24v 280ah Fogstar Drift - Battery Box source

[shogran]

Hi all,

I'm in the process of converting a van and have settled on a 24v 280ah system. After looking at multiple sources I ended up ordering my grade A 280ah EVE cells from Fogstar here in the UK. They should be arriving in the next week or so, very exciting!

I've since noticed that Fogstar offer their own prebuilt packages with the Fogstar Drift range which includes a 24v 280ah battery. I cannot for love nor money seem to source a battery box large enough to hold my cells, let alone one that will take a BMS as well and based on some other topics here others have had the same problem. Does anybody know where they may be sourcing these? This is the battery: https://www.fogstar.co.uk/products/lithium-leisure-battery-fogstar-drift-24v-280ah

I reached out to see if I could purchase one a while ago but they didn't have any around and said they'd get back to me if there were any updates, but no joy. I was recently in touch to check the status of my cells and asked again and their seemed to be some confusion as the person on the other end didn't seem to think it would be possible to get that many cells in a box despite them selling the battery.

Any advice would be gratefully received!

Kind regards,

Josh

 

[meetyg]

I've seen those dimensions on Aliexpress and Alibaba:

https://www.aliexpress.com/item/1005005069924185.html

Seems to fit 8 x LF280 cells. The height is a bit tight, but I'm guessing they put the BMS to the side of the cells rather than on top.

 

[shogran]

Amazing, thanks so much, just ordered one. I've searched for ages and couldn't seem to find any that were bigger than 570 or so.

 

[shogran]

In case anybody else stumbles onto this, my case arrived today but unfortunately the dimensions that Fogstar list for the cells does not include the terminals! So I'm back to trying to source another box, building one, or working out a way to offset the lid by about another 10mm.

 

[meetyg]

In case anybody else stumbles onto this, my case arrived today but unfortunately the dimensions that Fogstar list for the cells does not include the terminals! So I'm back to trying to source another box, building one, or working out a way to offset the lid by about another 10mm.

Did you think about laying the cells on thier sides? I'm pretty sure it's the same box Fogstar uses.

 

[shogran]

I did consider that, but wasn't 100% sure how that would work with the busbars and compression. I could have each cell in a stack connected, then use a cable to connect to the next stack?

My current plan was to get some small plastic tube spacers to offset the lid, something like these https://uk.rs-online.com/web/p/spacers/1364355

All ears for any suggestions though, not something I want to rush into and make a mess of.

 

[meetyg]

I did consider that, but wasn't 100% sure how that would work with the busbars and compression. I could have each cell in a stack connected, then use a cable to connect to the next stack?

My current plan was to get some small plastic tube spacers to offset the lid, something like these https://uk.rs-online.com/web/p/spacers/1364355

All ears for any suggestions though, not something I want to rush into and make a mess of.

You don't need to stack them. You need to put 8 in series, but instead of terminals/busbars facing up, they should face the side.
So basically it's a similar orientation, with 8 in series and any fixture/compression you were planning, but the cells are rotated 90 degrees (either left or right, whatever works for you).

 

[shogran]

I was envisioning having to lay them on their widest edges in stacks of 3 or so to make them fit. But I went out earlier and had a bit of a "doh" moment when they all fit in their narrower sides (obviously as they fit standing up).

My only concern now is that their seems to be a bit of a split on whether or not prismatic cells should be orientated this way as the electrolyte fluid may not be in contact with all plates. But I don't see any reason why I can't put them physically in the box in their side, and then secure the battery box on its side so the cells are the "right way" up.

 

[meetyg]

I was envisioning having to lay them on their widest edges in stacks of 3 or so to make them fit. But I went out earlier and had a bit of a "doh" moment when they all fit in their narrower sides (obviously as they fit standing up).

My only concern now is that their seems to be a bit of a split on whether or not prismatic cells should be orientated this way as the electrolyte fluid may not be in contact with all plates. But I don't see any reason why I can't put them physically in the box in their side, and then secure the battery box on its side so the cells are the "right way" up.

Exactly... I'm glad you had that "doh" moment.
Anyways, yes, I 'm aware of the conflict about cell orientation. What is surely problematic is cells laying on thier wide side, or straight but upside down. Laying on the narrow side is the question. I have seen many teardowns of 100Ah (and above) Lifepo4 batteries, and many of them have the cells laying on the narrow side.
Having said that, I haven't seen seen builds with 280Ah cells and above on thier narrow sides. You might try to contact Fogstar or EVE to get some sort of answer.

 

[shogran]

Thanks for sticking with me on this!

Been doing some digging and from the general consensus and some YouTube teardown videos (thanks for the idea!) I'm happy that for my purposes lying them on their side will be fine. I have previously reached out to Fogstar but the person I got seemed unsure about how it was configured. I reached out again for some clarification yesterday so will see what they say but hopefully now on to building!

 

[littleharbor2]

All ears for any suggestions though, not something I want to rush into and make a mess of.

Sounds like by now you have solved your problem but I thought, instead of raising the lid I would have lowered the bottom by removing the lowest 1" or so of the box and reattaching it with additional sidewall. Anyway, my $0.02.