mac portable replacement power cord

[Sphensilhagen]

ive been searching the forums and learned much about the portable, how it utilizes both batteries and how the charger needs to be very specific and only charges the battery (does not power the computer) etc etc, but is there any reason no one seems to use a newer/replacement power brick? woudlnt it be possible to use something like this?

Adjustable Voltage 3 to 24V AC /DC Switch Power Supply Adapter w/ Polarity Cord | eBay

Reverse Polarity Converter Cable. Reverse Polarity what you want, fit for keyboard and guitar effect pedal. Output: DC 3-24V (adjustable). Product type: Adjustable Power Adapter. 1 Adjustable Power Adapter (US Plug).

www.ebay.com

or any dc power brick that supplies 7.5v at 1.5a max? sorry i am not an electrical engineer, but curious why i cant find anyone doing this. most seem to hard wire alligator clips onto the installed battery with a trickle charger or something?

would love to know a bit more detail, before i start going down the road of rebuilding our original mac portable

thanks so much!

 

[Sphensilhagen]

just bought this FWIW:

https://www.amazon.com/gp/product/B07BGV378Y

 

[ExplorerZ]

Also interested in this. Did it work?

 

[4seasonphoto]

Also interested in this. Did it work?

Can't imagine why it wouldn't work, as long as care is taken to ensure correct polarity of the plug, and max current is limited to some reasonable value.

 

[3lectr1cPPC]

The portable MUST have a supply of exactly 1.5A, no more, no less. The power manager is poorly designed and while using a 2A adapter on a circuit designed for 1.5 wouldn’t usually cause any harm. In fact, I’m using a supply for one of my old laptops that’s rated some 10A higher than the original. But the portable is a strange duck in that way and you’ll end up blowing a MOSFET I believe if you use a higher rated supply. Must be 1.5A exactly.

 

[Dogmander]

The portable MUST have a supply of exactly 1.5A, no more, no less. The power manager is poorly designed and while using a 2A adapter on a circuit designed for 1.5 wouldn’t usually cause any harm. In fact, I’m using a supply for one of my old laptops that’s rated some 10A higher than the original. But the portable is a strange duck in that way and you’ll end up blowing a MOSFET I believe if you use a higher rated supply. Must be 1.5A exactly.

Does the early PowerBook 100 or later 140/170 suffer from the same issue or is it just the Portable? I know the PB100 is largely based on the Portable's hardware, so I was wondering if it also suffers from many of its same problems.

 

[3lectr1cPPC]

No. The original supply for the PowerBook 100 is a 2A supply actually. That’s why people warn strongly against using a PowerBook supply with a portable. I can’t say I’d recommend using a 3A supply (made for the color 100 series) on the original 100 though. Don’t know if it would do any damage but because of that basis I wouldn’t call it a great idea.

 

[JustG]

I haven't tried one yet but I've been told that these will work with a Portable:

https://www.digikey.com/en/products/detail/triad-magnetics/WSU075-1500/3105438

Looks to be both the correct voltage and amperage.

 

[micheledipaola]

I haven't tried one yet but I've been told that these will work with a Portable:

https://www.digikey.com/en/products/detail/triad-magnetics/WSU075-1500/3105438

Looks to be both the correct voltage and amperage.

It seems polarity is wrong from what I could see.

I am looking for the same replacements, I have found some 7.5v / 1.5a adapters but being a total noob about electricty, I am also wondering about wattage, because I see values from 11w to 30w and I cannot make up my mind.

Same for the batteries: is a modern 6v 4.5a ok? That should be the values of the original I guess. Then again, is a 6v 5a harmful instead?

 

[SuperSVGA]

Same for the batteries: is a modern 6v 4.5a ok? That should be the values of the original I guess. Then again, is a 6v 5a harmful instead?

That's 4.5Ah. It's basically the capacity, so on paper with a constant 4.5 Ampere draw it should last an hour, or 4.5 hours at 1A.

 

[micheledipaola]

That's 4.5Ah. It's basically the capacity, so on paper with a constant 4.5 Ampere draw it should last an hour, or 4.5 hours at 1A.

You are totally right, it's Ah

My question stands anyway: I have a new 6V 5Ah sealed lead battery now in my Portable, and it anyway doesn't seem to supply enough power for the boot, even with a blueScsi instead of the original spinner HD. I tested the Portable (with the battery in, and the 9v startup one as well...) plugged to a 7.5v 2a adapter and it works, but I would not let the Portable draw 2a as I understood it could harm the board, so I am waiting for an adapter giving the correct 1.5a (and my other question: what wattage is recommended here?).

Anyway if the battery values are right as they look to me, I am starting to think that it is not only a battery related issue, and there is something somewhere that needs checking...

 

[SuperSVGA]

You are totally right, it's Ah

My question stands anyway: I have a new 6V 5Ah sealed lead battery now in my Portable, and it anyway doesn't seem to supply enough power for the boot, even with a blueScsi instead of the original spinner HD. I tested the Portable (with the battery in, and the 9v startup one as well...) plugged to a 7.5v 2a adapter and it works, but I would not let the Portable draw 2a as I understood it could harm the board, so I am waiting for an adapter giving the correct 1.5a (and my other question: what wattage is recommended here?).

Anyway if the battery values are right as they look to me, I am starting to think that it is not only a battery related issue, and there is something somewhere that needs checking...

So it boots without the power adapter if no SCSI device is plugged in correct? What does it do when it doesn't boot?

A BlueSCSI shouldn't be able to draw enough power to cause that, and typically the battery should be able to provide enough power to blow the fuse.

If you have an oscilloscope or a fast multimeter you can watch the battery voltage at the external video connector to look for any drops.
You can also check the SCSI +5V to see what's going on there.

 

[micheledipaola]

So it boots without the power adapter if no SCSI device is plugged in correct? What does it do when it doesn't boot?

A BlueSCSI shouldn't be able to draw enough power to cause that, and typically the battery should be able to provide enough power to blow the fuse.

If you have an oscilloscope or a fast multimeter you can watch the battery voltage at the external video connector to look for any drops.
You can also check the SCSI +5V to see what's going on there.

No boot ended up in power off - but anyway I had made a "flying" connection of the battery with simple alligator clips for testing... now I made proper connection cables with faston clips and everything seems ok: it boots without power cable even with blueScsi, it gets to the desktop and the battery applet shows battery discharging, the Portable can go into sleep mode and recovers.

Same behavior either with a 6V 5Ah and a 6V 4.5Ah battery, so I would use the latter in the second Portable where I do all testing.

I would anyway do some checks with a multimeter on the video out port - would you be so kind to tell me which pins I should check? or even better, if you have a pin-out of the port, it could be useful for other purposes as well

thanks!

 

[LaPorta]

Some batteries do not have enough "peak amperage", meaning they cannot supply enough amps fast enough. I ran into this when I originally tried to get a battery for my Portable. This one works perfectly with mine, as it is basically an exact replacement:

https://www.batteriesplus.com/battery/sla-sealed-lead-acid/6/hawk0809=0012

 

[micheledipaola]

Some batteries do not have enough "peak amperage", meaning they cannot supply enough amps fast enough. I ran into this when I originally tried to get a battery for my Portable. This one works perfectly with mine, as it is basically an exact replacement:

https://www.batteriesplus.com/battery/sla-sealed-lead-acid/6/hawk0809=0012

Thanks @LaPorta , I even managed to find a reseller in Europe with direct online shops in Italy (!), Spain, France and UK so I am putting the link here for reference, as I know that it's always a bit more complicated for us this side of the pond

Batteria Cyclon Enersys 0809-0012 Monobloc (X cell) 6V 5Ah F6.35

Ordina Batteria Cyclon Enersys 0809-0012 Monobloc (X cell) 6V 5Ah F6.35 (AMP3702) al miglior prezzo su All-batteries.it.

www.all-batteries.it

 

[SuperSVGA]

I would anyway do some checks with a multimeter on the video out port - would you be so kind to tell me which pins I should check? or even better, if you have a pin-out of the port, it could be useful for other purposes as well

Here's the pinout from the female connector end: