aa battery pack


monstercameron

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maybe pandora can save cost by selling some units sans lipo/lion battery packs and allow for the usemof aa or aaa batteries. I bet the pandora could fit 9 aa batteries like sanyo eneloops.
 
I wouldn't buy the P2 if it uses regular batteries.
 
You'd need 6 high capacity (2400+mAh) AA NiMH batteries to match the capacity of Pandora's battery. AAA's are out of the question, you'd need something like 13 of them. The packaging makes them weight inefficient and the cylindrical shape makes them especially volume inefficient so you add a lot of extra weight and size to a device that's trying to trim down on both. If it needed AAs you'll inevitably get people who try using alkalines as a backup in a pinch and being pretty unhappy when they find them drained in a few minutes flat.


Craig will tell you the battery isn't really that expensive and not the place to start looking to make compromises. I mean seriously, 9 AA batteries? In an expensive device that's trying to look modern?
 
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Actually - I think he's onto something, but maybe not for the right reasons. Hear me out on this a bit.


Yes, the device should ship with a high capacity rechargeable battery using the best available technology of that time. It would mount into a compartment and make contact with the device much the same way as the existing Pandora battery.


However, the slot that the battery fits into would have extra contacts at both ends of it to be able to accept nine AAA batteries in 3 banks of 3 - for emergency use only.


The scenario is that if/when traveling on delayed flights and rushed airports, your main battery concs out and all you have is an airport convenience store and a credit card and 5 minutes to your next flight, you can purchase $15 worth of extremely common AAA batteries to put in your P2 and enjoy ~3 hours of entertainment on the next flight.


This isn't about replacing the main battery - it's about having a backup plan.


What we should debate on this is if the additional 3mm or so of battery compartment case width (for contacts/springs) and designing the main battery to the dimensions dictated by 9 AAA batteries arranged in a flat grid would be worth it for the rare case that having it would be handy.


Now that I've laid out a logical case of how/why this might be favorable, I'm going to state that it's a silly idea and should be skipped. If someone wants the ability to run the device on AA batteries, they can buy one of these and be done with it.


http://www.amazon.com/Goal-Zero-11406-Silver-Battery/dp/B007M5UAJC/ref=sr_1_2?s=automotive&ie=UTF8&qid=1355244854&sr=1-2&keywords=goal+zero+guide+10+plus
 
if we make the battery pack the size of slightly bigger than the size of two Aa batterys then we could make a adaptor where we could fit two aa batterys into itthen you get the best of both.
 
did i wake up in 1990? why would you use aa or aaa in anyhting but your tv remote and most of them don't use them, and as for a spare really there are hundreds of great battery packs that can run of or charge anthing with a usb and most are the sizeof a pack of 4 aa's and start at 10$ i myself have a newtrent it's about the size of a pack of cigs and was 60$ and can charge my pandora two times and stil have some juice left, also can have say my cell charging and my pandora charging at one time or even be playing my pano and running a usbled lamp off it now lets see your aa or aaa's do that
 
if we make the battery pack the size of slightly bigger than the size of two Aa batterys then we could make a adaptor where we could fit two aa batterys into itthen you get the best of both.

AA batteries are thick. There is a lot of packaging surrounding each cell. When placed into a rectangular container they loose all of the volume in the corners and between the cells. They have a very inefficient volume to power ratio as a result.


AA batteries are expensive. VERY expensive. The cheapest quality AA batteries I could find with a brief search was a 40 pack of Duracell batteries for $22.70.


So - if you have a $25 Pandora battery pack and take as many AA cells as you could jam into that volume - all 6 of them by my accounting, you -might- be able to run your Pandora for 30 minutes per AA cell - then throw away the cell. But, that's 3 hours use per battery load - that might make a light user through a day.


Six AA batteries per day * 30 days * $22.70/40 = $102/month to use AA batteries for 3 hours per day.


Pandora rechargeable battery = $25+shipping and lasts about for around a year or more of heavy use. Call it $2 and change per month.


Hmm... $2 vs $102....
 
However, the slot that the battery fits into would have extra contacts at both ends of it to be able to accept nine AAA batteries in 3 banks of 3 - for emergency use only.

The scenario is that if/when traveling on delayed flights and rushed airports, your main battery concs out and all you have is an airport convenience store and a credit card and 5 minutes to your next flight, you can purchase $15 worth of extremely common AAA batteries to put in your P2 and enjoy ~3 hours of entertainment on the next flight.

I already said this but it isn't going to work with alkalines because they can't handle the discharge current requirements. So unless you think that the emergency 5 minutes scenario consists of buying a bunch of lithium batteries it's not going to work.
 
did i wake up in 1990?

Yeah dude, It's 1997 and this is the best Idea ever, I can just slap this extra AA battery pack to my MiniDisc player and get an hour of extra use.
 
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two aa batterys Will on average give you 5ah at 3 volts.

Where did you get that from? from everything I read having two AA 1.5V batteries in series to provide 3V only supplies 2.60Ah.. 5Ah would be true if the batteries were in parallel, but that would only provide 1.5V.


Also Assuming a device only draws 500mA that is less than 4 hours of use.. The Pandora draws a bit more than this.
 
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Yeah dude, It's 1997 and this is the best Idea ever
Aren't pandoras supposed to help people relive past experiences with electronics?

Wouldn't you need three cells in series to get a reliable 3.7V?
 
Aren't pandoras supposed to help people relive past experiences with electronics?

Sure I fire up my MiniDisc player once a year or so.. I do need to use the optional AA battery pack that snaps on because the old NIHM battery stop working long ago.. Someday Minidisc will catch on I know it.
 
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two aa batterys Will on average give you 5ah at 3 volts.

You can either add the voltages (wire the batteries in serial) or add the currents (wire the batteries in parallel) but you don't get to add both, which is what you're doing.


Although alkaline batteries are often rated at 1.5V this is actually only what they start out at. Even under very low load currents their discharge graph is steeper than other battery types. So you don't even stay above 1.2V for very long. Under higher discharge currents like what you'd see in Pandora the curve looks really bad. For a mobile device like Pandora you'll need to consistently provide some voltage level, probably at least 3V but it could be more, given the Lithium Ion battery will provide that for most of its discharge cycle.


So you need to spec the battery configuration for the minimum voltage you expect the battery to provide. The higher the value you set, the more useful capacity you'll be throwing away as the battery dips below that voltage. But the lower you set it, the more of a voltage drop there'll be in the power regulators, which is less efficient. Ideally you want as flat a curve as possible. NiMH batteries are pretty good in this respect, similar to LiPo. But even they can dip below 1.2V for a big chunk of their discharge cycle. So it wouldn't be good to expect more than 3.6V out of three in series, unless you want to reduce their capacity by a lot. 3.3V is pretty reasonable.


But needing rechargeable batteries defeats the purpose, so unless you want to buy expensive lithium batteries for emergencies you're out of luck..
 
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