Pre-Order Discussions

the price of the LiFePO4 battery bank and its protection is definitely my 1st priority....

it would seem the inverter should have a soft shut down then... a design change needed

64 LiFePO4 cells are currently about $9600 dollars.... and that is just the cells for one smaller LiFePO4 battery using EVE brand LF280K cells....

I utilize more than that... in my off grid build so proper design is essential....🤔🤔🤔

3 hours ago, Sid Genetry Solar said:

 

• Still working with the capacitor company...but I think we have a deal.  Caps will have a slightly higher ESR of about 15mOhm (vs 11mOhm listed for the U.S. ones).  But that's going to be our best bet--I would much rather know what we have, than hope we happen to end up with something better.

How will you verify the capacitor specs?

I wouldn't trust datasheets from even actual Chinese component manufacturers.  They are often exaggerated to put it nicely.  Then there is manufacturing quality consistency beyond the great sample units they give you.

i use class T 400 amp fast blow fuse between the battery and inverter ( i consider it a catastrophe fuse to protect the inverter) as more than 25000 amps can come from the LiFePO4 battery...

and a slow reacting breaker will not save much....

loose connection are best avoided.

I've got an ESR meter, as well as a capacitance meter.

So I definitely believe you--yes, there's loads of counterfeit garbage and trashcan material from China.  I know that any screw-type capacitor from China is almost guaranteed to be counterfeit garbage that tests at less than 1/4 of the rated label value.  (Same for any super-cheap Li-Ion 18650s...they'll say "9800mAh" on the label, but actually only test at 800mAH.)

But at the same time, there's actually a lot of decent-quality stuff from China.  You just have to raise your sights a bit above the "Wal-Mart level" of flogging suppliers for pennies--because that's when a lot of the "cheap junk" gets manufactured, together with nice samples & junk bulk orders.  Also worth noting that "bait and switch" tactics are almost expected when ordering from trading companies...because that's how they try to skim money off of you.

I do not haggle with the suppliers on their price: if I don't like their price, I generally tell them that it's higher than I expected--and then I look elsewhere.  If I'm not browbeating them for pennies, I would think they would have a much lower likelihood of shipping me garbage--probably because I look like a cash cow to them. 
But if I am happy with their price, why beat them over the head and try to pinch them?

Also worth noting that most of the chips and parts on the GS inverters are directly sourced from Chinese suppliers.  And generally speaking, we haven't had quality issues that can be attributed to said parts.  (We had one SMD capacitor blow up on a control board...but out of several hundred control boards, there's only been one instance of that.  And I switched the cap to a different supplier anyway.)  We've had far more issues with the Microchip PICs (U.S. manufactured).

February 28, 2023:

• I am so disappointed in how slowly things are moving...but as we aren't responsible for manufacturing 100% of everything, we do have to wait on other companies sometimes...
• At the moment, I have been waiting on the local shipping company to give me a "partner shipping company consolidation address" in China.  Was told to expect communication yesterday...but never did.  Maybe it was the weather--Sean sent me photos that they'd gotten an ice storm in Michigan yesterday, and perhaps the power was out in Detroit...
  • We have 4-5 smaller boxes that would be nice to consolidate together with the main transformer order if possible...but until the transportation ducks are in a row, it's kinda hard to order stuff.
  • I may be better off getting all these smaller orders pulled together with direct express (air) shipping to us--and if the shipping company gets their ducks in a row for a more economical shipping option, then we can try to change the Alibaba order terms and get partial refunds from the suppliers for the express shipping costs.  Not sure what else to do honestly...
• Order from the capacitor company is up for payment (with express shipping direct to us), should be paid today and they can start on that.
• As per the requests, the transformer company has made 1pcs of both the 6kw and 12kw GS transformers before producing the main order. 
  • The 12kw transformer design is pretty close to what we want--though that plastic wrap is going to have to go....

    <fileStore.core_Attachment>/monthly_2023_02/trans12.jpg.1577ea5f2ccfcd6f2747241fd94c6c7e.jpg

     

  • 6kw design...well, they did get the primary lines *really* close to each other, though the design goal was for them to be a bit further apart!

    <fileStore.core_Attachment>/monthly_2023_02/trans6.jpg.1db500d5947a53347fa8bfc9a9eb6e75.jpg

• I'll see about getting the rest of the orders together tonight.  Unfortunately as with custom-spec stuff, it can take a few weeks to produce.  And I feel bad about this beyond-ridiculous delay with the preorders.  But we're going to get through it--and this type of issue won't happen again.
   

March 1st, 2023

• the lovely fun of trying to work with U.S. companies...and the delays of such companies.  (I know, I know, the irony here is not lost on me.)  I'm very impatiently waiting for "partner shipping addresses" in China for our local U.S. shipping company...so we can have the various packages of parts (coming from different provinces in China) consolidated into a single master shipment for ocean freight shipping.
  • I got several express shipping quotes from several suppliers (busbars, heatsinks), and the express DHL/FedEx/UPS shipping costs were beyond $600 per supplier (due to shipping weights >140lbs each).  That adds up really quickly...into one big fat "ouch."
  • Like Sean pointed out, there's really nothing gained by having packages arrive multiple before everything else...because you still can't do anything with the early parts.  I mean, aside from parading them over YouTube (which isn't a bad idea at this point anyway).
  • Yes, I've bugged the local shipping company for an update both yesterday and today.  At least they've been decent to respond--yesterday's response indicated that they're still sorting out logistics overseas.  Today's response had better have some answers in it!
• Capacitor order is paid.  They have a nail-biting 28-day lead time on the Alibaba order agreement time...but it should take 2-3 weeks to actually produce them. 
  • I honestly can't blame said company for allowing themselves a bit of headroom...because if they exceed the agreed-upon specified time allotment, Alibaba will penalize them. 
  • And we're definitely not out to "jump on everyone else just because we're Americans and we can."  Things can happen--and there can be honest mistakes.  It's when there's intent to defraud (or otherwise) that we have issues.
• Heatsink orders and busbar orders are ready for payment--but with well past $1,000 in nothing but shipping costs on just those 2 items...well, we're a bit loath to pay that amount if we can utilize said moneys for actual parts and equipment.  So these are technically waiting on the U.S. shipping company.
• I'm just about finished modifying the fastener order for the 5th time (that saleslady is being so patient with my constant changes and tweaks!)--but that one's going to have to go freight, as I'm expecting a shipping weight well in excess of 300lbs.
  • last night I added a number of 100C-rated 70A density rubber sheets for the transformer padding. 
    • We're going with 5mm thick padding; worth noting that PJ used ~3.5mm padding (and thinner than that on the smaller units).  Yes, it may appear as a "blanket" of sorts--but anything to keep the transformer windings from contacting the chassis is going to be well worth it.
    • our order quantities aren't high enough for custom shapes, so Sean's going to have to make a jig and cut the rubber into the desired shapes by hand.  Honestly...that's not going to be much of an issue.
  • my final tweaks today are to go through the list and make sure we have enough of all the fasteners--then this order will be finalized.  Nothing like trying to assemble "the last inverter" and run out of a specific bolt.  Or lose one nut on the ground, and then not have enough...
• trying to get our fan supplier to switch the connector ends on the fans from XH (JST spec) to XHB (Chinese latching).  There's no reason to have fan connectors falling out during shipping...when we can simply use a latching connector.
  • Said supplier is definitely patient with our low quantities...but I'm sure they'd be a lot perkier if we were ordering thousands of units at a time!  We'll get there...one day.

March 6, 2023:

• finally got some clarity from the shipping company, and have the heatsink, busbar and fastener orders ready for payment when Sean wakes in the morning.  Or tonight if he can't sleep 🤪
• worth noting that the transformer and capacitor orders are already placed and in production as of right now.
• Sean is planning to order the chassis and packaging boxes (both locally produced) when the bulk parts order from China actually ships on the ocean freighter. 
  • I'm planning to do a similar timing for ordering the remaining PCBs (mainboards, FET boards, etc.), as they go by air freight anyway.
• We're going to get this all the way through.  I do fully acknowledge that this has been painfully slow for us to figure out completely new sourcing and transportation channels--and I wish there was something I could do to time warp the logistics.  But due to the weight of the transformers, air freight is pretty much out of the question (without basically tripling the cost of the order!)
  • the only ones who never complete a job are those that quit......and we aren't quitting.  We've come way too far to quit...like I tell Sean, "We haven't gotten this far by quitting."

March 7, 2023:

• Remaining new orders are PAID...heatsinks, busbars, fasteners (connectors, lots of misc, etc.)
  • now trying to get the fan company to put an order up so we can pay it...
• We are discussing running the remaining PCB orders through our new PCB company (with partial PCB hardware assembly as well).  That should get rolling this week.

March 13, 2023:

• Transformer supplier says the transformer order should be completed this week.  Here's a photo of a 6K transformer with the leads spaced just a bit further out, and the plastic wrap almost completely removed:
  
• Capacitor supplier informed me that the production is expected to complete by the end of this month; that order ships by air anyway, so that's not going to delay anything.
• I've been tweaking the inverter chassis files...the latest version of FreeCAD has fixed some bugs with the Sheet Metal Workbench, allowing me to get the bends closer to the desired goal.
  • changing spec to allow use of 6AWG silicone wire for the AC output lines on the 12kw inverter; the 7AWG silicone I had specced for seems to be a bit difficult to find...
  • AC output lines on the 6kw will be changed to 8AWG; this is way overkill for 6kw 240v, but for 6kw 120v it'll be quite worth it to not have to replace the AC output wires...
  • de-ovaling the chassis mounting holes
  • updating the front panel to the new AC terminal block requirements

March 14, 2023:

• I promised to provide as many updates as possible.  Sometimes there's not much to report, but other times there's updates...
• Fastener company sent me photos of all of the items ordered that have arrived at the current time.  Real photos of the actual items, with measurements to show--so I'm happy.
  • Only problem I saw in the list was the fan grilles...we specified black metal fan grilles, but the ones that came in were stainless appearance.  (I told them that we want the black metal grilles for aesthetic reasons.)
  • from what I can see, everything else looks good
  • New chassis screws...serrated underside with a "cushion" hex head.  The serrated underside will prevent them from coming loose

    <fileStore.core_Attachment>/monthly_2023_03/image.png.77d859f023df4487423e7768fc2f06ea.png

  • Transformer bolts--these are for the 6kw inverters.  (12kw inverter transformer bolts haven't arrived at the fastener supplyhouse yet.)

    <fileStore.core_Attachment>/monthly_2023_03/image.png.e8920696327382530582a0c688cc4488.png

    yes, those are LARGE bolts!  SS304, too.

  • The new AC terminal blocks...60A for the 6kw, and 80A for the 12kw.

    <fileStore.core_Attachment>/monthly_2023_03/image.png.812e9bcf8269a03e8f78e3a731adb7ab.png

  • Battery terminals for the 6kw inverter...T3 red copper on these...

    <fileStore.core_Attachment>/monthly_2023_03/image.png.8ab04e49ab89c883aa4b159294d27af7.png

  • and yes, when I said 5mm thick rubber padding for the transformer, I meant it...

    <fileStore.core_Attachment>/monthly_2023_03/image.png.c1fe0feb089fc70559429a4e0520f48b.png

    (here's hoping I don't regret making it that thick, hehe!  Fortunately, I allowed for the transformer bracket being very difficult to put on...the bracket hold-down screws are far longer than might seem necessary, just for this purpose.)

• Despite the transformer order expected completion to be this weekend, the entire order (including fasteners, connectors, busbars, heatsinks, and fans) is still expected to ship by the end of this month.
  • busbars and heatsinks aren't completed yet...and it looks like I'm finally going to be able to place an order with the fan company.  Gotta pressure them a bit sometimes...but we definitely do need fans!
• Got quotes from the PCB company for 6KW and 12KW FET boards.  Looks like they are getting a considerably better price on the FETs than if we'd purchased them from LCSC, and the complete assembly cost is quite reasonable.  So that order should be placed within a few days.  (It ships via express DHL, so that's not going to be a holdup.)
  • mainboards and other little boards will be ordered from our regular PCB company, though that also won't be a hold-up, as it'll also ship via express air.
• Sean told me that he wants to get the inverter chassis' ordered as soon as possible.  I am trying to juggle a lot of stuff at the moment...but have been working on getting the chassis CAD files updated to the latest fixes before they are ordered.  Hopefully this will be done by the end of the week, and Sean can get the order placed into the production stream at the local (American) fab shop.
• Shipping boxes...I've got some design labeling ideas for those to "spice 'em up a bit", so hopefully the shipping boxes look like they mean business 😉

March 17, 2023:

• Finally got the fan company to create an order....whew....!  Fortunately, they estimate 10-15 working days to completion, so this should be able to ship with the rest of the orders.
  • adding laser engraving on the back of the fans so we can ID them!  Their normal MOQ is a bit higher than what we've been ordering, so there's no "sticky label".  However, a laser engraving in the plastic won't be able to fall off--so I think it's better.
• Heatsink company...I asked for a progress update, and they sent some photos of tubs with cut heatsinks in them (but the photo is really blurry).  I asked if they could clarify if these are our heatsinks, and they said yes.  Next step obviously is the drilling and threading of holes.

  <fileStore.core_Attachment>/monthly_2023_03/image.png.0a682533ab5e23bbb68a7f57c5ccb4c9.png

• Busbar company...I asked for a progress update.  Got some photos of busbars for the 6kw inverters...they've gotten them all laser-cut out of bulk copper, and now are on the "processing" phase: getting them all bent into the required curlicues and then nickel-plating them so they don't tarnish/corrode.

  <fileStore.core_Attachment>/monthly_2023_03/image.png.89e141cc3f1d75e7517db4d4007c572c.png

  GS 12kw positive busbars.  With that little "jig"...gotta love designing in 3D CAD 😉.

  <fileStore.core_Attachment>/monthly_2023_03/image.png.f71bd798c38ae48744331dec14be4e57.png

  GS 12kw negative busbar...the 2 halves...

• <fileStore.core_Attachment>/monthly_2023_03/image.png.27674135063ed246bde33103bf4b7ec2.png

  That's the 6kw positive busbar.  Looks right about like what I designed in 3D CAD 😉.
   

• Transformer company...I'll check in with them next week.  I'm not trying to nag the suppliers--but as the transformer order was placed about this time last month, they will (logically) be one of the first ones to complete.
• PCB company...well, we have several anyway.  The order for MOSFET boards has been placed.  (It ships by air.)  There's one more PCB order to place, but I'm not worried about it--we'll have the boards within 2 weeks of order date.
• I haven't completed the packaging boxes' graphics...or the inverter chassis updates yet.  Been busier than I expected--but I'm going to get both of those sorted ASAP so we can get those also ordered.  Both are local U.S. businesses (less than 2 hours' drive from Sean), so there won't be notable shipping transit time involved.

Will the 6k bus bars work on the old model by chance? and can they handle 300a of 24v?  Not sure if the old model had them or not.  since my main board is getting updated, if its got wires as the batter would love to switch them to bus bars. 

Absolutely not.  Everything to do with the DC power lines are completely different internally.

They'd better 😉.

March 21, 2023

• not many updates to provide at this point--so I'm going to bug all the suppliers tonight for progress updates!  I am hoping that by the end of this month, all of the orders will be ready for consolidation and bulk "express boat" shipping to the States.
• Fastener/"off-the-shelf" supplier has gotten all of the required materials ready.  Now they're just waiting for my word to get the goods off to the shipping company--which will happen when the other orders are also ready.  No reason to pay warehouse "storage fees" to the shipping company if we don't have to 😉.
• I've been updating the GS inverter chassis' designs to the latest changes...
  • tightening gaps up, as the (Michigan) metal fab shop basically hands us real life representations of the 3D models!  So I'd better make the 3D model match exactly what I want the real item to look like!
  • changing the design spec for the new and improved AC terminal connectors--the mounting screws and terminals are in different locations, necessitating slight adjustments there
  • beefing the AC output wires up a tad per Sean's desires...6kw gets 8AWG output wire (so we don't have to replace the output wires for 120v single-phase setups), while the 12kw gets 6AWG output wire (as I couldn't get 7AWG from a low-MOQ supplier). 
    • funny part here is that I had specced the rubber grommets for 10AWG on the 6kw and 7AWG on the 12kw...and since those are already ordered, I just have to enlarge the chassis holes to accommodate the bigger wires.  The rubber grommets can be expected to stretch 0.5mm to fit the bigger wire--that'll make a tighter fit anyway!  Not that we're making waterproof inverters or anything...
  • Finally update the inverter mounting holes to a keyhole design for 1/4" bolts...here's the 6kw in 3D CAD
    

March 22, 2023:

• Transformer order is completed!  They didn't take any "bulk order photos", but we did manage to get them to do a "unit sample test" of 5pcs each 6kw and 12kw transformers--which all specced out fine.  So this should be good to go.
  
  I believe all four wooden crates here comprise the total order.
   
• Capacitor order is expected to complete on the 27th.  Currently set for air shipping--but there's no real reason we couldn't dump that onto the bulk shipment...
• Heatsink order is expected to complete in ~2-3 days.
• Busbar order is expected to be done "by the end of the month"--so give 'em a week or so...
• still trying to get progress updates from the fan company...
• MOS board PCB supplier has the order under production; that one goes by air shipping anyway.
• I completed revisions on the 6kw & 12kw chassis 3D CAD designs, and sent them off to Sean...they can go to the fab shop for manufacturing.

   

• and of course, the fasteners/non-customized item supplier has already completed the order.  Just awaiting consolidation pickup right now.