DIY Lithium RV Battery Build - Part 3: Battery Box, Installation, and Converter Replacement

In Part 3 of this video series, we're wrapping up our Lithium RV Battery Upgrade project (for now!). Today we'll:
Build a solid, weather proof RV battery box for our custom LiFePO4 battery
Install the battery box and batteries in our travel trailer and wire everything up
Upgrade our RV converter to a Lithium converter
We might even build the second battery (hint!).
The result is a super compact 200 Amp Hour (AH) Lithium pack that looks better than anything that comes equipped on an RV from the factory, and will work in almost any trailer, motorhome, or van conversion. Impress your friends and fellow campers. Dive in, follow along, and build your Lithium battery pack!
DISCLAIMER:
Undertake any project at your own risk. I'm being as safe as I can be and making that judgment for myself. I'm sharing my knowledge as I go, but I could be incorrect or miss something, and do not know about every possible unexpected issue that could arise. I try to push myself, but I also know my limits and don't exceed them. Before you embark on a project, you should too.
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PARTS and SUPPLIES
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Case:
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Monoprice 20.3 Liter battery box (QTY 1) (www.amazon.com...)
Wiring:
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MSI Speedware through panel terminals (1 black, 1 red) (www.amazon.com...)
Silicone sealant (www.amazon.com...)
8-32 x 1 inch long stainless socket head cap screws (QTY 4)
8-32 flat washers (QTY 8)
8-32 nylon lock nuts (QTY 4)
Red and black Terminal covers (www.amazon.com...)
12 inch red 4 gauge x 5/16 lug battery cable (www.amazon.com...)
12 inch black 4 gauge x 5/16 lug battery cable (www.amazon.com...)
24 inch red 5 gauge x 5/16 lug battery cable (www.amazon.com...)
Kydex sheet (for insulating panel) (www.amazon.com...)
Case Mounting:
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Polyethylene packing foam (for retaining battery within case)
1.25 inch square tubing x 8 inches long [your quantity and dimensions may vary] (QTY 4)
5/16 x 3.5 inch carriage bolts [your length may vary] (QTY 4)
5/16 stainless fender washers (4)
5/16 nylon locknuts (4)
adhesive backed ratcheting cable clamps (QTY 2) (www.homedepot....)
Converter:
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WFCO 8950L2MBA (Only applies to replacing WFCO converter. Consult with your manufacturer for your best replacement option)
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WFCO 8950LIS-MBA (has switch to change between Lithium and Lead Acid charging)
Tools:
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1 inch hole saw (www.homedepot....)
5/32 drill bit
5/16 drill bit
7/16 drill bit
Philips screwdriver
Other Supplies:
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Black Paint
heat shrink tubing
Wire nut
Electrical tape