Using the all causes listings in Battle Of Britain Then and Now, 1,986 Luftwaffe aircraft destroyed and 926 damaged, which of course have a number of unknown cause losses. AA fire is considered responsible for 69 destroyed and 33 damaged, plus 21 destroyed and 7 damaged jointly with RAF fighters. Collisions cost the Luftwaffe 63 and take off accidents 66 aircraft. Barrage Balloons 3 aircraft
The lack of modern guns and the overall number of guns meant AA fire was not a big cause of loss or worry as far as the Luftwaffe was concerned unless for low level operations.
AIR 2/7772 German losses from captured Luftwaffe documents again plenty of unknown and enemy action causes, where AA is the cause, destroyed unless noted
1 fighter on 10 July, 1 bomber on 14 July, 1 fighter unspecified damage 14 July, 1 bomber unspecified damage 14 July, 1 bomber by infantry fire on 22 July, 1 bomber on 25 July, 1 bomber on 9 August, 1 bomber on 12 August, 2 fighters on 14 August. 2 bombers damaged on 15 August, 1 bomber on 16 August plus 1 bomber and 1 fighter unspecified damage, 6 bombers on 24 August, 1 bomber unspecified damage 26 August, 1 fighter on 2 September, 1 bomber damaged on 6 September, 1 bomber, 1 fighter destroyed, 2 bombers damaged, 3 bombers unspecified damage on 7 September, 2 bombers on 8 September, 1 bomber destroyed plus 2 damaged on 7 September, 2 bombers destroyed and 1 bomber unspecified damage on 11 September, 1 bomber destroyed, 1 damaged on 15 September, 1 bomber damaged 17 September, 1 fighter on 21 September, 1 fighter on 24 September, 1 bomber damaged on 1 October, 1 bomber and 1 fighter on 2 October, 1 bomber unspecified damage on 4 October, 3 bombers damaged on 8 October, 1 bomber on 17 October, 1 bomber unspecified damage 27 October, 1 fighter 29 October.
It seems clear only London had the AA defences that could start to worry the Luftwaffe. The Germans were reporting their AA was shooting down more RAF aircraft than the other way around.
"from 10th July to 31st October 1940. The Germans assessed their losses as 2,376 aircraft destroyed or damaged, of which 1,543 were assessed as destroyed by enemy action, 190 destroyed by other causes and 643 damaged but repairable. The claim we made at the time was that 2,637 German aircraft had been destroyed." Note dated 19 December 1945.