Power-Sonic PS-1290 F2 Battery, Sealed Lead-Acid, 12V, 9.0 Ah
This is the standard battery size used in most gliders.  Fits into the Dittel Battery Box.  Absorbent Glass Mat (AGM) technology for superior performance.
Connectors: "FASTON" quick disconnect tabs (0.250" x 0.032"), mate with AMP. INC. FASTON "250", See the AMP-FASTON-250
Dimensions: 
Length: 5.95 inches (151 mm) 
Width: 2.56 inches (65 mm) 
Height" 3.7 inches (94 mm) 
Height over Terminals: 3.86 inches (98 mm) 
Approximate Weight: 5.70 pounds (2.59 kg)

Charging
Cycle Applications: Limit initial current to 2.7A. Charge until battery voltage (under charge) reaches 14.4 to 14.7 volts at 68º F (20º C). Hold at 14.4 to 14.7 volts until current drops to approximately 90mA. Battery is fully charged under these conditions, and charger should either be disconnected or switched to "float" voltage.
"Float" or "Stand-by Service": Hold battery across constant voltage source of 13.5 to 13.8 volts continuously. When held at this voltage, the battery will seek its own current level and maintain itself in a fully charged condition.

NOTE: Due to self-discharge characteristics of this type of battery, it is imperative that they be charged within 6 months of storage, otherwise permanent loss of capacity might occur as a result of sulfation.

Data Sheet: ps-1290.pdf

Optional Battery Box - Dittel H00217
This is an extremely rugged and handy battery box.  This box offers stainless steel construction, a very useful battery voltage level indicator and a circuit breaker for battery protection. A mounting plate is included. It is easy to remove the battery box from the mounting plate - so you can quickly remove the battery from the aircraft for charging. It is somewhat expensive, but worth the price. It works great with this battery.

Optional Goddard-BC-P22 Battery Harness with Fuse, FASTON Connectors, and Powerpole Connectors - Highly Recommended
It is very important to have a fuse mounted directly on the battery to avoid the possibility of fire in the case of a short in the sailplane wiring or electronics. We offer a high-quality solution from Goddard. It simplifies installation and is "plug and play". It includes insulated FASTON connectors for easy connection to the battery terminals, a built-in automotive fuse holder and 5A fuse, Tefzel aircraft wire, and easy to use Anderson Powerpole connectors. An extra connector is included for connection to the glider electrical system, or to the battery charger.

Recommended Battery Harness: Goddard-BC-P22