Can I wire up multivoltage Led drivers is series on my e-bike?

Hi guys,

I have four 10V-30V DC amber led lights which I am fitting to my e-bike as indicators, my bike battery is 36 volts (it puts out 42.5 volts with no load and freshly charged). I would like to wire each pair up in series, which would save me having to buy a 30 volt regulator.

So is it all right to wire up these lights with their multivoltage led drivers in series so each driver receives around half the battery voltage? (I have a suitable multi voltage flasher unit with fuse).

Regards,

Rupert.

As I understand this, no. The drivers are not pure resistive loads. They do some weird things hooked in series. You are also using them as flashers so that's another wrinkle. Do they make nominal 12 volt regulators cheaper? The drivers likely turn a fair amount of heat dropping to the 10 volt base line the driver plus LEDs use.

BrianMc said:

As I understand this, no. The drivers are not pure resistive loads. They do some weird things hooked in series. You are also using them as flashers so that's another wrinkle. Do they make nominal 12 volt regulators cheaper? The drivers likely turn a fair amount of heat dropping to the 10 volt base line the driver plus LEDs use.

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Thank you for your reply, maybe I should wire them in parallel and use the voltage regulator. As regards efficiency I had asked supplier about approximate current draw for one light running at 12 volts and 30 volts, they said:

"54-LED Amber cluster: 140mA @12V. We can only test these from our end at 12V, but according to the comparison chart, at 30V the approximate current draw should be: 54-LED Amber cluster: 56mA @30V"

If this is correct ...given it shows same power use for both voltages?? I had assumed it would be best to buy/make a regulator using a LM317K IC which has an adjustable voltage 1.2V to 37V and run it at 30 volts.

I will try varying the voltage and measure the current draw.

^Sounds like a plan. I know other drivers like the Taskled ones, are less efficient the greater the voltage spread of supply and load. My guess is they calulated current at 30V for same power as 12 assuming same efficiency.

Taskled's Hyperbuck driver has an input voltage range of 8..80VDC and has an adjustable output current up to 1500mA. It is the "Ideal LED driver for ebikes with up to 80V battery packs."
http://www.taskled.com/hbuck.html