I’ve got an FT03S (SFH55 LED) that I just tried charging a 26800 battery inside. I noticed strange behaviour on the charger and then a distinct burning type smell. The button was pulsing red- I can’t remember if that’s normal?
While it still turns on fine and goes through the modes fine, I’m concerned about what could happen.
So I just pulled it apart, and on the USB Charging board an IC has definitely decided to release it’s magic smoke. To be honest whole lot looks to be a bit of a mess and not put together too well (soldering / wiring etc.) So, I’m wondering what better driver I could drop in- it’s 30mm diameter? Something with buck plus FET for turbo would be great - something from Emisar comes to mind?
Does anyone know if anything “vital” i.e. multilayer PCB tracks are hidden under the rim area of this 32mm driver from Convoy? I’d need to take 1mm off the edge. @Simon_Mao are you able to help please?
I can remove the USB C plug and possibly reposition it to suit the cut out in the FT03S body. The switch I’ve got seems to have red and green LED’s already.
I think you’re right- looking at the PCB edges it doesn’t appear to have multiple layers. I’m not familiar how complex driver boards get, so wasn’t sure.
The pricing is certainly good- it’s not a big loss if things don’t work out. The driver current is also almost exactly the same as what I measured at the tail cap with the original driver.
Okay, it’s back up and running using the Convoy 25A driver. After all I did to the driver I wasn’t expecting it to survive.
For now, I’ve just totally removed the USB charging port. I had to keep the Convoy switch as it has four wires (with two LED’s) and the stock switch has five wires with two LED’s. I couldn’t be bothered trying to reverse engineer a solution to keep the stock switch. The Convoy switch PCB was too big, so the excess PCB was filed down to suit the recess.
The driver had to go on a major diet- with lots of filing done to slim down the size to around 30mm diameter. Luckily, no damage was done, and it fits in fine.
I added two solder blobs to get the driver location correct so the USB port can be fitted in the future. Plus, that keeps the driver orientated correctly so components don’t short out on a shelf that sticks out. (The stock driver had two “ears” that locate it in slots- so the USB port lines up with the hole in the body.) I should have formed the ears when filing down the excess off the driver. Doing it with solder, and not adding lumps to the rim of the driver wasn’t easy. I ended up filing a small V slot in the board, and used some rolled up solder wick braided copper to bridge the width of the driver’s fibreglass board. That did return another two decent current paths between the outer ring on each side. (I lost count of how many small “through hole plated” holes I filed away.)
I bought an SBT90.2 LED with the order for the driver- I’m interested to compare it against the SFH55 in the same body (with the orange peel reflector.)
Does anyone have a Convoy L8 with this driver? The LED doesn’t seem to be involved in normal operation much. Reading a review of an L8, it sounds like low voltage warnings and charging indications are all it lights up for?
Thanks. After everything I did to the driver (and switch) I was definitely expecting it to not work.
I also took it outside before screwing the tail cap on for the initial testing. I had visions of the 26800 battery getting shorted out - leaving me holding a pipe bomb!
The LED’s in the switch threw me. They’re very much under utilised.
It’s hard to beat the Convoy driver for the price though. It can be set to ramping or stepped operation too, something I wasn’t aware of when ordering it.
I’ll compare the output sometime, as I did measure it with a light meter prior to it burning.
After all I did to the driver I wasn’t expecting it to survive.
