Drying rechargeable hearing aids

As a teenager I spent many days swimming in the ocean surf with goggles and flippers. My ears were wet most of the day. I dried out when I came out of the water or went home at night. The water wasn’t chlorinated and to the best of my recollection, I never got an ear infection from this activity. I did get an ear infection as an even younger kid who stuffed cotton in his ears to avoid hearing his parents yakking downstairs at night, then went swimming, forgetting to remove the cotton, and having in the wet mass in my ears for many days (and nights) straight. So the degree of moisture exposure vs. drying out is very important as well as the bacteria/mold/microbes, etc., you happen to be exposed to.

Edit_Update: to go along with links in my previous post, here’s a quote out of the Wikipedia article on “Swimmer’s Ear:”

" The two factors that are required for external otitis to develop are (1) the presence of germs that can infect the skin and (2) impairments in the integrity of the skin of the ear canal that allow an infection to occur. If the skin is healthy and uninjured, only exposure to a high concentration of pathogens, such as submersion in a pond contaminated by sewage, is likely to set off an episode."’

Was just looking at the Wiki article on antimicrobial effects of earwax and was considering sharing.

I am a newbie with a question following on from a little earlier in the discussion.
My bargain priced Phonak Audeo M 70 R hearing aids were delivered with two compact chargers but did not include the commonly supplied larger charger which has space for the small circular desiccant container.

What to do? Well I recycled several pill bottle silica gel sachets (after reactivating them) and I insert one of them whilst charging the HAs. I was not sure how much air might leak into the charger’s interior so I smeared some silicone sealant along the joint to minimise air entry so it is now mostly airtight.

Before organising this setup I had ordered from Ebay a USB powered dryer for $12.00

which arrived today. The dryer heats to 45°C (110°F) and It has a timer for three or six hours of drying time.

My question is:
What is the better option, or what combination of desiccant/heating will achieve the best moisture removal from the HAs. Charging for three hours then transferring the aids to the dryer in the middle of the night does not appeal at all.
I have included photos of the charging and drying devices connected to a USB power meter.

Technically inclined Readers may be interested to note that for my slightly discharged Phonak M 70s the charging current was pulsed approx 1 second on at 265milliamps, then 9 seconds off.

The dryer, advertised as operating at 50° C (+ -5°C) In my case the dryer seems to peak at 45° C.

Have you looked in your manual to see what it says about avoiding heat exposure to your HA’s? My ReSound manual for Li-ion rechargeable Quattro’s advises me to avoid heat exposure. Check out what Wikipedia, Battery University, etc., have to say about the effect of heat on the long-term use lifespan of a Li-ion battery. Avoid sub-zero temps, i.e., don’t freeze battery, and best charging temp is about 15 to 25 deg C (55 to 77 deg F). I once totalled a phone battery in short order by always recharging the phone on a very sunny window sill (heat of charging + heat of sun = :skull_and_crossbones:)!

I checked the manual, and the suggested max is 40 deg C but I take your point any elevation from ambient shortens the ultimate lifespan of Li-ion cells and probably most any cells that function via chemical reactions.

Yes, I imagine any decrease in battery longevity is a time-temperature averaged weighting. Samsung, for example, advises the user in wirelessly charging a phone or watch that the device will get warm but says (for the time involved) that this will not affect the expected lifespan of the device (and, of course, they probably mean you’re supposed to buy a new device from them every two to three years!).

Apple has some of the best advice on Li-ion battery care that I’ve seen anywhere (I guess because their devices are so expensive and they really care about having happy customers).

But in the following link, they mention the optimum temperature for getting the longest lifespan out of their Li-ion batteries - and presumably they’re using top quality stuff. Li-ion batteries can be used at cold temperatures down to about freezing but they should not be charged when very cold - sources vary. I’ve seen a lower limit as low as 45 deg F but I go with 55 deg F as the coldest temperature at which I will charge. Batteries - Maximizing Performance - Apple

" Avoid extreme ambient temperatures.

Your device is designed to perform well in a wide range of ambient temperatures, with 62° to 72° F (16° to 22° C) as the ideal comfort zone. It’s especially important to avoid exposing your device to ambient temperatures higher than 95° F (35° C), which can permanently damage battery capacity. That is, your battery won’t power your device as long on a given charge. Charging the device in high ambient temperatures can damage it further. Software may limit charging above 80% when the recommended battery temperatures are exceeded. Even storing a battery in a hot environment can damage it irreversibly. When using your device in a very cold environment, you may notice a decrease in battery life, but this condition is temporary. Once the battery’s temperature returns to its normal operating range, its performance will return to normal as well."

So, for example, don’t leave your HA’s, your phone, your wireless earbuds, etc., in a car on a hot day. The interior of a car left in a parking lot in southern parts of the U.S. can reach 135 deg F or more on a hot, sunny day in short order.

BTW, for anyone interested in monitoring how hot things are, one can buy very inexpensive thermal “guns” on Amazon in the $15 to $30 price range. You pull the trigger and it measures the infrared radiation being emitted by an object - the more expensive ones have a laser beam “targeting” feature to let you know what you’re “shooting” and adjustments for the infrared emissivity of the type of material, shiny metal surfaces emit less infrared radiation for a given actual temperature than a material that functions more like a “black body.”

Don’t know about the Apple Store but in the Android store you can get battery temperature monitoring apps and set the limit you want the app to beep at if your phone battery gets too hot. The app that I have consumes very little power and shows the temperature read from time to time as a notification as well as flashing a popup and making a noise when I exceed my preset limit. Apple warns you not to charge your iPhone with certain cases on the device. I always remove my phone case when charging my Galaxy Note. I charge my HA’s in their charger case with the lid open. I also remove the case (very carefully!) if I am intensively using the phone and it’s starting to get hot - or I slack off using the phone. Being at home much of the time, I will actually pop my phone into the refrigerator for 5 minutes or so the phone starts to get real hot but I’ve seen advice that temperature cycling, because things are expanding and contracting, is not a good idea to do intensively. I figure the phone normally goes through lots of expansion/contraction cycles just in normal use as its inside gets hot, cools down, gets hot again. So other than moisture condensation, I don’t worry about brief cooling trips to the frig and since my phone has an IP68 rating, I don’t worry about a modest amount of moisture condensation too much, either.

Update: With the thermal gun, you can find the coolest location(s) in your house to store Li-ion battery-powered stuff. If you have central forced-air AC, the coolest locations are usually where the duct work travels the shortest distance from the furnace/blower to a outlet vent - the air warms the least before it’s blown into a room. We’re fortunate enough to have a large walk-in master bedroom closet and I keep my tablets, phone, etc., there when not in use and we’re letting the rest of the house warm to 81 deg F during the summer (or more at times). The closet is at least 5 deg. F cooler than the main part of the house. OTH, running the AC just to keep some battery-powered stuff cool or opening and closing the frig door a lot could cost a lot more in the long run (and waste a lot of your time) than just wearing out a phone by not worrying at all about temperature and getting a new one as needed. I have a lot of battery-powered stuff, including my HA’s, that I’m interested in keeping cool to maximize useful lifespan.

Just curious–so your big closet has it’s own AC vent?

Yes, it does. And my wife does a good imitation of Imelda Marcos, keeping every shoe she’s ever owned in the closet, I think, and taking up most of the closet in the process. We went for a walk the other night and she wore a pair of athletic shoes she’s kept for 30 years or something. They disintegrated during the walk - so much for my theory of temperature preserving things …

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Funny. I’ve got a pair of 40 year old hiking boots that live in the garage and go through 100 degree plus summmers. :smile: They’re pretty solidly built. Who knows how long they’d last if I took care of them! I do think you’re right about electronics though,

I have Starkey Livio rechargeable RIC HAs and the charger has a dehumidifier built into in, so that it charges and dehumidifies at the same time.

What type of HA dryer do you have? Does it seem to work well?

PerfectDry Lux. It’s not like I conciously chose this brand/model. I picked it up at Costco and it was the only one they carried.

Does it work well? I hadn’t really given it much thought until you asked. My first hearing aids got a little “glitchy” after three years. Hearing all the talk of dryers on this forum, I decided maybe I should get one, perhaps moisture had done in my old aids.

I don’t use this daily. On my days off I tend to get up and have breakfast and tea with my wife before I take a shower. I put them in the dryer while I’m showering. So that’s two or three times per week.

But I wouldn’t really know how to gauge results. I guess I’m just hoping it’s doing its job. If anyone has an ideas on gauging results, I’m open to suggestions.

The device is small and unobtrusive. It’s all white and looks okay sitting on the desk in the living room. That got it my wife’s stamp of approval to sit out in the open. In that sense it works great.

Thanks. I understand what you mean about my question “does it work well?”
Maybe it wasn’t a good question. But if you aren’t having any problems due to moisture that seems to mean that the dry box could be effective. I live in the Northeast which tends to get humid especially during the summer.

I’m new to HA’s and in shopping for a good provider and devices no one talks about drying them. I have ordered rechargeable HA’s from Oticon and their charging dock is open and was trying to figure out when I’d dry them. Your two little lines in this forum thread seemed like a reasonable option.

No problems yet, but bear in mind that this set of aids is not quite a year old yet. The last time I went in for cleaning, the lady at the counter seemed a bit surprised at how little “gunk” they had. That might say something for the dryer, I don’t know. I have a Jodi-Vac, but recent home renovations caused that to get packed away, so I would have to say the lack of “gunk” must be at least partly due to the dryer.