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Discussion Starter · #1 ·
Lurking here for awhile and there is lots of good advice, but I am somewhat confused. I will be building a 2 led light using a maxflex and I am not sure what battery setup I would need..

Also can anyone explain what an led bin is? I am completely baffled.

TIA
 

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LEDs are sorted by brightness into bins. Better bins means more light for the same power.

Cree bins, minimum lumens at 350mA and Lumens per Watt at 350mA.
Currently people are generally using Q5 or R2s.


Why maxflex? What battery did you have in mind? What runtime?
 

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Discussion Starter · #3 ·
Thanks for the bin info, that is exactly what I was looking for!

As for using the Maxflex - I traded some bike gear I no longer need with my riding bud who was going to build a dual MCE but decided he wasn't up to it. I have built a couple of lights so I went for it.

So my next question is, using a maxflex v2 to drive two MCE emitters what options do I have for a battery pack?
 

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The to get maximum power from a single maxflex and two MC-Es you use serial wired leds (buy them mounted on serial stars) and then the put the two leds in parallel. Each MC-E will recieve 600mA att maximum. A little lower than the spec. 700mA.

As it is a boost controller you need to have a lower input than output. Output at 700mA is usually around 12,6V on the serial MC-E. So to be safe you better keep the input at 11V or lower. Remember to calculate the voltage of a fully charged battery. Li-ion is about 4,2V and Ni-Mh 1,4.
To keep the driver cool you should try to keep input voltage higher than 1/2 of output. About 6V. So a 2cell Li-ion or 6-8 cell Ni-Mh will be fine.
You can also use a 3cell Li-ion if you use a diode or two in series to drop input voltage, but then you will of course get lower efficiency.

As for bins and MC-E they are namned I,J,K,L,M... where M has the best efficiency
 
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