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EVE 280ah 24v battery frame

Thanks for that. Question has been answered. :) I think fast acting Class T is the way to go or use the MRBF fuse Samlex recommends.

Agreed, the more I learn the more I'm starting to lean towards Class-T for main battery fuse, though I think either would probably be fine since MRBF fuses were specifically designed to be main battery fuses and the ABYC okay'd them (though not sure how this applies to lithium in particular).
 
Why you need to keep space in the enclosure to breath for the cells. In drop ins they are sealed and sometimes even encapsulated in glue or resin? This is to minimize corrosion and oxidation on all parts.
why the eve or lishen or alike build prismatic cells should be different?
plan to build a box of nylon boards and seal the battery as it is used in marine environment on a cat.
 
Why you need to keep space in the enclosure to breath for the cells. In drop ins they are sealed and sometimes even encapsulated in glue or resin? This is to minimize corrosion and oxidation on all parts.
why the eve or lishen or alike build prismatic cells should be different?
plan to build a box of nylon boards and seal the battery as it is used in marine environment on a cat.
The cells expand slightly when fully charged and deflate when discharged. Compressing the cells prevents terminal stress. Too much compression is worse than no compression. If using braided busbars then this would not be a huge deal. Proper compression using springs will extend cycle life but keeping the cells SOC between the knees will also extend cycle life. If you want to learn more refer to this post and thread. There is much discussion regarding compression if you search the forum. :)
 
The cells expand slightly when fully charged and deflate when discharged. Compressing the cells prevents terminal stress. Too much compression is worse than no compression. If using braided busbars then this would not be a huge deal. Proper compression using springs will extend cycle life but keeping the cells SOC between the knees will also extend cycle life. If you want to learn more refer to this post and thread. There is much discussion regarding compression if you search the forum. :)
I didn't ask about compression, I asked about sealing the enclosure and the cells don't need any air to Operate, just a small hole where potential gas could exit.
Eg Victron LifePo4 are completely sealed (inside 4 Winston cells, BMS... That's it) and when gasing they bloat and more the case cracks...
Compression is clear and planned like you did with threaded rods, how many NM did you apply on each nut of the rods, cannot find any clear spec on that for Lishen
 
I didn't ask about compression, I asked about sealing the enclosure and the cells don't need any air to Operate, just a small hole where potential gas could exit.
Eg Victron LifePo4 are completely sealed (inside 4 Winston cells, BMS... That's it) and when gasing they bloat and more the case cracks...
Compression is clear and planned like you did with threaded rods, how many NM did you apply on each nut of the rods, cannot find any clear spec on that for Lishen
I hand tightened the nuts with the cells at a full SOC. But my cells are in a stationary environment. Lishen might have different compression specs than EVE so it might be best to contact them directly. I don't think anyone has as far as I know. Other than that I don't see anything wrong with your plan and sorry I misunderstood you.

You have been around long enough you probably have noticed a cell doesn't vent on it's own, something has to cause it. I have seen many severely bloated cells from being over charged and they did not vent. If I recall correctly the only cells that vented were involved in a fire and possibly because the cells cases were touching each other, or the case was touching the metal frame they were mounted in. I don't believe you have anything to worry about sealing your cells in an enclosure made of nylon. Also a properly constructed cell using a properly mounted pressure relief valve should not emit any gas.
 
I hand tightened the nuts with the cells at a full SOC. But my cells are in a stationary environment. Lishen might have different compression specs than EVE so it might be best to contact them directly. I don't think anyone has as far as I know. Other than that I don't see anything wrong with your plan and sorry I misunderstood you.

You have been around long enough you probably have noticed a cell doesn't vent on it's own, something has to cause it. I have seen many severely bloated cells from being over charged and they did not vent. If I recall correctly the only cells that vented were involved in a fire and possibly because the cells cases were touching each other, or the case was touching the metal frame they were mounted in. I don't believe you have anything to worry about sealing your cells in an enclosure made of nylon. Also a properly constructed cell using a properly mounted pressure relief valve should not emit any gas.
Thank you. Lishen has the same 12PSi pressure at 50% Soc then Eve..I have 12cells in a row, 6 threaded M8 rods to compress them...To a simple metric guy how many NM I have to tighten each nut to get 12PSI pressure?
 
I'm going to use the Victron Multiplus 24/3000/70. They recommend a 300A fuse and up to 100mm2 cable (2 x 50) depending on length . 4/0 cable is 107 mm2.

View attachment 23105

Here are the overload ratings of the Victron inverters (link). So it could handle 6000w for 1/2 second and 3900w for 30 minutes. All values would be de-rated based on increased temperatures. I'd rather oversize than undersize.
View attachment 23110
I have a Victron MultiPlus 24/3000 as well, but as far as I can see, the battery cable (from cells to shunt/connection and then to the MultiPlus) can be 50mm2, cause you're way below 5m. Or am I missing something?
 
I'll take another stab at this ...
A fuse has at least 3 critical ratings: 1) Voltage, 2) over-current rating, 3) Interrupt rating. All 3 should be satisfied in a system design.

You're good on #1 - voltage.
It looks like you're good on #2 - over-current rating (e.g. a 150 amp fuse protecting a 4 AWG wire
However, #3 seems to be the most misunderstood problem which I only came to understand myself recently.
Just because a fuse will blow if you reach or somewhat exceed its over-current rating (150 in this case) does not mean it will properly blow and stop the flow of current if you literally short-circuit the circuit. The reason is due to the extremely high amperage that can happen in that situation with this battery chemistry. The fuse element will melt as it should, but that doesn't mean that an arc inside the fuse won't set up and continue to allow the current to flow. Or that the melted element inside the fuse sets up in a way that allows the current to flow through the melted remains.

My 48v 280Ah pack can do something like 16,000 amps under short circuit, and only a Class T fuse is rated for that level of interrupt. The fuse is 300 amps, but has something like a 200,000 amp interrupt. ANL, MRBF, etc are not rated for this. The others might happen to work, but it's not designed for it and could fail to interrupt the circuit and leave you with an unprotected system.

Hope that helps!
This is something I've been wondering about as well. Guess I'll get myself a class-T fuse fitted from battery to first busbar.
 
i doubt if the lfp pack can do 16kamps trough a wire.
It does apply to a direct short between poles, but even the smallest cable length will drop this significantly.

I haven’t been able to test this yet, but i doubt if it will even reach 2k+ amps, unless you use really massive cables and very short lengths.
Also, terminal quality and proper torqing will make a huge difference.

Also, ratings generally are for the maximum voltage.
I have seen some vendors also specifying rates at lower voltages (eg 2000a @ 32V, 5000A@12V)

I personally think it will do for a regular 1 string bank.

Having multiple in parallel will require better fuses regarding its IR capability, but for a single battery string to 300-400Ah you might be good with a anl fuse.

If someone has the tools to do short current measuring that would be nice to see.

If someone has the equipment to do proper low resistance measuring (cable and terminal loss), and eg a storage oscilloscope to log the voltage drop during the full short (or a high current meter with sufficient fast response) I would love to see the outcome.

Maybe something @Will Prowse can do?

It will answer the question is a high ir rated fuse lile like eg the classT or similar required, adviced or not nessecary in certain cases
 
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