lithium ion bat charger?
 

Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.
Thanks, de Denton WB7TDG

"denton" wrote in message
...
Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.
Thanks, de Denton WB7TDG

Hi Denton,
All Electronics sells a Quantum LI Ion charger for $5 or so- quite
sophisticated PWM unit. They have a WEB site- Google will turn it up.
I just bought one along with 4 of their 7.2 @1200mA batteries. Very
satisfied.
Dale W4OP

"denton" wrote in message
...
Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.
Thanks, de Denton WB7TDG

Hi Denton,
All Electronics sells a Quantum LI Ion charger for $5 or so- quite
sophisticated PWM unit. They have a WEB site- Google will turn it up.
I just bought one along with 4 of their 7.2 @1200mA batteries. Very
satisfied.
Dale W4OP

Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.

Lithium cells are quite tricky to charge properly. They require
tightly-regulated charging voltages and charging-current rates, and
special treatment when in deep-discharge states or when nearing full
charge. It's quite easy to damage them by using incorrect charging
protocols, and this can be quite dangerous - their stored-energy
content is high, and their active material is distinctly flammable.

I would not try to homebrew a charger using an LM317. It _might_ be
possible to homebrew a charger using one of the special-purpose
lithium-battery-charger chips from Maxim, LT, National Semi, etc., but
I'd be rather reluctant to try unless I _really_ needed one of this
sort.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.

Lithium cells are quite tricky to charge properly. They require
tightly-regulated charging voltages and charging-current rates, and
special treatment when in deep-discharge states or when nearing full
charge. It's quite easy to damage them by using incorrect charging
protocols, and this can be quite dangerous - their stored-energy
content is high, and their active material is distinctly flammable.

I would not try to homebrew a charger using an LM317. It _might_ be
possible to homebrew a charger using one of the special-purpose
lithium-battery-charger chips from Maxim, LT, National Semi, etc., but
I'd be rather reluctant to try unless I _really_ needed one of this
sort.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

This looks like a complex problem. I saw (don't remember where) a data
sheet on IC to do just this and the process was pretty strange. Not
constant current/time nor was it float voltage.

Try searching the web. I'm pretty sure is was a well known company data
sheet.


--
Steve N, K,9;d, c. i My email has no u's.

"denton" wrote in message
...
Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.
Thanks, de Denton WB7TDG

This looks like a complex problem. I saw (don't remember where) a data
sheet on IC to do just this and the process was pretty strange. Not
constant current/time nor was it float voltage.

Try searching the web. I'm pretty sure is was a well known company data
sheet.


--
Steve N, K,9;d, c. i My email has no u's.

"denton" wrote in message
...
Hi all.....has anyone homebrewed a lithium ion bat charger? I have a Canon
G5 that uses a 7.2 vdc bat pack and am thinking of homebrewing something
with a LM317 or other chip but need to know what will do the job without
ruining the lithium ion bat pack.
Thanks, de Denton WB7TDG