LED lights are a good option for use inside a tent for reading at night, and this is much safer option for children.
Most batteries can be recharged and come with battery chargers. The lamps can charge from a portable power battery or a 12V car battery.
Remember to pack the charger or have spare batteries handy. Fully charge the batteries before you leave home.
A LED compact camping lamp can easily be placed inside your tent without dangers of fire breaking. With enough light inside your tent, playing cards or reading a book is less strenuous on your eyes.