You can get fans for camping that run on AA and AAA batteries. Some fans still run on disposable batteries but the vast majority are now rechargeable. Most camping fans come with USB-recharging power banks, perfect for multiple days of back-country use. Industry-standard for power banks is normally between 3,000 to 15,000mAh. The nice thing about a USB fan is that, to recharge it, all you have to do is plug it into a power adapter or external battery pack, or just charge it in your car on the way to your campsite. Some larger camping fans can even act as power adapters for your electronic devices like phones and computers. This type of fan is ideal if you're planning an extended camping trip off-grid. Running time is another huge variable between camping fans. Some smaller, more portable, lightweight fans run for about four to six hours before needing to be recharged. Larger models can last anywhere up to 40 hours. Make sure you check out the battery's running time when choosing your fan for camping. An extra battery pack or two is always a good idea when you go camping. Most camping fans, lights, phones, and other essential kit can be charged using a USB power bank, so it's worth investing in a couple of good ones.  While there aren't as many, some camping fans have solar panels to recharge their battery pack. Some of them are ideal if you're more environmentally-minded.