How fast can the battery be charged?

The FW16 supports up to 240W power supply. Let’s the the battery is drained and the laptop is off, how much of this can go to the battery? I suppose charging with 240W is a bit much.

Batteries are not charged by the power of the supply but through the PD protocol ask for a specific voltage at a given time.

As long as the power unit can provide the max the computer asks for then it will charge at a maximum rate, probably a max of 80W. A lower spec power unit will prolong the charging time and if the laptop is being used lower it so much it may not even charge the battery.

So battery takes a max of 80W the rest is available for the laptop’s use.

A 240W power unit is fine as it won’t get stretched.

Downsides are:

Not specific to the Framework so if there is a support request around power, then it’s not so easy to deal with
It’s a bit heavier to lug around, so maybe another for day travelling
It will use more power in proportion to that used. i.e. if efficiency is best at 80% then you will require to load the supply with the best part of 200W. lower power uses are usually less efficient. No worry unless you are out in the woods, in a cabin, with solar, in the winter :rofl: And I’m not concerned with the notion of ‘waste’ and the ecology, else I wouldn’t buy a computer.

I think amoun is correct. It can allow up to 240W (PD 3.1), but I doubt the battery will be charged at that rate. Power usage is for the entire unit (battery charging, and the other laptop components such as CPU, GPU, memory, display, etc). Maybe 80W is safe like you said. If that’s the case, the rest of the power can be used elsewhere or just not used.

My current laptop has a 65W PSU. When completely dead, it can actually pull 50W to charge the battery (with laptop off). With it on, it uses the whole 65W (observed through a Kill-A-Watt meter). When fully charged, even if I max out CPU (it’s only iGPU), I only see 55W of usage. So there’s definitely power budgeting going on there.


How flexible is the charge controller?

If I provide is 25w from a charger will it charge still if I’m drawing sub 25w? Yet supplement the battery if drawing above?

You can provide 25W, the computer asks via a PD protocol for a voltage, not watts.

Not sure what the rest means, can you explain a bit more?

The laptop runs from the battery.
The power unit charges the battery via PD, which the computer negotiates.

If the laptop uses 25W and the power unit can deliver 24W at some voltage then the battery state will slowly decrease as the 24W of power let’s say at 12V x 2A as there is inefficiencies and the battery is only 90% efficient at best.

For my Gen 11 Batch 1 FW13, a 30 watt charger will charge while in use, (not Heavy use, though). Anything smaller didn’t really want to charge, while the computer is in use. Turned off, it would charge slowly.

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My work laptop won’t charge at all unless it’s negotiated 20v5a minimum

My partner’s laptop is smaller and wants 20v3a minimum.

Both laptops won’t likely draw this but they want to negotiate that.

Will the fw13 charge on a 25 or 45w pd charger even if the battery depletes a bit?

Let’s say I’m using 45w total power and supplying 25w, will it then just pull 20w from the battery?

Or just stop using ac unless I can supply enough power?

I have not seen any reports of a minimum cut-off where the laptop will not charge if it’s unable to negotiate high enough. In fact an “emergency charge” exists where it will take 5v.

That being said, a 45w (and especially a 25w) will charge slower because the voltages available are less than what Framework’s supplied adapter can provide.

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Depends upon the load. Power will go to the battery but if more is being drawn that can be drawn from the power unit, then it will discharge.

Yes, maybe a bit more due to efficiencies.

On both Framework Laptop 13 and Framework Laptop 16, the batteries are designed to charge at 1C, and the charging circuitry will only ever charge up to that rate, regardless of the power adapter wattage. That means up to 55W/61W on 13 and 85W on 16. Charging above 1C would require either putting extra wear on the battery that limits cycle life, or using a battery chemistry that has less energy density.

There is some loss in the charging circuity, so you’ll need something like a >60W/65W power adapter for 13 and a >90W power adapter for 16 to charge the battery at full rate if the system is in standby, or more if the system is in active use.


You mentioning 1C, is this what you mean?

Not nrp answering but

1C is the max, so 84W ÷ 16V is some 5A, but this is only done for a short time as 5A would kill the battery, even explode it if the battery is really flat or nearly fully changed so it can take two hours or more to charge.

The rate is lowered not just to save an explosion but to reduce wear which is largely down to heat.

Charging an empty or nearly full battery requires a lot of force, which generates heat, so at both extremes the voltage may be 5V and 0.9A the basis of USB A 2

Now a charger may be able to provide 5A at 20V so 100W

85W divided by voltage give the max current for charging

Anyone can answer, doesn’t have to be nrp but thanks

I’ve changed the link to this

Is that just the battery?

I.e there is benefits in having a 100w charger? 1c into the battery. If you have a 65w charger you have nothing left over. So if I draw 40w on the platform, only 25w can go into the battery?

If I have 100w it means 60w can go into the battery while 40w can be used by the system

Yes. But be aware that li-ions don’t charge at full current all the way to 100%. Charge rate tapers off in the later half.

Example li-ion charge profile at 1C

In that example, the charge current starts to drop even before the battery reaches 60%.

Thanks! Even better than I guess. You’re less likely to affect charge beyond 60% if using it plugged in on a lowe spec charger.

Here is a real test I did on my 11th Gen


Sorry I’m struggling to work out this graph?

The red line is the draw on the power unit from dead to 100% maxing at around 50W for one hour

The green is the accumulated watts over 4 hours.

You can see for the first hour the charge was around 15W and after three hours less than 10W down to just about zero.

It was so long ago I can’t quite understand the green line, I’m working on that :slight_smile:

Yup got it thanks, so total watts is akin to percentage charge? Also do you have a max %?

Thats a strange power curve unless you was using it a lot for the first hour and had less AC available for the batter?