Honda/Huasheng/Titan,Lighting & Electrical System.

[duivendyk]

It's the usual story,all sorts of sage talk& airchair theorizing.Unless you characterize these outputs in some fashion,for instance in the way I have outlined before, you don't know enough to arrive at an optimal,efficient design.There is prob. not all that much power to be had anyway.

 

[BSA]

Count me as interested.

and me aswell please

BSA

 

[MotorbikeMike]

Off topic, but great idea

Hi Irish John, I would welcome a good source for springer with cantilever studs I already have a use for it!

Thanks, Mike

 

[skyl4rk]

I measured my new out of the box Titan motor, which is similar or the same as a Huasheng 50cc four cycle motor.

At idle, the wire to the kill switch is at 9V. At fast rpm, the wire is at 17V.

I put a potentiometer in line with the kill switch wire to ground. The motor idled fine until resistance of 600 ohms. Higher ohms and the motor ran fine.

Here is my take on it:

The maximum amps that you can draw at idle speeds are 9V / 600 ohm = 0.015 amps or 15 milliamps. That is not a lot. I do not believe that the motor electrical system can handle powering lighting at idle speeds. You may be able to draw more amps at higher motor rpm.

The voltage is not bad for charging a 12V lead acid battery. If a blocking diode is placed between the kill switch wire and the battery, it will drop voltage about 1.4V. Voltage changes as rpm changes, but at a fairly high speed it was 16 or 17V, so after the voltage drop from the diode, voltage available to charge the battery is about 15 to 16V. It might be possible to put in a zener diode that bleeds off any voltage above 14V, or you could use a voltage regulator to hold the voltage at about 14V.

I don't think a zener diode or voltage regulator would kill the motor. As soon as voltage drops to the voltage of the battery, no current would flow through the blocking diode, so this would save the motor's power if there were a "heavy" load on the battery. Perhaps if the battery got discharged it might cause the motor to die.

 

[Irish John]

From Skyl4rk's report above it looks like the current isn't really much use because what is needed for the likes of myself who ride at night in the country is the ability to use a car halogen light and those are 12volt and probably a lot of amps. Being able to charge up the batteries as you proceed is good but only if it doesn't involve cumbersome equipment and engine die back. I have not used lead\acid batteries and have only got two Nimh and one lithium ion battery. The latter is by far the best and charges very quickly with a smart charger. The Nimh ones take ages and don't like being overcharged which is something that just happens quite often.
I was hoping to find that at last we could run the sort of light that really lights up a dark road but it seems we cannot.
I don't know what ohms are but in the UK it means On Her Majesty's Service.

 

[skyl4rk]

$0.93 battery charging circuit for the Huasheng 50cc motor and a 12V lead acid battery:

Rectifying Diode, 1 Amp
http://mouser.com/Search/ProductDetail.aspx?R=1N4935-E3/54virtualkey61370000virtualkey625-1N4935-E3

Resistor, 750 ohm, 5 Watt
http://mouser.com/Search/ProductDetail.aspx?R=286-750-RCvirtualkey21980000virtualkey286-750-RC

Zener Diode, 14V, 5 W
http://mouser.com/Search/ProductDetail.aspx?R=1N5351BGvirtualkey58410000virtualkey863-1N5351BG

Connect the Killswitch wire to the Diode with the white stripe AWAY from the Killswitch wire. You can still use the Killswitch.

Connect the white stripe side of the diode to the Resistor (either side of resistor).

Connect the other side of the resistor to the Zener Diode white stripe side.

Connect the other side of the Zener Diode to the motor body (ground).

Connect the battery positive between the Resistor and Zener Diode.

Connect the battery negative to motor body (ground).

Headlight, taillights and other loads are connected as usual to the battery with a fuse in line.

This circuit has not been tested, use at your own risk. I believe you might see a small charging current in the range of 0.1 Amp. This is not much but if you ride mostly during the day and only occasionally at night a small trickle charge might be all you need.

I suggest buying additional resistors, perhaps 400 ohm, 600 ohm and 800 ohm. If the motor will start and run with a 400 ohm resistor, I would use it because it will allow more voltage to the battery. The absolute minimum size of resistor to use is 100 ohms. This minimum is needed to protect the Zener Diode. I am not sure if the motor will run or be shut off by this low resistance, it depends on how much other resistance is in the circuit. I used a potentiometer and decreased the resistance between the Killswitch wire and ground until the motor quit. The motor quit at 600 ohms. However, the charging circuit Resistor is on the other side of the Rectifying Diode from the motor, so the motor may get enough current during the time it is producing less than the 12V it takes to match the battery voltage. I would experiment. You are not going to hurt anything as long as the resistor is over 100 ohm, it is just that the motor may not start.

You may want to put a switch in line between the Killswitch wire and this circuit. It may be easier to start the motor when no amps are being drawn by this circuit. You could try it without a switch first. I believe it will work without a switch.

I have oversized the ratings of the components mainly because they are cheap and it makes the circuit more durable. Higher rated parts are also usually a little larger and easier for me to work with.

Theory:

The Rectifying Diode allows current to flow from the Killswitch wire to the battery but not in the other direction. When the motor is producing less than the battery voltage, no current will pass the Rectifying Diode in either direction. When the motor is producing more than the battery voltage (minus the voltage drop of the Rectifying Diode - 1.2V) then current will flow in the direction of the battery.

The Resistor does two things: it makes sure that the minimum resistance of the circuit is always above the motor shut off resistance which I measured on my motor. The Resistor also protects the Zener Diode from too much current.

The Zener Diode does not allow any flow of current if the voltage is less than 14 V. If the voltage is above 14V, the Zener Diode allows current through to the ground, "short circuiting" any current over 14V. This means that the voltage on the white stripe side of the Zener Diode will not exceed 14V. 14V was selected because it is a good charging voltage for a 12V lead acid battery. As long as the motor puts out over 14V, the battery will see 14V.

 

[Irish John]

That's great stuff. Just a few queries Skyl4rk:
Are the above Rectifying and Zenor Diodes and Resistor all weatherproofed for use on a bike?
Does anyone use a 12volt lead acid battery?
Will it work with standard 6 volt NiMh bike light batteries for halogen or HID lights?

 

[skyl4rk]

The circuit would have to be weatherproofed, although none of these components are sensitive to water. The Zener Diode will create some heat so it needs to have air circulation.

This circuit will charge any battery that can be charged at 14V.

It will not work on 6V NiMH.

Going from the motor's 17V to 14V is pretty easy. Going from 17V to 6V means a little more calcuation and maybe a different strategy to deal with the voltage drop.

 

[skyl4rk]

IMPORTANT

Add a 1A fuse in line between the Killswitch wire and this circuit.

 

[fetor56]

@sky14
How confident are u that this will work,or rather should i say how confident are u that no harm will be done?
Don't mind me man....i'm just paraniod about the electrical system cos i don't know enough about electronics.