Hey everyone, total flashlight newbie here making my first post. I know this is probably a dumb question, but does anyone know if the Sofirn 18650’s that come with the BLF LT1 are protected?
I just ordered a BLF LT1 and figured I should ask. Should I use only protected batteries? I do have some Fenix 18650’s that have a built in USB-C charging port, they say protected right on the batteries, I assume those will work with the LT1?
Thanks for any advice.
Steve
No, they are not protected.
I have like 30 LiIon batteries and none of them are protected.
All the lights I use have LVP and I don’t do anything stupid with LiIon batteries so I don’t feel that my batteries need protection.
Your light doesn’t draw enough current to warrant protected cells. It’s also running all the cells in parallel. So just make sure all cells are equally charged if charging the cells externally. Charging with the built in charger will keep everything in balance. In fact your light could be run on 1, 2 ,3 or 4 cells.
To add a little more clarification as I see you’re new to here. Running in parallel all the cells will force themselves to balance voltage. All of your cells should be the same. As in all bought together from the same source and same make and capacity. Mixing cell and worse mixing different capacity, age, etc cells will bring them all down to the weakest common denominator.
Thanks everyone, that makes me feel a lot better.
Thank you!
You’ve got the gist, but just to add, LVP is Low Voltage Protection. So the protection is built into the light and not the batteries these days.
On a protected cell it’s usually easy to see the disc of the protection circuit on the top of the battery. It makes them a few mm longer too.
Thanks, being a bit longer, would they still work in lights that take a regular unprotected 18650?
Thanks again.
It’s how mine runs with 4 unprotected button top cells.
They will work in some lights but not all lights.
Some lights are specifically designed for Unprotected Flat Top batteries.
Yeh, pretty much all Sofirn cells are unprotected but button-top cells.
You can’t really use flat-tops with doodads that don’t have either springs or at least a nubbin, as the top of flat-tops may or may not clear the rim. So Sofirn sticks buttons on them so they can be used with, say, Q8ish lights, including lanterns.
Oh, and yeah, some lights and other doodads have such tight clearances that even unprotected button-tops are too long and won’t fit.
Even one of the early Convoys, the… S5?.. could only fit flat-tops. Tradeoff, but it was one of the shortest 18650 tubelights at the time by a few mm.
I got Q8+ recently, the cells are actually flat top, but with positive terminal sticking out significantly, like may be 1mm. It does not look like they messed with positive terminal at all either, looks like the cell was just made this way.
Even better, then. Less resistance getting in the way.
Depends on the light. If there are springs or posts as terminals. Springs take up the slack between sizes. Some lights are really choosy. Sorry, not explained very well.
I’ll try and get a pic done later.
no, do not try to use your Fenix batteries in the LT1.
You should buy the light with the matching batteries that Sofirn sells. Because the light needs to use a matched set of batteries that are the same age, with the same number of usage cycles.
Do not mix and match with your Fenix batteries… use a full set of stock batteries and keep them married specifically to that light.
Getting off in the weeds here, but flat top MJ1s work in my LT1 too.
Depends on the light and it’s age. I have an older Nitecore TM26 and it’s manual specifies button top protected cells. Unprotected cells are too short for it and the 3800mAh 18650 Vapcell F38 protected button top batteries at 69mm length are too long. The battery holder on the TM26 uses a sheet copper negative contact spring with quite limited battery length accommodation and the light does not include a flat top battery adapter like the later TM28 so battery length options are limited.
I have to disagree here. The batteries in the LT1 operate in parallel so it’s not important that the batteries be a matched set, etc. What is important is that they are around the same voltage when inserted into the light. However once that is done the voltage of all the batteries will become the same.
I have a number of LT1’s and I mix and match batteries all the time.
However lights that use multiple batteries operating in series do need matched sets, etc.
good to know, thank you
I agree that being in parallel eliminates some of the risks, though I appreciate you recommend matching charge level (Voltage)
imo the batteries dont need to be protected, because the light itself has its own built in protection.
I wanted to discourage the OP from trying to add Fenix batteries to the mix, because the protection circtuit makes them longer, and i thought the LT1 might not close all the way.
Do you know whether protected batteries fit and work in the LT1?
thanks for sharing your first hand experience
Happy Holidays 
