Dan-O's DIY 105ah LiFePO4 cell holder springy contraption things!

Electro Dan-O

Current Situation
Joined
Nov 15, 2020
Messages
35
Location
Middle TN
After searching the forum, robbing ideas, asking questions, and learning a couple things the hard way, this is what I came up with for my first DIY solar boat batteries. Is this the best way? Highly doubtful. This is just how I did it and I feel like it will work great for me. Maybe this will give you some ideas and hopefully something to improve on....

I originally was going to do a few rounds of electrical tape, throw them in a plastic container and call it a day. All was good until I came across the cell compression with springs thread...

I'm all for saving money and using whatever I have on hand if possible, so a lot of this stuff is just leftovers or saved from the dumpster. I'm just a hillbilly with a small garage and a big dream of having a cheap boat that never runs out of fuel and never breaks down.:p

I started with cutting up some 1/2" Douglas Fir plywood 1" larger than the cell dimensions.
NrD0dhS.jpg


Ordered up some stainless hardware including 5/16-24 threaded rods. Also 10ft of 8mm ID silicone hose. I still have quite a bit left over...
81u4aE4.jpg


Saved some .030 plexiglass from old picture frames and cut them to cell size. These are insulators to go between the cells.
rXG6d7y.jpg

VjUlYUg.jpg


Decided to round the top corners because..... it looks better?
7v0uabl.jpg


I saved a UTV/SXS windshield from the dumpster(6mm thick plexiglass) and cut that up for the baseplates and top covers. Also, ordered a couple small stainless hinges from Amazon...

ld6PCWL.jpg


Also from Amazon, these small cast aluminum L brackets. I sanded them for a nicer look...
LyxdJ4q.jpg

Rv3scvx.jpg

vTnaMQ6.jpg


Next up was sealing/strengthening both sides of the wood with fiberglass cloth and just a touch of tint to make them black.
l0SIlLk.jpg


I had some carbon fiber scraps that have been sitting here for a while. Hmmmmm.... I had just BARELY enough to pull it off! No point in doing this at all but it looks cool and added that much more strength so.....
fbhYFU9.jpg

aqYZbsM.jpg


Getting there...
o95MIzL.jpg



Ordered up some 135lb springs to hit our goal of 12psi of compression. Also, drilled holes for BMS wiring and used some of that silicone tubing as grommets.
NnNpwd5.jpg


Time for some flexible bus bars! I robbed this idea from member upnorthandpersonal and made my own from 3/4" wide braided copper and 1/2" copper pipe. Very cool! DIY tin plating is on the list BTW.
M9STm1F.jpg

JAyYU1d.jpg

ySOcsgZ.jpg

9XW3L0q.jpg

OJTYcV0.jpg


Made the handles with paracord and spare vacuum tubing. Also, used 1/2" adhesive backed closed cell foam on the bottom to keep vibration down and not scratch my boat!
xmbjZuR.jpg


I know, a lot I'm leaving out. This is all of the pictures for now at least. I'll come back and post links/details ASAP. There's still a few small things I want to do before we call these "done" but they are ready to put in work as is.
 
Last edited:

Mike Jordan

Solar Addict
Joined
Jun 15, 2020
Messages
390
WOW! very nice.

Where did you find the braided copper?

Was there any tricks to get the flat braid into a round hole while crashing the pipe?
 

Electro Dan-O

Current Situation
Joined
Nov 15, 2020
Messages
35
Location
Middle TN
Thanks guys! Fun little project!

Got the braided copper from Ebay.

We smashed the copper pipe some first and then put in the braid. Final smash from there! After that, I cleaned up the ends with a sanding disk and sanded everything flat using 120-220-400 grit paper on a flat table.
eJmHSuf.jpg


s2vjJw1.jpg

yfJGv5T.jpg
 
Last edited:

Electro Dan-O

Current Situation
Joined
Nov 15, 2020
Messages
35
Location
Middle TN
Well, for whatever reason, I can't go back and edit the original post now... Oh well. Any questions, just ask and I will do my best to keep checking in.;)
 

DriveHomeRV

New Member
Joined
Feb 22, 2021
Messages
3
Location
New York's Beautiful and Historic Hudson Valley
After searching the forum, robbing ideas, asking questions, and learning a couple things the hard way, this is what I came up with for my first DIY solar boat batteries. Is this the best way? Highly doubtful. This is just how I did it and I feel like it will work great for me. Maybe this will give you some ideas and hopefully something to improve on....

I originally was going to do a few rounds of electrical tape, throw them in a plastic container and call it a day. All was good until I came across the cell compression with springs thread...

I'm all for saving money and using whatever I have on hand if possible, so a lot of this stuff is just leftovers or saved from the dumpster. I'm just a hillbilly with a small garage and a big dream of having a cheap boat that never runs out of fuel and never breaks down.:p

I started with cutting up some 1/2" Douglas Fir plywood 1" larger than the cell dimensions.
NrD0dhS.jpg


Ordered up some stainless hardware including 5/16-24 threaded rods. Also 10ft of 8mm ID silicone hose. I still have quite a bit left over...
81u4aE4.jpg


Saved some .030 plexiglass from old picture frames and cut them to cell size. These are insulators to go between the cells.
rXG6d7y.jpg

VjUlYUg.jpg


Decided to round the top corners because..... it looks better?
7v0uabl.jpg


I saved a UTV/SXS windshield from the dumpster(6mm thick plexiglass) and cut that up for the baseplates and top covers. Also, ordered a couple small stainless hinges from Amazon...

ld6PCWL.jpg


Also from Amazon, these small cast aluminum L brackets. I sanded them for a nicer look...
LyxdJ4q.jpg

Rv3scvx.jpg

vTnaMQ6.jpg


Next up was sealing/strengthening both sides of the wood with fiberglass cloth and just a touch of tint to make them black.
l0SIlLk.jpg


I had some carbon fiber scraps that have been sitting here for a while. Hmmmmm.... I had just BARELY enough to pull it off! No point in doing this at all but it looks cool and added that much more strength so.....
fbhYFU9.jpg

aqYZbsM.jpg


Getting there...
o95MIzL.jpg



Ordered up some 135lb springs to hit our goal of 12psi of compression. Also, drilled holes for BMS wiring and used some of that silicone tubing as grommets.
NnNpwd5.jpg


Time for some flexible bus bars! I robbed this idea from member upnorthandpersonal and made my own from 3/4" wide braided copper and 1/2" copper pipe. Very cool! DIY tin plating is on the list BTW.
M9STm1F.jpg

JAyYU1d.jpg

ySOcsgZ.jpg

9XW3L0q.jpg

OJTYcV0.jpg


Made the handles with paracord and spare vacuum tubing. Also, used 1/2" adhesive backed closed cell foam on the bottom to keep vibration down and not scratch my boat!
xmbjZuR.jpg


I know, a lot I'm leaving out. This is all of the pictures for now at least. I'll come back and post links/details ASAP. There's still a few small things I want to do before we call these "done" but they are ready to put in work as is.
Wow, where I come from we call that redneck engineering. No disrespect meant to my hillbilly friend!
 

Electro Dan-O

Current Situation
Joined
Nov 15, 2020
Messages
35
Location
Middle TN
What kind of press is that? How much force?
Just a standard 20 ton shop press with a bottle jack. Waaaay overkill, I'm sure. I'd imagine that a good bench vise would do the job just fine also. Especially if you added some heat to the copper(I didn't). I would definitely call this a "cold weld"...:cool:
rpB0gUp.jpg



Edit: Would like to add, make sure whatever you're using to press with is as flat as possible(even the texture)! This will save a TON of time sanding/cleaning them up and keep more copper where it needs to be rather than dust on the floor. I learned that the hard way on the first one we made...
6jMuWaR.jpg
 
Last edited:

Mike Jordan

Solar Addict
Joined
Jun 15, 2020
Messages
390
Just a standard 20 ton shop press with a bottle jack. Waaaay overkill, I'm sure. I'd imagine that a good bench vise would do the job just fine also. Especially if you added some heat to the copper(I didn't). I would definitely call this a "cold weld"...:cool:
rpB0gUp.jpg



Edit: Would like to add, make sure whatever you're using to press with is as flat as possible(even the texture)! This will save a TON of time sanding/cleaning them up and keep more copper where it needs to be rather than dust on the floor. I learned that the hard way on the first one we made...
6jMuWaR.jpg
the edit image didn't come through for me. But question relating to the clean cold weld. In the press picture above, there is copper mesh beyond the pipe, as you are ready to press. How did you clean that up?
 
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