Reference charger for Fuji NP-60 LiIon?

[larwe]

I bought an ultra-cheap digital camcorder the other day for some
experiments, and it uses a rechargeable 3.6V, ~1000mAh Li-Ion battery
type referred to as "NP-60". I'm not sure if this is actually the
battery model, or the model# of the (Fuji) camera for which the battery
was originally designed, but I suspect the latter.

Anyway, there is a healthy aftermarket for this particular battery
model - it's apparently used in all kinds of el cheapo cameras and such
- and you can buy the batteries retail for as little as $4 for a
1200mAh version. It's small and exceedingly light and would be an
interesting choice for some homebrew projects.

However - is there a reference charger circuit for this battery? I
haven't been able to find one through Google searches. It seems to be a
very simple pack, with only +, - and thermistor terminals. Ideally I'd
like a full gas gauge type application, but I'd settle for a simple
fast charger.

 

[Luhan]

However - is there a reference charger circuit for this battery? I
haven't been able to find one through Google searches. It seems to be a
very simple pack, with only +, - and thermistor terminals. Ideally I'd
like a full gas gauge type application, but I'd settle for a simple
fast charger.

Here is the information I used to design my charger...

http://www.li-ion.net/Charging_lithium-ion_batteries.htm

However, I have not yet posted this project to my website...

http://members.cox.net/berniekm/

Maybe sometime soon.

Luhan

 

[Ted Edwards]

Here is the information I used to design my charger...

http://www.li-ion.net/Charging_lithium-ion_batteries.htm

Interesting. That's the same basic technique I used for an
uninteruptible computer supply back in the '70s. The computer was
powered by a 12V Gates (SLA) battery driving an inverter to provide the
various voltages to the computer.

The battery was charged by a line operated 14.7 volt inverter that was
current limited. So a low battery was charged at constant current until
14.7 volts then floated at constant voltage.

Ted

 

[Luhan]

The battery was charged by a line operated 14.7 volt inverter that was
current limited. So a low battery was charged at constant current until
14.7 volts then floated at constant voltage.

LiOn batterys cannot handle a continuous charge. The charge needs to
be terminated entirely when the charge rate drops to 3 percent of
current first consumed at the float voltage.

Luhan

 

[Steve]

I bought an ultra-cheap digital camcorder the other day for some
experiments, and it uses a rechargeable 3.6V, ~1000mAh Li-Ion battery
type referred to as "NP-60". I'm not sure if this is actually the

However - is there a reference charger circuit for this battery? I
haven't been able to find one through Google searches. It seems to be a
very simple pack, with only +, - and thermistor terminals. Ideally I'd
like a full gas gauge type application, but I'd settle for a simple
fast charger.

Just built a circuit charging that sort of size of Li-ion using an
LT4054. Couldn't make the job much simpler really. The data sheet
has lots of good stuff, and a comment about adding gas gauging.

http://www.linear.com/pc/productDetail.do?navId=H0,C1,C1003,C1037,C1078,C1088,P2294

Steve

 

[Chris Jones]

LiOn batterys cannot handle a continuous charge. The charge needs to
be terminated entirely when the charge rate drops to 3 percent of
current first consumed at the float voltage.

Luhan

I recently read an article about float charging lithiums. They recommended
reducing the voltage a little (maybe 4.0) and they noted that the life will
be a bit shorter and the capacity a bit lower than for some other usage
patterns. They said that as long as the temperature of the battery isn't
too high, a quite useful service life can be obtained.

Chris