mndare
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That would be hard since she used my name in the video she sent me. I watched the other video and the music is different as is the location she is at.
Just Place new Order on Alibaba- 280AH x 8 for 1260.00 USD Delivered, Grade A to Canada
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mndare
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She used my name in my video and also mentioned being en-route to a dance class with her daughter which we had discussed in our thread.
nosys70
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quick question. The EVE pdf posted above seems ton confirm that screw size is M4.
does somebody knows if the material of the screw has some importance ?
Copper screws are hard to find or super expensive (but conductivity=1) . aluminium screw is ok but does standard steel screw is ok ?
or does it simply not matter. ?
I plan to use copper strip 2mm thick (by 25 wide) so the equivalent of a 50mm2 wire.
adding a 1/1.5mm copper washer is 3-4 mm. the screw hole seems to be 6mm deep, so a 8mm screw will fit perfectly.
here i will take M4 x 14mm x 1.5mm
does somebody knows if the material of the screw has some importance ?
Copper screws are hard to find or super expensive (but conductivity=1) . aluminium screw is ok but does standard steel screw is ok ?
or does it simply not matter. ?
I plan to use copper strip 2mm thick (by 25 wide) so the equivalent of a 50mm2 wire.
adding a 1/1.5mm copper washer is 3-4 mm. the screw hole seems to be 6mm deep, so a 8mm screw will fit perfectly.
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here i will take M4 x 14mm x 1.5mm
M4 inner diameter Copper washers flat gasket marine watch washer 6mm-14mm OD | eBay
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Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Stainless Steel screws are best with a light dab of noalox / oxguard on the contact points.
! WARNING ! Make sure the screws are not too long, you do not want them to bottom out in the tapped hole, if you break through the top (it has happened) you will wreck the cell and quite possibly get magic smoke.
Surprising they did not offer the busbars & screws with the cells, most usually do, deligreen tosses them in for $1.50 each if I remember right.
M4 seems awful small....
! WARNING ! Make sure the screws are not too long, you do not want them to bottom out in the tapped hole, if you break through the top (it has happened) you will wreck the cell and quite possibly get magic smoke.
Surprising they did not offer the busbars & screws with the cells, most usually do, deligreen tosses them in for $1.50 each if I remember right.
M4 seems awful small....
nosys70
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for me stainless steel is at the bottom of conductivity list, so i would even prefer aluminium (best after gold and copper) or at worst Brass.
Iron would be ok, but Iron rust very fast, and the contact in the battery is made from aluminium, so there is less chance to get the screw stuck in the threading by some chemical reaction between two different metals.
from what i calculated (this is not indicated in the spec sheet) diameter of battery contact is about 16mm
so, i will made my copper bar (25mm wide) clean, drill the M4 hole, cover both side of the hole with a sticker about 18-20mm diam. and varnish the copper strip with transparent varnish. then remove sticker to expose copper.
this way i will get clean copper and able to see trough varnish if problem (oxidation) occurs anyway.
it is recommended to use big copper/aluminium plate to join the electrod (not only for current) , but because they can act as heatsink to
regultate the heat of the battery. it seems it is more efficient to catch heat from this place, than waiting it reach te outside of the case.
using aluminium heatsink with fins could even be a good idea to get
1) same metal on on contacts (all aluminium) for oxydation
2) good conductivity
3) cheaper than copper
4) good thermal dissipation
Iron would be ok, but Iron rust very fast, and the contact in the battery is made from aluminium, so there is less chance to get the screw stuck in the threading by some chemical reaction between two different metals.
from what i calculated (this is not indicated in the spec sheet) diameter of battery contact is about 16mm
so, i will made my copper bar (25mm wide) clean, drill the M4 hole, cover both side of the hole with a sticker about 18-20mm diam. and varnish the copper strip with transparent varnish. then remove sticker to expose copper.
this way i will get clean copper and able to see trough varnish if problem (oxidation) occurs anyway.
it is recommended to use big copper/aluminium plate to join the electrod (not only for current) , but because they can act as heatsink to
regultate the heat of the battery. it seems it is more efficient to catch heat from this place, than waiting it reach te outside of the case.
using aluminium heatsink with fins could even be a good idea to get
1) same metal on on contacts (all aluminium) for oxydation
2) good conductivity
3) cheaper than copper
4) good thermal dissipation
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Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
If your relying on the bolt to be the conductor, well... good luck with that. Putting anything "painted" on busbars which can heat up is simply silly. You will never see that in any commercial installation, unless it's a marine coating. Noalox / Oxgard are the GOTO for contact corrosion protection.
Nosys70, why don't you post an thread about your build, your gear with photo's of how you have it all setup and how you got to where you are today an when you started on this path. Also don;t forget to include links to the equipment you used is not the usual mainstream stuff to be found everywhere. Everyoe could benefit from seeing such details, people like pictures of working & functional systems that have lasted for years of service.
Nosys70, why don't you post an thread about your build, your gear with photo's of how you have it all setup and how you got to where you are today an when you started on this path. Also don;t forget to include links to the equipment you used is not the usual mainstream stuff to be found everywhere. Everyoe could benefit from seeing such details, people like pictures of working & functional systems that have lasted for years of service.
nosys70
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it is not about relying on the bolt to be conductor, it is just logical thinking (reason given above).
I forget to give another reason is that torque applied to the screw must be reasonable since the electrode goes straight in the battery.
and putting excessive toque on the screw (paper says less than 8kg) could ruin battery.
an aluminium screw will probably break before. so i prefer to break a screw than a battery.
in that particular case i had to design a system to at is fully "no maintenance", and will last as long as possible.
for the "paint" on the busbar, i do not see any problem since usually busbar come isolated with a plastic shrink tube.
So layer of this or a layer of that is just suppose to help and i doubt a bus bar will go hot enough to pose problem.
and if it is the case, i think more important problem will come first.
since you seems somebody who lives on a boat you recommend a product for boat. I take note since usually these product are very good quality (but expensive). I know there are also epoxy products where you can dip the bus bar.
I do not want to be overkill in every details anyway, just choose the best when it is only a matter of choice. (if you live on a boat you know that 2 different metal in contact is just a recipee for problems).
i can not yet put picture for this project since it is only at the "assembling the good parts" step.
and there are several constraint that are not yet clear that could require custom made part, where normal situation would just to purchase them.
I forget to give another reason is that torque applied to the screw must be reasonable since the electrode goes straight in the battery.
and putting excessive toque on the screw (paper says less than 8kg) could ruin battery.
an aluminium screw will probably break before. so i prefer to break a screw than a battery.
in that particular case i had to design a system to at is fully "no maintenance", and will last as long as possible.
for the "paint" on the busbar, i do not see any problem since usually busbar come isolated with a plastic shrink tube.
So layer of this or a layer of that is just suppose to help and i doubt a bus bar will go hot enough to pose problem.
and if it is the case, i think more important problem will come first.
since you seems somebody who lives on a boat you recommend a product for boat. I take note since usually these product are very good quality (but expensive). I know there are also epoxy products where you can dip the bus bar.
I do not want to be overkill in every details anyway, just choose the best when it is only a matter of choice. (if you live on a boat you know that 2 different metal in contact is just a recipee for problems).
i can not yet put picture for this project since it is only at the "assembling the good parts" step.
and there are several constraint that are not yet clear that could require custom made part, where normal situation would just to purchase them.
going to take longer than a week ! Still waiting for mine since Jan 7. will take about 4-6 weeks is my guess as fedex still shows not having received them yet state side. but; there's a photo in a prior post of them sitting on the shipping floor. : )
nosys70
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interestingly , my tracking order shows that my china order, is delivered from germany.
so the question is : Why did they send me picture and video from packing the batteries from china ?
I give up to understand chinese business...
so the question is : Why did they send me picture and video from packing the batteries from china ?
I give up to understand chinese business...
Last edited:
boboxx
New Member
I had the same thing happened to me, the first tracking number was for a different receiver. It's just a delay tactic, then they blamed the logistic company.
nosys70
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so apparently, even if it is a legit business, they do all to look like scammers.
prices to good to be true.
send same video or picture to different customers as proof.
making things fuzzy about shipment.
let's see if my batteries are delivered , they still deserve presumption of innocence.
I understand that people are reluctant to purchase on Alibaba or Aliexpress.
I ordered the batteries only for test, so i am not that stressed.
prices to good to be true.
send same video or picture to different customers as proof.
making things fuzzy about shipment.
let's see if my batteries are delivered , they still deserve presumption of innocence.
I understand that people are reluctant to purchase on Alibaba or Aliexpress.
I ordered the batteries only for test, so i am not that stressed.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
I was just looking at another vendor via DHGate as they also have some incredible deals on A-Grade LFP bundles including free shipping. I noticed at the bottom of their info page, they can ship from warehouses in USA, Germany, Switzerland and a couple of other countries. Pondering that potentially as it may result in faster shipping obviously if it's more local (as in, on the same continent) but I see a catch there... Are cells checked at the warehouse ? Old Stock sitting for who knows how long or whatever else may pop up.
Never dealt with vendors through DHgate or Bangood - tbh, makes me a bit nervous dealing with far off vendors.
Never dealt with vendors through DHgate or Bangood - tbh, makes me a bit nervous dealing with far off vendors.
nosys70
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please , a link. so we can test it
this one pretty cool'
this one pretty cool'
D
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Cycle life is stated @ 3500. Here is a cut and past from the Product Specification Sheet.
"After standard charged and 30mins rest, discharge to 2.5V cutoff with the current of 1.0C(A) at (25±2) ℃, and then start the next cycle, end with the capacity decrease to 80% of the initial capacity. The number of cycles is defined as the cycle life of the battery. "
As I read it, to achieve 3500 cycles only do a 80% DoD. Yes, No?
"After standard charged and 30mins rest, discharge to 2.5V cutoff with the current of 1.0C(A) at (25±2) ℃, and then start the next cycle, end with the capacity decrease to 80% of the initial capacity. The number of cycles is defined as the cycle life of the battery. "
As I read it, to achieve 3500 cycles only do a 80% DoD. Yes, No?
nosys70
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thats' what they call at least a full cycle, , they do not tell on the impact.
anyway it is an urban legend that Lifepo4 can be totally drained from 100 to 0%.
you can do that to a lead battery also and still get it to work for a few time.
this is valid for emergency systems where priority is energy and battery is consummable.
where do you think all this 2nd hand batteries comes from ?
Mission critical systems receive a new battery every 18 months, whatever the status the battery is,
because it cost less to change blindly, than waiting for a problem.
anyway it is an urban legend that Lifepo4 can be totally drained from 100 to 0%.
you can do that to a lead battery also and still get it to work for a few time.
this is valid for emergency systems where priority is energy and battery is consummable.
where do you think all this 2nd hand batteries comes from ?
Mission critical systems receive a new battery every 18 months, whatever the status the battery is,
because it cost less to change blindly, than waiting for a problem.
mndare
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I can't believe it. My batteries arrived today as promised, that's 12 days after payment. I have opened one of the three boxes, very well packed and the cell I have looked at is brand new, definitely grade A Cells. I will do an unpacking video and a full capacity test today and post. So far everything as promised. WOW
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Very nice!
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