@Arko

So, mister Always Helpful, what is it you need help with now?

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@olegil

>>Person B wants to make his own shell AND battery pack. He MUST know the voltage, he doesn't NEED to know the current.

Assuming that Person B is me... (I am going to deny everything, it feels like being back at school).

What voltages do I need to know to power a SAM460+SSD+LCD (LED?) screen?
I need to feed the lot with 12V correct? KABOOM!

_________________
www.loriano.pwp.blueyonder.co.uk

@olegil

Quote:

olegil wrote: @Arko So, mister Always Helpful, what is it you need help with now?

No, it's not me searching for help with used Laptop hardware and exotic motherboards.
No, it's not me who is always asking things, that where told before.
No, it's not me who can't buy a Laptop for his preferred OS.
No, it's not me who started this thread.


Rhetorical questions are often seen as some kind of attack.

And no, it’s not me spreading this kind of negativeness in this thread.


I had built my Amiga portable years ago and I had a lot to do with hardware designed for portable PCs.
That’s why I used to tell about possible problems hobbyists will have with missing drivers and hardware.
That’s why I try to convince some people not to ask for a full mobile laptop.

_________________
AmigaONE. Haha. Just because you can put label on it does not make it Amiga.

I borrowed this comments from here (#27 & #28):
http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=38873&forum=2&start=20&order=0

@olegil

ah alright. I misundertood the thread then. I thought the goal was to create a "laptop for evey amigans" like a production batch.

Thanks

_________________
Philippe 'Elwood' Ferrucci
Sam460 1.10 Ghz
AmigaOS 4 betatester
Amiga Translator Organisation

@elwood

“production batch.”

well actually we are just on the planing stage, people will try to produce some thing, if we have some success whit that, then maybe some will make a production batch.

First you see bunch of ugly experiments, hopefully whit a bit of work some one can make something that looks nice.

Last edited by NutsAboutAmiga on 04-Dec-2013 at 08:39 PM.

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Quote:

elwood wrote: ah alright. I misundertood the thread then. I thought the goal was to create a "laptop for evey amigans" like a production batch.

Different people have different approaches to the general topic at hand.

Some of us talk about makin ga custom laptop case to put one of our smaller desktop boards into.

Some of us talk about hacking up a PC laptop shell to fit a potentially hacked up board into.

Some of us talk about Hacking a board into an old suitcase.

Some of us talk about making a new motherboard design to fit cleanly into some suitable PC laptop shell as if the entire package was designed that way.

There's tradeoffs each way around.

_________________
All glory to the Hypnotoad!

@olegil

I'm a person A, I have 5 different laptops I can hack apart and possibly put in a Sam440ep board.

If I were to be successful we would all know which size case would be necessary and then possibly reproduce the case + board and do a mass product.

_________________
1 AmigaOne G4XE (OS4 Pre-Release Update4)
Minimig
Sam440ep + OS4.1FE
Sam460cr + OS4.1FE

@TheDaddy

I already explained this a few times:

You need a wall-wart suitable for a laptop, and a socket you can put in your case which fits the plug on the wall-wart. This will have an output that you can feed to the input side of the battery management board I linked to earlier. See the spec for that one which voltages will work. It depends on how many cells you want total, for 6 or 9 cells use three in series, for 4/8 use 4 and for 5/10 use 5 in series. 5 cells gives you a top voltage of 21.5V, 3 would only be 12.6V. So the ball is in your court on that one

Next, the battery (constructed from the cells) connect to the same management board, on the battery side.

Then there's the PicoPSU which connects to the output side of the battery management board, this needs to also handle the highest voltage you can have (which is about 4.3V per cell).

Go back and check out the items I linked to again.

The voltage I mentioned in the post you quoted is for estimating how much charge is on the battery, measuring the voltage should generally be considered "good enough" if you don't have a gazillion other Power Management features. This means you'll know in percentage that you're running out but won't get the "time left to (dis)charge" indicator that some people like to use. My wifes HTC One doesn't have this, it only gives state of charge as a percentage with a few warnings as it drops to 14, 7, 6, 5, 4, 3 percents and finally it just shuts power. If millions of phone users can do with only knowing the voltage, so can you

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@1Mouse

If the laptop is recent enough then ebay should cover us for years to come (mine is 10 years old and I still found 50 on them on ebay yesterday if I had needed them).

The thing is: Some laptops have EXTREMELY small motherboards. These are a problem. A laptop with dedicated GPU is best bet for big enough board. The modern ultrathin ones are right out. This is the reason why I would go with an older case instead of spending time searching for a modern one.

This won't be an ultralight, it'll be what we comfortably carried around 4 years ago.

Edit:
I forgot to mention. I'm person A as well. And a little of person D from the list billt gave

Actually, I WANT to be person D but have realized that a lot of what person D needs to know before he can succeed will lead to very easily being person A first. So person A is a stepping stone towards person D here

Last edited by olegil on 05-Dec-2013 at 10:25 AM.

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@billt

And some of us just generally like to talk

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@olegil

Thank you for explaining it to me again.

What happens if you give more volts than the system requires to function?

What kills an electronic component like a motherboard?

_________________
www.loriano.pwp.blueyonder.co.uk

@TheDaddy

If the motherboard is being fed by the Pico PSU, then its output will be safe for the mobo. The weak point is likely to be the maximum input voltage that the Pico PSU can tolerate.

I don't know what that is. I only know about the "Pico-like" PSU that I bought some years ago, that HAD to have a regulated (exact) 12V input, nothing more, nothing less. The real Pico may be different.

[edit]
After looking up some details for one of the Pico PSU models, I see that it also requires an exact 12V input. That means that you will need another regulator from (whatever your battery voltage is) down to 12V (to feed the Pico).

It was for that reason that I converted my "Pico-like" PSU from 12V input to 12-24V input. I use a separate 12V regulator (home brewed) only to supply the 12V loads in the machine. It is switched on/off by the ATX power switch in the Pico PSU.
[/edit]

Last edited by tonyw on 05-Dec-2013 at 09:33 PM.

_________________
cheers
tony

Hyperion Support Forum: http://forum.hyperion-entertainment.biz/index.php

@tonyw

I've explained that several times in this thread as well. PicoPSU comes in two types: 12V only, and 12-25V. The latter is slightly more expensive and only available in select models.

The 12V model can not be used as the voltage will be above 12V in certain cases and this WILL fry electronics.

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@olegil

Sorry, I hadn't seen where you mentioned that. A wide input tolerance certainly is a great advantage.

_________________
cheers
tony

Hyperion Support Forum: http://forum.hyperion-entertainment.biz/index.php

@tonyw and olegil,

Great that makes sense. What about amps? When do they come in to play?
What do we look for?

_________________
www.loriano.pwp.blueyonder.co.uk

@TheDaddy

Think about AMPS is like water flow, if you think about a river, where you have waterfall the higher the water fall, the more potential energy (or pressure) similar to voltage.

You can think about voltage as consistent, a 5V battery and it will be 5v to 4.5v until it runs out, newer battery's types are better and might keep 5vdc until it runs out, when it runs out drops off to 0v, the AMPS however is depended on the resistance, lower resistance higher flow of electrons (higher amps).

Battery have amps/hours sticker on it, it tell you how long the batter last, from this you can calculate how long the battery last depending on current or flow.

Battery connected in parallel can give out more amps, batteries connected in serial gives you more volt.

Resistance is like a water tap, it restricts the flow of electrons, everything has resistance.

Ohms low, states this mathematical formula.

U = I * R
P = I * U
P = I^2 * R

Last edited by NutsAboutAmiga on 06-Dec-2013 at 12:59 PM.
Last edited by NutsAboutAmiga on 06-Dec-2013 at 04:33 AM.
Last edited by NutsAboutAmiga on 06-Dec-2013 at 02:30 AM.
Last edited by NutsAboutAmiga on 05-Dec-2013 at 10:44 PM.

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Facebook::LiveForIt Software for AmigaOS

@NutsAboutAmiga

About the only thing I liked in that post are equations (though they are a MAJOR simplification to the real world, but close enough for most uses )

analogy for DC:
potential (symbol U, unit V) as pressure
current (symbol I, unit A) as flow
resistance (symbol R, unit ohm) as narrowing of the outlet.
power (symbol P, unit W)

As you turn the tap towards open, R becomes smaller and I increases.

Battery capacity is measured in current over time. If you do 1 A for 1 h you have used 1Ah from that battery. The energy you got from the battery is dependant also on the potential, how many Volts you had. For a battery this is NOT a fixed value, as it decreases with the remaining charge.

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@olegil

This is what I found about battery discharge curve.

Quote:

Discharge Curve The voltage of a cell drops over the course of its life as it discharges. The characteristic discharge curve varies considerably over different types of cell. For example, alkaline cells have a fairly linear drop from full cell voltage to zero volts. Since the drop is gradual, it is usually easy to tell when the battery capacity is used up and the battery needs replacement. Nickel cadmium cells have a slower linear voltage drop region up to a certain point after which the voltage then falls off sharply. The more constant voltage is important for some applications, but it also means that nickel cadmium cells will appear to suddenly "die" with no warning.

Well I'm not so shore about the battery subject, because I know there has been a lot of progress into making better batteries lately.



The problem here is to do whit finding out when the battery has used 10%, it has used 50% and when it has used 80%,
Lithium-thionyl chloride battery will have more less constant voltage to 60% of the battery.
Lithium-sulphur-dioxide battery will have constant voltage to about 90% of battery.
Lithium-manganese dioxide battery increases in volt over time and drops at about 60%

Last edited by NutsAboutAmiga on 06-Dec-2013 at 02:34 PM.
Last edited by NutsAboutAmiga on 06-Dec-2013 at 02:33 PM.
Last edited by NutsAboutAmiga on 06-Dec-2013 at 01:47 PM.

_________________
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Facebook::LiveForIt Software for AmigaOS

@TheDaddy

The reason that no one has given you the answers you want is that "it depends". There are too many choices. I hope this will show you what the choices are and how to make your decision.

Ignore the too-much-information. Forget about how many cells we need in the battery for the moment, just think first about the capacity that we want.

Regardless of the battery voltage and current, the mobo and other loads add up to a certain number of watts. That power (watts) is made up of the power taken by each of the various loads (5V, 3.3V, 12V, etc). The individual currents don't matter. The total power needed is the product of the voltage at the input to the power supply and the current drawn from the battery.

The power supply will produce all the right voltages for the loads when fed a suitable input voltage. If you increase the input voltage, the power supply will take less current from the battery - the product will remain the same (within limits). If you use a lower battery voltage (or as the battery runs down), the power supply will take more current from the battery to get the same amount of power to run the computer.

That's a simplification, of course. The power supply has a finite efficiency, probably about 80%. So it's going to take a bit more from the battery than the computer needs, and parts of it are going to get warm. Suppose that we need 15 watts power to run the computer (total). That leads us to estimate an input to the power supply of about 18 watts. We could provide that by using a 12 V battery and the power supply will draw 1.5 A from it (1.5 * 12 = 18). Otherwise we could use an 18 V battery and only have to provide 1 A, or a 24 V battery and only 0.75 A (etc).

Depending on the voltage of the available cells, we can choose a convenient number of cells to connect together as a battery. The diagram above shows that modern Lithium thionyl cells generate about 3.6 V, although it changes over the discharge cycle.

Assuming a cell voltage of 3.6 V, then we could use say 5 cells in series to get about 18 volts. Ideal for the input to the power supply, you might think. But then you have to consider how long it's going to last before it runs down.

If the battery delivers 18V to the power supply for a total of 18 Watts, then clearly the power supply is going to take about 1 Amp. An "AA" size Li-Ion cell has a capacity of 2.1 Amp-hours, so in theory will provide (when new and fully charged) a product of 2.1 (amps * hours) over its discharge cycle. In practice, you need to use a bigger capacity because draining the cell(s) completely to zero is bad for them over time. The makers usually recommend draining only 50% of the capacity for long life. Of course, it doesn't matter how the cell voltage changes as the battery runs down - the power supply adjusts its current drain so as to provide the correct outputs to the computer.

So you could double the number of cells from 5 to 10, giving you 36 V, but that is too high a voltage for the power supply to handle. Reconnect the 10 cells so that you have two strings of 5 cells each, in parallel. Now you have an 18 V battery again, but with twice the capacity. Or else you could use a cell in a larger case (more capacity). The choice is yours.

Of course, if you are looking at using an existing laptop case, the smart thing to do would be to reuse the old battery - it fits, has a built-in mounting and charger, can be replaced, etc, etc.

_________________
cheers
tony

Hyperion Support Forum: http://forum.hyperion-entertainment.biz/index.php

@thread

In case this helps on battery decisions...

My recent-vintage HP laptop runs off a 14.4V battery. The laptop works fine until the voltage starts getting close to 12V. I presume parts of the system such as the CCFL driver need the 12V.

If we are talking 3.6V cells then that's 4 cells.

These appear to be a ton of 14.4V Li-ion laptop batteries on eBay. In theory you should be able to find a generic charging circuit that will work with those? Whatever laptop shell you start from will accept a matching battery, likely Li-ion. Note: Upon further digging there is a lot of complicated communication going on between the battery and the laptops that appears to vary by make/model. Best left to a later phase, if ever.

Last edited by gregthecanuck on 07-Dec-2013 at 01:05 AM.
Last edited by gregthecanuck on 07-Dec-2013 at 12:52 AM.