can i over-volt LED lights?

i do not profess to understand electronics, besides, i’m colour blind.

have the lumicycle 14.4v battery. have found 12v mr11 LEDs. they should fit straight into the housing but will they blow?

experinces?

cheers

J

You need to find out the max input voltage of the circuit board that is driving the LEDs, do you have a link to them?

Should work. I’ve run some of a motorbike battery, but I haven’t done it for long, so I don’t know if there are any heat issues.

As snaps says you need to know the specs to be sure. Most designs accept a sensible range so I’d be happy to give it a go at 14.4 personally (if they’re reasonably cheap).

interested if that works, and if it gives more lightoutput that say a 20W halogen. what LEDs are they? Might try that with one of my plumbing fitting halogen bodges!

Not sure about this – In the case of the cutter kit I’m running now it will accept a range of input voltages but it will only draw what it needs. Over volting it doesn’t make it any brighter.

It all depends on the electrickery running the lamps

overvolting won’t do anything to the brightness – agreed, as its the amps which the LED draws which ultimately dictates how bright, however if there is an alternative to re-building a halogen set up with an LED kit which just plugs in is very interesting especially if its any good.

Probably worth posting up a link to the bulb too – most of these are a complete waste of money for bike lights*, and they can be quite expensive.

There appear to be hundreds of MR11 sized LED lamps, and I’ve not yet seen one that’s any use. Certainly nothing that is going to be anywhere near as bright as a 20w halogen.

Joe

I agree with Joe. You might get a light to be seen by but not one to see by

Certainly the last time I looked there were no drop in MR11s that produced any useful light. There are some MR16 ones that are passable though.

I agree with Joe. You might get a light to be seen by but not one to see by

have seen them in local diy place. currently running 12 spot and 35 spread.

wouldn’t be worried if they weren’t any brighter although have seen LED at 15w.

how easy is the CREE/cutter conversion thing to do? can i run it off the 14.4v lith battery? how much effort and money do i need? are the results worth it?

can usually get 4hours riding from current set up (12/35), more if being economical with the 35.

cheers

J

The plug in MR16 and MR11 LED units that I’ve used are a case of 12V MINIMUM required, and are generally safe up to about 18V.

I did a test on the one I was using to check the current and the voltage etc. I found that when my 14.4V pack was freshly charged it was chucking out 16.28V even under load (the LED is a very minimal load though in comparison to a 20W Halogen), the LED was only drawing 0.20A. By the time the voltage had dropped to it’s “nominal” 14.4V, the LED was drawing 0.23A.

Seems the LED draws the “power” it requires, regulating the current as the voltage of the power source drops. DO NOT try it with a battery of low voltage, or a fully discharged Nimh pack though. I learnt this the expensive way! Everything got VERY hot VERY quick, wires melted etc. Seems the LED was trying to draw a ridiculous current probably as the battery voltage was too low. Keep your 14.4V Nimh pack in good condition though and it will be fine.

The LED unit I was using was a 3xCree LEDs inside an MR16 sized “bulb”, with built in heatsinks etc. They’re about £20 each on ebay from the US (expensive, but they’re about 10 times better than any other LED “bulb” I’ve seen), and from what I can deduce draws roughly 3.3 Watts of power. Quick calculations based on my 14.4V 4800mah pack shows that I could expect over 20 hours runtime on a freshly charged battery! Oh, and the “bulb” is probably about as bright as a 10 or 12W halogen unit I’d say, if I had to guess 200ish Lumens or so. Perfect for “just getting about, and most offroad riding”, but it needed the 20W halogen on the bars too for any technical riding.

Given it all up now as I decided the new LED lights were the way to go, have a P7 flood on the bars now, and an R2 on the helmet for penetration.

wouldn’t be worried if they weren’t any brighter although have seen LED at 15w

Is it labelled ’15W equivalent’ or actually taking in 15W of power?

If it is 15W equivalent, then in the real world that seems to mean about 3-5w equivalent. If it is actually 15W, then find out what it is, cos everyone will want one.

Joe

how easy is the CREE/cutter conversion thing to do? can i run it off the 14.4v lith battery? how much effort and money do i need? are the results worth it?

Pretty easy – I needed help from Rob to as I’m not handy enough with a soldering iron. I can run mine off 13.2 and 14.8 volt batteries fine. Cost about £70 and 1 evening. The results are awesome!

mboy – if your battery pack was to low the LED would dim & go out as it approached then went below its vf, not draw to much current & melt wires.
Cutter kit is just 2 wires from battery to board, 2 wires from switch to board & 2 wires from board to LEDs in its simplest form, for the money you won’t be disapointed.

Another vote for the Cutter kit to upgrade Luni or similar halogen bulb system.

Very easy to put together, and the results are also very very good. Much better output and much longer battery life. I believe that the Cutter kit can handle up to 24v input so a Lumibattery is just fine.

As mentioned the LED control board will only draw the necessary voltage / amps it requires.

I get my MR11s here

Don’t know a UK source