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Using a Dell battery in another project, need advice

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abuthemagician

New Member
Ok, so my though was to take an unmodified Dell battery (11.1v), attach an iPhone car charger to it and use it to power my phone on my plane ride to Hawaii. Last night I was using spade connectors to probe for voltage, but all I could find was 3vdc, not the 11.1vdc it is rated at. So I poked around some other sites, and found one where a guy used a notebook battery for a robotics project, and that certain pins had to be shorted to make the battery "activate". So, I then probed the connector on my notebook (the one the battery is from) and found the following:

There are 9 pins on the notebook side. Pins 1, 2 and 4 all have continuity between them. Pins 8 an 9 have continuity between them. On the battery, I get 3vdc between pins 1 and 4, 2 and 4, 8 and 4, and 9 and 4.

My question is, does anyone think i will get 11.1vdc on another pin on the battery if i short 1, 2 and 4?

Unfortunately I cannot open the battery because it is a spare I wish to keep around, but still would love to use this. The rest of the project will be two wires going to a car power port outlet so i can plug my phone charger in. I am trying to get this setup passed the TSA at the airport, and my thought is that some wires soldered to the notebook side connector would pass way better than a box with wires, resistors and voltage regulators...
 

blueroomelectronics

Well-Known Member
Check with your airlines, they may have chargers in the seats. Also any homebrew battery contraption will probably not be welcome on the plane.
 

abuthemagician

New Member
I already know they do not have chargers in the seats. I plan to fully test this setup before taking it anywhere and especially monitor the battery temps to make sure it doesn't catch fire. Regardless of whether I take this on a plane or not, there are lots of people looking for the answer to my question, and I seem to be the first to do preliminary testing to find that answer. I just want to know if other people think its a good idea to short pins 1, 2 and 4 then probe for voltage on the other pins.
 

abuthemagician

New Member
I already own the dell battery, and the addon is $99 for something i will only use a few times. I plan to use the car charger attached to the battery. The car charger works with voltages from 10 to 16 vdc so i don't need a custom circuit. I plan to break a connector off a dead dell motherboard, the same that fits the battery, then solder a car power port to the + and - leads, and then plug my car charger into that. Then i can just attach it to the battery and i am good to go
 
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JimB

Super Moderator
Most Helpful Member
Ok, so my though was to take an unmodified Dell battery (11.1v), attach an iPhone car charger to it and use it to power my phone on my plane ride to Hawaii.
Woh boy! Hold it right there.
Use a cell phone on the plane?
I dont think so.

JimB
 

fernando_g

New Member
I am trying to get this setup passed the TSA at the airport, and my thought is that some wires soldered to the notebook side connector would pass way better than a box with wires, resistors and voltage regulators...
And better yet, put some LARGE red LED display counting down seconds, with a buzzer doing beep-beep-beep.
Just like a Holywood movie.:D

Now seriously, the reason you are not getting the proper voltage is that high capacity lithium batteries are very dangerous, and have a lot of safeguards to activate them.
Nominally, some of the mosre advanced packs have a communication interface with the host computer, which will provide a long authentication string to fully enable the battery pack.

Several of these safeguards were implemented after several infamous lithium battery fires.

I don't know what vintage your battery pack is, but if it is relatively recent, it will have the safeguards built in.
 

abuthemagician

New Member
Thanks for the link, but i already made a AA booster. I was just trying to use what i have to get the longest life while playing movies on my phone.

I planned to plug the charging connector in and use rubber bands to hold it there. Also i wouldn't have the connector attached to the battery until i was ready to use it.

So aside from the TSA wanting to do a cavity search, or the fact that they may confiscate the "custom adapter" what are the chances that I would see 11.1v on a pin if i short pins 1, 2 and 4? Would you try it just out of curiosity?

On a side note, I have emailed the TSA about custom built battery extenders and they basically said, if it looks suspicious they will hand check it, then confiscate it if they don't like it. I am trying to come up with a solution that doesn't involve me spending money. If i have to i will waste space in my carry on with paperback books, but i really like having my phone for ebooks, music and movies. After all its a 16 hour flight to hawaii...
 

fernando_g

New Member
Well, you can always try and see what happens.

But if you do, wear eye -or better still- face protection. The shorting wires should be quite thin to act as fuses.

Lithium cells pack a lot of punch and may be dangerous... be aware of the implications.
 

Sceadwian

Banned
Spend the money, last thing you want is to get stuck at customs with a suspicious device. Stay up late the night before so you can sleep on the plane, or <gasp> read a book =) If you're going to short it don't dead short it, at the very least use a 1k ohm resistor, if that doesn't work go lower, but if you dead short the terminals of a 3 cell lithium pack it could be bad.
 

abuthemagician

New Member
Thanks for all the advice. Not sure if i will continue with this, but as far as shorting those pins, when the battery is in the notebook they are permanently shorted, and there is no resistance on the notebook connector side.

I do have a 4 AA battery holder that i might add another battery to, then just use resistors to hand power to my charging cable. I already have that circuit available to me. Just not sure how long those batteries will last...
 
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