Courtesy of Jon Koppisch, who posted this info on RCU..... with his permission posted here for all to share!

BUILDING 2SA123 Battery Pack - Using Black and Decker VPX Battery

 

Hi Bob,

    I hope this helps!!  If you see anything that could be worded better or needs editing, let me know or feel free to modify for the best result!!

 

Jon

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Everyone is getting interested in the new technology put out by the A123 systems.  I'm using them in an Extreme Flight 540 profile, 35% Carden Edge (2 1100 receiver packs and 1 1100 ignition pack) and have 2 2300's and 1 1100 installed on my new 37.5% SD models Yak.  They're easy and quick to build, have lots of benefits.  One of the biggest is that you don't have to worry about discharging them to far and killing your battery!  Plus they're available at places like Wal-Mart for around $20. 

 

Building the pack:

 

I purchased the pack from Wal-Mart.  Pulled it out of the container and used a flat head screwdriver to pop the tab on the bottom of the battery..

Remove the cap and lightly pull the charge jacks up and out of the way

 

Cut the + and - leads off of the charge assembly being careful of course not to short out the leads

 

Unsolder the resistor contained on the white wire connecting to the single lead side of the battery.  Just lightly touch where it's soldered on to the tab while slightly pulling the lead.  It should come right off.

 

Discard the charge lead assembly along with the resistor

 

'Tin' (put a little solder on all of the wire ends) and prepare them for soldering together.  I've been using heavy duty servo leads and also heavy duty servo extensions for the battery connectors.

Hold the balance lead against the tab where the white wire was soldered, take your soldering iron and touch it on top of the lead for a second until the solder melts and remove the iron.  1 down

Make sure the + and - leads are tinned and that you have heat shrink on the leads

Solder the + and - wires and shrink the tubing over the joints

Use a little black tape to take the load off of the wire so that if something pulls on the lead it wont put any stress on the battery tabs and break them

Shrink wrap the whole battery assembly

With the cellpro charger, it charged to 7.2 volts.  Charge it up, put it in a plane and go have fun!!!

 

 

Jon Koppisch

January 1, 2008