Blog #98 Micro$oft's Patented "Instaload" battery holders

[imanhp]

I would be surprised if they would get the patent approved due to this (5,431,575) older and very similar patent: http://www.google.com/patents/about?id=TGYgAAAAEBAJ&dq=5,431,575

[TheDirty]

I would be surprised if they would get the patent approved due to this (5,431,575) older and very similar patent: http://www.google.com/patents/about?id=TGYgAAAAEBAJ&dq=5,431,575

I thought they already got the patent, but ya, you found it.  That's the exact technology, already patented.  Minor differences that I can see from a quick scan, but really the same thing.

[David]

I would be surprised if they would get the patent approved due to this (5,431,575) older and very similar patent: http://www.google.com/patents/about?id=TGYgAAAAEBAJ&dq=5,431,575

It looks as if that patent is almost identical!

[Simon]

did M$ really do anything of their own ? no not that i can recall, half their OS is subcontracted and then they go messing with electronics......

[ThunderSqueak]

I have 2 computers that take AA batteries...

a Tandy TRS-80 Model 100 (maxed to 32k ram and has an assembler option rom installed) which According to Gates, "part of my nostalgia about this machine is this was the last machine where I wrote a very high percentage of the code in the product".

and an HP 200LX that has PC-GEOS installed on it.  Both still work great

[saturation]

I did know the Model 100 used AA, that's a lot of AA I guess!



While I like Li for power density, I'm not a fan of their erratic behavior if left unused or worse if fully discharged and stored, nor that it just ages and dies even if unused or violently explodes if charged improperly.



In my personal experience, I've seen some of Chinese no-name Li get unbearably hot and start deforming its casing for no apparent reason, it was fine when it was young.

NiMH can be stored as is and will stay relatively fresh if unused for years,

http://www.mrs.org/s_mrs/sec_subscribe.asp?CID=12302&DID=236622&action=detail

... just cycle them to get them awake, and if improperly overcharged will just bubble out and die a graceful but user safe death.

I've had this happen to me 2x but not as severe, using again, no-name Chinese NiMH cells charged properly in a charger.



Old NiMH past its lifetime get senile in terms of mAh and just sleep permanently neither blowing up, overheating, nor holding a charge.

So, I'm not just a fan of NiMH, AA, and AAA for its ubiquity and ease of working with, but its safety and low cost.  While the form factor leaves problems, an AA powered device from the 1990s likely will work today by just putting fresh cells into them, while a Li powered device will need a new battery or pack that may be difficult to find.

I have 2 computers that take AA batteries...

a Tandy TRS-80 Model 100 (maxed to 32k ram and has an assembler option rom installed) which According to Gates, "part of my nostalgia about this machine is this was the last machine where I wrote a very high percentage of the code in the product".

and an HP 200LX that has PC-GEOS installed on it.  Both still work great

[charliex]

A lot of laptops take A/AA cell batteries (and other sizes) they're just packed into a single unit, my vaio tr2a extended is like 9 of them if i recall.

Even some car batteries are just a whole stack of D cells.

[alm]

I think they use 18650 and similar sizes, I don't think there are many Li-Ion batteries in A/AA size, and nickel-based batteries haven't been used in laptops for a long time.

[saturation]

To add to Alms comment, Li are not widespread as AA or AAA to avoid accidentally selling them aftermarket or putting them in an AA or AAA required device by mistake.  The base voltage of Li is ~ 3.6V per cell, 3x that of single NiMH, which is the most common form for AA and AAA.

There are various cell types that look similar at face value, until you truly compare them side by side.  14500 is fairly close, but if you do insert it, some can be just a touch short and narrow.

A lot of laptops take A/AA cell batteries (and other sizes) they're just packed into a single unit, my vaio tr2a extended is like 9 of them if i recall.

Even some car batteries are just a whole stack of D cells.

[alm]

They are available in 1/2AA sizes (at least the primary lithium cells are), so you could put two of those in series if you're really motivated .

[charliex]

yeah 14500s are AA sized 50mm x 14mm
 

[NiHaoMike]

To add to Alms comment, Li are not made AA or AAA to avoid accidentally selling them aftermarket or putting them in an AA or AAA required device by mistake.  The base voltage of Li is ~ 3.6V per cell, 3x that of single NiMH, which is the most common form for AA and AAA.

I have 4 AAs that are LiFePO4. I bought them at Wal-Mart, probably originally intended for toy airplanes or something. (That was when LiFePO4 was just appearing on the market, very surprising to see them in a store that does not specialize in electronics.)

[DJPhil]

. . . PC-GEOS . . .

I did a double take on that one! 

I had to look it up. It seems the GEOS I remember for the Commodore was made by the same folks, and after changing hands a few times it's still going. It's now known as the Breadbox Ensemble, and the last update was Aug 2009!

Makes me wish I'd have kept up better, I was busy messing with Windows.

[Zero999]

It would be cool to have a laptop which takes standard AA batteries but it would need quite a lot of them, say 14V for a nominal voltage of 16.8V, 21V hot off the charger. The trouble is it would need to be quite large to accomodate all those batteries and it would need some protection to prevent the user doing something stupid like using ordinary alkaline cells. Still I like the idea of not having to go to a specialist supplier to replace the batteries.

[saturation]

If mA requirements are reduced, DC-DC conversion is about 90% efficient and can generate 5V easily from 1.2V.  The smaller the difference between required and supplied voltage, the more efficient the conversion is.

The real problem with AA is mostly the form factor than the power density.  The mass market is driven equally but style, rather than economy of use.  To keep the demand for electronics high, longevity isn't tops on manufacturer's list, so if you find an AA powered device, grab it while you can.

For example, in the exploding eReader market, the Ectaco jetbook lite, also known in China as the Dr Yi reader, has an AA powered version, and its sweet, IMHO.  Other versions are Li powered.  There is also another clone the Libre, but all 3 have different firmwares so they are more cousins than identical twins.

Dr Yi, Jetbook and Libre:

It would be cool to have a laptop which takes standard AA batteries but it would need quite a lot of them, say 14V for a nominal voltage of 16.8V, 21V hot off the charger. The trouble is it would need to be quite large to accomodate all those batteries and it would need some protection to prevent the user doing something stupid like using ordinary alkaline cells. Still I like the idea of not having to go to a specialist supplier to replace the batteries.

[charliex]

I guess i can't see the desire for wanting AA's over 18600 or packs. They're going to be workable for at least 6 months, then its typically just lower capacity. Which AA's aren't a good density anyway.  In most places i've been you can find a store that'll have some of the most common packs if you get stuck.

[saturation]

Uniformity.  I can use the same cells and a single type of AA/AAA charger to work many devices, AA/AAA is a lot easier to find anywhere in the world, and in a pinch, you can use alkaline disposables too.

Many retail place do carry Li packs but commonly for devices they sell, or for popular devices and all are specifically meant to be user serviceable: e.g. cell phones, PSP, digital cameras.  Finding iPods, iPhone, etc., battery packs won't be as easy and are not user serviceable batteries. 

To charge Li pack requires you bring individual chargers with you, or to buy a specific universal charger with the specific adapter per pack.  For AA/AAA its just one charger.

I guess i can't see the desire for wanting AA's over 18600 or packs. They're going to be workable for at least 6 months, then its typically just lower capacity. Which AA's aren't a good density anyway.  In most places i've been you can find a store that'll have some of the most common packs if you get stuck.

[Zero999]

he smaller the difference between required and supplied voltage, the more efficient the conversion is.

Only if it uses a buck or boost topology.

Using a transformer based topology means that the efficiency can be the same regardless of the input-output voltage differential.

The real problem with AA is mostly the form factor than the power density.

Are you sure?

I thought NiMH has a similar Wh/L as Li-ion.

http://en.wikipedia.org/wiki/Nickel_metal_hydride_battery

"NiMH has a volumetric energy density of about 300 W·h/L (1080 MJ/m³), significantly better than nickel-cadmium at 50–150 Wh/L, and about the same as Li-ion at 250-360 W·h/L."

  The mass market is driven equally but style, rather than economy of use. 

That's true, people are expected to upgrade fairly often.

I don't know, perhaps Li-ion is cheaper per Wh than NiMH.

[charliex]

I don't think i'd want an iPhone that ran off AA's , in a laptop with alkaline AA's i doubt you'd make it to the boot screen. Even my old nikon c900 lasts a very short time on 4 alkaline AA's. You could always just make a battery box with a hydra lead that could take AA's and use that for emergencies, i'm sure such things exist, solar chargers etc.

I think I'D rather AA went away , or at least something else became more common. But it seems that for that convience of uniformity and mass availability you're giving up stuff thats taller.

[saturation]

Yes, you are right on efficiency.

My bad, wrong term, not "power density", but specific energy.  Wh/L Li ~ NiMH, but specific energy Wh/kg Li 2-4x > NiMH.  Here is LiPo, but you can check on other Li varieties.

http://en.wikipedia.org/wiki/Lithium-ion_polymer_battery

As for cost per Wh, it depends on the usage and how the design uses the battery.  There are flame wars in digital camera newsgroups about this subject.  Since the 3.7V 1-2AHpack costs about $6-10, aftermarket, which equivalent is 3 NiMH cells 2-2.7AH ist $2-3@ = $6-10, they are about even.

http://batterydata.com/

What is certain between Li and NiMH is there are few Li standard sizes, many custom cell sizes, and Li age faster than NiMH after manufacture, so its use it, or lose it by 3-5 years.  Li cells are mostly specific for an intended device, whereas AA NiMH are generic sizes can be used on multiple devices, if you plan your device purchases to insure it supports AA.  NiMH loses capacity based on charge/discharge cycles, so the more cycles the faster it ages.

If NiMH is just stored at room temperature charged, it will still be usable many years after LiPo no longer works.  This assumes on NiMH you recondition it before use after stored, and you never deep discharge it past 0.5V by leaving it in a device left ON. I have NiMH cells still in service, between 7-10 years old. 

he smaller the difference between required and supplied voltage, the more efficient the conversion is.

Only if it uses a buck or boost topology.

Using a transformer based topology means that the efficiency can be the same regardless of the input-output voltage differential.

The real problem with AA is mostly the form factor than the power density.

Are you sure?

I thought NiMH has a similar Wh/L as Li-ion.

http://en.wikipedia.org/wiki/Nickel_metal_hydride_battery

"NiMH has a volumetric energy density of about 300 W·h/L (1080 MJ/m³), significantly better than nickel-cadmium at 50–150 Wh/L, and about the same as Li-ion at 250-360 W·h/L."

  The mass market is driven equally but style, rather than economy of use.

That's true, people are expected to upgrade fairly often.

I don't know, perhaps Li-ion is cheaper per Wh than NiMH.

[saturation]

Yes, neither would I, NiMH specific energy isn't practical for cellphone or laptop use.  We aren't even considering alkaline chemistry, because it cannot deliver high current. 

Li still cost more to manufacture versus NiMH in AA form, so for sheer economy of running, NiMH really is just the rechargeable version of were an alkaline battery is applicable.

As for wanting AA to go away, that maybe.  But if you had to choose what your device uses where both Li and NiMH AA are applicable, the bigger question is the importance of size, and weight over economy of operation.

I don't think i'd want an iPhone that ran off AA's , in a laptop with alkaline AA's i doubt you'd make it to the boot screen. Even my old nikon c900 lasts a very short time on 4 alkaline AA's. You could always just make a battery box with a hydra lead that could take AA's and use that for emergencies, i'm sure such things exist, solar chargers etc.

I think I'D rather AA went away , or at least something else became more common. But it seems that for that convience of uniformity and mass availability you're giving up stuff thats taller.