Confused about power adaptor for mac pro mid 2012

[baxterboy]

I just got a 13" mid 2012 mac pro for my 5 year old for his homeschooling.
The laptop didn't come with the magsafe charger.

I have an L style connector with a 85w magsafe adaptor which came with a 15" 2012 mac pro. This connector fits on the 13" mac pro.
However, since the 2012 mac pro takes a 60w charge, I didn't fancy using it for fear of the battery being a fire hazard.

Here's where I get a bit confused...

I have a 13" mid 2013 mac air which came with a 60w magsafe adapter with a magsafe 2 connector.

In 2021, I had a new battery put in it, and bought a new power adaptor recommended by the apple authorized service.

The new battery was a lithium ion # 661-04570. (One site, to my surprise, says this battery is designed not for 2013 mac airs but for 2012)
I bought the the power adaptor recommendation which was an 85w with a magsafe 2 connector.

Does anyone know if the 661-04570 battery is actually meant for 85w adaptor or is it meant for 60w?

And, if they're recommending a 85w for a battery on a 2013 mac air that takes a 60w, then doesn't it stand to reason that I can use a 85w magsafe adaptor on the 60w 2012 mac pro without having the fire department on standby?

 

[iMacDragon]

Using larger power adapters is fine, devices are in control of how much power is drawn upto what supply can give.

In exact same way, it's fine to charge an iphone with a 140W m1/m2 power brick.

 

[baxterboy]

Using larger power adapters is fine, devices are in control of how much power is drawn upto what supply can give.

In exact same way, it's fine to charge an iphone with a 140W m1/m2 power brick.

Thanks Dragon.

Two computer stores salesmen (not mac) just told me today that I can't use a 85w power adaptor on a 60w 2012 mac pro because too much power would go into the battery, swell it up, and risk fire.

 

[iMacDragon]

Thanks Dragon.

Two computer stores salesmen (not mac) just told me today that I can't use a 85w power adaptor on a 60w 2012 mac pro because too much power would go into the battery, swell it up, and risk fire.

Complete nonsense, on that basis plugging a charger into wall socket should also be too much power.. as wall socket has effectively 'unlimited' power available. One's AC and other's DC, but the principle of power draw is still basically the same.

 

[baxterboy]

Complete nonsense, on that basis plugging a charger into wall socket should also be too much power.. as wall socket has effectively 'unlimited' power available.

Well, that makes sense!
It is remarkable how they could provide such 'nonsense' particularly considering one of them is a technician who replaces phone batteries multiple times daily! Go figure.

At least, I, being a neanderthal when it comes to such things, have an excuse

 

[iMacDragon]

Well, that makes sense!
It is remarkable how they could provide such 'nonsense' particularly considering one of them is a technician who replaces phone batteries multiple times daily! Go figure.

At least, I, being a neanderthal when it comes to such things, have an excuse

It seems to be an ever present common misapprehension on how electricity works when it goes through a 'charger', it's only an issue if a product is badly designed in the first place to charge faster than it should if it has enough power available to it, but that would be device not charger issue, and certainly doesn't apply to laptops like this.

Wrong voltage is what's dangerous to plug into devices, so especially with barrel jack chargers one needs to be careful that the voltage levels match expected.

But something like magsafe is a smart negotiation of requested voltage from charger, so no worries there.