I looked on the Phonak website, what’s the difference between the two? I know the 13 battery is physically larger than the 312, does it give longer life or more power?
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Hi @Recoil_Rob,
I think output power is more a function of receiver type than hearing aid form factor. But yes, in my experience, the 13’s (shick I wear) last longer than the 312s.
Only difference is battery size, which leads to both a slightly larger hearing aid, and slightly longer battery life.
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Here’s a good link to battery info. 13 has almost twice the battery capacity of a 312.
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OK, thanks. I’m happy with my current 312’s so the smaller size is good.
If you’re upgrading from the HA without streaming (media, calls) onto marvels, and you plan to stream, 312 won’t probably last as long as current HAs serve you. But, use it on trial if you can and test for yourself. I l’m testing 312 and since I don’t stream much (less than 30 min a day, if that) and wear it for 6h a day or so, I don’t feel much difference from widex dream 312, my previous HA.
@MDB this is survey set doesn’t take into the account actual power usage per user.
I’ve read a paper where they compared several brands and all 4 major sizes, and gave mAh values and were simulatin usage until full drain (so all batteries were tested under the same load), and results were that for rayovac, duracell, powerone, mAh usually differ by 30% more and time would follow that ratio as well. Very roughly said. I was checking for durability / price, I think duracell was best for size 13 and rayovac/powerone for size 312 or something.
Ok paper wasn’t new, but I still find the method more informative than poll.
If I remember correctly it was study from brasil, I might be able to dig up link from my history if you’d like to see it 
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I included article (survey) mainly to show approximate capacities of different sizes. Very loosely, each increase in battery size roughly doubles battery capacity.
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Yes, I understand, however my article said it’s only around 30% up. That’s big difference, don’t you think?
Judging by mAh differences, I which are more aligned to that paper, I’m more inclined to count on only 30% increase when I calculate costs (my question to answer was battery vs rechargeable and in which time would price become equivalent). Also price was roughly 30% up for size 13 that I was checking, so at the end, cody would be roughly the same. Assuming all of this before.
However, I do really hope thatyour estimates are right since I’m planning to go 13T route for my aids 
Hm, I should really write down when I swap this trial 312 next time. Then I’ll be able to compare.
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I think typical 312 is 180 mah and 13 is about 310. That’s a difference of 130. 130/180 is about 70%. Regarding cost, I believe all battery sizes are the same cost. I know it’s that way at Costco ($8.49 for 48) and I think Hearingtracker also charges the same regardless of battery size. The 312 to 13 size difference is the one that doesn’t quite meet my doubling standard, but 10 to 312 and 13 to 675 do. Dimension wise, I believe 13 is twice as thick as 312, but diameter is same. For Phonak Marvels there is remarkably little difference in size between the 312 and 13 models, but markedly better battery life with the 13.
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I found the link
I remembered wrong, it wasn’t 30%, but more around 50% difference in working hours for power one and rayovac, size 13 giving longer (276h for size 13 for both, while for size 312 is 192h for powerone and 204h for rayovac). Duracell gives the same for both sizes, 276h.
Those numbers are more aligned from your mAh observation also.
If that poll says double, to me that just doesn’t look logical, so it definitely must be affected by various usage patterns.
Prices on amazon.de aren’t equal for some brands, and also depend on amount bought. But are the lowest that I found from short search. I didn’t search too much.
Anyhow, size 13 gives more, unless you use duracell (which here is a bit more expensive than powerone/rayovac, if I remember correctly). But also, that’s old study and from Brasil, who knows what are the exact numbers today, so I’d stick with more general ‘size 13 gives more’.
And yes, size of those two HAs differ for what, 2mm in width? Unless you have really little space, very small ears and wear glasses, I’d say size 13 is way to go with marvels.
“Working hours” isn’t a very helpful unit for comparing batteries as they’re used in different kinds of hearing aids. You’d never use a 10 in a power aid and never use a 675 in an IIC. I was the one that said approximately double and was referring to the milliamp hours. It varies depending on manufacturer, but it’s roughly 90-180-310-610 for 10, 312, 13, 675 batteries. Anybody know how the different sized batteries got their names?
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I was referring to this article working hours. Also, btw, in the article they even mentioned difference in measured load when feedback control is turned on or off.
You’re right, it’s expected from bigger battery to be under heavier load based on device itself. However, in this topic comparison was 312 and 13 on the same device type/model and user, so we can assume equal load.
From that perspective, comparing constant drain gives some information for the ratio of endurance, however, I definitely agree, not for exact endurance.
Wouldn’t it be great that batteries last 200h in HA…
I should express more clearly earlier that information which I get from the article is ratio between size 13 and size 312 for the same HA and same user is around 50% better for size 13. And that looks logical to me, also the one about 70% that you’ve mentioned based on mAh, while 100% didn’t seemed logical.
Until now.
I just thought of another explanation where difference could reach doubles. I read somewhere that streaming is really power draining and for smaller batteries can basically kill them faster (like their properties, overdrain them or something, not just impact the power left in them). And that size 13 can sustain heavier load with less impact on battery life.
Hope it’s clear now what I meant, and I’ll stop here. Thanks for being patient and respectful conversation partner in this my brain-storm 
I have Marvels with size 13s. They are a little thicker than the 312 aids, obviously because of the battery. I have been using Power One brand because that is what the VA has under contract. I wear mine mostly when watching TV because of the TV Connector. I don’t know how long the batteries would last without streaming, but with a good bit of streaming they last 2 and a half days. I don’t use them with Bluetooth to do phone calls. I asked the VA if 2 and a half days was normal and they said it didn’t sound abnormal. Some folks here are of the opinion that my batteries must be inferior because of the short life when streaming. I can’t say, but I chose to get the ones with size 13s both because I wanted a T coil, and they come standard with one, and I anticipated that the wireless capabilities would drain the battery faster. The size battery one chooses is a very personal decision. The extra width might be a concern for some folks, but not others.
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If you are on the phone (streaming) a lot) you would almost cetainly want the HA w. the larger battery.
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i researched this thing a year ago before pulling the trigger while in my trial pair.
I opted for the 13… significantly more battery capacity with only just a negligible increase in size of the aid. To me it was a no-brainer… My audiologist balked just a little at first, kinda as if the larger batteries would only be used for someone requiring more power for a more significant loss… but the size of the aids are so close I’d bet most people would be hard pressed to tell
I also went with the 13 over rechargeable that the audi was pushing… change battery weekly (less with this current set of garbage batteries) or recharge daily… also an easy choice for me.
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Heh, my fitter agreed with me about regular batteries, he also is sceptic about rechargeable battery life 
Once you try rechargeable you will never go back.
I’m trying them just now since my fitter didn’t have battery version for trial. I confirmed that I definitely don’t like them
Especially hardware, those lights I can’t see unless I hope them on the right angle, charger and force needed… Not for me, confirmed. For those who don’t DIY them and don’t need to see the light for connecting with noahlink wireless, they’re probably great.
And they need more time to connect with my phone than 312 version needed, when I open the app. At home it’s longer but outside is crazy longer. Latest firmware is in them. BT fixed. I think it was the same for old ones but I need to check.
Plus, yesterday, with my pathetic use of 8-10 hours, with one 1h+ long WhatsApp call and some setup with target and little commuting, and cca 2-3h tv streaming and they were on around 60% or something less. Both. And good ear receiver is S with what, 5-7 db gain for normal loud sounds. Bad ear is P close to the possible maximum (open fit version) and is also main HA for BT connection.
I’m definitely not impressed with battery life for my use case. And yes, those trials are probably not new, so that’s even more useful for me and estimating battery life. 312 went long enough that I didn’t notice difference from my previous one (so 7-10 days range, but calls I have one per week, parents ). Mine will be size 13. I suppose that I’ll forget where are my replacements are by the time they die
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