Roast my 280ah build for boat

[BigVT]

Xuba 280ah cells with JBD BMS in a Peli style case. Snug fit and some minor work left to tidy it all up (isolations on connectors etc). Tried to make it as "secure" as possible given vibrations; loctite on pretty much everything, 20mm stainless studs for poles, cells taped to a bottom plate of plywood, everything squeezed in the case between the foam. Ran a 1h test with 60A load and temp was 35C on BMS and 20C on cells, but will do a longer test with higher load. Two of these will power a max of 100A combined when put to use. Any input before I finalize it?

 

[ZebraPainter]

Pretty slick. What size BMS did you choose?

 

[BiduleOhm]

I would not trust tape for a marine application.

Apart from that very nice build

 

[ianganderton]

Would you be better off having more wiggle room in the bus bars seeing as it’s going on a boat. Using the earth strapping style bus bar would massively reduce the stress on the terminals which could be a point of failure.

 

[iceledoar]

Xuba 280ah cells with JBD BMS in a Peli style case. Snug fit and some minor work left to tidy it all up (isolations on connectors etc). Tried to make it as "secure" as possible given vibrations; loctite on pretty much everything, 20mm stainless studs for poles, cells taped to a bottom plate of plywood, everything squeezed in the case between the foam. Ran a 1h test with 60A load and temp was 35C on BMS and 20C on cells, but will do a longer test with higher load. Two of these will power a max of 100A combined when put to use. Any input before I finalize it?



View attachment 20176

Very cool build, the tape should work as long as the batteries can't move around...ruff sea's will move anything not tied down move, so they have to be tightly fitted.
1. I'd like to see the spaces on the right and top (by the handle) of the battery filled to prevent lateral movement.
2. Positive lead is too long, get rid of the loop, as the kink at the top of the loop is causing resistance and has stressed the connection at the battery. Possibly some heat shrink to the connections.
3. Does the positive need to be fused between the battery and the case?

 

[BigVT]

Pretty slick. What size BMS did you choose?

Thanks! 120a

I would not trust tape for a marine application.

Apart from that very nice build

Thanks. I thought I'd get away with it given the case will cramp it all together (can barely close it). But you're right, I'll see if I can fit some metal bars along the sides but there's almost no space left.

Would you be better off having more wiggle room in the bus bars seeing as it’s going on a boat. Using the earth strapping style bus bar would massively reduce the stress on the terminals which could be a point of failure.

Good point - and I've been looking at them but I figured if I could make it tight enough it would be overkill and save me some. It's definitely a valid point though, and good alternative if I can't get metal bars around the cells.

@iceledoar 1 & 2, agreed - good input! It's so tight nothing can move, but I have filler foam from the case I can use too. 3, it would be fused after the case

 

[rickypr]

Nice work! I have seen comments that those batteries should not be installed in a vertical position, not sure about it.
Can you share the link for that case?

Thanks!

 

[ianganderton]

Good point - and I've been looking at them but I figured if I could make it tight enough it would be overkill and save me some. It's definitely a valid point though, and good alternative if I can't get metal bars around the cells.

I would do it anyway. People have expressed the opinion that these 280Ah cells aren't ideally suited to mobile applications. They are big and heavy (compared with other sizes) and have relatively small terminals that will stress easily. Even with compression, there is a strong chance of the cells 'flexing' with occasional, unseen high loads. These cells are going to be in use a long time, they need to be to get value out of them. Worth giving them the best chance of providing value.

 

[Argosy]

Id remove the terminals you have mounted on the case, and have wires from BMS coming straight through a hole with grommet. Then should go straight to fuse and busbars. These style terminals will loosen with vibration.

Also, get rid of that soft foam and at put some great stuff expanding foam in there to keep everything from moving around and water tight.

 

[Luthj]

An easy way to make strong restraints is to cover the surfaces with clear packing tape. Then use some great stuff foam in 2" layers. Letting it cure between layers. The tape will let you remove the foam later if needed.

 

[BigVT]

Nice work! I have seen comments that those batteries should not be installed in a vertical position, not sure about it.
Can you share the link for that case?

Thanks!

It's a Swedish retailer, but here's the link nevertheless; https://www.jula.se/catalog/bygg-oc...ksforvaring/verktygslador/skyddsvaska-001594/

 

[BigVT]

I tried with metal bars and studs around the cells, but can't close the lid because of the extra centimeter in width. I'll get some copper braid straps and will put a layer of shrink plastic around the pack (mostly for aesthetics though) but the cells are pretty tight as is (and case will help compress too) and with the straps minor movement should be fine. I picked up some anderson power plugs rated for 175a instead of the terminals.

 

[BiduleOhm]

Then please use flexible busbars as the cells will still move relative to each other (foam and tape have some flexibility, busbars have pretty much none)

 

[rickypr]

It's a Swedish retailer, but here's the link nevertheless; https://www.jula.se/catalog/bygg-oc...ksforvaring/verktygslador/skyddsvaska-001594/

Thank you!