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diy solar

Future of DIY LiFePO4 looks bleak…

From what supplier? I'm in the market for grade A cells.
docan tech - warehouse in houston
jennywu896@gmail.com
Docan just told me yesterday that they have no stock of ~300Ah cells in the USA or in China, and that they don't expect them for quite some time.

I have decided to go with 16S2P of 230Ah cells to get the capacity and a bit of redundancy. Two parallel strings will allow me to take one offline for service if needed.
 
Prob lack of stock in the US as well, with unknown shipping dates from China, similar to 300+Ah cells.

In case you haven’t heard they are going through a bit of a rough patch over there right now.
 
It'll get worse before it gets better - I expect prices of LiFePO4, and indeed other goods, electronics especially, to keep increasing in price substantially this year. Component shortages are still not solved and don't appear to be for some time to come. I even have my doubts these cells will be readily available like they have been until now...
 
I have 560Ah (8x 280's) and with 150A BMS' my cost shipped to Canada was 1125$US which is <17c/wH for the components. I used what I had for the wiring & boxes but even so that might have added 50$ if I had to buy it. I'm retired so my time is free :)
 
I have 560Ah (8x 280's) and with 150A BMS' my cost shipped to Canada was 1125$US which is <17c/wH for the components. I used what I had for the wiring & boxes but even so that might have added 50$ if I had to buy it. I'm retired so my time is free :)
My 108kwh, 18650 powerwall is at ~$220/kwh = ~22c/wh including everything except A LOT of free labor on my part. Also, I'm operating <40% average DOD to try to get the cycle count one would expect from 80% DOD LifePo4 - so you could say I've paid 44c/wh for the hope of a similar cycle count (and again, expended A LOT of free labor)
 
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Alas - shipping would probably be $1600 for each one ;)
just spent two hours on the phone with the CEO. They stock and ship out of Georgia.

Shipping cost of a singe 51kWh battery to the Bay Area is $230.

These batteries are very impressively designed. Welded terminal connections and the heating solution is very elegant for anyone needing to charge below freezing.

I don’t believe it would be possible to build a LiFePO4 battery of this sophistication and performance for lower cost than what they are asking..,
 
Welded terminal connections

If a single cell fails, you can't perform any maintenance or replace them. Warranty you say - but what if the manufacturer is no longer around?

I don’t believe it would be possible to build a LiFePO4 battery of this sophistication and performance for lower cost than what they are asking

Hold my beer :)
 
I have 560Ah (8x 280's) and with 150A BMS' my cost shipped to Canada was 1125$US which is <17c/wH for the components. I used what I had for the wiring & boxes but even so that might have added 50$ if I had to buy it. I'm retired so my time is free :)
$1175 for 7kWh is $0.17/Wh.

The Trophy 304A 48V battery is $4695 for 15.36kWh or $0.3057/Wh.

So the OTS battery including greater capability such as heating pads, cell-level low/voltage and high-voltage warning, 200A / 10kW charge and discharge limit costs less than twice as much as your DIY battery.

I doubt you could build a battery with all that capability for even 20% less.

And we haven’t even mentioned the 10-year non-prorated warranty: https://trophybattery.com/index.php/warranty/

That alone is worth the pemium.

My 2-year-old 560Ah / 24V / 14kWh battery cost me about as much as your battery (so $0.085/Wh) but I will never build another DIY battery after seeing quality OTS offerings at price points such as this reach the marketplace.

P.S. my budget cells did not deliver the full 14kWh promised, so my delivered cost per Wh was actually quite a bit higher…).
 
If a single cell fails, you can't perform any maintenance or replace them. Warranty you say - but what if the manufacturer is no longer around?
They replace the full pack of cells if one cell fails prematurely (they are welded in a pack).

If you don’t have the wherewithal to replace components / cellpacks, they replace the entire battery.

The risk associated with manufacturers going out of business long before the term of a warranty exists with everything we purchase.

I’ve got 12 335W Solar panels with a 30-year warranty thst I purchased from Sun Edison in 2016, but the Company went bankrupt.

In the Wild West of today’s solar world, you are best off sticking to very large companies such as SunRun/Tesla if that is your top priority…
Hold my beer :)
 
in ideal, welded terminals with warranty sounds really nice.

but the maintenance part sounds undesirable personally.

i assume the entire pack needs to be transported to repair one cell?

even though my current locale is near civilization, i still have a handful of spare cells in case a pack goes sideways.

dealing with terminals as DIY is kind of annoying, but i have confidence for now in nylock and assembly paste with strong m12 threaded stud.

i'm still learning and doing DIY primarily for the fun of learning, gain knowledge and ability to do maintenance, get specific feature sets. saving money vs an off the shelf device would be nice. being able to repair it myself is very valuable to me and warrants paying a bit extra.

but as always, to each their own, and every project has slightly different goals ??️
 
in ideal, welded terminals with warranty sounds really nice.

but the maintenance part sounds undesirable personally.

i assume the entire pack needs to be transported to repair one cell?
They cannot replace a single cell. The entire pack of cells is welded together as a monolithic unit, so the best they can do is replace the entire pack of cells (note we were discussing the 100Ah battery, so larger sizes may be composed of multiple strings/packs in parallel from a mechanics standpoint).

So for customers with the wherewithal to open the box and replace either a defective BMS or a defective cell/pack, they will manage a warranty claim that way.

For customers without that wherewithal or preferring a complete replacement, they will replace the entire battery.

even though my current locale is near civilization, i still have a handful of spare cells in case a pack goes sideways.

dealing with terminals as DIY is kind of annoying, but i have confidence for now in nylock and assembly paste with strong m12 threaded stud.

i'm still learning and doing DIY primarily for the fun of learning, gain knowledge and ability to do maintenance, get specific feature sets. saving money vs an off the shelf device would be nice. being able to repair it myself is very valuable to me and warrants paying a bit extra.
As I believe I stated when I started the thread, those whole prefer DIY batteries for the ‘hobby’ of it all will keep building DIY batteries as long as cells are made available.

But that is a limited / niche market that is going to become a smaller and smaller % of the overall number of home & RV batteries as the market continues to expand..
but as always, to each their own, and every project has slightly different goals ??️
Absolutely.
 
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But that is a limited / niche market that is going to become a smaller and smaller % of the overall number of home & RV batteries as the market continues to expand..
I agree with this.

  1. There will be a large number of folks that will buy pre-built batteries that would never attempt building their own
  2. There will be a group of people that would have built their own to save money but will switch to pre-built as they become more competitive in price to DIY. A sub group of these will switch to pre-built because of a combination of price, ease, and 'clean/orderly result of a pre-built battery.
  3. There will be a group that will always do DIY for various reasons. The fun, the customization, the knowledge, special needs, etc.
Personally, I am probably in the 2nd group at this stage, but I will still price out DIY before I make my final decision for a particular build.
 
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