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diy solar

My build thread with LF280K from 18650batterystore and Sun Fun Kits sfk v4 Heated Kit

EastFalcon

New Member
Joined
May 12, 2023
Messages
121
Location
Ashburn, VA
Hello,
I would like to share with you my battery build, after seeing videos on Nate's DIY youtube I decided to do the same:

I chose cells from 18650batterystore the LF280K grade A, and the standard heated kit V4 with heating.

The total cost for cells was $644 delivered to Virginia and $373 for the kit. My total spent: $1,017 for all. I think this is going to be a good battery that is heated, has low temperature protection, heating, and Bluetooth connection.
 

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One of the cells on has some liquid under the blue cover, I called 18650batterystore and James tells me its nothing to worry about I also read a few people on the forums have this as well and it is ok.

The Sun Fun Kits is most assembled, I chose the option to get my pads soldered for easier connection, I also selected the sidewall as they say it is easier to install this way.
 

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So the standard version you can pay to have the wires crimped, but I already have a hydraulic crimper so I will make my own wires, but everything is included actually there is more wire then needed. Its nice silicone 6 awg wire, it is also sfk's own brand.
 

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So I started by installing the cells using the 1.00 3d printer walls. They went in fairly easily, its a very nice fit with the foam and the bracket.
 

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So this is how far I have gotten to, I install the cells, SFK told me that for the dual terminals you will need 16 m8 bolts and they sent it to me at no charge. They said not use to use the threaded rod included with the package form 18650 as it can not be tighten properly. However, I will show you what I'm stuck on.
 

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So here is where I'm stuck at at, they have this part that increases the height but one of its "branches" is hitting the bolt. I sent this to SFK and they said they are shipping a replacement riser to me and it should be arriving today.

So this is where I am at till now, its been pretty good so far except for the cell incompatibility.
 

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Hey there,

Nice to see more people building SFK kits, I was going to post my build thread too, but you beat me too it :LOL:. I went with the v4 standard without heating for 2 of them I also have a v3.5 kit with LF280K non heating as well. Love them.
 
I think you are right they are m6 sorry, I not good with metric its about 1/4" thread. But good news I got this new adapter and it fits. Transferred over the electronic board to the new one and now I put on the BMS board. Its pretty nice and thick about 1/8" and is machined fiberglass.
 

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Ok so I'll finish up the rest tomorrow, but almost done, I have the wires attached to the top of the case and the heating pad connected to the switch.

Pretty smooth so far. Making the cables and crimping the colored connectors took the longest out of everything.
 

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All done! I'm going to charge it and run a capacity test when I get home.
 

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Ok I think I have everything set! I'm using this heater and a 1500 watt inverter along with the BMS capacity benchmark. Its running now.
Overall the kit was easy to build I think anyone can do it, the only hard parts are the making the cables and crimps.
 

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Test completed last night, I got 278AH.
Is this normal for grade A cells? I was under the impression these usually test much higher because they are grade A.
 
I see, very cool thanks Sam!

 
278 AH is very common for LF280K grade A. This is all you can expect. EVE is making a version 3 that is supposed to increase capacity a bit more. I would say your capacity is good.
 
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