Phonak Cros

My new Phonak Cros are sucking down the 312 batteries. Somewhere between 2 - 3 days per battery. I’ve ordered some of the cheaper batteries from the forum sponsor just to see how they work. I’m happy with the Cros but now I have to carry batteries around with me. I’ve tried carrying them in a pill container but they dont seem to be any good when I need them. Does it have anything to do with them touching each other? The packages the batteries come in aren’t very good for carrying them around in my pocket. Any ideas?


I don’t know about how to solve the problem of carrying them around but I know the standard battery life for CROS users is 2 to 3 days and that is it.

2-3 d/battery is normal. The HA’s use an internal antenna to communicate with each other and it draws a tremendous amount of power from the battery. Phonak just came out with the H20 version CROS which has a size 13 battery and as a result, closer to 5-6 days battery life instead of 2-3.

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I usually get about three day’s battery life with my Phonak Audeo BiCros system, although I have gotten much less in some circumstances. I carry a pair of spare batteries in the Phonak hard plastic case that comes with the aids. So long as the plastic activation strips stay in place on the batteries before use, battery life isn’t affected. Vic

For CROS, if you want a longer battery life, you can also use the H20 CROS which uses a size 13 battery, which will last closer to 5 days.

I have Phonak CROS too and that’s about the right time estimation for how long 312 batteries last for them. As for storing extra batteries to keep with you, I originally had gotten a metal pill case to keep them in (they were touching). After a few batteries in the case went bad, I did a search and found some people saying not to carry batteries in a metal case (or it could also be the batteries touching). Are you using a metal or plastic case? If it’s plastic, perhaps the batteries touching is causing the issue. I got a mini separated pill case to keep mine in now–there are 2 small side-by-side compartments and one battery goes in each compartment. It’s worked pretty well and you can find them at any pharmacy.

I keep a small unopened pack in my billfold, but I found that body heat seems to reduce baattery life.

Thanks for the replies, I kinda figured that the 2 - 3 days was normal. I’m carrying extra batteries in the package they come in, but I put them in a little coin purse thingey that came with the aids. So far it seems to work ok


Are the H2O larger than the audeo cros? Or are they close to the same size?

about 15-20% larger I’d say. It’s not enough to make it more noticeable when wearing though.

I was just curious about them and their size. I’ve seen pics of them but I haven’t found any pics of anyone modeling them or any youtube reviews of them yet. I’ve been considering them for cros aids because I’ve heard they have better battery life than the audeo cros.

Yes, much better. The size diff is minimal, but the additional couple days is worth it, IMHO.

But then, I don’t have to wear them either…lol

How many hours of daily use are you using for the batteries to go down after 2-3 days? Also which particular Phonak aids are you using for your cros?

The circuit utilized for the Phonak CROS won’t effect the battery life. A 312 will last 2-3 days, a 13 will last a couple days more, with normal wearing time (10-14 hours/day). Reason is the CROS uses a wireless antenna which is on all the time. The antenna places a significant drain on the battery resulting in the short life-span.

How many hours a day of using does it take for the 312 battery to go down with the 2-3days? Is it the same 10-14 hours as the 13 batteries?

Just a tip, with the newer hearing aids you should really let the battery sit for a full 2 minutes after removing the tab before putting it in the hearing aid. With older hearing aids it didn’t really matter, but the new ones need all the voltage they can get.

One of the manufacturer R&D peeps was told by their engineers that we should do this, so the R&D department ran some tests to see if it did make a difference. Lo and behold, they were able to get about 18 more hours out of the batteries by letting them fully charge before putting them in the aids.

Reason why they last so little as its a phonak CROS which streams 100% of the time, therefore draining batteries a lot faster.

One reason I was curious about the difference with the hours per day for wearing an aid in relation to draining was that I’am needing a cros but I’am trying to decide between the audeo models or the H20. I mainly plan on wearing my aid for work reasons and some social situations. I won’t be wearing them all the time. Most work situations would involve wearing an aid for 8hr days mon-fri. So I wanted to get an idea if the audeo(312) batteries would give me a decent amount of battery life compared to the H20(13) batteries for how I’am planning to use them.

Def get the size 13 battery H2O. The H2O also has a water resistant rating of IP67. That would def last longer. Even tho you won’t be wearing them all the time, the battery will still discharge when the aid is off.

If size doesn’t matter then I would always go for the bigger battery. :slight_smile:

Battery Size: Milliamp Hours:
675 600 mah
13 260 mah
312 130 mha
10A 70 mah
5A 35 mah

You get double the mah with the size 13 battery.

Hi all,

i wear phonak cros with size 312 batteries and was very tempted to change to the H20 for longer battery life and waterproof feature. As this was my first hearing aid the larger size was what put me off. This is my first post and hopefully i am attaching a photo!? Im generally very happy with the cros in most situations.