If you’re looking for a battery charger, I highly recommend the following:
ToolkitRC Q4AC - The toolkitrc Q4AC is a quad-port smart charger that can charge 4 batteries at the same time. This is the battery charger that I use personally, and I am a big fan of it. Depending on where and when you buy it you might be able to find it on sale, I bought mine for $75 when it was discounted, shop around. This unit does use XT60 ports, so you will need to additionally purchase this 4-pack of XT60 Female to XT30 Male adapters in order to charge your XT30 batteries.
Hitec RDX2 200 - The Hitec RDX2 200 is a two-port smart charger that can charge 2 batteries at the same time, and this charger has the additional feature of being able to measure the internal resistance of your batteries built into the charger. This unit costs $140 from goBILDA, but you might be able to find it cheaper elsewhere online. It also uses XT60 ports, but two XT60-XT30 adapters are included in this bundle (if you buy the charger elsewhere, the adapters will not be included).
Tektite Charge 2B - The Tektite Charge 2B is a two-port smart charger that can charge 2 batteries at a time, and this interesting little device can charge from several different charge sources. This device comes with all of the bells and whistles of a more expensive charger, but in a smaller package. What does not come with this device is a 65W USB-C charger and cable, which you will need to buy separately.
goBILDA 12V Battery Charger - This simple charger is just a single-battery charger. What I like about this charger is its simplicity and cost, and it charges at a steady 1A charge rate for maximum battery lifetime.
I’m sure you can find at least one of these battery chargers available in the UK!