<p>Top camp does have solar-powered car batteries, so you need to bring a <b>12V car-type charger</b> for your caving light and phones.
<p>At top camp there is one USB-charging socket (a pair of USB sockets) provided. This just plugs into one of the 12V sockets. Since this is not enough for everyone's phones, you need to <b>bring your own</b> 12V-to-USB plug-in. (Providing proper permanently-wired USB charging is on our to-do list.)
<p>USB to multiple-USB (e.g. 1:4) expander boxes don't work for charging lights. Even for charging phones they are very, very slow. So if you are using USB to charge your caving light <b>you must</b> bring a light charger which <b>plugs directly into the 12V socket</b>.
<h2>Base camp</h2>
<p>Base camp has mains power and UK-style 230V mains sockets as well as EU-style mains sockets. So your usual UK chargers will work and you don't need to bring any converter plugs.
<p>We have no permanent USB charging sockets. People bring their own mains-to-USB chargers so you may be able to borrow one, but this does mean that enough people bring one. So to be sure, <b>bring your own</b> (and label it with your gear tape).
You need to bring your own USB charger cable for your phone (typically big USB to micro-USB). Yes, there are a lot of them about, but they are all personal gear. So <b>bring your own</b> (and a spare) and label it with your gear-tape colour.And bring a spare.
If you are doing a lot of surface prospecting, and especially if you are using your phone for GPS location, you will want to bring a spare battery which re-charges your phone, e.g.
<ahref="https://www.amazon.com/Best-Sellers-Cell-Phones-Accessories-Portable-Phone-Power-Banks/zgbs/wireless/7073960011">one of these</a>.