bought a new charger last week (as I accidentally sprayed the last one while filling the tanks in the vans (the pump is a 320ltr/min sub pump so it was loads of water over the charger) - I bought a Ring Smart Charger 16Amp, £60 but a really good piece of kit, it can repair damaged/old batteries and have already fixed 2 old batteries which weren't holding any charge (both 130Ah) so its made its money back already.
well worth buying.