i want to make something

[ZippyDan]

1. I want to attach a bunch of cell phone batteries together to get me a longer run time... I assume this is as easy as wiring them together in parallel

2. I want to power a cell phone AND some miscellaneous other devices from the same aforementioned battery pack. As I remember, amperage doesn't really matter as long as enough is available, but the devices do all run at different volts (none require more than the output of a single cell phone battery). I'm not really sure how to wire multiple devices to run from the same battery pack and all at different voltages.

3. I want to charge the battery pack using the microUSB connector of the aforementioned cell phone AND the jack of a laptop motherboard as the power source (I will solder a microUSB cable from the jack to the phone). Again, I think the input voltage from the wall adaptor and the required charging voltage may not be the same. To make things more complicated, I expect to still simultaneously charge the laptop's battery and run the laptop at the same time. How can I do this?

If you are curious as to what exactly I am trying to accomplish, you can search for my other thread in the general hardware forum.

 

[Cogman]

I want to attach a bunch of cell phone batteries together to get me a longer run time... I assume this is as easy as wiring them together in parallel

Ehh... depends on the type of cellphone. The overcharge protector might (probably will) give you some headaches.

I want to power a cell phone AND some miscellaneous other devices from the same aforementioned battery pack. As I remember, amperage doesn't really matter as long as enough is available, but the devices do all run at different volts (none require more than the output of a single cell phone battery). I'm not really sure how to wire multiple devices to run from the same battery pack and all at different voltages.

In parallel if you get past problem 1 and with something like this in between the battery and the device.

I want to charge the battery pack using the microUSB connector of the aforementioned cell phone AND the jack of a laptop motherboard as the power source (I will solder a microUSB cable from the jack to the phone). Again, I think the input voltage from the wall adaptor and the required charging voltage may not be the same. To make things more complicated, I expect to still simultaneously charge the laptop's battery and run the laptop at the same time. How can I do this?

This sounds like a good way to ruin a lot of batteries and potentially start a fire. If these are lithium ion batteries, you want to make sure that you aren't overcharging the things (fire) and undercharging them will permanently damage the batteries. What you are proposing here sounds dangerously close to something that is going to bypass circuit charging protection.

Be very, VERY, careful if you decide to go forward with this.

 

[ZippyDan]

Thanks for your help.

So basically I'm trying to incorporate a GPS and RF tracker into a laptop for the purposes of catching a habitual thief. The thief is smart enough to wipe the hard drive, but (I don't think) not enough to disassemble the computer. I need the tracking devices to operate independently of the laptop battery so that the thief can't just turn off the computer, hence the need to use a separate cell phone battery. I want to use several batteries in parallel simply to extend the run time. I want all the batteries to recharge whenever the thief charges the laptop to allow the tracking to work indefinitely if needed.

Ehh... depends on the type of cellphone. The overcharge protector might (probably will) give you some headaches.

This is why I was planning to charge the batteries through the USB port of the cell phone circuit board, because then I assume I would be using the built-in overcharging circuitry. Since many cell phones can accept oversized batteries, and since a battery is made up of several cells in parallel, I figured this should not give me much of a problem. That said, I am a little concerned about the extra contacts aside from positive and negative that are often on these batteries (usually there are 3 or 4 contacts in total). I believe the extra contacts are usually for a thermistor? Or they perform other functions related to tracking the battery's status (charge, heat, etc.). Should I wire these extra contacts in parallel as well? Or just connect one of the three batteries?

In parallel if you get past problem 1 and with something like this in between the battery and the device.

I'm a little fuzzy on this part. Basically all 3 batteries are wired in parallel as if they are one battery, and then all 3 current-drawing devices are also wired in parallel as if they were one?

Looking at the devices I have to work with, I see my laptop adapter outputs 19V. My cell phone wants 5V on the USB port, but the battery itself claims to output 3.7V. The two smaller devices I want to run from the same 3.7V battery probably only need like 1.2V.

So am I understanding this right?

DC adapter jack (19V output) -> 5V Vregulator -> USB of cell phone -> Cell phone battery (3.7V output) -> 1.2V Vregulator -> Smaller devices

Another thing I'm wondering here is ... if all the devices will draw power as if they were one, then they will all shut off around the same time? If the voltage of the battery pack drops too low to power the phone (and the phone will probably shut off automatically at this point) can the other two smaller, lower power devices continue to run on the remaining voltage?

This sounds like a good way to ruin a lot of batteries and potentially start a fire. If these are lithium ion batteries, you want to make sure that you aren't overcharging the things (fire) and undercharging them will permanently damage the batteries. What you are proposing here sounds dangerously close to something that is going to bypass circuit charging protection.

Be very, VERY, careful if you decide to go forward with this.

I want to catch the 19V output BEFORE it gets to the laptop battery (and I assume it or the laptop motherboard have charging protection built-in) and I will still use the cell phone circuit board to charge the cell phone batteries so I am assuming that they will also still have charging protection. What I'm really worried about is whether drawing that extra power off the 19V incoming from the DC input will significantly affect the charging/operation of the laptop.

The idea is that if the laptop is connected to AC/DC power (running or not), then the cell phone batteries will charge, but if the laptop is running off of battery power only then the tracking devices will run off the cell phone batteries only and will not charge.

 

[SOFTengCOMPelec]

I want to make some criticisms about what you are trying to do, and how you are reporting them on these forums. I hope you don't mind. If you do, it is probably best to stop reading, NOW.

If you are curious as to what exactly I am trying to accomplish, you can search for my other thread in the general hardware forum.

What if I said on these forums ...

I'm making a new computer, cheap, g2120 based, for less than $200, just for web browsing.

For hard disk details, please find my thread under hard disks somewhere

For cpu details, please find my thread under cpus and overclocking somewhwre

For case details, please find my thread under cases somewhere

....Another 20 similar places to go .....

Do you think anyone would help me on a (factitious for this example) new computer build ?

Somehow, please try to stick to a single thread, I certainly can't be bothered to go searching for other thread(s), which you have not even bothered to link to, either.

So am I understanding this right?

DC adapter jack (19V output) -> 5V Vregulator -> USB of cell phone -> Cell phone battery (3.7V output) -> 1.2V Vregulator -> Smaller devices

You seem to be describing things, which are ridiculously over complicated, and sound much more likely to spontaneously burst into flames and explode, rather then ever work.

E.g. (Factitious)

My monitor is about one metre from my computer, but the lead is black, I want a grey lead, so this is how I did it.

DVI ==>> HDMI (converter) ==>> VGA (converter) ==>> Displayport (converter) ==>> DVI (converter), BUT it includes a nice grey lead ==>> My monitor

You could do the above, but it would not be likely to work, and if it did, the picture may look all wonky, and funny.



------------------------------------------------------------

I would suggest you try to come up with relatively simple things/ideas.
One thing, which simply plugs into something else, and that is the end of it.

Why can't you place a (secret, NOT in the laptop) cctv/video recording device (hidden), which finds out who is doing it ?

I have read reports of GPS tracking being unhelpful, because when you go to the criminal premises, they deny any knowledge of your laptop, and the police will not go in to investigate, without proof.

Maybe there is a better/easier way of achieving what you want ?

Lock it away, hide it, security cable devices, cctv, keep it with you, etc, etc.

 

[PottedMeat]

yeah, just have multiple cameras on the trash laptop.

besides have you considered the space you need to implement this idea? having a phone + gps reciever + batteries in a space meant for a dvdrw or a hard drive probably isn't going to happen.

and what exactly do you do when the thief takes this home?

 

[SOFTengCOMPelec]

and what exactly do you do when the thief takes this home?

I've heard that in many countries, the criminals simply come up with clever statements.

Example
When I woke up today, I found the laptop abandoned outside my front door. I assumed they no longer wanted it.
The theft, "nothing to do with me, officer".

Video evidence at your premises (or where the laptop is stolen) is best, as otherwise it is probably VERY difficult to prove that they actually stole it.

 

[Cerb]

besides have you considered the space you need to implement this idea? having a phone + gps reciever + batteries in a space meant for a dvdrw or a hard drive probably isn't going to happen.

Since it would be obvious, then the DVD drive didn't work, that something was, up, yes. That said, while I agree that this is way complicated, v. getting a laptop with some type of find me feature built in (some with included cell modems have such things, IIRC), larger notebooks often have a 2nd full-size HDD bay, which, with the caddy removed, might be big enough to fit plain AAA batteries, which would be easy to charge (trickle off a 5V line?), safe, and could provide nominally 3.6V (3) or 5V (4.8V before near-dead). If not, AAAA would definitely fit, and are available from electronics stores.

Unless it's just a hacker/boredom-born project, though, it's probably not worth bothering with, and there are surely dedicated devices for the job.

I also agree with others. I have read a few cases of people remoting in to their own laptops, and thus gaining evidence, but I'm not sure a GPS coordinate would be sufficient.

 

[SOFTengCOMPelec]

Since it would be obvious, then the DVD drive didn't work, that something was, up, yes. That said, while I agree that this is way complicated, v. getting a laptop with some type of find me feature built in (some with included cell modems have such things, IIRC), larger notebooks often have a 2nd full-size HDD bay, which, with the caddy removed, might be big enough to fit plain AAA batteries, which would be easy to charge (trickle off a 5V line?), safe, and could provide nominally 3.6V (3) or 5V (4.8V before near-dead). If not, AAAA would definitely fit, and are available from electronics stores.

Unless it's just a hacker/boredom-born project, though, it's probably not worth bothering with, and there are surely dedicated devices for the job.

I also agree with others. I have read a few cases of people remoting in to their own laptops, and thus gaining evidence, but I'm not sure a GPS coordinate would be sufficient.

It gets worse though.

I thought all/most/many Android phones (cheapish, these days), include EVERYTHING.

i.e. Batteries, ability to "phone home", and GPS.
A quickish app could be written, which periodically sends GPS phone-home coordinates, if I-am-stolen detected, and because it only switches on, say 1 minute every 2 hours (or something), the fully charged batteries could last months at time. You could phone up your phone, ONLY when you want it to tell you its current GPS coordinates, so whatever its standby time was would apply I guess.

This SO reminds me of (suppose to be inaccurate) stories, that NASA spent $Millions and $millions developing a "space pen", which took millions of man hours, from highly clever Nasa scientists/engineers/inventors, to come up with, eventually.
But at least they had a pen which could amazingly, write upside down, i.e. in gravity free space.

Russian equivalent of Nasa, took less than one minute to decide to use $0.10 pencils. Works gravity free, no problem.

 

[SOFTengCOMPelec]

In my original post in this thread, have I been TOO critical of the OP, about multiple threads, and over complicating things ?
If anyone thinks so, I can edit it out.

Sometimes being a tiny bit nasty, is actually a somewhat kind thing really ("being cruel to be nice"), as it can help people improve for the future, but I am NOT the best at judging when to apply such thinking.

 

[Jeff7]

...
This SO reminds me of (suppose to be inaccurate) stories, that NASA spent $Millions and $millions developing a "space pen", which took millions of man hours, from highly clever Nasa scientists/engineers/inventors, to come up with, eventually.
But at least they had a pen which could amazingly, write upside down, i.e. in gravity free space.

Russian equivalent of Nasa, took less than one minute to decide to use $0.10 pencils. Works gravity free, no problem.

OT - yes, it is inaccurate.
- It was private enterprise that developed this pen.
- It was not that expensive.
- Pencils are bad in spacecraft: They leave behind floating graphite dust, or broken-off tips. Graphite dust is not only flammable, it's also conductive. While that bit of graphite wouldn't release much energy if it were to burn, tiny conductive particles floating around the interior of an electronics-laden spacecraft is not an ideal situation.

 

[SOFTengCOMPelec]

OT - yes, it is inaccurate.
- It was private enterprise that developed this pen.
- It was not that expensive.
- Pencils are bad in spacecraft: They leave behind floating graphite dust, or broken-off tips. Graphite dust is not only flammable, it's also conductive. While that bit of graphite wouldn't release much energy if it were to burn, tiny conductive particles floating around the interior of an electronics-laden spacecraft is not an ideal situation.

Agreed.

The first (1969) manned moon landing, was the cause for Nasa to make many great and useful inventions.

Back on topic.

This is why (OP) I am concerned if you want to work with these batteries.

Don't do this at home

 

[Cerb]

This is why (OP) I am concerned if you want to work with these batteries.

Don't do this at home

If it says Lithium, but nothing about Iron Phosphate or Magnanese Oxide, it needs lots of care to be taken with it. One of those two are what power tools use, and what RC and radio folks have been switching to. I've swapped over to LiFePO4 for my flashlights, too. IMR (Magnanese) are just as finicky about charging and discharging as typical Lithium Cobolt types, and only perform better under high drain, but are nominally safe. Lithium Iron Phosphate (LiFePO4) have lower voltage and current capacity (about half the life, typically), but are tolerance to high discharges (overcharging will ruin them just as well as any other, though), nominally OK not being perfectly balanced in multicell packs, and have a really flat disharge curve, while also being safe. So, basically, there are Lithiums safe for people that don't have teams of engineers at their disposal (but then again, Boeing ), but only a few.

Now, nothing is safe from a stray short. Modern NIMH batteries, particularly the ever-popular low self-discharge types, will gladly give you 10 amps. In a pack, they can burn up thin wire. They won't last long, and the heat probably isn't good for them either, but there's a common myth, probably from when the tech was less mature, that they are a safer chemistry in that aspect, too. Lithium-Ion and NIMH are both susceptible to burning things up from that kind of failure, today (also lead acid, but lead acid are big and heavy, and people are used to respecting the dangers of those batteries). Most Lithium chemistries suffer from potential for thermal runaway, with fire and noxious fumes, on top of that, though.

 

[SOFTengCOMPelec]

@Cerb Good post!

Now, nothing is safe from a stray short.

I generally agree, but ...

Some of the (especially Lithium Ion) batteries, already come with built in IC (Integrated circuit) protection circuits built in to them.
E.g. Most modern laptop Lithium ion battery packs, and some other battery types.

I can't reel off a list from memory, but there are sources (internet/google) available.

These protection circuits, try to keep charging currents and usable currents to safe limits, and if they are exceeded and/or temperatures go too high, they automatically enforce these limits. I'm quoting from memory, and can't remember the exact spec of what these protectors do.

But even batteries with built in protector circuits, still need a degree of safe handling, as I would not be surprised to learn that there are still sillies, even with protected battery (packs or singles).

Even (non-rechargeable) single use batteries have their dangers. E.g. Long term short circuits.

Protected single small battery example - TrustFire Protected 18650 3.7V 2500mAh Lithium Battery Blue

 

[ZippyDan]

I want to make some criticisms about what you are trying to do, and how you are reporting them on these forums. I hope you don't mind. If you do, it is probably best to stop reading, NOW.

What if I said on these forums ...

I'm making a new computer, cheap, g2120 based, for less than $200, just for web browsing.

For hard disk details, please find my thread under hard disks somewhere

I will be defensive because I think your criticisms are unwarranted. I described everything that I wanted to do technically in these highly technical forums. My motivation was not relevant to the technical discussion so I chose to leave it out. When making a post, you often have to strike a balance between detail and brevity. Sometimes people will skip over a thread if the explanation is too long, meandering, and does not get to the point.

You seem to be describing things, which are ridiculously over complicated, and sound much more likely to spontaneously burst into flames and explode, rather then ever work.

Which is why I came here for advice. Honestly, my goal does not seem so overly complicated as I am sure there are devices that can accomplish the end result. If you can suggest a better way to accomplish the same task then I welcome your suggestions.

I would suggest you try to come up with relatively simple things/ideas.
One thing, which simply plugs into something else, and that is the end of it.

Why can't you place a (secret, NOT in the laptop) cctv/video recording device (hidden), which finds out who is doing it ?

I have already thought of all possibilities and I don't think there is a better one. Since you are being so critical I will give you more details. I already know "who" is stealing stuff. I live in a 3rd world country and there are motorcycle gangs that snatch stuff out of people's hands while driving by (one driver and one snatcher riding behind). They wear helmets, their bikes don't have any license plates, they travel at high speed, they operate almost exclusively at night,
and the exact location where they will strike is impossible to predetermine. For all of those reasons, CCTV is pretty much useless. The only other option is to have police units waiting to chase and capture, but they are underfunded and uninterested here.

I have read reports of GPS tracking being unhelpful, because when you go to the criminal premises, they deny any knowledge of your laptop, and the police will not go in to investigate, without proof.

That said, I have direct face to face communication with the local chief of police, and he has already demonstrated that he is willing to help if I can get the bad guys to take my bait first. Since this is a third world country, privacy concerns and due process is not really an issue. We have already conducted field tests using a GPS device and an RF tracker and have been able to find a "stolen" laptop down to the exact cabinet in a house. The signal is itself all the "proof" that the police needs to conduct the search, especially since they are aware of the sting operation from the beginning.

The only difference is that I want to now integrate the GPS and RF tracker INTO the laptop so that the thieves cannot easily find them.

Maybe there is a better/easier way of achieving what you want ?

Nope

Lock it away, hide it, security cable devices, cctv, keep it with you, etc, etc.

Stuff has already been stolen. We are looking to retrieve it. So most of your suggestions are uselessly preemptive. We need to go on the offensive.

 

[SOFTengCOMPelec]

I somewhat agree with much of your points.

Sorry.

Maybe there is a better/easier way of achieving what you want ?

Nope

I think you are showing at least a tiny bit of over-confidence, by saying that.

Anyway good luck, and be careful.

Tackling criminal gangs is not so straight forward, because they may take revenge if you do succeed in "getting them".

 

[SecurityTheatre]

Wiring cell phone batteries together in parallel is tricky and probably dangerous.

I've seen a parallel-wired lithium polymer pack go up in pretty nasty oxygen-fanned flames after bursting a pack from unbalanced charging.

Granted, it takes some period of misuse for this to happen, but in theory it could happen in as little as 4-6 hours of improper charging.

better than wiring a bunch of batteries together might be to find one of those external USB battery packs that will give you 4-5 days of battery life. I would hesitate to bother trying to wire it into the laptop and charge it... seems over complicated.

All of the batteries and chargers in these devices will be tailored to the expected load and capacity of the battery they are charging. Many of them will have electronic circuits that track the charge level and cut off charging or discharging after a certain amount of use. This is likely not compatible with putting multiple packs in parallel.

 

[Hitman928]

ZippyDan,

I think what you are describing is much more complicated than you are thinking it will be. However, I will try to help if I can:

DC adapter jack (19V output) -> 5V Vregulator -> USB of cell phone -> Cell phone battery (3.7V output) -> 1.2V Vregulator -> Smaller devices

Will absolutely not work. A 19V to 5V drop should not be done with a linear regulator. Look at getting a http://www.adafruit.com/products/1065, they are made for larger dc/dc step down drops. Do you know what gps unit you'll be using? What it's power requirements are? It may be much easier to go with a simple battery pack. You should be able to find one that can give you at least a couple of days of use. Is the RF component necessary? How much space do you have to work with inside the laptop (an empty hdd compartment would probably be ideal).

 

[SOFTengCOMPelec]

ZippyDan,

I think what you are describing is much more complicated than you are thinking it will be. However, I will try to help if I can:


Will absolutely not work. A 19V to 5V drop should not be done with a linear regulator. Look at getting a http://www.adafruit.com/products/1065, they are made for larger dc/dc step down drops. Do you know what gps unit you'll be using? What it's power requirements are? It may be much easier to go with a simple battery pack. You should be able to find one that can give you at least a couple of days of use. Is the RF component necessary? How much space do you have to work with inside the laptop (an empty hdd compartment would probably be ideal).

Sorry Hitman928, I hope you don't mind me quickly jumping in and offering an alternative solution, to your lovely DC to DC solution.

I don't know how familiar the OP is, with using electronics like this, and how easy is it for him to buy it.

Another solution, might be to use a mobile phone car charger (IF it can handle 19V, for the few days that it needs to work for this project, cars are about 14V++ (engine running, nearer 12V engine off).
If you are worried about excess voltage, 19V down to 14V or less can be done via asking here (possible solution = Zener 6V, suitable wattage, assuming current is fairly low).
To save room, you could disassemble the car (mobile phone) charger adaptor.
It potentially would be easier to get hold of, and may be cheaper, and already have some of the right leads, already fitted to it, especially the microUSB one.

 

[ZippyDan]

ZippyDan,

I think what you are describing is much more complicated than you are thinking it will be. However, I will try to help if I can:

Will absolutely not work. A 19V to 5V drop should not be done with a linear regulator. Look at getting a http://www.adafruit.com/products/1065, they are made for larger dc/dc step down drops. Do you know what gps unit you'll be using? What it's power requirements are? It may be much easier to go with a simple battery pack. You should be able to find one that can give you at least a couple of days of use. Is the RF component necessary? How much space do you have to work with inside the laptop (an empty hdd compartment would probably be ideal).

Since I've already tested it successfully and it gives me plenty of flexibility and control options, I will be using an HTC cell phone as my GPS unit (with the casing, LCD screen etc. removed so that only the circuit board is necessary to save space).

The RF component is absolutely necessary as demonstrated in the two field tests I have conducted with the police. In a best case scenario, the GPS signal can only narrow down the device's location to an entire house. If the thieves are smart of have warning, they can hide the laptop. In a worst case scenario, the GPS signal may not be able to get a good fix indoors and may only be accurate to within 10 meters or more.

Locating a stolen device is really a two stage process: the GPS gets you to the general vicinity within meters, but the RF signal has the granularity to get you within less than a foot or two.

 

[ZippyDan]

It gets worse though.

I thought all/most/many Android phones (cheapish, these days), include EVERYTHING.

i.e. Batteries, ability to "phone home", and GPS.
A quickish app could be written, which periodically sends GPS phone-home coordinates, if I-am-stolen detected, and because it only switches on, say 1 minute every 2 hours (or something), the fully charged batteries could last months at time. You could phone up your phone, ONLY when you want it to tell you its current GPS coordinates, so whatever its standby time was would apply I guess.

I have successfully tested both the AndroidLost app and the Avast! mobile security app and they are both free and fantastic.

AndroidLost provides the ability to remotely control the phone via text messages (amongst many other features), while Avast! let's me setup the phone to auto-report its GPS coordinates every X minutes and logs all of that location history to a website where it can be viewed on a map (amongst many other features).

 

[SOFTengCOMPelec]

I have successfully tested both the AndroidLost app and the Avast! mobile security app and they are both free and fantastic.

AndroidLost provides the ability to remotely control the phone via text messages (amongst many other features), while Avast! let's me setup the phone to auto-report its GPS coordinates every X minutes and logs all of that location history to a website where it can be viewed on a map (amongst many other features).

I don't know what country you live in, but anyway.

In the many countries I know about (which may, or may not be yours), a common way stolen computer laptop equipment is handled (from good quality, reliable sources of information), is that the stolen equipment, gets transferred to other people, who handle the stolen laptops. E.g. Erase/reformat or remove the HDD, and other IT stuff.

Therefore, if you want a near 100% way of handling ALL eventualities, you may want to consider any Android software, which can track the movements (every 15 minutes or whatever) of GPS location data, and be ready to text? it to you, on request (or automatically).
This also means, you would have a trail to follow, if it was discovered (the GPS etc modifications), and then dumped/disposed of.

Be careful if you plan on de-casing phones, as they may have precautions against it, which if triggered, will disable the phone and/or other stuff. It may be done to hinder defeating its security, or for other reasons.

I DON'T KNOW if this applies to your phone, but I know of AT LEAST ONE PHONE, which does exactly this, because I was in discussions about it, a while ago.

It's very easy to accidently damage something, if you start removing bits you think it does not need.

EDIT: Correction: What I meant was, opening the phone might be ok, but if the phone detects hardware modification(s), such as removal of the display, I know of at least one phone, which detects this, and refuses to work, afterwords.

I have NO IDEA, if this applies to Android phones, or not. (It was an iphone, which is probably much more security conscience anyway).
I would imagine there are internet guides for the phone you choose.

 

[Dodgexander]

There are anti theft apps available for android phones. You should just use one of those and track it online.

A couple of points: police can obtain the location of a mobile phone using the wireless radio of the phone. 2 transmitters=10m accuracy, 3 is within 1m.

GPS is far more accurate, but only when locking on to two-three satellites.

So potentially you can achieve all of what you want with just a mobile. There are apps that track GPS and apps where you can gain it on demand.

On a side note, why not try one of the GPS and rf devices they use for animals? Much smaller and can be purchased easily

 

[SOFTengCOMPelec]

On a side note, why not try one of the GPS and rf devices they use for animals? Much smaller and can be purchased easily

Very interesting.

I googled it!

Example

I want to buy one now, and I don't even have the OP's problem!

 

[ZippyDan]

so can we get back to my original question? can I at least get a 5V USB line off of the main DC jack that will charge whenever the laptop is plugged in, even if it is off?

 

[PottedMeat]

so can we get back to my original question? can I at least get a 5V USB line off of the main DC jack that will charge whenever the laptop is plugged in, even if it is off?

you would have to solder wires from the main dc jack to whatever chamber you are using and put in a dc-dc converter module, a linear regulator like a 7805 would dissipate too much power. Max power dissipation for a linear regulator with a high current usb peripheral like a smartphone is (Vin-Vout)*Iout = (~20VDC - 5VDC)*(2 Amps) = 30W!!! One adjustable DC-DC converter is the LM2596 off ebay for ~$5.


Have you actually put the stripped phone inside the laptop and gotten a signal? Sometimes the expansion bays are shielded.