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wsuetholz
Hello,
Would this type of battery work? If so, then could the battery be integrated into where the hinge is? I realize that this is probably not workable, but, cheap batteries, and the possibility of simplifying the system board layout by not putting the battery in the middle of it, ok, to one side.

2700ma AA rechargeables
Da_Blitz
i dont think that making a model that runs off AA battries would be too hard, it would require a diffrent charger IC so it might be worth ronsidering putting an 8 bit micro in thier to handle charging. that way we wouldnt need a diffrent hardware rivision.

the only thing i can see wrong with AA battries is that they are quite high. but i think my Z's battrey is a bit higher sad.gif

where this would work well is in the sidekick gull/wing type design where we could put the battries right at the edge and leave all of the middle just for PCB

i am considering the battry placment to be off to one side or if we use AA at the back
BarryW
Has anybody looked into the sony video camera batteries?? Would be kinda cool, if you had to be away from power for awhile just pop in one of the really big ones.
Da_Blitz
i belive someone mentioned that, guess it all depends on the case, which seems to be having a huge impact on this project (more than i would have thoght)
Ferret-Simpson
I think digital Camcorder batteries are the best option. Chaging over a USB connector?

We're looking at 2 USB ports. . . I vote we make one an OTG port with that lovely little connector and use that to charge, like on the Universal, and my Abacus. That could be the one on the back for stacking with expansion packs? Makes a docking cradle as simple as a usb cable connected straight to a 5v line (via some sort of regulator and switch to autoselect between power from USB cable and power from Mains Charger) and from the USB cable's data lines. Just mount that on a moulded or formed aluminium base, stick in a blue LED to look cool and away we go! Then just use the USB cable as a network to your linux box (Because Windows 5ux><0RZ, naturally!) and away we go! Suddenly you have a bluetooth, Wifi and 3G access point for your aged pre-wireless Vaio.

Ok, that's SLIGHTLY off topic. . . but yeah, Camcorder battery.
daniel3000
Having AA batteries (optionally rechargeable) would be awesome!
Imagine batteries are empty on the go, and you can simply go into the next shop and buy a pair of new ones for a few dollars.

That was one of the big advantages of the HP 200LX (sorry to mention that again! ;-)

Also, a buffer would be good so that the device doesn't have to be rebooted on battery exchange. Tat's one thing I don't like with the Zaurus.

daniel
Ferret-Simpson
Yeah, but how many mAh does a normal AA hold? E.G. A Duracell Ultra. . .?

It's a goo idea to be able to do that, but Not all batteries are the same. . You'll find yourself suddenly going dead. . .
desertrat
QUOTE(Ferret-Simpson @ Aug 18 2006, 12:31 PM)
Yeah, but how many mAh does a normal AA hold? E.G. A Duracell Ultra. . .?

NiMH batteries goes up to 2700mAh at least, I suspect alkalines (or other non-rechargeables) will do quite a bit more. Using AA batteries will make it "future-proof", ie you can instantly take advantage of any advances in that technology, eg my first set of NiMH AAs were rated 1300mAh, my latest at 2700mAh.

-- cheers
Da_Blitz
actually from what i have seen alkalines only do about 1000maH but the battery discharge curve is diffrent which for some applications means it gets a longer life

basically an alkilines charge can be worked out from the voltage because as the charge goes down so does the voltage, with the rechargables its at about 90%-100% voltage until you hit 80% capacity, at which point the voltage drops throgh the floor

now if you have a device that requires x volts and is sensetive to changes then you can see that an alkaline would dip past there sooner. however wether or not this would effect s would have to do with the chipset i use for charging, and a bit of testing however i am inclined to use li-Ion due to the weight/capacity advantages

one other thing to note that 1 3.7v litium ion battery @ 1000maH is equal to 3x 1.2v NiMihs @ 1000maH (you cant jus mach maH you have to match the power (power = voltage x current/maH)) so even if the NiMih is 1000mah, i have to pull tricks to bump that up to 3.3v and 5v (cpu IO and USB and perhaps 2.5v) but to do so i have to consume extra current

i am tired at the moment so there may be a mistake in the above statment but basically you dont get somthing for free
zedkatuf2
QUOTE(desertrat @ Aug 18 2006, 03:24 PM)
QUOTE(Ferret-Simpson @ Aug 18 2006, 12:31 PM)
Yeah, but how many mAh does a normal AA hold? E.G. A Duracell Ultra. . .?

NiMH batteries goes up to 2700mAh at least, I suspect alkalines (or other non-rechargeables) will do quite a bit more. Using AA batteries will make it "future-proof", ie you can instantly take advantage of any advances in that technology, eg my first set of NiMH AAs were rated 1300mAh, my latest at 2700mAh.

-- cheers
*



The "energy density" ie [mAh x Voltage]/mass for NiMh batteries isn't so good (ie it's smaller) compared to Li-ion or Li-polymer batteries.

I've not been following this thread, but generally it seems that Li-polymers are the best approach (more expensive, but worth it IMO)

zedkatuf
Ferret-Simpson
http://www.mobilefun.co.uk/product/11276.htm

Beat THAT for a PDA battery!

3200mAh, and although it's not the smallest battery ever, it's not worldbeatingly huge. It's a standard accessory for the HTC Universal phones, so they're a commercially viable option. I can't see how we could feasibly get a higher capacity battery, of an acceptable size, for the same price.

Opinions? Gotta love the Universal. . .Solving so many problems. . .
Ferret-Simpson
Does No-One have an opinion on this?
zedkatuf2
QUOTE(Ferret-Simpson @ Aug 26 2006, 12:24 PM)
Does No-One have an opinion on this?
*


Looks good smile.gif
Da_Blitz
i havent had a chance to look at the link 9still on the command line with links here and will be for a couple more days) however if its anything like the mega backpak for the xda2 form li-ion.com (i belive thats the link) then its worth looking into

hopfully we can get a rectangular square battery, i do like nice flat ones instead of a thick brick as it gives me more horizontal board space and makes the board easier to route

an unexpected side effect is that we can take a nokia battery and stack several side by side meaning we get the magical "hot swap" ability, just dont pull all the battries at once, anyone got any idea what the maximum capacity for one of those batteries are, hopfully its 1Ah and we can get 2 side by side, if we can get 3 then 800mAh should be enogh

anyway i should have my new Xen setup running in the next day or two so i can do experiment with the pcb stuff in windows in a virtual machine (got to love the new x86s)
Da_Blitz
forgot to mention the obvious wink.gif however nokia or mobile phone battries should be easy to get so they work out well, in fact they are litterly off the shelf items smile.gif happy hunting
Ferret-Simpson
You picked the right guy. XD

The newer Nokia batteries are a little odd. . However the past standard batteries are the BL-5C, as seen in the 6230, and the BL-4C slimline, which is a little older.

The 4C is 750, the 5C is 850. I'm going to guess you'd connect them in parallel. . ? Or each with a controller separately? They're 3.7V models, the ones that people hack for the 5500.

I've ordered one of the 3200mAh Universal batteries for my XDA, but I don;t know yet how large they are. Will measure it when it arrives. 2 Nokias fit in the same space as the standard 1620mAh Uni battery, but this thing is designed to be double the power rating, so I'm going to guess at about double the size.

If you can get 3 Nokia batteries in this thing (What about the Second Serial Screen?) then we've got 2550.
Da_Blitz
still havent seen the pic is it a rectangular battery or is it desined to be integrated with the back plate?, if it isn't rectangular (like the nokias) and instead is designed to seamlessly fit as one peice to the back of the xda then i would have to rule it out
Ferret-Simpson
Mine hasn't arrived yet, but it's separate from the backplate. (A new backplate is supplied as it doesn't fit under the standard one, but the two are not attached.) If you have a Normal Uni battery, it's the same but a few MM deeper. (And Double the capacity.) You'd need at least 3 Nokia's in the PDA to get a worthwhile battery capacity, Four of the Larger Nokia's before you could outrank this battery. Only problem with it of course, is that it's deep. I'll give accurate measurements of mine before I install it.

In terms of the nokia batteries, Since the PocketPenguin has a lrager screen, we could feasibly get four in (3400mAh) by having them in pairs, Oriented the same way as the device, two rows, two columns. . . And we'd still be able to hotswap batteries. However, Four Nokia Batteries can cost up to £100. . (From say. . A nokia shop.) £40 is the cheapest non-Ebay you'll find, Whereas a Jasjar is about £25. http://www.mobilefun.co.uk/product/11055.htm - Wouldn't mind four of THOSE in it, (4000mAh PDA) Hey DB, If we do go down the Nokia route, want to design a 6-Battery external Charging Unit for Nokia BL-5C and compatible Batteries?
Da_Blitz
once i have X up and running ill have a look, at the moment i am only getting an hour at a time to fix my PC which is slowing me down but if its seperate then that might be a better route as "IF" we do the folding keyboard then the thinner the battery the better and if its thinner than a nokia then it looks like the one to get, plus we know we will be able to get the batteries for at least 2 years
Ferret-Simpson
Nono, It's thicker than a Nokia. About Double the depth I think. Which is Why I said maybe the Standard Nokia's in a 2x2 matrix was probably a better idea. . .?
Da_Blitz
my bad, i will need to check the mesurements for nokia battries, 4 seems like alot

as long as this is planned out well you wight still be able to use the xda battery pack
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