Modding my ipad to run without batteries.

I've modded a first gen ipad air (a1474) to run directly from a power supply, without any battery installed.

[@gengen5607]

Good idea indeed

[@kazuhiro3739]

How about to mount a TP4056 to provide 4.2V to BMS port.

[@InfoDav]

By not connecting your negative to the BMS, you are essentially skipping it. Which is not a bad idea because the BMS will disconnect those terminals if the voltage goes under a certain threshold (normally to protect the batteries, so probably around 3.6v), which would essentially always happen when you disconnect your device.

[@DrPluring]

I believe something like that happened with my initial run, running ground through the BMS. Voltage for the "cells" droppen very low, seems the BMS disconnected them permanently. ipad itself seems fine with the BMS though, no complaints, constant 71% battery level. Anyway, the iPad is on a wall in the kitchen now and has been on with the screen on too 24/7 since around when this video was made :)

[@Nebulon0]

sorry but can I ask what happen if I connected the negative to the BMS not the metal peace on the side ( witch used as a ground)

[@Nebulon0]

and if I connected the battery parallel to it would it short or charge or what thank you very much

[@Nebulon0]

@DrPluring did you mean that you connected the diodes in parallel or series because I believe it should be in series or is it in parallel because of the (BMS) having 2 positive slots?

[@DrPluring]

I used two in parallel for capacity. I have no numbers to back this up, I simply went with two in parallel because I thought one would not be enough, or would drop too much voltage.

[@Nebulon0]

ok thanks❤

[@UKenGB]

This iPad now runs from 'battery' only, no USB power. The iPhone you show however has Lightning/USB connected AS WELL as power to simulate battery. Why? Does the iPhone not work with battery simulator only? Should be same as iPad surely.

[@DrPluring]

You are correct in your observations. The ipad fluctuates a bit in battery level, 60-80%, the iphone stays at 100. The iphone would probably run fine without the lightning port connected. I do not remember. The lightning port ought to be a cleaner power source. The diodes are quite crude, the more power the thing needs, the lower the voltage will be, and the diodes will get hot. I've not had any problems with either device though. The lightning port was broken on the ipad, which is why I took it apart in the first place. It is no longer there as I tried to come in that way with the power cable.

[@UKenGB]

@@DrPluring I was wondering if some circuitry could be devised to simply imitate a battery. Capacitor(s) etc. So just that, instead of the battery and it would be powered just from the device being connected to USB power as normal and ideally sufficient to keep it running long enough to e.g. change cables. Acting like and seen by the device as a small capacity battery. I’m sure it would be possible (and extremely useful), but not sure I have the ability to design it.

[@taturick]

Im try to do this. But my ipad Reboot 3-4 minutes after on. What the Power charger you use? My power is not a original power charger, but im using a charger with 5v. Im remember the charger of ipad have a 10v What you recomend?

[@atarihuana]

The charger seems to be an IKEA one

[@skinnypotato4452]

can we do this for iphone 3g-gs too? I tried running iphone 3g with nokia battery but it kept reboot itself every 3-4 minutes.

[@DrPluring]

I have no 3g to try with. But I think the key point to get it working is to keep the BMS portion of the original battery. So the phone can talk to it, check temperature and so on. And make sure the power supply never drops below 3.3-3.4v, the ipad rebooted instantly if that happened.

[@tanweerchiktay]

Hello

[@christopherkise]

what is the point of the diodes?, just to protect the psu?

[@DrPluring]

To drop the voltage. Power supply is 5v, nominal voltage for battery ~3.6v.

[@pablocorral]

After woke up I realized that he didn’t clean (well) the LCD and neither explain or show the process

[@Nebulon0]

I used a dc-dc step down it powered up for a sec and it never did it again

[@DrPluring]

Same thing happened to me. My theory is the bms saw a voltage it didn’t like at all and bricked itself for safety reasons, hence why I grounded it through the cassis and not the bms. Thereby only using the bms portion of the battery for the connector really and bypassing all its intelligence. What voltage did you set your buck converter to?

[@Nebulon0]

@@DrPluring 3.8v exactly because that what was on the batteries back measured it through AVO so nothing was wrong when I connected everything it worked for a second and then nothing.

[@DrPluring]

Are you running both positive and negative through the bms?

[@Nebulon0]

@@DrPluring firstly yes and then did it your way it worked for a sec like how it did to you but after no response after that i did contact the positive to the bms and the negative to ground your why but didn't light up sooo im kind of confused the current is running thru capacitor in the step down and the voltage is correct i dont konw why isn't it working im gonna try 1 more time tonight but do you have any tips for it

[@DrPluring]

@@Nebulon0 I regret I don't know what's going on for you. I would check the voltage at the ipad, to verify enough of a voltage is supplied, and that i doesn't drop too much when trying to power on. I would also measure the current, that might say something - if it is trying to do something, or if it's completely dead.