12v batteries in series with two motors

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jyracing
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Re: 12v batteries in series with two motors

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

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Also, what is the power supply for?

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"Why the power supply?"

The "Power Supply" is my secret weapon that will give me a 200+ mile range and charge the batteries fully in 45 seconds, once the chain reaction starts. Its a small nuclear fission reactor that splits only three atoms. I invented it years ago. :jawdrop:

I like that road amp-hour meter. Does it have cruise control too? Its got everything else. Gotta have one of those. There goes the budget.

Speaking of cruise control... Cant I use a half twist throttle and one of those motorcycle throttle cruise control clampon devices?

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I would use the second direction

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Pick the second direction

I agree. I will eventually. Both of these controllers are made by the same company and use the exact same connector array. So changing out the controllers is easy and just hook up the third battery and the second direction is completed. That is, after I get the first direction up and running. For a few days, I am going to try one motor and the 24V controller to form a baseline.

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If you would stop changing your mind, we could finally come to a decision

I'm sorry. I say the same thing to my GF all the time.

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What are you going to use to charge up the batteries?

I have a 12v 2/20/100A charger that I can charge them one at a time, but I want a 36v/3amp charger that I can leave connected when not riding to keep the batteries topped off. That "Vector charger" sounds good. Why would I need two?

So, I will shunt the Lock connector. I dont need it because I will use a 50A main toggle switch to shut everything down at the batteries. That should eliminate a drain on my batteries from the controller being unlocked, right?

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They're big, heavy, not very energy dense, and don't last very long

I'm big, heavy, and dense, but I last a long time.

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Safety? What's that?

I know, someday I am going to have to add brakes. I was afraid one motor would get lugged down, Thats why I added the second motor originally. I wanna do 30+mph without pedaling... after I get brakes or steal the drag chute off of my race car.

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You got yours really REALLY cheap at $0.05 w/hr.

Thats why I bought them. I sacrafice weight for AH.

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

Oh, okay, I will try not to.

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I said 2 controllers before was to give you the control you wanted

Oh, I will still have control but I'm not telling you how. (see new drawing below)

You lost me one this Chas.

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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.

But I have fried a dozen 10A switches over the years drawing 30A thru them. The didnt butn up when I flicked the switch but they did after the switch was on for a while. If the controller is capable of 40A wont it potentially draw 40A thru the main switch? Thats like saying I can use tiny wire as long as the amps increase slowly. More amps equals more heat. Low Amp switches will melt with high amps flowing thru them for very long, wont they? That's why I just bought a 50A toggle switch for the main.

Opps, left out a battery, I was tired. Is this better?
NewDirectionOne36vController2motors4.gif

Notice the motor switches Chas? I added them just for you ;)

Here's something that puzzles me. Any difference? as long as the last battery's positive goes to the positive on the controller???
battery_puzzle.gif

The "Power Supply" is just the connector from the controller that goes to the batteries.
But the nuclear thingy sounded good :)

JY

ps Check out these cool 8 gauge fuse holders I just bought on ebay for 3 bucks. And they even come with two 40A fuses too.
8gaugefuseholder.jpg
I just cant figure out how to hook them up. The wire is in a loop. There is no end to attach to anything. At least the fuse never blows that way. :puzzled: LMAO!!!

e-doggies
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Re: 12v batteries in series with two motors

'Here's something that puzzles me. Any difference? as long as the last battery's positive goes to the positive on the controller???'

battery_puzzle.gif

Both images are identical electrically, however, I believe they are both incorrect. The wiring is the same as if you were putting all three batteries in parallel, but the middle batttery is facing backwards. If you connect the batts this way, it will short immediately. You need to start on one terminal of battery 1. Let's say that's "+". Connect that terminal to "+" on the controller (after you go thru fuses and switches, etc). The "-" on Batt 1 goes to "+" on Batt 2. The "-" on Batt 2 goes to "+" on Batt 3, and the "-" on Batt 3 goes to the controller.

LinkOfHyrule
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Points: 730
Re: 12v batteries in series with two motors

"I like that road amp-hour meter. Does it have cruise control too? Its got everything else. Gotta have one of those. There goes the budget."

Sadly, no. That would require interfacing the throttle, controller, and brake through it.

There is something like that (Cycle Analyst), but it costs much more, and will only work with certain controllers.

"I have a 12v 2/20/100A charger that I can charge them one at a time, but I want a 36v/3amp charger that I can leave connected when not riding to keep the batteries topped off. That "Vector charger" sounds good. Why would I need two?"

So that you don't have to switch one over when the first battery is done. If you already have one suitable charger and are willing to charge one at a time, then you don't need them.

"So, I will shunt the Lock connector. I dont need it because I will use a 50A main toggle switch to shut everything down at the batteries. That should eliminate a drain on my batteries from the controller being unlocked, right?"

Right. The lock connector is good if you want to have a key, though.

"I'm big, heavy, and dense, but I last a long time."

LOL, why do I get an answer like that every time I say it? Last time, whoever I was telling to said, "Sounds like my ex wife."

"But I have fried a dozen 10A switches over the years drawing 30A thru them. The didnt butn up when I flicked the switch but they did after the switch was on for a while. If the controller is capable of 40A wont it potentially draw 40A thru the main switch? Thats like saying I can use tiny wire as long as the amps increase slowly. More amps equals more heat. Low Amp switches will melt with high amps flowing thru them for very long, wont they?"

Indeed. I think Chas is thinking of relay contacts, which are rated by switching current. I think regular switches are rated by carrying capacity.

Contactors are rated by switching amps because if they try to switch a large current, they will weld shut. Smaller switches that aren't made for powering things as large as a motor don't really have this problem.

"Is this better?"

No. The batteries are gonna explode again.

"The "Power Supply" is just the connector from the controller that goes to the batteries.
But the nuclear thingy sounded good."

LOL, okay. Leave it out then. Or put in a power inverter and install a mini t.v. (I have done this, and it's pretty awesome ;)).

"I just cant figure out how to hook them up. The wire is in a loop. There is no end to attach to anything. At least the fuse never blows that way."

I think you're supposed to cut it and add your own connectors. Very clever way of keeping the wires tidy in shipping, actually.

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jyracing
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Points: 112
Re: 12v batteries in series with two motors

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No. The batteries are gonna explode again.

Damn it. Back to Chas' drawing...
series_parallel_batteries.gif

Okay, I see it finally. Like This???
batteryseriescorreect.gif

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Sadly, no. That would require interfacing the throttle, controller, and brake through it

The manual motorcycle clamp-on cruise control should do the trick.

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LOL, why do I get an answer like that every time I say it?

Dense minds think alike?

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Indeed. I think Chas is thinking of relay contacts, which are rated by switching current. I think regular switches are rated by carrying capacity.

OMG! Chas was wrong? Dont tell Chas. I know he is going to quote some Bio-labeil-electrical-frickative Law that will prove he is right, once again. :)

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LOL, okay. Leave it out then. Or put in a power inverter and install a mini t.v. (I have done this, and it's pretty awesome

Accessory Plug?! Gotta have one. Actually, its one of the controller connectors, I cant leave it out. There wont be any power to the controller if I leave it out. LOL

NewDirectionOne36vController2motorsACC1.gif

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I think you're supposed to cut it and add your own connectors.

I was trying to be funny. Hence, no where to attach it and at least the fuse will never blow. I'm still laughing about that. Laugh Link laugh! Its funny to me. :)

BTW, Thanks for Inkscape Frxdy!
Victory.jpg

chas_stevenson
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Points: 1309
Re: 12v batteries in series with two motors

I have been staying out of it for a while because you guys are answering for me... LOL You are all doing fine with one exception, I don't know why you roasted the 10 amp switches I have been using the same Radio Shack - 15 amp Toggle Switches on 3 different bikes with NO problems for several years. I can only guess your 10 amp switches were very cheap. How ever as I write this post there is one other reason I over-looked till now. The switches I have been using are DPDT. And I use both sets of contacts, causing the switch to be used in a 30 amp configuration. Maybe that is the real secret, I just never thought it through that far before.

Grandpa Chas S.

Frxdy
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Joined: 01/03/2008
Points: 20
Re: 12v batteries in series with two motors

I was reading that when you switch DC off, it tends to make an arc. In a high amp circumstance they will turn on OK, but if you try to turn them off while under load, it will draw an arc inside the switch, possibly ruining the switch, or welding them shut so it won't turn off. I bought a contactor that I think has a magnet inside that pulls the arc away? So, the question is... just how much voltage or amps does it take to make this an issue that has to be dealt with? Or, put another way... at what volts & amps do you need a contactor instead of just a switch?

Ya! Isn't Inkscape a good lil' program? It will also make vectors from bitmaps in case you need a file that a CNC machine can use.

chas_stevenson
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Re: 12v batteries in series with two motors

Frxdy wrote:

I was reading that when you switch DC off, it tends to make an arc. In a high amp circumstance they will turn on OK, but if you try to turn them off while under load, it will draw an arc inside the switch, possibly ruining the switch, or welding them shut so it won't turn off.

This might help explain why I have been able to run these switches so long as well because when I turn them on or off the only current flowing is what the controller draws during standby (Throttle off condition).

Grandpa Chas S.

LinkOfHyrule
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Points: 730
Re: 12v batteries in series with two motors

"Okay, I see it finally. Like This???"

Yay :)!

"The manual motorcycle clamp-on cruise control should do the trick."

Mine came with an inadvertent cruise control, actually.

I use a half-twist throttle, so it's in two pieces. If you push the two halves together so that they rub together slightly, it will hold itself in place. People wonder how I can ride no handed without pedaling after about a quarter mile, LOL.

"Laugh Link laugh! Its funny to me."

I'll take your word for it :P.

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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" contained herein.

jyracing
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Points: 112
Re: 12v batteries in series with two motors

Chas, Link, and Frxdy, I want to sincerely thank you guys for all your time and priceless help. You have saved me 100's of hours and 100's of dollars with your knowledge, input, and ideas on how to build my electrical system. I couldn't do it without your help. And, thank you for you patience with me while teaching me the basic electric knowledge that I sorely lack. Maybe other novice EVers will benefit from this thread. I wish that I had something to offer to repay you guys for all your help. The best thing I think I can do is spread the word about this great site and the great people that are here.

JY

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