[Battery problems on my 2022 HRV]

I have had issues with two batteries, including Yuasa.  Both times it took a long time to diagnose and the last occasion I had to resort to an Auto Electrician who diagnosed it as being 'unstable'.  The battery was still under warranty so I had it exchanged without problem, although I had the cost of the Electrician to bear.  One of the symptons I noticed was the HR-V's reluctance to shut off when idling, but at that time I didn't know what the problem was.

[2007 Civic Horn]

I have had Lionel from new and have wanted to upgrade the feeble horn.  How do I get to it and can I fit another one adjacent?  I fitted another one in parallel on my Jazz and it sounded great afterwards.  That location was in front of the o/s front wheel behind the wheel arch liner.

 

I have finally discovered it down by aircon heat exchanger, RH side when viewed from front.  It looks extremely difficult to connect another one in parallel unless I remove sump guard etc.