aa battery pack

[ryan27968]

sorry. forgot about that. but still, you wouldnt need 6 aa batterys, only four.

 

[Exophase]

You would need 3 NiMH batteries in serial to even have a shot at providing enough voltage. Your battery configurations therefore must be in multiples of 3. 4 is not a multiple of 3.


You would need 6 high capacity (2200+mAh) NiMH AA batteries to match Pandora's current battery capacity. Alkalines will never work unless you have the Pandora sleeping the whole time.

 

[overgauss]

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 like the way you are thinking. You're saying take some of the cost of manufacturing the device and allow the user to take up that burden. For instance if it were possible to use AA batteries, many people might already have rechargeable AA's laying around (especially in the case that they have recharge packs for xbox360 controllers for instance). Heck I've got 6 or more laying around somewhere that I've forgotton since most/any of my current devices us AAs. In fact I emember buying quite a few rechargeable battery packs.


So if it were possible to do as you suggested would require OPT to invest money in creating something that requires additional effort and introduces its own set of design problems.


That being said OPT can still offset the cost of their batteries used in the pandora onto some of the users themselves, similar to what your original solution set out to do. What if instead of making another alteration, or different type of case, they sold back-up battery packs at a profit?


They could sell regular backup batteries, or extended (larger) batteries, or even batteries with extra attachments in the housing. The last two introduce similar cost (production, design etc). But in later stages of the P2's life, for example, could actually generate sizable profit with minimal upfront cost that would address a larger demographic than I would expect an AA battery solution to address.


Your idea has merit and I wish that more people would pose what if questions as you have.

 

[hedwards]

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

Travel, AA batteries are still the most easily obtained source of power when you're away from an outlet.


But, making them integrated into the device would be a bad idea. A much better idea would be to just buy or make a charger that takes AA or AAA batteries and feeds it to the charging circuit. For those that really need that. I used to have an Energizer booster pack for my Cellphone that would take a pair of AA batteries and give me an emergency charge if I needed it.


AA powered cameras are very popular for some people for that very reason. You don't get anywhere near as much charge, but you are much more likely to be able to get some form of AA battery in case you run out.


I think for the relatively few number of people who would want that, it makes more sense for them to buy it separately. Or, make it themselves, I can't imagine the electronics being that hard to design.

You would need 3 NiMH batteries in serial to even have a shot at providing enough voltage. Your battery configurations therefore must be in multiples of 3. 4 is not a multiple of 3.


You would need 6 high capacity (2200+mAh) NiMH AA batteries to match Pandora's current battery capacity. Alkalines will never work unless you have the Pandora sleeping the whole time.

Well, technically speaking, Alkalines would work briefly, it's just that they would lose the necessary voltage much more quickly. Probably quickly enough to be unusable for anything other than emergency use. Your typical NIMH is going to be 1.2v and 2200+mAh depending on the specifics, whereas the typical AA battery will be 1.5v, and whatever mAh, but the voltage will drop much more quickly, leaving much of the charge unusable.

 

[Exophase]

Well, technically speaking, Alkalines would work briefly, it's just that they would lose the necessary voltage much more quickly. Probably quickly enough to be unusable for anything other than emergency use. Your typical NIMH is going to be 1.2v and 2200+mAh depending on the specifics, whereas the typical AA battery will be 1.5v, and whatever mAh, but the voltage will drop much more quickly, leaving much of the charge unusable.

Read the first couple posts I made please.

 

[hedwards]

Well, technically speaking, Alkalines would work briefly, it's just that they would lose the necessary voltage much more quickly. Probably quickly enough to be unusable for anything other than emergency use. Your typical NIMH is going to be 1.2v and 2200+mAh depending on the specifics, whereas the typical AA battery will be 1.5v, and whatever mAh, but the voltage will drop much more quickly, leaving much of the charge unusable.

Read the first couple posts I made please.

I did read your posts. I'm not really sure you read mine with any comprehension.


Like I said, really only usfeful in some sort of emergency, unless of course you raft a crapload of them together in an appropriate combination of series and parallels with appropriate voltage regulation. I've had a few times here in China where 5 minutes or even 2 minutes of run time would have been more than worth the cost and inconvenience as I absolutely had to have something on my computer.


At any rate, the thing was moot from the point where it required one to modify the case. At that point, it would almost certainly cost more money than it would cost, even if a few people were interested in running NIMHs off it.

 

[Exophase]

I did read your posts. I'm not really sure you read mine with any comprehension.

What about your post did you think I didn't comprehend? I think you're bitter because I asked you to read my posts, but maybe I should have been clearer why - FYI it wasn't because you said anything wrong, it's because you were saying things I already said (in a response directed to me). Excuse me if I'm going off on you over this but it's a pet peeve of mine when people want to educate me on things where it should have been clear from my posts that I already know it. And I didn't think you had a comprehension problem, what I thought is you must have read the thread without reading all the posts first.


In case you don't see it still, I'm referring to this:

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.

And this:

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.

Where it should be clear that I don't literally think alkalines won't even power on the unit, and when I say "won't work" I meant for any reasonable period of time.


The number of cases where getting a few minutes of charge is valuable is pretty slim. If there's proper suspend you shouldn't need that time to save things. If you have enough time to buy batteries in an airport you have enough time to find an outlet to get those few minutes.

 

[Wally]

Why not run the Pandora on these

Seems to be the most LOGICAL thing

 

[overgauss]

Coin richiuhmu batteriis offer a different set of problems

 

[Binky]

You'd need 18 of those to get 4Ah


Double that (in parallel) to avoid the voltage dropping too low.


36 CR2032s @ £2 each = £72 for 15h of pandoraing

 

[Exophase]

He was joking. Geez.

 

[_wb_]

Judging from the price for a spare Pandora battery, it is not a very expensive component. Replacing it with some other kind of batteries might make the P2 maybe $15 cheaper, and would require people to buy maybe $30 worth of high-end AA batteries, while they get poorer battery life and a heavier device, and much more trouble to recharge it or swap batteries. Not a good idea.

 

[SNESFAN]

just carry a spare stock battery


what would be cool (but not needed IMO) is an "extended" battery, slap 2 stock batteries together, extend the housing a bit, but I've not once used my pandora till the battery died under normal usage before being near a mini usb or an outlet.

 

[_wb_]

It would also be cool to have an optional "light" battery, with a smaller capacity and also significantly less weight. In some use cases I would be fine with a shorter battery life (e.g. at home when a charger is always nearby, or on short commute trips where I only need the Pandora for 30 mins to work and 30 mins back). It would be nice if the weight could be reduced from ~330 grams to ~250 grams or so in this way.


Or why not make it so that you have 2 battery slots, which makes it possible to hot-swap batteries and also to reduce the weight by fitting only one battery. The downside is that the battery packaging overhead is a bit larger, but not hugely so. Maybe it's also more complicated to design, I have no idea about that.


Perhaps one of the battery slots could then also be used as an internal USB port (one that is normally not usable because it points towards the space occupied by one of the batteries). So you could take out one battery and use that space to plug in a USB memory stick or 3G dongle or whatever small USB device, and then close the case again. Nice to have nothing stick out of the device and still be able to use small USB devices! Eventually the OPT could even design their own USB "addons" that fit exactly in this space and offer some set of additional functionality like rumble, gps, whatever.

 

[Grench]

That wraps back to the 'modular' case design that has a whole 'nother thread on it.


If you have the main unit with screen, keyboard & nubs, headphone jack, wireless radios, microUSB 3.0 OTG, motherboard. It would have TWO (left and right) docking clamps with pins on the bottom of the main unit - both the same size. Note there are no thick ports here. This top layer should be kept under 12mm thin.


Each 'module' with a footprint of 50% of the base of the P2mod has docking connections top & bottom and can be mounted on the left or right side. These would all need to be uniform - so 10mm thick.


Battery modules, being fully symmetrical can mount left or right or both. You could have one, two or even ten batteries connected to the bottom of it if you want to.


A 'standard multimedia and IO' module would contain RCA jack audio in/out, HDMI out, UART pins behind a knockout, two USB 3.0 host ports. This would entail ports front & back. Since you could mount it on either the left or right, you'd get to choose which ports are pointed forward or back. If you HAVE to have them all out the back, buy two of this module and mount one to each side.


An SDXC data storage module could have 4 SDXC and 4 microSDXC ports on it - two SD front, two SD back. 4 microSD on the side.


A 'quadrupledoubleboomboxmodule' - quadruple thick, full Pandora width - could add bigger speakers, a 'notebeook subwoofer' and a stereo amplifier.


A 'hackers' module would be an empty box with all of the potential of the docking port brought out into a long pin header inside it and 'knock out' panels and holes on the front/back and side.


A single layer plastic 'bottom' module that protects that nasty @50pin port off of the bottom-most module in the stack.


I'm pretty sure you all get the idea.


The obvious huge drawbacks to that kind of system revolve around development costs - that's a whole lot of case plastics.

 

[Exophase]

I talked to an EE at work and he told me the dual battery idea would require different/additional charging circuitry to handle properly, as is the case for laptops with multi-cell batteries.


This could be problematic if the PMICs available don't support this.

 

[Grench]

I talked to an EE at work and he told me the dual battery idea would require different/additional charging circuitry to handle properly, as is the case for laptops with multi-cell batteries.


This could be problematic if the PMICs available don't support this.

That can be conquered.


The docking plug/port/whatchamacallit would need to have circuitry to tell the main unit what is plugged into it - some sort of module type and ID.


The battery module would need it's own 'id' - kind of like a MAC address as well as some basic on-board logic so it can be told by it's ID to charge or discharge over a common set of rails - so that they charge/discharge one at a time.


The main unit pulls charge from whatever the last battery in the stack is until it claims '95% depleted' then moves over and up the 'stack'. If it's the last one, it could query through the batteries to see if any then have charge - if not it prompts the user to shut down.


For charging it starts with the top/closest battery and charges until it says '100% full' then moves to the next and stops or recycles the list as appropriate.


Or were you back on the 'AA battery pack' idea again?

 

[Exophase]

No I'm not on the AA battery pack idea, that idea sucks Of course you can do this with custom battery circuitry (or some additional chip) if the PMIC doesn't already support it. That isn't the point. The point is that that's a really big design effort for something like Pandora, and not really worth it for a feature most won't want to use, especially if it eats up precious board space. To facilitate hot swapping one of two batteries you would also have to design it so the battery you aren't removing stays securely in place while you swap the other one out.


I really don't understand the point of hot swapping batteries to begin with, when the OS should be capable of suspend, including automatic suspend + shutdown when the battery gets low. Then you can do a complete swap instead of only swapping out the batteries in 50% capacity increments, and just have to spend several seconds to get in and out of suspend.


_wb_ says he wants to be able to use smaller batteries because it lowers the weight of the device. Having used the Pandora w/o a battery I really don't like this kind of weight reduction because it makes it partially hollow and uneven.

 

[SNESFAN]

Agreed on the weight balancing concern.


You can get those super extended batteries for smartphones that double or tripple the stock mah. It was my understanding that the battery its self had a chip that regulated and controlled how the voltage was used to charge and discharge the battery.


I can see a cheap hack not working but if op ordered batteries with double the mah and a extended battery housing surely it would work right?

 

[Binky]

I'd have a central rib along the bottom of the unit, with a USB 3.0 port (electrically, maybe not physically) front and back.


The main unit would have a permanent, high-speed memory chip (16GB?) primarily for boot and a microSD slot for user data (by default), and microUSB otg.


Possible modules would include:

Slim battery - 2Ah

Extended battery - 4Ah

Community favourites pack - twin fullSDXC, R2 & L2, and two fullUSB ports

Bonus connectivity pack - ethernet, eSATA, fullHDMI out, PS2

Super sensors - GPS, DAB/DVB, Accelerometer, Magnometer, Gyro

Hacker module - arduino-compatible board in a mostly empty bot (with knock-out panels)

A blank (empty) box for people wanting to save weight or money

A typical android user might like a slim battery and a super sensors module


I would like an extended battery and community favourites pack (but would swap all of the others in from time to time.


fitting two extended batteries would make your P2 very chunky, but would provide a stupendous battery life.


A single slim battery would be very light and rather boring


I realise that three of those would take a lot of effort to design, and all would come at a cost.


If such a system were in place, the P2 would be my perfect toy computer