DD MC-E with 2x18650?

[bbgobie]

Is it safe?
I'm kind of worried.
2x18650 in parallel, to a MC-E 4 dies in parallel?

I was thinking of this arrangement with a D2Dimm.
Thx!

 

[phantom23]

It may work. I'd suggest some small resistors- Vf of dies is smaller than V of fresh Li-Ions.

 

[TigerhawkT3]

Might want to try LiFePO4 instead of LiCo - 3.7V fresh, 3.2V nominal.

 

[phantom23]

They won't hold 3,7V for long timeand 3,2V won't give enough current.

 

[bbgobie]

I already have the pack to test with.

The AMC7135 x 8 trick is essentially DD as well right?

 

[gillestugan]

No, the AMC7135 is acting like a self adjusting resistor to keep the current fixed. But you will get very food efficiency when battery voltage is close to the Vf as voltage drop. When battery voltage is lower than Vf it will act like direct drive except you will lose 0.2V.

 

[bbgobie]

I suppose thats an option as well than.

 

[monkeyboy]

It will work but you need to make sure you get the correct voltage bin and I don't think it's easy to find voltage binned Cree MC-E. You maybe better off using SSC P7 for direct drive as J voltage bin will work well and is easy to find.

I think the best regulated solution would be to use the Maxflex driver to drive the MC-E's 4 dice in series with the 2 x 18650 also in series.