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DerBen • Feb 7, 2009

is there and easy way to make LED(s) run on 48v

I have very basic knowledge of electricity.. I have an electric bike that is powered by 48V of batteries. I wanted to convert the standard filament bulbs with LEDs. From what I understand resistors fail above 12 or 24 volts.

So what would be an easy and cheap alternative to convert about 8 bulbs to LED lights? Considering for the headlight it may take up to 10 LEDs to get the brightness required, while still keeping the LED's lower energy consumption vs the incandescent bulb.
Rifaa • Feb 7, 2009
yup u could do it. tell me what type of LEDs u have and how many.
ya, and also the battery capacity.
ashuashi • Feb 8, 2009
looks good. 😉

I would also like to get this done for my bike ... ;-)
DerBen • Feb 8, 2009
Well for any other lights one LED 'should' work.. But the headlight.. I'd probably need 5.
the leds I have:
Emitted Colour : White
Size (mm) : 5mm
Lens Colour : Water Clear
Forward Voltage (V) : 3.2 ~ 3.6

The battery.. heh.. is the tough one.
Battery capacity: 48V14AH+7AH
that tell you anything?
Quite possible,you can use somekind of regulator circuit,even semiconductors are available in that range!!!
Rifaa • Feb 9, 2009
For the head light you have to use a combination of series parallel LED's, since white LED's have a variety of voltage drop which could range from 3V to 4.5V.
Currently White LED's that I have works at 4.2V :-o
So here we have to do a trail and error method here.
First take 12 white LED's and wire it series together with 470 ohm 2W resistor.
I want you to measure the current through the LED's when you apply 48 VDC to this string.

NEVER GIVE 48V DC to a single LED, If u want it to blow. plus

"be careful with this voltage, it will give u quite a shock, be careful not to touch battery terminals. Do this at your own RISK". I or CE cannot be held responsible for your negligence, and also have some one with you to help. This will reduce the danger of doing something wrong and use one hand to deal with high Voltage.

Any voltage above 24V whether AC or DC is enough to kill if certain conditions are met, better to avoid them, than end up in the hospital.

If in doubt in how to wire this, ask and I'll provide u a schema.
Remember all the LED's and resistor should be in series. Measure the current through the string and the voltage drop across the resistor, and also the voltage drop across each LED's. and post it here.
Next is tht if u like to have more than twelve LED's in the head light, find out how many you can fix in to the head light you have right now.
I'll say you can have around 36 white LED's which will give quite a bright head light 😁

One more thing, the Energy consumption is nothing compared to a filament bulb. I don't thin even 50 LED's will be close to a single bulb, and you can have blinding head light

Do this and from there we'll go on.

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