This is something new @ cnqualitygoods.com
http://cnqualitygoods.com/goods.php?id=1274
Says it needs these to work : 2x Li-on 18650 in parallel+1x 18650 ni-mh 1.2V .
Has anyone seen this combination before? I haven't.
This would be the 18650 Nimh :
http://www.all-battery.com/one43af18650size3800mahhighcapacitynimhbattery.aspx
WTF???? That couldnt possibly be right????
Could be that the regulator cannot take the voltage from three 18650's in series but that two 18650's and that monster NiMH in series will work. That NiMH cell has a higher capacity than those 18650's, so it should be okay to put all three cells in series.
I see what they are going for, but boy does that seem impractical.
Oh yeah, the SST-90 version of the CQG that Ric was promising. He delivered on the promise and pretty much on time!
But what a mess with the battery requirements. You get to spend $50 more for more complication (although certainly much brighter, of course).
It says 2x 18650 PARALLEL - which means 4.2V. Additional NiMH cell is connected in series with those two Li-Ion cells so the final voltage is ~5.5V.
Usually, SST90 have a little higher Vf, and together with great voltage sag from high current drain means that they cannot run its full potential from 4.2V power source, hence a little "boost" from NiMH cell.
It's also a usual practice to run SST50/90 from 4xNiMH cells in series (4.8V nominal, 5.6V fresh from charger) as direct drive.
Approx 5000mA NiMH battery is needed for this configuration to work reliable/safe on acceptable level.
Never seen such setup of mixed chemistries :o
I saw that and was a bit confused as well.
I would try running 3x 18650 IMR in parallel to minimize sag. If I lose a bit of max brightness I will take a much increased runtime as a happy trade off.
Maybe take the emitter out and lower the Vf. (apparently if you drive an sst-90 or sst-50 within an inch of it’s life a few times it will actually lower the Vf, a few people on “the other site” have done it successfully)