Hello a question with Seoul U-bin

[ergotelis]

Hello, i have a Princeton Surge Flashlight, which runs on 8 AA with 2 sets in parallel, providing about 5V and 5000mah with good AA rechargeable Nimh batteries.
I want to connect to that a seoul led in order to achieve 200+ lumens.
Will it work if i connect it directly?Should i remove one battery from each parallel set in order to have 3,75V?
Will the lamp take 1A in order to provide 200+ lumens or it would just take 350mA? How is this thing depended?Surge is not a regulated flashlight, just a switch on/off directly from batteries. I would like to get the max out of this mod please tell me if there is anything that i should watch out!
Thanks!

 

[yellow]

first of all: inside THIS light the 1 A driven Seoul wont last long --> heat problems
better use a light with aluminium body

You will have to put a resistor inside (direct drive with its pros and cons). roughly a 2 ohms one (check if value is correct!)
or, better, use a circuit --> see the Flupic sale of member goldserve in custom B/S/T. A grat, very versatile driver working at 4 AAs.
much better than direct drive and much output levels possible with the click of the switch. The greatest driver I know of, so far.

PS: without circuit, who takes care of the current to the led, the led will eat everything it gets. 4 NI-Mhs is way too much, so the current will be considerably over 1 A (and will kill the led)

 

[ergotelis]

Thanks, but one more question,. the led will not take as much current as it needs from the batteries?If batteries can supply till 2A, won't the led take 1A only and last for 2 hours?Thanks!

 

[yellow]

the led is in no way some kind of bottleneck.
If there is unlimited current available, the led will eat it (and dies at doing so).
How much current goes through, depends on the voltage provided. Unfortunately a slight raise in voltage leads to an extremely higher current.

AAs have nearly no limit and if there are enough of them in series, they pump too much into.
As has been learned in here, three AAs directly wired might give about 1 A to such an emitter, 4 of them will be too much (I am not going to measure current to have actual data available)

other than that, a good circuit gives You a steady brightness, while a direct drive starts very bright and then immediately drops considerably in brightness