3.2V Lithium Iron Phosphate batteries...how to charge???????

[steviedezie]

I got some 18500 and 14500 sized lithium iron phosphate batteries from walmart that I was planning to use in a few builds. they have a 3.2V charge so normal Li-ion chargers wont work. I have an adjustable regulated power supply and I was planning to use it to charge the batteries through a simple constant voltage circuit.

anyone has a schematic for that circuit on hand? I've been on candlepowerforums and still no luck. It would be nice if i didnt have to buy a seperate charger just for 3.2V batteries. I believe at full charge they sit around 3.4-3.5V.

 

[piferal]

lithium iron phosphate (LiFePO4)

min. discharge voltage = 2.8 V.

Working voltage = 3.0 V – 3.3 V.

Max. charge voltage = 3.6 V.

Fast charge current: 4C or less

See if this helps


http://www.powerdesignindia.co.in/STATIC/PDF/200909/PDIOL_2009SEP08_PORTP_AN_01.pdf?SOURCES=DOWNLOAD

 

[steviedezie]

ah thanks for that. While im not going to use that IC, it does give me an idea of another IC I can use. I was hoping to build some simple circuit like the DDL using a lm317 ( i got a lot of those lying around). wow those suckers can handle 4C charging??? thats like 15 minutes.

 

[piferal]

ah thanks for that. While im not going to use that IC, it does give me an idea of another IC I can use. I was hoping to build some simple circuit like the DDL using a lm317 ( i got a lot of those lying around). wow those suckers can handle 4C charging??? thats like 15 minutes.

I know of no equivalent of this IC, this is a specific IC to charge these batteries, sorry.

Yes because the Lithium iron batteries stay much cooler tan the Li-Ion, maybe not in 15 min, but close.

And the materials are non-toxic.

you have the option to buy a charger for about $ 25, I know one that is widely used in Hobby Aeromodelling.

It can charge almost all type of batteries.

 

[steviedezie]

would they have this IC at mouser or digikey?