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Take a look around at the various battery repair and battery build threads; there are some that show a few different ways you could do ti.
 
Thanks for all the help so far from the forum on my a2b metro.

Now I have to figure out what to do with that 6 pin barrel connector going to the second battery location where I plan to put my new battery.

Should I run a new set of wires for the new battery or try to interface to that plug?

anyone know the pin out on that plug or the recommended alternative option for the a2b metro?
 
middriveebike said:
Anyone tried to create a push button for throttle that can use together with the hall sensor twist throttle for ebike?

The easiest way would be to find a push button that's double throw (like most microswitches). Run the common contact to the controller input and the normally closed contact to the throttle so it behaves normally when the button isn't pressed. The normally open contact can then go to the 5v or to a potentiometer to make it adjustable. Note: some controllers will fault if you tie the throttle signal directly to the 5v line and will need the pot.
EDIT: potentiometer can be about anything, but I would suggest 10K. from 1K to 100K should work.
Pushbutton Throttle.jpg
 
if your throttle has a max voltage of 4.7V i bet you could use two fixed resistors in series to convert the 5V power to a 4.7V signal. use a 5.9k ohm resistor above and a 93.1k resistor and the voltage should be 4.7 on the terminal between them that you would connect to the switch.
 
using a multiturn trimpot like that is easiest way to find the exact max voltage. you want one with a high enuff resistance that it doesn't drain a ton of current from the 5V power line so i just used the 100k total. but the signal line will use some current also but i figured the input impedance on the signal line was in the megaohm range but the trimpot will give you a good way to compensate for it. you could even set it up using a trimpot and then measure the resistance from the wiper to each end and use fixed resistors of the same value or ratio with total resistance close to it. sometimes the bournes trimpots can be a little more expensive than leaded 1/4W resistor or two.
 
the controller has a default shut down if the throttle voltage is the same as the 5V supply voltage. it is there to protect against a throttle signal wire shorted to the 5V power which would lead to unexpected and uncontrolled WOT.

if you use an ebrake switch then you could use a rocker switch for the cruise controller and then if you had to do an emergency stop the ebrake switch would shut off the controller until you reset the throttle switch.
 
Right, some controllers have this safety feature and some do not. Alternately you could use a resistor in series with the 5v but you would need to experiment to find the right value. If you're lucky, straight 5v would work.
 
Here is my ebike's full schematic.
I placed the battery and controller inside the truck so that it is much more difficult to jump start my bike.
The ignition is connected to the main power through a relay, which is controlled by an FM transmitter key chain.
The throttle is controlled by the twist throttle or non self locking cruise button as suggested by fecher.
 

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Avoiding discharge through BMS mosfets limiting current.
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I dont know if it is clear enough, never the less, when key switch is disengaged relay is in NORMALY OPEN state. When key switch is engaged it engages relay and we get connection between conroller positive ad ignition wire (orange) so the controller is live. When a cell reaches LVS, BMS cuts off P- and there fore disengages relay braking connection of ignition wire to positive.

Am i thinking the right direction? What sort of relay/relay contactor i would need to suit all the voltages, say up to 100vdc in?
 
I think that would work. The current in the key line to the controller is typically way less than 1A, so a very small relay could work. My guess is you could just use a 120vac relay with contacts rated for 3A or so and it would work fine on DC.
 
OK, so i pulled out a relay from washing machine circuit board, its 4 pole 12VDC to 230VAC -JW1AFSN-DC12V. I hooked it up to my 24S 81V battery and its clicking making connection. i have then hooked it to my 21V 5S battery module and its working as well. Should i be concerned using 12VDC relay for this design and voltages as high as 24S? What occurs inside relay when higher voltage is applied? Would there be arcing or it would damage the coil in short while?
I have a 15A BMS and 10 18650 cells, 6 3.4ah, 4 2.6ah. Will get them connected in to 10S and test if it is working the way i want it to.
 
Frog box volt meter re-calibration: http://endless-sphere.com/forums/viewtopic.php?f=14&t=50901
 
agniusm said:
Should i be concerned using 12VDC relay for this design and voltages as high as 24S? What occurs inside relay when higher voltage is applied? Would there be arcing or it would damage the coil in short while?

The coil rating and the contact rating are two separate things. Putting a 24s worth of voltage into a 12v coil will burn out the coil quickly. The coil needs to be fed with 12v. The contacts are another story. The contacts don't care what the voltage is unless you try to open them under load. Under load, there is the possibility of drawing an arc that would destroy the unit quickly. At light load, it should be no problem.

To get 12v for the coil, it's best to use a dc-dc converter. You could also use a large resistor of the right value, but it will run very hot. If you measure the coil resistance, the resistor value and heat can be calculated.
 
Hi guys,

I kindly ask for your help and advise, as I´m a real noob when it comes to cabling. :oops:

Can you please have a look, if the below scheme is complete and OK? Any suggestions are more than welcome. Thanks!!

Kind regards
Lars
 

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The key switch needs to handle the full battery current, so would need to be a very big one. If you have a big key switch, then that's OK.

Many systems use a small key switch that only powers the controller logic through a small wire going to the controller and just use a big connector to unplug the battery.
 
Most controllers I've tested have about a 20k resistor from the signal pin to ground inside the controller. This makes another divider with the 550k and results in not enough output. If you have a voltmeter, you could measure the signal pin when you hit the button.

To make it work right, you may need some kind of amplifier.

Another approach would be to use something like the throttle tamer: http://endless-sphere.com/forums/viewtopic.php?f=31&t=51460
 
fechter said:
Most controllers I've tested have about a 20k resistor from the signal pin to ground inside the controller. This makes another divider with the 550k and results in not enough output.

Ahah! You have helped me enormously. Armed with that knowledge, and some help from d8veh in the other thread, I have managed to get it to work. Swapped the 100k and 550k resistors out for 1k and 5k, dropped the 22k altogether and put in a 100microF cap to keep the ramp about the same, and bam! it works! Very nice. See http://endless-sphere.com/forums/viewtopic.php?f=2&t=50843&p=797385#p797385.

Anyway, as noted there, I find it seems to work quite nicely, I am going to test it 'in anger' for a little while and see how I go. The only issue so far is that the cap drain time, while it is quite a lot quicker than the ramp up, still results in a little bit of 'run on' when you release the throttle. Not badly, but it's noticeable, and would be nicer without.

Can you suggest a modification to the circuit which would allow the capacitor to drain faster, when the button is released?

many thanks for your help so far!
 
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