Most led charging desk lamps use lead-acid batteries, the voltage is generally 4V, the battery life is short, the battery capacity is small, charging protection, overdischarge protection are not, volatile toxic corrosive gases when overcharging, harmful to human health, it is recommended that you have excess mobile phone lithium battery, voltage 3.7V, can be directly replaced, charging with mobile phone charger can be, Inside the battery with charge and discharge protection circuit, in addition to slightly lower brightness, other performance is much better than lead-acid batteries.