I assume by "bangers" you mean what we typically call a "bratwurst".. aka the sausage thing.
BTW.. for most of use in the US, to BBQ means long/slow indirect heat (with charcoal and/or wood) typically producing some smoke, where as to "grill" means direct heat (charcoal or gas).
As others have mentioned, the key is to use indirect heat, that is to say, push your charcoal either all to one side OR... split your coals in two, pushing them to each side and cook your "bangers" in the middle.
Many "bbq aficionados" here will simmer our "bangers/brauts" in beer seasoned with onion, garlic, etc. first... then toss them on the indirect heat of a grill to crisp up. It should take you about 20-25 minutes to get a nice crisp coating to your bangers... turn them at least once during that time to get more even crisping..
More than you want to know about grilling and barbecue can be found here: