Letas
Well-Known Member
This was a fun little thought experiment for me. Slate has confirmed it won't be offered, but I just wanted to think about it.Battery upgrade or upgradeable battery.
I have assumed and likely others have, the Slate will offer upgrade from Standard to Extended, but no details on the how other than initial order.
I think more attractive maybe 1 battery, but upgradeable. All in keeping with known Slate philosophies of minimal parts, reusability, upgradeability, even DYI
My view
It’s all about the battery container. Word is Slate is sourcing the cell modules from SK ON, but building the container in house and assembling.
Considerations:
0ne container for all battery configurations. That one container in all Blank Slate builds. Possibly installed early process even without the modules.
That container is mounted and completely accessible/ serviceable from underneath with minimal body impediment. Dropping the cover provides access to all components.
All internal and external wiring is separate from modules and exists in a single configuration. Am assuming the modules are connected via a bus arrangement. Module installs no contact other than buses
3 modules for Standard, 5 modules for extended according to CEO interview. Module installation could be separate from container install. Upgrade costs would be minimal except cost of the actual modules unless container was closed.
BMS/software should be autosensing, self configuring, regardless of number of modules. This would open the possibility of an intermediate upgrade of 4 modules (190 mile). Sure would suit my needs.
Based on what we have seen of the SK ON module they appear to use a blade type contact each end.
Might it be possible to develop a method, maybe even a tool where a module can be added with minimal to no risk of installer accidentally making a hot contact? Minimize module insertion error, maybe color code bus and module end? Am assuming serial buses so modules might alternate? Sure could open up the post manufacture upgrade process.
Desire to upgrade to 4 or 5 modules for the mileage after purchase, simply drop battery cover, inserted new module(s) and reinstall cover. Next powerup, BMS senses additional module(s) and adjusts. Worse case, make a configuration option in the software.
I really hope Slate engineers are considering and implement such an approach.
For us, the cost to upgrade would be near the cost of the 2 additional modules if during initial build and more palatable than a battery swap. add an installation cost if after build and not DYI.
This approach could also benefit future upgradeability as SK ON or 3rd party would only have to match current module configuration and whatever software update.
My apologies if I mangled anything technically, but hopefully the idea is clear.
First of all, I think the regulations and/or liability would be a nightmare, but I don't know much about that, so I can't comment on it.
What I do have a fair bit of knowledge about is what these packs look like when you open em up. Full disclosure, I don't know much about SK on specifically, but have plenty of experience with GM mods, which are similar style.
So first of all, that picture you sent, is not a module. It is a pouch, also known as a cell (although cell is more commonly used for cylindrical cells, as opposed to these flat ones). These cells get stacked into an array (maybe 2 wide, 10 tall- not sure exact) and put into an aluminum housing to make a module.
That module will look something like this. These are pretty heavy. I believe around 80 lbs? I forget off the top of my head. Not so heavy that they can't be handled by one person, but a bit unwieldy to try to guarantee no hot connections. The good thing is, Slate could ship them in a low voltage state so if you do add your body to the circuit, it'll just supplement your morning coffee, not send you to the ER.
For some more visibility, the modules get put into a pack, which looks something like this.
Notice the bars running across parallel to the mods- I believe this is one of the busbars, although could be wrong. A key point here is that the mods are inserted and supported from the top-down, not bottom up.
For your use case, they would have to find a way to "suspend" the batteries, rather than resting them inside. Not impossible, just not the current standard.
But, the bottom-up approach opens another interesting issue. Under the mods isn't just metal housing, there is protection, insulation, etc. Depends exactly on what the manufacture is, as they vary, but current batteries are not meant to be accessed from below.
There's two pictures that better demonstrate the undercarriage of the mods, that would add to the challenge. I don't think it's impossible, but definitely some difficult considerations to make. What I actually think would be easier is to sell all Slates with the same size "cutout" for battery packs, and on the smaller version of the battery, put in a dummy filler in the undercarriage. Then that filler can be removed, and an entire extended pack sold, which would be a much simpler (and safer) install. Drop dummy, mount pack, plug into a main BMS, and run two packs. Biggest challenge there is the weight of a pack, would not be a garage job, but more accessible at least.
Maybe none of this makes sense. I was thinking about it last night and it made sense in my head.
