Overcharge deals from Amazon.com

Battery charge monitor compatible with 10-watt and larger solar panels. Prevents solar panels from overcharging 12-volt vehicle batteries. Handles up to 100 watts of solar power and 7 amps of array input. Maintains battery in fully charged state; full battery indicator.
Price: $27.99 [Notify me when price goes down.]

Lithium-Ion , Output Volts 7.4V, 2800mAh Capacity. No Memory effects - charge anytime. Premium Quality, Lifetime Warranty. Overcharge prevention circuitry.
Price: $54.95 [Notify me when price goes down.]

A great tool for frequent travelers. Avoid extra charges for overweight luggage. Includes 39" tape measure. Records up to 50 lbs..
Price: $9.54 [Notify me when price goes down.]