Prismatic cell orientation

[mcswain29]

Greetings all


I am in the process of planning an upgrade to my (pathetic) DC house bank which consists of a single JCI (Costco) Group 27FLA... Drop-in or DIY is the question at hand and for the space the new bank will live. I am height limited to approx 8" which leads me to either a drop-in built with cylindrical cells that can live on it's side (BB, Expion) or shorty prismatic cells. I have only been able to find EVE cells in a form factor that will fit without tipping them - EVE-LF100MA from evcomponents. Has anybody dealt with them? Recommendations?



For the DIY build route - I have a question for those who have... For the sake of conversation and so we don't get into a first-or-third angle projection debate - l'll describe a single prismatic cell as: TOP - face with terminals, FRONT - flat face with the largest surface area, SIDE - skinny long face


Has anybody oriented their bank with cells on their "side"? Any ill effects? I am having difficulty getting a straight answer out of the cell manufacturers for the cells that I have easy access to... Bank would either be CALB 230ah or EVE 105ah cells (as that is what I can easily procure (Grade A) from a reputable distributor in Canada without dealing with cross border shopping/shipping issues)


It seems that a lot of server rack banks have their cells in this orientation, but without knowing the manufacturer and a bunch of other info - this doesn't mean much to me...

[Loredo]

Since you got no answers thus far, I'll try to give you my opinion.
I've just finished the build of my battery out of Eve 280 AH cells since those were also for me the only ones I could fit into the spaces available in my boat. Like you, I did a longish research around the LFP cells. What I've come up with is my understanding that LFP cells need to be installed in such way that their pressure relief valve remains on the top of the cells. Means, no laying them on their sides, upside down... Anyhow, I've not seen any clear answer from a MFR either for this reason I can only give you my opinion no real hard data.

[wholybee]

I actually thought I responded to this a while back. Maybe I didn't click post. You need to check with the manufacturer. In general, the issue is that the electrolyte is a liquid, and the plates (spiral) need to be fully submerged. Depending on how full the cell is, and how much of a gas area exists on the top, affects what orientation can be used. Lying on the large side potentially exposes a very large area of the spiral. On the short side, there is less likely to be a problem.
If you are buying your cells from Alixxx, ebay, or even Amazon, and shopping for price, be aware that one of the reasons cells might be sold at a discount would be variation in weight, which equals variation in the level of electrolyte. This could result in a cell that passes every test in every other way, but can't be placed on it's side.
The vent location doesn't really matter, unless it pops, in which case you have a huge issue anyway, so it still doesn't matter in the grand scheme.

[donradcliffe]

My DIY have been on their side for 3 years with no problems.

https://relionbattery.com/blog/mounting-lithium-battery

[mcswain29]

Thank you all

A bit more digging and it seems that the vast majority of mfgs do not recommend placing a prismatic cell any other way than "up" at moment. Some so far as reneging on that it "could" be done.

As far as drop-in mfgs go - only those who use 26650 cells and provide this info as part of the specs will specify in the installation instructions that any orientation is permissable (BB, expion, relion, to name a few)

I have, since posting last week, seen assembly videos on youtube/promo material for battery factories assembling "drop in" replacements and they jam the prismatic cells on their big flat sides in the box. Just another reason to look before you leap when buying a "drop in" replacement

I digress, but I am slowly moving out of the FLA mentality and have potentially found a better location for my housebank. Finding some NOS yellow cells still in their crates (brand name start with a "W") precipitated this rapid advancement in LFP thinking

[diydude]

Originally Posted by donradcliffe

My DIY have been on their side for 3 years with no problems.

https://relionbattery.com/blog/mounting-lithium-battery

Hi, donradcliffe. RELiON batteries are built with cylindrical cells, not prismatic.

[CaptainRivet]

Originally Posted by mcswain29

Greetings all


I am in the process of planning an upgrade to my (pathetic) DC house bank which consists of a single JCI (Costco) Group 27FLA... Drop-in or DIY is the question at hand and for the space the new bank will live. I am height limited to approx 8" which leads me to either a drop-in built with cylindrical cells that can live on it's side (BB, Expion) or shorty prismatic cells. I have only been able to find EVE cells in a form factor that will fit without tipping them - EVE-LF100MA from evcomponents. Has anybody dealt with them? Recommendations?



For the DIY build route - I have a question for those who have... For the sake of conversation and so we don't get into a first-or-third angle projection debate - l'll describe a single prismatic cell as: TOP - face with terminals, FRONT - flat face with the largest surface area, SIDE - skinny long face


Has anybody oriented their bank with cells on their "side"? Any ill effects? I am having difficulty getting a straight answer out of the cell manufacturers for the cells that I have easy access to... Bank would either be CALB 230ah or EVE 105ah cells (as that is what I can easily procure (Grade A) from a reputable distributor in Canada without dealing with cross border shopping/shipping issues)


It seems that a lot of server rack banks have their cells in this orientation, but without knowing the manufacturer and a bunch of other info - this doesn't mean much to me...

simple answer: write to EV components=the seller if you can put them on the FRONT side and stack them. They sell so the need to know.
the 280AH and 304 EVE you can put on the FRONT side and stack, there are commercial server rack batteries sold where this is done but if you can do that is cell specific.
First it is safe to do with 230, 280 and 304 EVE BUT Downside to this FRONT orientation is that the overpressure valve releases earlier means in case of cell bloating the time you have till it gets nasty and really expensive is shorter. And the construction/spec of the overpressure valve also really defines if you can mount them FRONT or not.



what doesn't work is the SIDE down, thats not allowed in all prismatic cells unless the manufacturer explicitly states thats ok (means the cell is 100% fulid filled or eg pouch cells) as that would distrubte whatvever liquid mix they have in there is ditributed unevenly to the terminal down compared to terminal up means Anode and Catode below the terminal inside the cell.

[donradcliffe]

Originally Posted by diydude

Hi, donradcliffe. RELiON batteries are built with cylindrical cells, not prismatic.

Interesting point. I actually have been using some salvaged EVE prismatic cells. I have read the EVE spec sheet, and it doesn't mention orientation. However on one of the DIY forums there is a response from EVE in Chinglish which translates to "it doesn't matter".

My cells are oriented short side down, in two 1P2S sub packs, held together with electrical tape, Will Prowse style. There are no signs of bulging.