After doing the straps I tried threaded rods, they are Soo much better. I recommend giving them a shot, up to 24 in a single set. Threaded rods were at home depot. I still need to test and see how tight one needs to get for the proper pressure.
Seems like a good idea, as long as you are certain that you will not have to move them in the future. Weight of a full 24s pack would be an issue, especially with the 280AH cells.
@@metagrid9453 yeah I'd have to completely rebuild to move them, but that's alright! I would just have to remember to drain most of the capacity first so I could get the proper compression.
@@metagrid9453 the specs say 71.5mm at 30% state of charge and 72.0mm fully changed. For mine that is a full 1.3cm difference! That's why I'm binding before I charge them and am going to mark the ends to see if there is actually expansion.
Tried those. They work pretty well. I do like the electrical tape better though as it is quicker and seems to spread the compression evenly over the cells.
I'm trying the strap method and found I couldn't get it right either, so I'm trying wood blocks to get them tighter. I'm curious how close to the 600lb target that tape gets.
I do not know how close to the target the tape gets and cannot think of a way to measure that. My gut feeling is that it is close to that level. The main difference with this method is that the compression is even over the entire outer surface of the cell pack. Also, the cells are very secure and form a tight physical bond with each other in this method.
That's an interesting idea. I will keep that in mind if I have problems down the rd. So far my bundle is stable. I did add more straps and some electrical tape though.
@@metagrid9453 I think your tape will hold up securely. It only becomes problematic when the temperatures get higher. The electrical tape then becomes soft and stretches.
That’s crazy, do these cells have a tendency to expand or swell? If they do is it ok to compress them or reinforce them to prevent the swelling? ... 16 more to go! :)
I like the strapping tape deal. I'm going to put some thin pvc at the ends of my battery packs (3x8dx280ah) and set my charge profile to 80/20. We live full time on our boat so that should last decades ....
Have not noticed any expansion of the tape. I pre-stretched it as I was wrapping. I have several packs that I did 2 weeks ago with no noticable expansion of the tape. The cells are just as secure as when they were wrapped. I feel that pre-stretching while wrapping the stretchy electrical tape is key to this method.
@@jvf6257 Thanks! The battery is being designed for long term storage of off-grid produced solar power. The charge and discharge rates should never be enough to generate any significant battery heat.
No. This is not the way to do it, sorry. With time and discharging cycles, your tape will expand. And if a cell is bad, what do you do to replace it? The way to do it is to insert 1/16 plastic sheet (cutting board style) between each cell and use a 3/4 plywood on each end connected with a1/2 treated rod wrapped in PEX tubing and nit and washer licks on each end. 2 rods on each side.
@DIY Projects My 12v/280AH system has cycled 30 or 40 times with no noticeable issues so far. Of course it's double protected from overcharge, overdischarge and also from cell balance issues.
Should use plastic board ( starboard ) instead of the combustible wood!
Would plastic be combustible too?
@@metagrid9453 yes but at much higher heat so this is better, everything is combustible at enough heat!
After doing the straps I tried threaded rods, they are Soo much better. I recommend giving them a shot, up to 24 in a single set. Threaded rods were at home depot. I still need to test and see how tight one needs to get for the proper pressure.
OK, thanks. Mine seem to be working fine for now. I did add some straps and some electrical tape to the bundle strategy to get it where I wanted.
William on DIY Solar also uses the same tape !
Cool! The strechiness of it is what I find useful. It is easy to tailor the compression force by how much stretch you put on each wrap.
I'm wrapping mine in place as a full 24s battery.
Seems like a good idea, as long as you are certain that you will not have to move them in the future. Weight of a full 24s pack would be an issue, especially with the 280AH cells.
@@metagrid9453 yeah I'd have to completely rebuild to move them, but that's alright! I would just have to remember to drain most of the capacity first so I could get the proper compression.
@@Zorlig Cool! Any idea how much they contract when dischaged?
@@metagrid9453 the specs say 71.5mm at 30% state of charge and 72.0mm fully changed. For mine that is a full 1.3cm difference! That's why I'm binding before I charge them and am going to mark the ends to see if there is actually expansion.
@@Zorlig That's pretty significant expansion.
Try those self locking cable loop ties,, and wooden board at the bottom of the cells
Tried those. They work pretty well. I do like the electrical tape better though as it is quicker and seems to spread the compression evenly over the cells.
I'm trying the strap method and found I couldn't get it right either, so I'm trying wood blocks to get them tighter. I'm curious how close to the 600lb target that tape gets.
I do not know how close to the target the tape gets and cannot think of a way to measure that. My gut feeling is that it is close to that level. The main difference with this method is that the compression is even over the entire outer surface of the cell pack. Also, the cells are very secure and form a tight physical bond with each other in this method.
You’re nowhere near enough compression to make any difference.
@@snivesz32 I ended to using threaded rods, which worked perfectly. Cells haven't moved in years!!
Kompress it with "OX-P201224 Pro Heavy Clamp" and a fiber reinforced 3M Tape. This will work better an will last for years. ;-)
That's an interesting idea. I will keep that in mind if I have problems down the rd. So far my bundle is stable. I did add more straps and some electrical tape though.
@@metagrid9453 I think your tape will hold up securely. It only becomes problematic when the temperatures get higher. The electrical tape then becomes soft and stretches.
That’s crazy, do these cells have a tendency to expand or swell? If they do is it ok to compress them or reinforce them to prevent the swelling?
...
16 more to go! :)
Yes, they do normally expand and contract according to charge state. It is recommended to compress them.
I’m using strapping tape
My 12V pack is still doing ok with the strapping tape.
I like the strapping tape deal. I'm going to put some thin pvc at the ends of my battery packs (3x8dx280ah) and set my charge profile to 80/20. We live full time on our boat so that should last decades ....
hi Mr. Do you have sell battery? I want to buy 8 battery 3.2v 280ah. thank you so much.
buy them from Alibaba or aliexpress.
Use short straps dude, electric tape expand , get few in harbor freight for few bucks
Have not noticed any expansion of the tape. I pre-stretched it as I was wrapping. I have several packs that I did 2 weeks ago with no noticable expansion of the tape. The cells are just as secure as when they were wrapped. I feel that pre-stretching while wrapping the stretchy electrical tape is key to this method.
@@metagrid9453 hope that works but if the batteries get to a lot of heat they will crack at sometime
@@jvf6257 Thanks! The battery is being designed for long term storage of off-grid produced solar power. The charge and discharge rates should never be enough to generate any significant battery heat.
No. This is not the way to do it, sorry. With time and discharging cycles, your tape will expand. And if a cell is bad, what do you do to replace it? The way to do it is to insert 1/16 plastic sheet (cutting board style) between each cell and use a 3/4 plywood on each end connected with a1/2 treated rod wrapped in PEX tubing and nit and washer licks on each end. 2 rods on each side.
Tapes dont work,,i tried those,,
I have several packs that I taped up 2 weeks ago that are still firmly compressed.
@DIY Projects My 12v/280AH system has cycled 30 or 40 times with no noticeable issues so far. Of course it's double protected from overcharge, overdischarge and also from cell balance issues.
@DIY Projects Wow, I would watch that video. (-;