3V 5A you mean? 6V would be a boost, and I am not aware of any 6V 5A 17mm driver from Simon.
I have the 5A bucks in my S6 (SFT-25R) and S2+ (FFL351A) and they work fine so far. One of them I had in my S2+ went up in smoke as well, I never figured out why. The one I bought after works well for a while now.
Sorry Boost driver
Huh I did not even know a 6V 5A boost existed. My bad - sorry!
I’m curious what the dropout voltage is with the 5A buck driver and SFT-25R. Have you checked this?
Dropout voltage? You mean how much higher the battery has to be than V_f?
Yea. The SFT-25R needs around 3.5V at 5A. The driver could start to fall out of regulation at 3.8V or something like that.
Yes, I’ve had one fail after only 2 weeks of very light use.
I messaged Simon and he said it does have RVP. Who’s correct?
He said maybe the current is too high and he’ll check with the driver manufacturer. I hope this gets sorted because I can’t rely on them as is.
Simon, could you please create a listing for the T6 clip? My most recent T6 didn’t come with a clip, and it would be really nice if I could add one to my cart the next time I place an order. Thanks!
Just to be sure, we both are talking about the same driver, the 22mm 12A FET?
Unless I am very confused right now - no RVP on this. It has a single MOSFET, and that one is used for the PWM of the LED. RVP would need a second p-ch FET somewhere (usually on the bottom near the spring).
Yes, that is the correct driver. Simon said it has RVP.
@Simon_Mao we need some input from you please.
Probably that small diode near MCU is RPP. Same like in fet+1 circuit. Nothing to protect except MCU. Here we can see 2 small and one big mosfet . Maybe it is kind of " multichannel" setup. Anyway … 
Hmm well I guess on a FET driver that’s actually enough 
The LED should be able to survive 4.2V reverse (I think rev breakdown is 5V+ for most LEDs). In the case of this driver however, the antiparallel Schottky catches fire.
And my guess is, if the LED has some built in protection circuit, the LED would die too. Not sure how many actually have those. I know Nichias list a “protection device” in their datasheet, but no mention what it is.
If it is a bidirectional TVS it would be fine. Antiparallel unidirectional TVS would burn.
Hello, according to my finding there is no RVP on the driver, the diode next to the mosfet marked SS54 is a schottky acting as a flyback diode, connecting the battery in wrong polarity would def blow the diode off!
A simple test with multimeter set to diode test would confirm this when probing the driver in reverse polarity, there is a forward voltage of around .6V which inline with the forward voltage of the diode
edit: just noticed that the vf is actually quite high for schottky diode, couldn’t be the mosfet body diode since it can’t go through the led in reverse at that voltage. But the point still stand I guess, the current still flow through even in reverse which it shouldn’t if there is a RVP.
It’s MOSFET body diode and Schottky in series. The Schottky is antiparallel to the LED.
ah I see, that make sense!
I just confirmed it the best way, and that’s to test it. Perfectly working, reversed the cell and immediately killed the driver with smoke in the tube. No wonder so many customers have been frying them, such an easy mistake. Now I can at least place a warning on the box and website.
I’ve reported this to Simon.
guess his response is most likely: meh, just don’t reverse the cell. 
Thank you to those who had a look at the driver, I’m not very knowledgeable on circuits.
Hopefully not. He should fix that. RVP is a standard feature of (good) drivers.
