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I used 3/8 threaded rod. I used a scale between two 2x4 to see how much pressure was required, it got to 300lbs with a bit more than totally flattened lock washer. I then did that amount of force by hand on the cells with two sets to get close to 600lbs. It seems really solid. I have 24 cells...

For the price and time to do all that work I just ordered a second string. Skipped that leaves me very satisfied. People buying used battery packs deal with weak cells all the time, even as a rule (which is why they ended up on the used market), and we pay less than those units sell for!!

I just finished a capacity test for my 280ah EVE 2p24s battery wall. I had just put the cells in randomly without testing them so the weakest two cells limited the whole pack. I ran the test with a space heater at 1590 watts for the duration. Started with the cells floating at 3.4v (so not...

I'm always wondering about their credit card acceptance. Mine was capital one as well and had zero issue.

Yeah they use a consolidator for crossing the ocean, but you get no tracking for that. The tracking you get is for final delivery. I imagine the boxes are all labeled the shipping information before they leave China, then they take them out of the container, move them to the proper warehouse...

The ops question was about what SOC to marry them. I included the answer and the related problem from which it is derived. For some reason the other posts are very long for something so simple. Hook up one, charge it to full. Swap with the other, repeat. Then parallel. Done.

They have a plan for this type of situation and they are following it... I'd be skeptical of any shipper who didn't.

I'm confused, are you saying it does this even when you randomly rearrange the cells? Why are you bottom balancing when it seems like it's top balance you care about?

You can do terminals up or on it's side with the fat side down. You can't do it on it's side with the skinny side down.

I just need an inverter that can exploit time of use for a few thousand so it will make economic sense - and we are finally moving in that direction.

Compression is the manufacturer instruction. The only reason why it's unclear is that people won't know or acknowledge results until they really have gone through the 10+ years of use. The off grid garage positions are generally a bit foolish, he doesn't know and his positions aren't...

They probably gave you someone else's tracking. I assume your contact has the right address, so just send them a message to verify the tracking number. They should be shipped directly to you. Mine sure were.

It's on the resources drop down, third page I think. There is also a new version uploaded to the clamping thread too I think. If people want to disagree with me I just ask them that they source and backup their assertions, or if they disagree with the manufactures instructions, by telling me...

I trigger active balancing are .01 with my test setup, but that's only because a lower number would be overwhelmed by a .3a balance current.

You can't get them cheap enough anymore? Mine were $90 a cell back in 2020 shipped, looking at the same supplier (basen) they now have them for $110 instead of the $77 I paid. So now it's $150/kWh instead of the $100 before, still much better than $300.

These companies have gotten really good at selling to us. They know what matters, what to communicate, what standard they need to hit - and they've done well The need to ask a million questions is gone. Honestly I'm surprised about the need to ask Amy for sea shipping, it should be the default...

The only issue with over pressure is crushing, a cell that is not being crushed when empty (which is when you will compress them) will not be crushed when it's full. Therefore there isn't really risk of over pressure on the high end of a charge cycle. Instead the battery simply doesn't provide...

This is what I did and recommend as well. Just set your inverter change/float voltage for whatever the pack voltage is when the first cell gets to 3.4v (or whatever). Come back after a few days and reset that voltage. After a few cycles it should be balanced and you can remove the active...

From what I understand 3.4v is enough to fully charge a cell, you don't need 3.6. everything above that is just about getting to fill capacity quicker, but my understanding is that leaving a cell at 3.6 would damage it.

Two rows has twice the surface area, so twice the pressure.

If the pressure is caused by gas created at full charge, then heat would increase the pressure, but a slow charge rate would not avoid the problem. And higher pressure inside the cells would increase the amount of energy required to charge. Hence why the unclamped cells look to have higher...

I've been thinking about what it would take to build an inverter without a transformer, going for maximum efficiency, that's about how many it would take.

It was on the battery docs for the EVE cells, the one with two lifecycle charts, one with fixture and one without. Without fixture starts with a higher capacity. It's been noted previously on these boards.

No it won't. .2C is a fine charging rate

You can get a 20s bms and put some lifepo4 together

Voltages on lifepo4 have little meaning and the cells we buy are factory rejects that have different voltage curves, especially at the top. To know for sure you need to set the charger to hold voltage for every cell at 3.4, then watch it during a discharge and charge cycle. That will tell you...

The interesting thing about their charts, if I'm reading it right, is that they lose capacity faster with the fixtures and the high cycles exists only in their extrapolation. It suggests that taking a uncompressed cell and compressing it will decrease capacity, and the opposite will increase...

We will finally have the answered if you post the picture!!!

4 cells plus bms works. Since you are using lifepo4 it will work with the voltage expectations of all the equipment made to work with a car battery. For voltage I would suggest using whatever the "other small devices" require. Those 12-24v freezers that have compressors are really nice and your...

This is not something you need to worry about. 3.33 isn't even full and real damage comes from overcharging, which they are not, being disconnected while in transit!