Do EV pouch cells prefer to be laid flat/horizontal?

[cycleops612]

I have never seen reference to it being relevant, but intuitively, road shocks on a vertical long thin delicate pouch cell do sound stressful.

It would be good if I could be reassured that any positioning for my lifepo4 battery on my ebike is ok though.

 

[Syonyk]

I've never known that it mattered. You should probably keep them physically secured under a slight bit of pressure such that they can't move relative to each other anyway.

 

[Gregory]

I think flat is best, on their ends if you must, and never on their thin edges.

 

[Adverse Effects]

I think flat is best, on their ends if you must, and never on their thin edges.

and how did you come up with that conclusion?

 

[Adverse Effects]

I've never known that it mattered. You should probably keep them physically secured under a slight bit of pressure such that they can't move relative to each other anyway.

that is correct and that helps stop the liquid in them settling to the lowest point and keep all the internals wet

best way is to have hard end / side plates pulling together on at lest all 4 corners or more if needed

doing this will let you mount them in any orientation

 

[cycleops612]

I've never known that it mattered. You should probably keep them physically secured under a slight bit of pressure such that they can't move relative to each other anyway.

that is correct and that helps stop the liquid in them settling to the lowest point and keep all the internals wet

best way is to have hard end / side plates pulling together on at lest all 4 corners or more if needed

doing this will let you mount them in any orientation

"best way is to have hard end / side plates pulling together on at lest all 4 corners or more if needed"

Its not clear to me. can you eleborate pls. are u suggesting i do this in addition to the existing shell, i.e. as part of securing it to the bike? Its a chinese blue shrink wrap job. No details given re construction, but clearly a hard plastic shell of some kind within.

Is it reasonable to assume they know their job & any orientation is fine?

Having seen a teardown of a pouch cell, I am inclined to think flat is good, so electrolyte doesnt "sag" & unevenly cover the metal foil.

Of dubious relevance: Rear rack batteries always seem flat, even tho they could be slanted for better/lower weight placement.

 

[Adverse Effects]

Its not clear to me. can you eleborate pls. are u suggesting i do this in addition to the existing shell, i.e. as part of securing it to the bike? Its a chinese blue shrink wrap job. No details given re construction, but clearly a hard plastic shell of some kind within.

so what is it? hard plastic or shrink wrap?

hard plastic = well its in a hard box no point in trying to squash it any more really unless you have intentions of really abusing it so it swells more than the case can handle

shrink wrap = they will swell even with lite use and reducing the amount they can swell is better for the cells
look up something like strapping lipo cells

Having seen a teardown of a pouch cell, I am inclined to think flat is good, so electrolyte doesnt "sag" & unevenly cover the metal foil.

if the cells are kept compressed something called capillary motion, or wicking will happen and wick the liquid through out the cell

Of dubious relevance: Rear rack batteries always seem flat

that is done for a different reason

stand it on its side then see how hard it is to balance a bag / port / box / ... on it