diy solar

diy solar

LFP for EV's projected to be less than $56 per kWh within 6 months

upnorthandpersonal said:
@G00SE 280Ah has been around for longer that the 304Ah ones. 280 goes back to 2017 if I remember correctly. I believe (and this is just my thinking) is that the 304 is the result of a new line at EVE, while the 280 kept being developed in a different line. We also see the 560 now - which is probably spun off from the 280 line.
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Oh that makes more sense. I simply had it backwards in timeline. 🤦‍♂️ thanks for clearing it up!
 
silverstone said:
Damn I just bought 32 new LF304 cells.

But of course twice the capacity means twice the size/weight and probably (almost ?) twice the cost.
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When I was looking a while back the 304's seemed to be the same size as the 280, I was of the impression that a technology improvement created a modicum of density improvement. Someone feel free to enlighten further. I would have expected a '608' as the double size cell. At some point it get's a little ugly with very large heavy low voltage cells. When you need 16 to get to 48V it requires a lot of storage space / volume.
 
ksmithaz1 said:
When I was looking a while back the 304's seemed to be the same size as the 280, I was of the impression that a technology improvement created a modicum of density improvement. Someone feel free to enlighten further. I would have expected a '608' as the double size cell. At some point it get's a little ugly with very large heavy low voltage cells. When you need 16 to get to 48V it requires a lot of storage space / volume.
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In my case the main argument for LF304 was availability and the double threaded terminals.

So no funky way to (properly) secure BMS voltage measurement / balancing current leads, threaded posts that are too short to hold busbar+cable lug+flat washer+spring washer+nut, ... LF280k with custom made hole and self-clinching nut for the BMS measurement kinda worked, but it's A LOT of extra time, work, for (probably) a worse result.

With 2 terminals I'm NOT too scared of using 1 hole for the BMS AND the power connection, being quite certain that the other hole will hold the power connection well.

And in my case (RMS current <= 100 A, most likely <63A even) I think that's plenty.
 
ksmithaz1 said:
When I was looking a while back the 304's seemed to be the same size as the 280, I was of the impression that a technology improvement created a modicum of density improvement. Someone feel free to enlighten further. I would have expected a '608' as the double size cell. At some point it get's a little ugly with very large heavy low voltage cells. When you need 16 to get to 48V it requires a lot of storage space / volume.
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I can't find a spec sheet on the 560 anywhere. Lots of pictures lacking anything to allow for a size reference.

1709400864279.png

No 560 in their pics either.
 
Is anyone in this thread thinking long term? There will be a glut of cells now and then prices will sky rocket as they get either old or there is less production?
 
myles said:
Is anyone in this thread thinking long term? There will be a glut of cells now and then prices will sky rocket as they get either old or there is less production?
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I don't think so. I can't see long-term demand going anywhere but up. I'm not sure what the material cost is in building these things, but I think the floor could be much lower. I would guess a glut of manufacturing capacity and cells would lead to a significant increase in demand, and thus feed a new cycle of cost reduction over the long term. I'm think it would be like RAM production, build enough, and someone will figure out a way to do it cheaper. Short term there may be some volatility in pricing.

Graphene Manufacturing Group just completed testing of their Al prototype pouch cells:

graphenemg.com

GMG’s Graphene Aluminium-Ion Battery Update: Minimal Temperature Rise Identified While Fast Charging - Graphene Manufacturing Group | GMG

Experience GMG's cutting-edge graphene production in Richlands. Scalable, sustainable, and shaping the future of advanced materials.
graphenemg.com graphenemg.com

They have produced and tested 1000MAH pouches. It remains to be seen if the tech is viable, but this could take EV's to the next level if they can get it stable. Something like this could cause a severe disruption, as the charge/discharge rates are radically higher, and there is an expected density improvement. Pretty interesting, and they are actually making the product. Very long term, since the c/d rates are so high it could offer some interesting capabilities for demand storage.

Lot's of exciting tech on the way.
 
myles said:
Is anyone in this thread thinking long term? There will be a glut of cells now and then prices will sky rocket as they get either old or there is less production?
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I also think that after this year’s price dip, the longer term factors will drive prices back upwards. Timing a purchase decision correctly will be a good trick to pull off.
 
Checkthisout said:
What does moving them up out of the low voltage category do with certs if anything?

Makes the DC side a lot more dangerous for DIY for sure.
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Voltage needs to go up towards EV car battery pack voltages to help lower copper requirements, lower volumes of bulk systems, further press costs down and create more competitive options. Among other things, like reducing line losses for DC transport.

Higher voltage safety exists. We just need to grow with it. All the reasons we aren't using 12V or 24V as primary in home systems are reasons to keep going up further. Higher voltage means less amps.
 
PreppenWolf said:
Voltage needs to go up towards EV car battery pack voltages to help lower copper requirements, lower volumes of bulk systems, further press costs down and create more competitive options. Among other things, like reducing line losses for DC transport.

Higher voltage safety exists. We just need to grow with it. All the reasons we aren't using 12V or 24V as primary in home systems are reasons to keep going up further. Higher voltage means less amps.
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Sure. But higher insulation levels. Same as in MMC Converters and HVDC stations. "Plastic" is typically cheaper than copper, so the logic is valid to some extent.

But then you'll have your battery pack sitting on a 500mm (or more) tall electrical insulator. And your communication system/controller and power supplies will need to be isolated accordingly too.
 
PreppenWolf said:
Voltage needs to go up towards EV car battery pack voltages to help lower copper requirements, lower volumes of bulk systems, further press costs down and create more competitive options. Among other things, like reducing line losses for DC transport.

Higher voltage safety exists. We just need to grow with it. All the reasons we aren't using 12V or 24V as primary in home systems are reasons to keep going up further. Higher voltage means less amps.
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Don't disagree with the benefits but for us DIY people, the higher DC voltage creates a new animal that will necessitate we do things "by the book".

No more diy boxes and cells sitting on shelves if we are going to up to EV voltages.
 
silverstone said:
Sure. But higher insulation levels. Same as in MMC Converters and HVDC stations. "Plastic" is typically cheaper than copper, so the logic is valid to some extent.

But then you'll have your battery pack sitting on a 500mm (or more) tall electrical insulator. And your communication system/controller and power supplies will need to be isolated accordingly too.
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If common insulation can manage 600v without blinking an eye it’s only a matter of time 96v is the new 48v.

Just think 1 pack of 32 560ah cells, sure she’ll weigh more than twoton Tanya you met at the bar last nights but, that’s a one bank whole house setup.
 
740GLE said:
If common insulation can manage 600v without blinking an eye it’s only a matter of time 96v is the new 48v.

Just think 1 pack of 32 560ah cells, sure she’ll weigh more than twoton Tanya you met at the bar last nights but, that’s a one bank whole house setup.
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Fair enough, you're not planning an HVDC station yet ?

But also at 600V it's not only a matter of "normal" insulation.

Plastic insulation / "thickness-wise" is OK, but you must also factor in your clearance, creepage, impulse voltage, etc.

Also 96V (DC !) is quite a lot for many DC MCBs breakers that have a 6kA-10kA. Granted there are some models available in 2P format and there are MCCBs available too. Not sure how much I'd trust those chinese MCCBs though ...

Example for Schneider C120H which can be used for

A9N18458 - Miniature circuit-breaker, Acti9 C120H, 2P, 100 A, C curve, 15000 A (IEC 60898-1), 15 kA (IEC 60947-2) | Schneider Electric UK

A9N18458 - Miniature circuit-breaker, Acti9 C120H, 2P, 100 A, C curve, 15000 A (IEC 60898-1), 15 kA (IEC 60947-2)
www.se.com www.se.com


1709421836222.png

That's just the cheapest and still reputable brand I can buy. Other brands such as ABB (S800N/S800S series especially), Siemens, etc are probably similar.

Even if 1P is sufficient according to Datasheet, I always install 2P. Disconnect on both poles in case of maintenance

EDIT 1

Breaking a arc is difficult, so as voltage goes up, also clearances from breaker/fuse to earthed parts, other live parts, etc, increase, due to the ionization of the air during an air break (air becomes conductive due to ionized gasses).

If you look at the standards even at 690 VAC (800 VAC) you only need something like 5.5 mm (or 8.0 mm) but in real life even with ~20mm you can have issues. Sometimes you just have to ensure that there is no line of sight between your live parts, other live parts and frame/chassis/earth.

EDIT 2
If you take the "smaller brother" iC60H then you could get by with a 2P version.
1709422213348.png

So essentially, as voltage goes up, your choices go down. And price increases A LOT !

Fuses up to approx. 500 VDC with a L/R = 10ms time constant exist and might be the much cheaper option. But they also have other problems (gG = too slow characteristic, aR = lack of full protection and extremely high power dissipation, gS = good compromise, ...).
 
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740GLE said:
If common insulation can manage 600v without blinking an eye it’s only a matter of time 96v is the new 48v.

Just think 1 pack of 32 560ah cells, sure she’ll weigh more than twoton Tanya you met at the bar last nights but, that’s a one bank whole house setup.
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Skinny girls never do much for you anyway.

Ask me how I know? Well, I'm running 24 volts wishing it was 48.🥺

Also, trying not to buy 16 cells from 18650 right now....
 
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