houseofancients
Solar Wizard
and to add, how are your connections done to your inverters/busbars ?
custom made battery box for eve LF280K cells
- Thread starter sergea
- Start date
Yes they were. They were assembled in China. Seplos shipped the box to my cell supplier who did the top balance, assembled them and shipped the packs to me.
Yes, Bus bars.
Ron-ski
Solar Enthusiast
But how are they connected?
A picture may help.
Battery connections should all be the same cable and length to the Inverter, otherwise different batteries will supply more or less current.
Sanwizard
Solar Wizard
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Thats good that you trust your supplier. I would have done it myself to be sure.
Hi,
I started to assemble my Mason DIY 280 today, and I'm not sure about the torque for the different parts.
On the seplos webwite, I saw this page : https://www.seplos.com/mason-280-51-2v-280ah-Lithium-battery-pack-assembling-guide.html
With some numbers, for exemple "Set the torque index of the electric screwdriver to 3", or with specific Nm for exemple "Set the torque index to 8-9 Nm"
In the video guide (www.youtube.com/watch?v=z-w3F7GhYJE), the guy from seplos says numbers, for exemple : "set the torque to 7" but it's specific for his screwdriver no ?
For exemple, my electric screwdriver is rated up to 30nm and numbers I can set on it are between 1 and 10, so I don't think it's the torque in nm.
Do you know were I can find the torque values ? Or it's not important except for the busbar (I saw 5 or 6 Nm on seplos docs), and for the orange busbar on the BMS at 7Nm ?
I started to assemble my Mason DIY 280 today, and I'm not sure about the torque for the different parts.
On the seplos webwite, I saw this page : https://www.seplos.com/mason-280-51-2v-280ah-Lithium-battery-pack-assembling-guide.html
With some numbers, for exemple "Set the torque index of the electric screwdriver to 3", or with specific Nm for exemple "Set the torque index to 8-9 Nm"
In the video guide (www.youtube.com/watch?v=z-w3F7GhYJE), the guy from seplos says numbers, for exemple : "set the torque to 7" but it's specific for his screwdriver no ?
For exemple, my electric screwdriver is rated up to 30nm and numbers I can set on it are between 1 and 10, so I don't think it's the torque in nm.
Do you know were I can find the torque values ? Or it's not important except for the busbar (I saw 5 or 6 Nm on seplos docs), and for the orange busbar on the BMS at 7Nm ?
houseofancients
Solar Wizard
with the exception of the busbars and compression/fixation it isnt all that important.
for my cells and bussbar i used 4-5 nm
for compression/fixation plate i use 9 nm
I think Andy refers to the various torques in his video. May be worth a watch. I built mine watching this rather than using the docs.
Torque is specified by the size and material of the fastener. A 6mm stainless bolt should have 8.7 Nm (77 in-lbs) of torque, assuming a clean, dry thread. A lubricated thread requires less torque.
https://crafter.fastenal.com/static-assets/pdfs/Torque_of_Metric_Stainless_Steel.pdf
houseofancients
Solar Wizard
you put that much torque on a cellstud, you'll be breaking it off, and can throw away your cell
You are suggesting that 8.7 Nm is *not* the correct torque for a 6mm stainless bolt? Please provide your torque table.
houseofancients
Solar Wizard
i am stating that if you put that much torque on the soft aluminium battery studs, they will break off or strip..
do a forum search
Sanwizard
Solar Wizard
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Totally agree with @houseofancients. I use 4-5nm tops with the 280ah cells. That also is what Andy at off grid garage uses.
Others who have exceeded that here have had terminal issues with stripping the threads. Its soft aluminum, not steel.
houseofancients
Solar Wizard
they are, and soft aluminium.
the grubnut/stud is stainless steel..
steel will always win over soft aluminium
Thank you for all the replies and advices. I torqued the BMS busbars at 7 Nm and the cells busbars at 5 Nm
I torqued the compression plate at 9 Nm and the rest manually, like houseofancients said it's less important.
I also watched the Andy's video and saw he didn't put the copper washers between the cells terminals and the busbars.
When I assembled the battery, I put them, but now I think it was maybe not a good idea, as the terminals and seplos busbars are in aluminium, what is the goal to had copper beetween ?
I also "cleaned" cells terminals with a 600 sand paper (using a technique I saw on a "Ray builds cool stuff" video) and sand the part of the aluminium busbars in contact with the copper washer.
I also added MG847 paste between cell terminal and copper washer (but not between copper washer and aluminium busbars)
Do you know why Seplos choose aluminium busbars ?
After reading lot's of threads and comments under Andy's video, I think it maybe not a good idea to keep aluminium busbars / copper washers
I still have the tinted copper busbars delivered with my Docan's cells.
What do you advice me to do for good and long lasting connections ?
1) Keep it like that (Seplos aluminium busbars + Seplos copper washers on cell terminals)
2) Replace aluminium busbar by Docan's tinted copper busbars (and keep or remove copper washers ?)
3) Other solutions ?
I torqued the compression plate at 9 Nm and the rest manually, like houseofancients said it's less important.
I also watched the Andy's video and saw he didn't put the copper washers between the cells terminals and the busbars.
When I assembled the battery, I put them, but now I think it was maybe not a good idea, as the terminals and seplos busbars are in aluminium, what is the goal to had copper beetween ?
I also "cleaned" cells terminals with a 600 sand paper (using a technique I saw on a "Ray builds cool stuff" video) and sand the part of the aluminium busbars in contact with the copper washer.
I also added MG847 paste between cell terminal and copper washer (but not between copper washer and aluminium busbars)
Do you know why Seplos choose aluminium busbars ?
After reading lot's of threads and comments under Andy's video, I think it maybe not a good idea to keep aluminium busbars / copper washers
I still have the tinted copper busbars delivered with my Docan's cells.
What do you advice me to do for good and long lasting connections ?
1) Keep it like that (Seplos aluminium busbars + Seplos copper washers on cell terminals)
2) Replace aluminium busbar by Docan's tinted copper busbars (and keep or remove copper washers ?)
3) Other solutions ?
Sanwizard
Solar Wizard
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- Feb 2, 2021
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- 2,715
I did NOT use the aluminum busbars, as they were too wide, and almost contacted the center metal bar. I used the tinned copper busbars that came with my cells.
As above. I also used the nickel plated busbars that came with my cells (no copper washers). You can request nickel copper busbars as opposed to aluminium ones from Seplos as well as busbars that will fit the EVE double terminals, as this is what I did with my last Seplos Mason order. Whether they will arrive is another thing, but you can ask. ?
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