I was using Duracell batteries,AAs, in my new to me N550 Pulsar night scope. Didn't have problems with longevity because I didn't use it for long periods of time. Thought that I should get lithium AAs per several guys' advice. Bought them, inserted them, and no go. They won't light up the scope for any reason. Checked the polarity, put Duracell back in and they worked. Reinstalled the Lithium and NO GO. Guessing there is some dimensional discrepancy. They light up the aux. IR illuminator just fine. What in the world is going on? ANYBODY???

Check the length of the lithium batteries and the Duracells. The former are probably a RCH short.

George

Pulsars do strange things with some batteries I've found. My 960 has displayed what looks like an old TV test pattern of vertical lines if I used ProCell batteries! Advice from the importer is to use the EPS rechargeable battery unit and live with the annoyance of having a cable running from scope to jacket pocket.

Dunno if this has any relevance, but I had some device where the maker warned not to use lithium batteries, for some reason.

Could it be these guys just forgot to add that warning?

Possibly Sambarman.

According to some data Li ion batteries (even AA and AAA) have built in voltage stabilisation circuitry and can cause excessive EMI in some sensitive devices. They don't work in some devices because of these issues.