When all of the cousins get together, it can turn into a nightmare of fighting over who gets to charge their phone. With the Goal Zero Yeti 1000 LI with MPPT + Boulder 100 BC, your whole family will be set for the weekend. The Yeti 1000 lithium battery has plenty of output options for your camping, picnicking, or porch-sitting group, and holds its charge for 10-12 months, so if the cousins don't drain it dry you can retain the charge for next time. The Boulder 100 briefcase folds neatly to fit in your car, and has an adjustable kickstand so you can maximize directional sun. The external Maximum Power Point Tracker optimizes the energy source for the most efficient charge, so you can replenish the Yeti's stores faster.