers control max amp output.
But, what monitors and protects against low amperage? A simple ampmeter gauge and I keep an eye on it? Or, does voltage level drain directly correspond to the amp drain? Say: 12 volts = 125AH (a 10.416666 to 1 ratio), 11 volts = 114.5 AH, 10 volts = 104 AH, 9 volts = 93.75 AH, and so on? I a probably doing thiscompletely wrong but it sounds like the AH drain is not relevant because the controller will shut down long before the amps become a problem anyway?

Earlier Link said...

No. One suitably sized controller will be fine... There aren't that many controllers that are 24V 40A, though, because most systems of over 400W or so run off 36V. Less resistive losses that way.

And Chas said...

I would use a PWM controller and the motors in parallel.

I am so overwhelmed with this controller info that I cant remember why I wanted two controllers in the first place. Oh yeah, I'm a control freak. Okay, so I am letting go of my control and giving it back (temporarily) to the PWM 36V/40 amp/1000 watt (really 1440 watt) CT-660B9 motor controller that I just bought. I need to go back and read this whole thread a few more times before I start drawing a new single controller setup.

Thanks guys

JY

jyracing
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Re: 12v batteries in series with two motors

Okay, I went back and reread everything twice and wrote most of it down.

If you guys dont mind, I would like your input on these parts I just bought? I took what you guys said and my newly acquired limited knowledge and start over in two slightly different directions?

First direction:

24V/125AH battery pack
one 24V/250W/30A CT302S9 controller
one throttle
one 24V/350w/22A motor
NewDirectionOne24vController1.gif

Second direction:

36V/125AH battery pack
one 36V/1000W/40A CT660B9 controller
one throttle
NewDirectionOne36vController2motors1.gif

I probably missed something that is important, but based on what I think you guys said this is what I come up with. The batteries are in series and I think I have the motors in parallel. What do you think?

JY

chas_stevenson
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Re: 12v batteries in series with two motors

Now that you have given up some of that control freak stuff I would use the second direction. The only reason I said 2 controllers before was to give you the control you wanted. A single controller is the best solution. The diagram is however missing a battery. If you would stop changing your mind, we could finally come to a decision.

I do have to ask what is the box labeled "Power Supply"?

I also use the power indicator connection to power an LED tail light.
I never use the charger connection I connect the charger to the batteries.

One other very important item about these controllers. The Key or Lock connection does NOT power off the controller, it just disables the controllers outputs. The controller remains connected to the batteries and continues to draw a very small amount of current which can drain them to nothing and of course you now know what that will do.
DEAD BATTERY!!!

Grandpa Chas S.

LinkOfHyrule
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Re: 12v batteries in series with two motors

"That's what it states on the battery. Bare in mind that these are not scooter batteries. They are big, boat batteries: 50+ pounds and they measure 13x7x10 inches. Probably not the best battery to use, but they are comparatively cheap and available at Walmart for $75 plus core. Do you know of a better battery that I can use in this price range with more AH?"

You want MORE!?! O_o Geeze...

They're big, heavy, not very energy dense, and don't last very long, but for sheer $ to w/hr capacity, you can't beat lead-acids, so they're about the best option. However, keep in mind that the more common sizes are cheaper. If I walk into my local electronics store, I can buy SLAs that cost nearly $1/wrh because they're an uncommon size, or I can buy a PS-12350 for $0.19/whr. You got yours really REALLY cheap at $0.05 w/hr. Honestly, I can't think of anything that even comes CLOSE to being that cheap, other than perhaps a more common size of battery. But I don't even know where to BEGIN to look. And at the price you got them for, I don't really think you could find them much cheaper.

"Why? To reduce the speed for safety? To reduce the amp draw due to the extra torque required for those low end sluggish hi speed #25 55 tooth gears?"

Safety? What's that? :P

You might be pulling too hard with the bigger sprockets. Those batteries can take it no problem, but the motor brushes might not last very long that way.

I don't think you'll gain too much distance, but it's hard to say without some hard data.

"So, the slower I go, the further my batteries will take me indistance. I like that.

I would need to have two of each, but they are 10 bucks each. So, it would be about 100 bucks with shipping to have all 4 (8 total) of them sitting around to experiment with. I am trying to keep on some kind of imaginary budget. There is no money amount limit, but when I can save money and not sacrifice, I want to. Like the deals on ebay I just got. The more powerful 36V CT-660B9 controller for half the price of the less powerful JC 116-3. Also, I bought the 55 tooth because that keeps me close to the max speed allowed under California's electric bicycle/trike law of 20 mph and under with assisted peddling."

4 sets of gears might be overkill. I'd probably keep two extra sprockets around, but one extra is good, too.

Your budget is set up like mine :P.

Heh, heh. Mine does 30+mph without pedaling.

"Okay, so the batteries shouldn't go below 10 volts and I shouldn't use more than 80% (preferrably 60%) of my batteries available power. The controllers shut down at ~10.5 volts so the low voltage problem is covered. And the controllers control max amp output.
But, what monitors and protects against low amperage? A simple ampmeter gauge and I keep an eye on it?"

I HIGHLY recommend a Watts Up meter like this..

What this is is a road amp-hour meter. It shows how many Ah you've used since you turned it on. Not only that, but it shows your current voltage (up to 60), current amp/watt draw, and records lowest voltage/highest amperage. It's basically a fuel gauge for an ebike.

Mine cost me $60 delivered. A little steep, but again, it's a borderline MUST.

"Or, does voltage level drain directly correspond to the amp drain? Say: 12 volts = 125AH (a 10.416666 to 1 ratio), 11 volts = 114.5 AH, 10 volts = 104 AH, 9 volts = 93.75 AH, and so on?

Sorta. Like I said, the faster you drain the batts, the less energy you get out of them. In addition, the batteries will sag under load, so voltage isn't the best way to measure what's left. The Watts Up meter is a much better way to do it.

"I a probably doing thiscompletely wrong but it sounds like the AH drain is not relevant because the controller will shut down long before the amps become a problem anyway?"

Not necessarily. It's generally not a good idea to drain SLA's even to a controller's LVC.

Pick the second direction. You've got it right. But, I am going to mimic Chas and ask, "Why the power supply?" You're also missing a battery in the second pic.

On another note: What are you going to use to charge up the batteries? Those are really big. Your average charger would take several days of charging to finish. Even my 2/4/6A Vector charger would take a day. You need a charger that's designed for about 20A, and those only really come in 12V designs.

Do a search on eBay for "Vector charger". Pick one that will do 20A. They have selectable charge rates. If you get one of the 75A models resist the urge to go above 20A or so. It's okay if you need a fast charge for something occasionally, but it does shorten the battery life by just a little bit.

Keep in mind that you'll either need two, or have to charge the batteries one at a time.

Also, what is the power supply for?

"One other very important item about these controllers. The Key or Lock connection does NOT power off the controller, it just disables the controllers outputs. The controller remains connected to the batteries and continues to draw a very small amount of current which can drain them to nothing and of course you now know what that will do.
DEAD BATTERY!!!"

He's right: They only disable the controller output. But, I don't really think you'll kill the batteries. Even at a relatively high 10mA quiescent current, it'll take 100 hours to even drain 1Ah out of the battery. Meaning that your batteries could power the controller alone for over a year and a half :P.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

chas_stevenson
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Re: 12v batteries in series with two motors

He's right: They only disable the controller output. But, I don't really think you'll kill the batteries. Even at a relatively high 10mA quiescent current, it'll take 100 hours to even drain 1Ah out of the battery. Meaning that your batteries could power the controller alone for over a year and a half

I have been using these controllers for over 5 years and if they are not disconnected they will drain my 24-AH pack to 3-volts in a week. So Based on 12-AH that would take about 10 weeks on your batteries but in far less time the batteries are down to well below 50% discharge which will cause a lose of range.

I use a 15amp switch to turn on and off my batteries. Remember the rating of the switch is the amount of current they can switch. Once the switch is closed it can carry many times as much current. Look at it this way, if you connect 2 wires together and there is a large current there will be a large spark but if the current is small the spark will be small increasing the current after the connection is made does not create any more sparking. When you power on the controller there is only a small current flowing the large current does not flow until you hit the throttle so there should be only a small spark or ark in the switch. Knowing this we can now use a smaller rating on the switch because after it is closed is when we will hit the throttle and draw larger amounts of current which the closed switch can carry easily.

Grandpa Chas S.

LinkOfHyrule
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Re: 12v batteries in series with two motors

Really? Only a week to three volts on your pack? Have you ever measured the quiescent current on your controller?

I've never checked proper, but it doesn't even register 100mA on the Doc Wattson. Might do that...

Perhaps the logic on mine just doesn't use very much power.

Breakers are great for high-current switches because they're pretty cheap and available.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

chas_stevenson
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Re: 12v batteries in series with two motors

Yes 3 weeks and they were junk!!!

Grandpa Chas S.

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