It’s been a long time since we last were on here or had a working eSk8 (enertion raptor v1 at release, self built with nese 3dprinted modules that ended up dead after 2km and us too annoyed to try fixing it, and then the choochoo board with torqueboards directdrive and sadly we left the battery lying around too long and it died before we ever got to ride it)
Atleast four years, possibly five even
We still have new battery cells lying around (which are surprisingly still on 3.5V) from around then
Our idea since a long time was to build a modular batterie, where cells could be easily replaced
Our current question is, how warm do battery cells get (for material selection)? And does anyone have any suggestion on construction or maybe there’s already an alternative to the nese (as those were a pain to work with (screwing throu the plastic took a lot of effort)
Interesting project and welcome back!
How hot they get depends on the cells and how hard you discharge and charge them. If it’s helpful for a ballpark figure you really don’t want to get them above 80C, even 60C is really quite hot.
So not pla, ideally not petg if it needs to have much real strength right on the cells.
which brings us back to our initial issue; wanting a material that is (atleast somewhat) ecological
by know kinda unsure we’ll manage to ever get it done. thinking of just buying a spotwelded pack
Just for reference I have a modular battery design in my boards.
I don’t charge such that the cells get hot at all. The plastic I used is HDPE, called Starboard at TAP plastics.
are the pcbs screwed on?
also are they separated or are they connected as 2s?
how do you connect the individual pcbs?
the standoffs at the side of the 3d print is for spacing in your enclosure?
sorry for all the questions ^^"
liking the idea of the spring loaded pcbs (feels more stable than eg copper mesh that could potentially have a disconnect)
You’re alright. It’s an electric skateboard, it’s a pretty eco-friendly mode of transport already.
And it’s about the weight of plastic that you would find in a dustbin anyway and something biodegradable will biodegrade and you’ll need more. An esk8 is a harsh environment so splash out!
Yes, the PCB’s are screwed into nylon rods that have been cut to precision length, drilled and tapped. I originally used aluminum rods but the chance of something bad happening was just too high. So far I’ve not had a strip-out with the nylon.
Here’s a picture of the complete assemblies.
you can see the power connector screw terminals on the PCB. They are 2@ 5P per frame for a total of 12S5P on the board
The spring terminals were indeed an optimization of my original design which still had terminals but they didn’t have nearly as much spring distance to them.
really nice! 
do you, by any chance, have the stl files up somewhere?
depends on what you compare it too. still has all the issues of mining for minerals, electronics that probably wont get recycled…
muscle work also consumes energy, but atleast growing crops can be done in an ecological way (though it rarely is done that way)
Currently it’s a balancing of trying to get it working while keeping the system (us) happy and this involves a lot of eco-consciousness, so just mindlessly buying things doesnt work.
jap, thanks so much!
have a friend who said they’d help us after easter hollidays, and already have some ideas on adapting the design to the idea we have. finally this is going somewhere. yeepeeeee
I recommend checking closely into what temp your material choice starts to lose its stiffness/strength since that’s critical in a good cell compression holder design. A lot of 3DP materials start to soften at the higher cell temps a pack might see.
Ping me if you need more info on the BOM or other parts.
I love the ability to swap in fresh cells and be able to re-purpose older cells to less demanding tasks without having to de-spot weld them and clean them up.
Some time next winter I hope to attempt to build a modular pack for this board.
I’ll be interested in whether I can adapt or adopt your design.
Please show a pic of the spring and did u add them yourself or a pcb place did it?
will do!
idea is to ditch the screws and have them clip in (basically like with consumer electronics)
still have some metal tabs with foam attached lying around. think they were a standalone buy from the nese modules
Sourced here
Notice that you have to cut the bottom off each clip so that it’s flat.
I used solder paste and a reflow oven to place them.
I had one of these cheapie reflow ovens from another contract so that was handy.
Lastly when you order your boards use the 2mm PCB thickness, not the standard 1.6.
Any reason you chose that one? Any you know of that could be attached without a reflow oven?