Macbook Pro mid 2015 battery required to boot?

[twonk9098]

I have read many forums that state the Macbook Pro 2015 needs / does not need a battery to boot. I'm not convinced as yet which is correct.
The Macbook Pro mid 2015 I have has no battery and do not really want to buy one just to test.
This model has the newer trackpad which is not clickable when turned off.
At the moment, without battery it does turn on with no display (with backlight), no chime and then turns off after 13 seconds. I see this from the power draw on my DTPS.
If I hold the power button whilst connecting the magsafe 2 charger it turns on, again no image but it does chime and the fans run high, restarts after about 20 seconds to the same results.

Can anybody confirm that this model does indeed need a battery for image / boot etc?

Thank you.

[piernov]

https://logi.wiki/index.php/A1398_Co...163,_820-00426)

2015 dedicated graphics (820-00163, 820-00426)

These boards absolutely require a good charged battery to fully boot into macOS. As usual it's not uncommon to get 2 or 3 bad batteries in a row so make sure you are using a known good one, one that for sure works with others 15" 2015 DG boards.

With a bad battery or no battery, the machine will reboot during or at the end of macOS boot. In this case disconnecting the touchpad often allows it to boot fully since it causes throttling and lowers the overall power consumption of the machine.

[twonk9098]

Thanks for the response however the board in this is a 820-00138-A which from what I see does not have a dedicated graphics chip.

Thank you

[mon2]

Disconnect the trackpad. Attach a suitable (original preferred) magsafe power adapter. If the adapter is under rated, the unit will not boot and the PM_BATLOW_L signal on the board will be LOW to denote the adapter is not suitable.

You have high fan spin due to a missing sensor on the board - perhaps from this trackpad. For now, disconnect the trackpad, this will force a high fan spin and will throttle the speed of the logic board.

Does the board continue to boot in this configuration?

If not, suggest to probe each SMBUS line (SDA / SCL) for possible shorts that is forcing this power cycling.

See here:

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

[reformatt]

I just refurbished two 2015 A1398 with missing batteries. One was EMC 2909 (IG), the other EMC 2910 (DG). The IG machine will boot into MAC OS without battery, but will be throttled and slow. The DG machine will crash during boot as the peak current demand cannot be met with the charger alone. Actually as an aside, the DG machine did have a faulty trackpad and did boot to the desktop ok (minus trackpad and keyboard of course). These machines will pull up to 4 amps or more during boot, so your power supply must be able to at least deliver that.

Chime isn't always a reliable indication of a boot as sound may be muted; just do a PRAM reset to remove that. If you're just trying to work out if the board is booting, put it standalone on the bench with magsafe connected and it should try to boot automatically. I use a Chipmunk USB tester to verify the board has booted when the green status LED blinks indicating the port is being probed for a boot source. I haven't had the problem on the A1398 boards, but 820-00165 boards do not boot with non-genuine magsafe 2 chargers and no battery, as PM_BATLOW prevents the board reaching PM_SLP_S4.