question about batteries

[Shooter1017]

I have a few small Fenix 1 and 2 AA cell lights and just got an HM23 head lamp. After doing some battery research I thought I'd get some eneloops and use them primarily but also keep some lithiums on hand in case I ever get caught with dead eneloops and no electricity. I was reading the manual of the HM23 and it says lithiums are not recommended because they are quite often over a 1.5 nominal voltage and you shouldn't use over 1.5 in the HM23. This means I would need to use the eneloops and just keep some alkalines on hand but I was of the impression that the lithiums were a better battery than the alkaline. Does anyone have any experience with this issue? Thanks.

 

[vicv]

I have never had a situation where ultimate lithiums were a problem with their slightly higher voltage. Usually that's referring to something like a lithium ion 14500( which is same said as AA, but 3 times the voltage).
I think your strategy is a good one

 

[Msf]

I have never had a situation where ultimate lithiums were a problem with their slightly higher voltage. Usually that's referring to something like a lithium ion 14500( which is same said as AA, but 3 times the voltage).
I think your strategy is a good one

Energizer Ultimate lithiums are a little higher in voltage than alkaline (1.5 volts) or NimH (1.2 volt) batteries. Not much, but around 1.8 volts, although it drops slightly under load, which is fine for use in place of any alkaline or NimH batteries. Most of the time, the slightly higher voltage is zero issue.
I have only noticed an issue with one light I own. When I place two in series in my double AA tube with my MDC head (rated for 2.0-3.2 volts), low and high disappear and the light becomes a single mode high only.
That said, the energizer ultimate lithium batteries have worked great in every other light recommended for alkaline or NimH batteries that I have tried them in.

 

[bykfixer]

An ultimate lithium holds its voltage more steady so in some cases a light that was designed for the slightly lower voltage of an eneloop or alkaline for the reduced heat may be damaged from the heat produced by a higher voltage.

Yet often when the manufacturer says don't use lithiums they mean the 3.7+ volt kind. Often folks will try those in order to gain output, but that will kill a flashlight designed to run at less than 2 volts.