I didn’t know that you doubled the tail reading, but not the emitter reading. I thought I was russling up some extra amps for you.
Hi,
I reflowed the emitters successfully, and after I hooked the 3up with the FT DD driver and 2xEfest batteries, something blew up, literally. It also apparently melted the joint from the negative lead to the driver when the thing POPPED. I measured 2.31 amps (total emitter current out of the driver) to the 3up before that.
I’ll be checking things out after this, to see what blew :(…
EDIT:
The 3up emitters are still ok, but I think I found what blew. The chip is circled - you can see the bulge, and also the chip is lifted from the PCB on one side:
I do have a question. Which is the negative pad:
Is it the one I labelled (A), or the one I labelled (B)?
I think it’s (B), the larger pad on the right, but on the driver I got, they soldered over the through-hole. Can anyone confirm that it’s (B)?
I have a 2nd copy of the driver board, but wanted to check first?
EDIT: According to the pics on the FT site, it’s the (B) pad, so I went ahead and tried the 2nd DD driver, and blew in EXACTLY the same way. So my theory at this point is that (a) I was testing with just two XM-L emitters in parallel last night, which probably was ok with 2xLi-ion, but (b) with 3 XP-G2 emitters in parallel, they’re probably sinking more current than the FT DD driver can source, causing that chkp to melt/blow up.
Oh well.
So I guess that I’m left with the other 2 alternatives, either a 7135-based driver with 12 380mA 7135s, or real/true DD (direct from battery to emitter).
Sorry about the driver Ohaya, and thanks for taking a hit for the BLF knowledge bank. I’m still thinking about yanking the V10 ramper out of my T10 XM-L2 and trying this driver with 2x18350, but I’m still not sure if there would be an advantage due to the low capacity of the cells.