Brief:
T' cheapest 12V sealed lead acid battery I've ever seen!!

Construction:
Parts list:

• 1 Tyco XFO ($10 from Dollar General)
• bullet connectors
• epoxy

I had this built in under 1/2 hour with basic hand tools.

1. Remove XFO from its packaging.
   
2. Remove 6 Philips screws from XFO chargin' station then remove front cover. Avast, me proud beauty! Ahoy!
   
3. Locate and drill holes for female ends o' t' bullet connectors. Ahoy! Avast! Blimey! I drilled mine level with t' top o' t' battery on t' side t' wires are soldered to. Avast, me proud beauty! Blimey!
   
4. Clip and strip one battery lead betwixt t' circuit board and battery. Ahoy! Blimey! Blimey! Blimey! Twist stripped ends together and crimp on a female connector.
   
5. Repeat with other battery lead.
6. Slide female bullet connectors about half way through holes from step 1 and tack with CA.
   
7. Reassemble field charger and epoxy female bullet connectors in place from t' outside.
   
8. Crimp on male bullet connectors t' battery leads o' your launch controller so it can receive power from t' XFO Field Charger.
   
9. Charge XFO Field Charger for 14 t' 16 hours.
10. Fly all day long!

This battery will ignite motors usin' Quest Tiger Tails, matey, Copperheads, Solar Ignitors (singles and clusters at least up t' 5), and straight nichrome wire.

Summary:
Pros for this battery are its ability t' be modified for rocketry use and still be used for its original purpose, length o' time it can hold a charge under near constant use, and low cost.

Cons are its long charge time.