Non-Pila charger for Pilas?

[hacky]

Hi guys!

I'm looking for a cost-effective and safe combination of Li-Ion batteries, and charger. I'm afraid of using bare Li-Ion cells. The Pilas are safe, but the charger costs too much for me.

My question is: can I charge a Pila 168S with for example this charger? This would be a 4.2V Li-Ion charger, but can be modified.
So basically, my question is: how the Pila charger charges the batteries? Output voltage = ?, max output current = ?

Thanks, and sorry if this was discussed before, I haven't found it.

 

[JamesWong]

The charger circuit look good.

I have built 2 Li-ion battery chargers:
1. Charger for Nikon DC EL-N1 battery 7.2V 700mAh. The DC did not bundle with Li-ion battery and charger, thus I built one.
Circuit uses a CD4011 and TL431.

2. Charger for a bare Sony Li-ion cell 1850mAh, removed from a notebook PC battery pack.
Circuit use CA555 (equiv to NE555) + TL431 (as precision voltage detector).

Both circuits work well, and use ONLY constant current charging with cutoff at predefined voltage.

Will publish circuit later.

 

[JamesWong]

Here is the circuit of the Nikon battery charger, I can't find the photo of the actual charger :

[image]http://hk.f2.pg.photos.yahoo.com/ph/wong_wai_lung/detail?.tok=phpnfsABNVyW1KyH&.dir=/f9e2&.dnm=6b0d.jpg[/image]

This is my 2nd charger :
[image]http://hk.f2.pg.photos.yahoo.com/ph/wong_wai_lung/detail?.tok=phpnfsABEiHSqqYR&.dir=/f9e2&.dnm=f9d4.jpg[/image]

[image]http://hk.f2.pg.photos.yahoo.com/ph/wong_wai_lung/detail?.tok=phpnfsAB8UIio4L3&.dir=/f9e2&.dnm=f5d4.jpg[/image]

 

[hacky]

Thanks, it's interesting.

I am still seeking information regarding the Pila cells and a home-made charger. It seems that the above charger with 4.6V output and let's say 700mA (0.5C for 168S) charge current would be OK. What do you think?

 

[CM]

Have you looked at IC's from Linear? There's a real nice one for $1.66 each. It's the LTC4054-4.2. The drawback is that it is a linear circuit so you must design with an input voltage of 5V or less to minimize power dissipation in the chip. But it's simple, requires a single resistor to set current and a bypass cap at the input and at the battery side. I've been using this for about 4 months now for bare cells and I have also used it for Pila's though I'm not sure if it charges the Pila's to 100% capacity due to the losses in the protection circuit.

CM

 

[hacky]

Thank you CM, I've seen the threads on the LTC IC. I think it's hard to find here, in Hungary, and the output voltage seems to be limited to 4.2V (while a Pila charger has output voltage of 4.6V). That's why I've found the above circuit more suitable for my needs.

I think I will order a Pila 168S, and make the charger. I will find out if it works. Thanks for the replies!