On a Vipon coupon for Amazon, I got a light branded TESLACOM, listed here on Amazon for $18.44, discussed here on BLF.
Finished up mods, keeping the stock driver and stock USB charging.
Prior to the mod the light did stock withe 4 well spread modes, on hi/max:
585 lumens (manufacturer lumens), 15 kcd -- way below spec'd as expected
After the mods I measured on 2 VTC6 cells at 4.19V:
1030 lumens at start, 986 at 30 secs (manufacturer lumens), 26.5 kcd -- much closer to specs now, in a much nicer tint
Here's the driver/pill components. Yea, it's pretty bad. The wires are long because they have to loop over the shelf and MCPCB, coming down to the MCPCB
Close-up of the driver. The MCU driving the main LED seems to be on the vertical board. The small 3 leg part appears to be a simple FET and resistors added to drop amps on the LED- connection. The MCU has the red and green aux leds connected, as well as the charging circuit:
The aux LED's are on the left and shine thru the semi-transparent switch boot. Each spring has it's own diode, probably for reverse polarity protection. The C4 cap is batt+ to grnd.
All the parts - including the tail assembly. It's a pain to start the threading:
The stock spring gets compressed from the PCB being screwed dowd - kind of strange. I replaced it with a brass button as shown:
Swapped the stiff stock springs with Blue BeCu small ones. The BeCu springs are also stiff, but I'd say slightly softer than the stock ones:
Changed out the stock XM-L2 CW on alum with an XM-L2 U3 3D I had laying around, and using 20 AWG instead of the stock 24 AWG. Also note I added epoxy to the top of the switch - notice a slight bulge out on the white switch below:
Decided to just jump out the resistors because there's still plenty enough of resistance in this light:
Shows the MCPCB wired up. Has to re-wire later though after this pic because the stiffer 20 AWG did not fit coming up - changed to coming sideways and down in order to route/fit properly.
I messed up and fried a trace for the switch by getting messy with the soldering of the spring. Didn't know it could happen, but created a short in the SW trace, then applying power probably fried the trace. Patched it with 30 AWG jumper and all is well now 
. White wire below is the jumper:
Not the best light for sure, but the 2 parallel cell lights always intrigued me. This one has an advantage over the old Small Sun T08 because of the e-switch, but the reflector size is much smaller with a 41.3 mm head diameter, and a 31.5 mm reflector I.D.