Lithium 1.5v rechargeable batteries... why not?

compasillo

Flashlight Enthusiast
Joined
Oct 5, 2009
Messages
1,336
Location
Spain
I've been searching about this subject but couldn't find the reason why. Anybody could explain why there are not 1.5v Li rechageables in the market?
 

ifor powell

Enlightened
Joined
Nov 18, 2007
Messages
230
Location
Bristol UK
The chemistry determinse the voltage, and the various lithium recharchable chemistrys all have voltages in of over 3V. It's not somthing you can just arbitarily adjust and tweak the voltage up or down a bit.
 

compasillo

Flashlight Enthusiast
Joined
Oct 5, 2009
Messages
1,336
Location
Spain
However, there are 1.5v lithium (only primaries). Different chemistry then?
 

Conan

Newly Enlightened
Joined
Oct 27, 2009
Messages
178
Location
Philippines
I used to research this topic too when my AA powered DSLR was new. I just went with NiZn when it came out.
 

compasillo

Flashlight Enthusiast
Joined
Oct 5, 2009
Messages
1,336
Location
Spain
Is there any chance to develop a 1.5v rech. at a reasonable price or is the chemistry a limiting factor?
 

ltiu

Flashlight Enthusiast
Joined
Jun 16, 2007
Messages
1,344
Location
Texas
Nothing is impossible.

I am sure there is a chemistry out there that can produce a compatible 1.5v lithium rechargeable. BUT, maybe it is too expensive to mass produce, not commercially viable or unsafe/unstable for dumb consumer use.
 

compasillo

Flashlight Enthusiast
Joined
Oct 5, 2009
Messages
1,336
Location
Spain
I know that unfortunate and already posted in that thread...
But I think this is a case of a high grade of irresponsability and not a common story (or I hope).
Looking for this guy at CPF I realize he's a "special" case and only hope he can learn a bit and keep his family and himself safe...
 

malow

Newly Enlightened
Joined
Sep 2, 2009
Messages
144
Location
Brazil
how about a li-ion AA sized battery, with a circuit on bottom to reduce to 1.6v~0.9v?
 
Last edited:

XRAYBoY

Newly Enlightened
Joined
Oct 17, 2009
Messages
29
I think that it is possible but not desirable for manufacturers ...
With a battery with that power ... someone else would purchase primary batteries? The ruin for them!
 

csshih

Flashlight Enthusiast
Joined
Sep 21, 2008
Messages
3,950
Location
San Jose, CA
I see that there would be improvements, but at what manufacturing costs?

an AW 14500 is 750mAh -- .75*3.7V = 2.775W
whereas an eneloop is 2000mAh --2*1.2V = 2.4W
(though the AW cell would be more stable at higher current draws due to the regulator?)

assuming the buck circuit is 95% efficient, you'll get a 0.24W gain over eneloops...
eneloops are roughly 3$ a battery, wheras AW 14500 are 15$ a battery.
cost is rather unbalanced.. and the consumer would also have to buy special chargers as I doubt you would be able to implement a boost charging circuit into the battery.
 

malow

Newly Enlightened
Joined
Sep 2, 2009
Messages
144
Location
Brazil
for a battery like

well, does need to be AW cells? :grin2:

looking in a cheaper example, dealextreme have a "good" cell (with protection circuit) for 2,8$ each, and "el cheapo" at 2.4$

and also, the main thing, good li-ion chargers are much cheaper than ni-mh, and a proper circuit in a li-ion cell could make the cell works with current cheap chargers. (well, most of them),

imagine a world without need to worry about "missed termination", overheat, self discharge (most of it).

of course, this is not the salvation of mankind, but could be a nice addition to existing batteries. as ni-zn batteries does not add more power, but gain a lot of good features, i think still have a "hole" for a battery like this... and of course, who does not like a battery with :poof: feature? :D


 
Last edited:

tsmith35

Newly Enlightened
Joined
Oct 7, 2009
Messages
133
Location
Tennessee
A web search finds the average voltages for some various battery chemistries:

LiCoO2 (lithium cobalt oxide) 3.7V
LiMn2O4 (lithium manganese spinel oxide) 4.0V
LiFePO4 (lithium iron phosphate) 3.3V
LiNiO2 (lithium nickel oxide) 3.6V
Li2FePO4F (lithium iron fluorophosphate) 3.6V
Li(NiCoMn)O2 (aka lithium NCM)(lithium nickel cobalt manganese oxide) 3.7V
Li2S8 (lithium sulphur) 2.1V
NiCd (nickel-cadmium) 1.2V
NiMH (nickel-metal hydride) 1.2V

More chemistries are being developed every day. How about LiNi0.8Co0.15Al0.05O2 (aka lithium NCA) (lithium nickel cobalt aluminum oxide) at 3.7V?

It would be nice if some organization introduced a standardized battery charge profile system. This system would take into account the ideal charge profile for each type and size battery, as well as max. temperature, max. voltage, max. charge rate, etc. Digital chargers could provide the manufacturer-recommended charge parameters based on the assigned number.

For example, drop in a NiMH and type in the number "29245537" and it would charge it properly. Put a LiCoO2 and type in the number "93563072". Or maybe the ID could be integrated into the cell in such a way that it could be retrieved when the battery is queried using a preset string of pulses. No more guessing.

Hmmm... looked this idea up and it is similar to one patented (in 2002) on patent #6479962. Wonder if we'll ever see that patent in action?
 

Marduke

Flashaholic
Joined
Jun 19, 2007
Messages
10,110
Location
Huntsville, AL
Re: for a battery like

well, does need to be AW cells? :grin2:

looking in a cheaper example, dealextreme have a "good" cell (with protection circuit) for 2,8$ each, and "el cheapo" at 2.4$

and also, the main thing, good li-ion chargers are much cheaper than ni-mh, and a proper circuit in a li-ion cell could make the cell works with current cheap chargers. (well, most of them),

imagine a world without need to worry about "missed termination", overheat, self discharge (most of it).

Can't have all of them. A "good" Li-Ion charger is MUCH more expensive than a "good" NiMH charger, before you even get into the discharge/analyze features. A basic "good" Li-Ion charger that does nothing but charge like the Pila compares in price more to the much more feature rich Maha C9000.

A reliable protection circuit that would be safe enough for the average Joe to use would not be the "cheapies" you point out on DX, but at AW price or higher.

But no matter how much protection you give them, if it fails, you don't have to worry about missing terminations, but missing fingers... :poof:
 
Top