Relative to the comment that rechargeable batteries have come a long way, I think that’s also true of moisture resistance, at least for receivers, if not the HA bodies themselves. Many HA’s these days are rated ip68. I’ve worn my receivers usually for 14 to 16 hours per day, sometimes more when I fall asleep while wearing my HA’s(!). I have ~a closed fit (~no venting). I don’t make any special effort to dry out my HA’s other than letting them sit out at room temperature and charging them for no more than 50 min per day or so. My right and left receivers are still going strong 2.3 years after purchase. (I have had problems with my left HA body, which I think is ReSound QC and nothing to do with moisture since my right HA body is still the original). If Apple can make a watch that’s water-resistant to 50 METERS and has a decent microphone and speaker, then HA makers are really a backwards lot if they can’t at least soon make an HA that’s water-resistant to the moisture in your ear canal and your sweat.
The main drawback of rechargeables that I see is that if you live in a hot climate, like southern Texas, Arizona, etc., you probably won’t get as much battery lifespan out of your rechargeables there. The ReSound instructions, for example, say not to use your rechargeables over 104 deg F (40 deg C) and it’s easy to go over those temperatures in the many places in the southwest US. A hot parking lot can easily be 135 deg F.
On going places with no electricity and electricity being unreliable, the ReSound “premium” charging case holds > 3 full charges of 30 hours. The HA’s hold 30 hours fully charged. That’s 120 hours of use (3/4 of a week) between having to recharge the case and HA’s (and then off to another 120 hours of use away from electricity). Buy a 2nd recharging case as a spare, you have ~1.5 weeks of use between electrical outlets. So “I’m going places where electricity is unreliable” is kinda of a strawman. In our civilized world, it’s a rare person that goes 1.5 weeks or more completely away from electricity and with a little bit more ingenuity, you could recharge your HA’s from your car, your RV, your ATV, your outboard, etc. It almost seems like an argument akin to “I’m never going to sell Nelly! Cars are so unreliable. There are so few gas stations and repair shops and most of the roads are dirt and gravel and will quickly kill those durn Model T’s. I’m sticking with my hoss Nelly forever!” The times they are a-changing.
Edit_Update: Actually my calculation of 120 hours of charge being 3/4 of a week of use is in error. If you only wear your HA’s 14 hours a day, 120/14 = ~8.5 days of use. 210/14 = ~15 days use with a spare case. With streaming, you’ll get less use. Streaming 12 hours per day for the Quattro’s according to ReSound, reduces useful charge a factor of 0.8, or to 6.8 days and 12 days of use streaming 12 hours a day with one or two premium charging cases as backup.
