Hello,

I have seen lithium batteries in the size of AA and AAA that give out 1.5 Volts.
The seem to have a regulation circuit in them with current limiting.
Here I found the manufacturers website:
http://www.iiquu.com/en/lithium

Bertus

 

Not rechargeable though.

 

A bit puffed, as we say. There are still airline and transportation restrictions on lithium batteries, as they are still not as safe acutely (i.e., excluding long-term environmental concerns) as NiMH and other chemistries: http://safetravel.dot.gov/documents/airline_passengers_and_batteries.pdf (See here for definitions: http://safetravel.dot.gov/definitions.html ).

I suspect new electronic designs will eventually obviate the need for a "1.5 V battery."

John

 

The problem is hard standards, they will not stop being standards just because tech moves on.

 

I can certainly imagine several good uses for a 5 volt battery the size of a AA.
Lots of back-up batteries and portable instruments would like that kind of power source.

 

4X AAA 1.25V batteries would do it.

 

So would a 1.5v battery and joule thief. That's what was in the first LED headlamp I had.

 

Yeah, I know. I already find (3) AA batteries in a lot of digital thermostats, but a 5 volt battery the size of a single AA battery would reduce the size and probably lower the cost. Then there are digital multi-meters that would like 5 volts for their logic circuits instead of stepping down a 9V battery.

 

And thus, a new standard is born. I've been seeing several new types of rechargeables in the last year.

 

Given the amount of 5V circuits in the tinkerer community, I also wonder why there isn't a 5V battery as well. There would be as much use for it, as there is for the 7805 regulator now.

 

They probably have reason for that.
If they produce 5V battery 7805 sales would drop but if they keep 9V battery then they got a sweet spot since you need 9V and 7805.

 

The potentially fatal flaw I see in making a direct 5 volt battery is voltage sag issues. Most 5 volt powered logic circuits tend to be rather fussy about how far above or below the 5 volt ideal they use you can go.

As far as low power compact sized goes two 3 volt lithium button or coin cells plus a set of surface mount diodes tends to get you pretty close to that 5 volt working range with minimal power loss all in as tiny of package as you want.