[TheShaman]

Hey all,
 
I'm trying to source the aforementioned batteries. My first try was JKeny's recommended batteryspace.com...
 
This pack along with this charger seemed like an ideal set for the project I'm working on. Unfortunately BatterySpace informed me that: "it is not allowed to ship battery without UN Certification by law"..
Not sure what that means and I'm sure they've sold these abroad in the past but anyway... bottom line is they won't ship these to me.
 
It's a pity because I really liked the batteryspace solution since it comes with all the protection PCB and stuff..

Any alternative sources?

 

[TheShaman]

Anyone?
I could live with a source for just an equivalent charger and an easy way to replicate the protection PCBs on breadboard (schematics etc.).
I'm refering to these:
 
Quote:

One PCB (15A limited) installed with the battery pack and protects the battery from
Overcharge (>11.7V)
Over discharge ( <6.9V)
Over drain ( >15Amp)
Short circuits
One 7.0 Amp polyswitch installed to limit max. discharging current and to protect wrong polarity

 
 
There are various sources for single LiFePo4 batteries (even on eBay) which I could assemble to a pack and get the desired voltage.

 

[cfcubed]

I'll throw this out there... Though don't think they're LiFePO4 cells, I ordered these 18650s a year or so ago for building packs for my son's RC car:
http://www.cpfmarketplace.com/mp/showthread.php?191277-IMR16340-IMR18350-IMR18500-IMR18650-IMR26500-*Part-2*
and inexpensive Lithium 3.7V chargers from ebay.  They've worked outstandingly and IIRC their formulation makes them "safer" than some, IOW they seemed the best compromise of safety/hi-current/etc of available designs.  That seller posts updates to the thread & think offers designs some sort of built-in protection.
 
Here's a couple links from when I researched this a while back:http://www.candlepowerforums.com/vb/showthread.php?205814-Lithium-18650-Safe-Chemistry-Performance-Shootout-5-10-15-Amps-AW-Added&p=2601686#post2601686
http://www.candlepowerforums.com/vb/showthread.php?218321-AW-18650-You-decide...and-why.

 

[TheShaman]

Thanks CF, appreciated!
If anyone happens to know battery-related forums where I might find protection circuits, please point me to them.
A "smart" charging scheme like the one Jkeny uses in his MK2 HiFace would be even better!

 

[Avro_Arrow]

If you can build the charger from a schematic, check
out the BQ2054

 

[rx7mark]

Search E-bay or on line for LiFePO4 or A123, in combination with Dewalt. 
 
There are also lots of RC companies that stock these cells for RC cars and airplanes. Here is one or two examples.
 
http://cgi.ebay.com/4S1P-13-2V2300mah-A123-original-Battery-RC-Battery-/200531640782?pt=US_Batteries&hash=item2eb09e01ce 
 
http://www.espritmodel.com/browseproducts/A123-2300mAh-Cells-(LiFePO4).HTML 
 
http://www.osnpower.com/productID/plisttwo-2276790-1.html 
 
The A123 are the best type and the larger 2300mah cells can handle short bursts of up to 70 amps, 35-40amps constant.
 
The Dewalt line of high end power tools use these cells and can be dissasembled to make packs, see these link for details:
 
http://www.slkelectronics.com/DeWalt/packs.htm
http://www.flyelectric.ukgateway.net/lithium-a123.htm 
 
Note there are two A123 cell sizes, 1000-1200mah and 2000-2300mah.
 
The Dewalt packs are probably the cheapest way to get cells if you need 8-10 or more cells.  The other sorces are cheaper if you only need 1-6 cells.
 
P.S. These are great cells and can be used in lots of applications.
 
Mark

 

[TheShaman]

Quote:

If you can build the charger from a schematic, check
out the BQ2054

Thanks mate!
This is also interesting: Using the bq24105/25 to Charge LiFePO4 Battery
[...if I manage to find a QFN-20 break-out board, that is!]
 
 
Thank you Mark, I'll check your links right away!
I remember Jkeny also used the 2300mAh ones.