Tuesday, May 5, 2020

powering apple ipad 1st gen without battery from power supply

got a 1st gen ipad (A1337)
when i plugged it into a charger
the screen start blinking dimly 
opened it up using a flat screwdriver 
checked the battery using a multi meter
voltage was zero volts and for any battery its not good news
seeing the prices for a replaceable battery 
i decided its not worth the money to buy a new battery
and that im going to use a 5V 2A usb charger i have
so i used a cutting knife to cut around the battery carefully
cut carefully along the green line

then i de-soldered the two dead battery cells
soldered four wires to the battery pads after checking the polarity
stripes is positive (+) and solid is ground (-)

i drilled two small holes at the side of the ipad for the wires

connected two diodes to the two positive wires
in order to decrease the voltage from 5v to about 4.3v
and two resistors between the positive and the negative wires
just to keep a small load on the diodes

the ipad still needed two quick jump-starts to boot
momentary connect and disconnect the usb charger
first jump-start showed an empty battery logo 

second jump-start started the ipad

success

now i have a useless 1st gen ipad running from a usb charger

 notes:
*used both battery pads and not single to share the load of the power consumption
*could use any kind of li-ion cell batteries instead of hooking it up to ac adapter
*battery manager comparing the voltages of the left and right cells and consume more from the higher one

2 comments:

  1. Great to find this. A few questions: what rating is needed for the resistor (watts?) and the diode (does it need to be 1A?)? Also, why do you have 4 wires coming for the USB charger (5v source)? Couldn't you just use 2 wires from the source and then solder a short "jumper" wire from one positive terminal on the iPad to the other positive terminal (and same for negative terminals)? Last question, there are similar blogs that show the use of 6 2200 uF capacitors. Do you know what that accomplishes vs your use of one 22 uF capacitor? Thanks for any additional info. -Mark

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