peterpeter has answered the question well - this is also my experience

10 hours with alkaline battery at 44.1k/16 bit. Max. Quality 96k/24bit.

The recording capacity depends on the recording quality and size of the micro SD card; up to 32 GB can be used. With an 8 GB card, between a good 3 (simple MP3) and over 350 hours (96k/256 bit/s) of recording capacity are available. Due to its enormous sensitivity, the device is particularly suitable for nature recordings ...

I have a memory card in it (32GB?), with which I could record 50 hours according to the display.
As far as the batteries are concerned, I always run the H1n with a power bank (note, not all the ones I have work), which I attach to the tripod with gaffa tape or something. I don't rely on the internal alkaline batteries or NiMH rechargeable batteries. All too often they were empty during the concert, even though I had used them fully beforehand.
The quality is excellent for routine concert recordings and "home use". If you want to continue working with the recordings (WAV), there is often a fine noise when normalising, but you can get a good grip on this with a de-esser.

Hello, unfortunately I have no idea, it was bought as a gift 🎁.