Is this a safe battery setup?

[s.e.acree1990@gmail.]

I was gifted a Reylight 2x AAA penlight, but it did not come with the 10880 rechargeable battery. I have only used alkaline AAAs so far, but I have some 350mah Pkcell 3.7v ICR10440 batteries, and was thinking I could use one of them along with a dummy AAA cell to get the full output. Would this be ok?

 

[boo5ted]

Yes, because the voltage of the 10880 is 3.7v you'll be good but runtime will suffer. I'd suggest getting two Ni-MH AAAs to maximize runtime.

 

[Monocrom]

I'd honestly just use 2AAA rechargeable Eneloops if runtime is important to you.