When looking at the graphics modules dimensions, you can have a thickness of 20,95 mm and a width of 356,6 mm.
You could fit 5 18650 Li-Ion batterys in the part where the heatsink sits. Combined they would get to a lenght of 325 mm (excluding connectors or nickel strips). When using these Samsung INR18650-35E (Samsung INR18650-35E 3,6V - 3,7V 3500mAh | akkuteile.de) you could get 64,75 Wh at 3,7 V. Max constant output power would be 148 W at 3,7V.
Or you could fit 5 21700 cells when making the part a bit thicker on the top (like 2 mm higher). Combined they would get to a lenght of 350 mm (with connectors it could be a bit to long). Using these Samsung INR21700-50E (Samsung INR21700-50E - 5000mAh 3,6-3,7V Lithium Ionen Akku | akkuteile.de) you could get a stunning 92,5 Wh at 3,7 V. Max constant output power would be 181,3 W at 3,7V.
The electronic components could fit where the Graphics Module PCB sits. There should be enough space.
The weight of just the battery would be 250 g for the 18650 and 350 g for the 21700. And you could get a combined energy storage of 149.75 Wh (+ 76,1 %) or 177,5 Wh (+ 108,8 %)!
He’s talking about placing the cells in a line along the back. It would be similar to how the GPU module sticks out the back. If I recall, Nirav mentioned cells in that location in an early video talking about the FW16.
The fans are “inside” the laptop while the heatsink fins are “outside” in the black plastic extension. The idea is to use the “inside” area for the very same fans and a PCB that contains the battery charging logic and the “outside” for the cells.
It’s possible that the PCB for the graphics board itself serves a structural purpose, but a quick and dirty approach would just get a pouch battery the same size as the GPU board, leave the GPU heatsink in place, and squeeze in a charge controller close to the interposer.
At least for prototyping- seeing if a battery would even charge and discharge in this space
To give another way of explaining it:
Heatsink is not the same as heatpipe. The heatsinks for the dGPU are in the very back of the expansion module, directly adjacent to the fans. The heatpipes are over the actual GPU chip and lead to the heatsinks.
Now where the misunderstanding happened: @Chr was talking about only “replacing” the heatsinks, which would give them the full length of the expansion module to work with. You thought they wanted to use the space where the GPU and heatpipes are.
A final product should use all available space imo. If you’re going about designing and manufacturing a battery module, you might as well go as big as you can (while sticking to regulations and limits, like the 100Wh for airplanes)
I’m curious how hard it would be to add an interoperator cable to the current battery header and then 3D print your own battery shell or adapter and include the necessary control circuitry in the bay you construct to allow hot swapping. Make it as big as you like, materials withstanding. IMO, it would be best to make the bay effectively an adapter for a secondary “mainstream” battery.
I’m Looking at the massive pile of old Dell Latitudes I have that shared basically the same battery for generations. With those I can use the bigger 97wh battery that hung off the back (I don’t recall the size on the even bigger one that lifted it up off the table) and then add a 2nd battery via the proprietary “e-port” for the dock in the bottom - another 97wh. And then I could still swap the hot swappable Slimline bay for a third 30wh battery. That’s THREE hot swappable OEM batteries on one Dell E6430 with an i7, 16GB DDR3, Nvidia 5200M, SSD, Wifi6+BT5.1 and various I/O ports. 224wh of juice…ahhhh, the freedom! THIS is what I’m looking to replace with a Framework. There’s obviously a market if Dell has been making these things for generations.
I too miss the days of the big honkin’ add-on battery options. Light weight? Heck no. But I don’t buy 17" laptops to be light weight, and now it’ll run for DAYS.
Anyone considered how it’ll affect the weight distribution? Is it going to make your Framework handle like a 1970s Porsche 911 with all that weight out the back?
Pretty close. Theoretically five 18650s should be 91% as wide as the laptop.
The largest 18650 cells I can find appear to be just over 12 Wh each, so five off those would be 60 Wh. A 71% improvement to battery life would make a big difference.
I will note that I personally would prefer a design that uses the normal expansion bay shell (not the larger graphics module shell) for the charging PCB and has a separate hot-swappable part that clips on the back (using the opening on the back of the shell for the connection). This would have a similar footprint to the graphics module based idea but would allow for it to be easily removed without needing to swap expansion bag modules. That would be more expensive, but I’d happily pay a couple hundred for that in a heartbeat.
Is that 12Wh each at 3.3v? I’d be guessing the 5 batteries need to be in serial to accommodate 15v (via 16.5v total across the 5 in series), which to my understanding means the only thing would only provide 12Wh. Another 5 cells in series could then provide another 12Wh, assuming those spec values are right and my math is to be believed.
The highest capacity 18650 cells I see are 3.55 Ah and 3.6 V, which calculates to 12.78 Wh.
If you wire cells in series the voltages add together while the amperage stays the same. So 5 of those cells would result in a battery that has effectively 3.55 Ah (same as each individual cell) and 18 v (same as all cells combined) which would calculate to 63.9 Wh.
If you wired the cells in parallel you would also reach 63.9 Wh, however through 17.75 Ah (same as all cells combined) and 3.6 v (each individual cell).
So regardless of how you wire it the total capacity (in Wh) of the pack would be the sum of the capacities (in Wh) of each individual cell.
Edit: For example the Framework’s main battery pack has four cells, each with rated for 5.491 Ah and 3.87 V rated voltage, which calculates to 21.25 Wh. Add those four together in series and you get a battery pack with an effective Ah of of 5.491 Ah and effective voltage of 15.48 v. That calculates to 85 Wh, which is the same as if you just summed the 21.25 Wh of each of the four cells.
