robbob2112
Doing more research, mosty harmless
To much heat to welding with anything but a laser
I WARNED YOU ALL! MB31/MB30 huge issue terminal snapping off
- Thread starter Alkaline
- Start date
To much heat to welding with anything but a laser
ghostwriter66
"Here - Hold my Beer"
We have had (794) of these MB31/MB30 in the field in VERTICAL EEL Boxes for over (4) months now -- and have not had a single issue. And these things are getting bounced all over the place during transit and operations.
We love that these have (2) contact points of failure instead of just one. In fact we are in the process of making (49) more 330Ah 54V LiFePO4 batteries this weekend.
We love that these have (2) contact points of failure instead of just one. In fact we are in the process of making (49) more 330Ah 54V LiFePO4 batteries this weekend.
ghostwriter66
"Here - Hold my Beer"
Don't over think it - simply screw the broken terminal head onto the broken battery post ... probably a dozen various ways of doing it but if it was me - I simply determine the TOTAL depth I need - predrill a smaller pilot hole - and then attach with a counter sink screw -- now thats the down and dirty way - I am going to assume that there will be better ideas how to do that making it prettier - BUT electrically its going to work just fine ... as long as you have at least 8N of pressure on each level (if you don't have a torque wrench then just snug it down firmly (also if you don't have a torque wrench that may be the reason it snapped off?)
This.
The jury is still out on if these terminals can be reinstalled with TIG. We've discussed it a lot but I don't think anyone has actually done it.
ghostwriter66
"Here - Hold my Beer"
We get our batteries DIRECTLY from EVE via EEL. I think EEL is one of the very few that is an actual true EVE distributor. If you take a look at the shipping boxes - you could literally drop these off a 2-story building and be fine. When I first started out doing this job the boxes were paper thin - half the batteries were always dented and None of them were ever the same voltage as the next.
Each of these batteries came with a written report - packed solidily in a 3/4' cushion - with plastic cover to protect terminals and a thick corrugated shipping box. AND 2 large anti-moisture packets .. AGAIN though - these came directly from EVE via EEL.
jorby
Solar Enthusiast
I doubt very much that they would be fine if dropped off a 2 story building. Don't be silly.
Brucey
Emperor Of Solar
From what I've seen the terminals that shear off seem to not have the threaded inserts of the "legit" ones
sailingharry
New Member
I figured I'd go ahead and take a pic. It's not a "torque wrench" issue -- I went and finally bought a torque screwdriver just for this project. The screws were all in an torqued, and then I was wrestling the 4/0 cable into place and levered the terminal off. I'd already pulled all the bolts, but the right cell is fine, the middle and left cell are broken off.
I did look closely at the broken terminal and post. If there is enough meat in the post, I could drill and tap it with an 8mm bolt, and bolt it on. Of course, if that were a viable solution, they'd already be built that way! Seriously, has anyone had success with this?
The irony is that my first design thought was bolting a strap of 2" wide x 1/4" thick copper on that middle cell, and bending it over the edge and onto my shut terminal. Then I found those 2-hole lugs that fit the cells, I thought the "flexibility" of the cable would be a benefit, so as not to lever off the terminals....LOL.
I did look closely at the broken terminal and post. If there is enough meat in the post, I could drill and tap it with an 8mm bolt, and bolt it on. Of course, if that were a viable solution, they'd already be built that way! Seriously, has anyone had success with this?
The irony is that my first design thought was bolting a strap of 2" wide x 1/4" thick copper on that middle cell, and bending it over the edge and onto my shut terminal. Then I found those 2-hole lugs that fit the cells, I thought the "flexibility" of the cable would be a benefit, so as not to lever off the terminals....LOL.
Attachments
Which, if so, means 18650 is selling gray market crap.
jorby
Solar Enthusiast
In hindsight, I think I might use multiple smaller cables for that connection. One on each cell.
rodrick
Free energy enthusiast
Using multiple smaller more flexible cables to me makes more sense than trying to connect something that resembles a piece of round stock steel
jjww
Stuck in PG&E Land
my 18650 cells came in exact same packaging.
ghostwriter66 nice busbars, do you make them?
ghostwriter66 nice busbars, do you make them?
ghostwriter66
"Here - Hold my Beer"
NO they came with the EEL VERTICAL batteries boxes.... however -- you can contact EEL and they can quote you just the busbars ... I think you can also look on aliexpress but EEL came in same price .. I have NO RELATIONSHIP with EEL but having gone through literally every distributor and vendor in this arena - EEL has turned out to be the 2nd easiest to work with ... DOCAN is the first BUT they do not have a Direct Ship agreement from EVE on these batteries ... Howard at EVE speaks perfect English although often his answers are shorter than I would like ... BUT when we opened up the case and saw printed reports from EVE on each battery we were pretty much sold ...
ghostwriter66
"Here - Hold my Beer"
So thats what we do also -- instead of having a huge 4/0 cable which due to its size and length can put MUCH more than just 8N on the terminal head (and thus tear it off) - but a 4/0 AWG wire is approximately 211,600 CM (circular mils) but instead we use (2) 2/0 AWG wires in parallel (each ~133,100 CM) which gives us acombined cross-sectional area of 266,200 CM, exceeding the 4/0 requirement. Plus they are much easier to work with - and find - and put lugs on ... etc etc
robbob2112
Doing more research, mosty harmless
not true apparently
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Brucey
Emperor Of Solar
Lots of variables I'll just stick with single post m6 avoid the drama.
ghostwriter66
"Here - Hold my Beer"
To answer that question – YES it is possible to TIG weld a LiFePO4 battery terminal – have we done it – YES – would we do it again – probably NOT … in fact NO..
We needed to add some special brackets to the terminals of some LiFePO4 batteries to make them able to fit inside a battery box from like the 1980’s or something like that without having to modify the box …
So we went to our RIG Welder who is like the god of welding here and asked him if he had a minute could he help us ..
WELL – the First thing we learned – the hard way – was that LiFePO4 batteries are much more heat-sensitive than what we thought. After about 10 seconds the factory smoke was released and well there went #1….
So for battery #2 we used plenty of 3M thermal barriers along with wet rags and a glob of thermal gel. That should have worked BUT the welder started off at a ever so slightly higher amperage then he should have and again – although this one lasted longer than #1 – again - the genie was released.
For the third attempt we got everything correct – something about low amperage and a tungsten electrode making the difference but way over my head. Also we found that welding nearly dead batteries went much better then nearly full – I have no scientific explanation to explain that …
SO – after we learned how to do it properly it took about an hour to get (4) of them fitted …
Meanwhile we were running out of time on site so on the remaining (4) that was next – my teammate, and a Master electrician that we are told use to ride dinosaurs to work – simply took a grinder – hit both the mount bottom and the terminal top – and then took (2) screws and at a 45 degree angle – screwed the top into the bottom … and it worked perfect – stronger than it needed to be
Total time to do all (4) the screw way – maybe 5 minutes … probably less …
So that’s how we do it now … we tried TIG – it worked – it was ass-painful – we ruined several batteries – and it took 10X longer than doing it by TIG …
ghostwriter66
"Here - Hold my Beer"
and again why even if we are going to get a solid discount from these battery manufacturers if we skip using the CC and wire them the money directly - we still use the CC -- that way you contact the seller - give them 24 hours to respond - then turn it over to the CC people -- we have NEVER lost a refund ... of course that was really important in the early days of LiFePO4 batteries when everything came dented, broken, leaking ... and the vendor that was your best buddy a month earlier now has ghosted you
@sailingharry , I recall you were having trouble sourcing busbars for between the cells terminals. Did you use the busbars that came with the cells or did you get busbars that covered all three cells at once?
I can't tell from your picture if that's a three-cell busbar or two two-cell busbars.
I can't tell from your picture if that's a three-cell busbar or two two-cell busbars.
ghostwriter66
"Here - Hold my Beer"
As far as I know, please correct me;
- EVE does not weld ANY terminal on the cells
- EVE does not ship in those packages
But, maybe you are special
Where, who, what is the name of your seller? Link, Alibaba?
Our boxes came directly from EVE via EEL ... The paperwork inside - to include info on the double terminal - is all from EVE.
These are what the cartons we got from EVE looks like ... so I am going to assume that EVE put the terminals on also ...
Our seller is EEL batteries
The cells in sailingharry's picture don't have the red/blue dots on them. My cells from Amy @ Luyuan do. If what you said is true (that cell terminals with red/blue dots are put on by EVE) then whatever third party put the terminals on his cells, they aren't up to the quality of what EVE is putting on.
robbob2112
Doing more research, mosty harmless
From some of the terminal pictures of those torn away it doesn't seem like they were welded to the 2mm that was specified in the EVE paperwork. I do wonder if that plays into it.
and note - I have super fine (3200 strand count) 8awg silicone 200c wire waiting on my battery build. I plan to run 2~3 strands of that from the end points of the bus bars to the case terminals or class T fuses. Far more bendable than the welding wire and should have zero strain if I bend them to the right direction before crimping the ends on.
and note - I have super fine (3200 strand count) 8awg silicone 200c wire waiting on my battery build. I plan to run 2~3 strands of that from the end points of the bus bars to the case terminals or class T fuses. Far more bendable than the welding wire and should have zero strain if I bend them to the right direction before crimping the ends on.
Daddy Tanuki
Emperor Of Solar
sorry bank wire transfers only due to location and government.
robbob2112
Doing more research, mosty harmless
And they leave no recourse if the batteries never show up, or if you get a box of bricks
Daddy Tanuki
Emperor Of Solar
exactly, thats why i was dancing about so much looking at different vendors and asking so many questions. guess it got on their nerves... thankfully winston was like warranty guranteed, shipping damage? real no BS insurance that covers it... you pay for the perks i guess.
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