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Mike Swanson aaf4172b3c sync: Add Wrightstown Solar and Smart Home projects

New projects from 2026-02-09 research session:

Wrightstown Solar:
- DIY 48V LiFePO4 battery storage (EVE C40 cells)
- Victron MultiPlus II whole-house UPS design
- BMS comparison (Victron CAN bus compatible)
- EV salvage analysis (new cells won)
- Full parts list and budget

Wrightstown Smart Home:
- Home Assistant Yellow setup (local voice, no cloud)
- Local LLM server build guide (Ollama + RTX 4090)
- Hybrid LLM bridge (LiteLLM + Claude API + Grok API)
- Network security (VLAN architecture, PII sanitization)

Machine: ACG-M-L5090
Timestamp: 2026-02-09

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

2026-02-10 18:44:35 -07:00

3.7 KiB

Raw Blame History

Wrightstown Solar - Project Index

Project: DIY Home Solar Battery Storage Location: Wrightstown (home) Status: Planning / Research Phase Created: 2026-02-09 Last Updated: 2026-02-09

Project Overview

DIY 48V LiFePO4 battery storage system for whole-house UPS / backup power with generator failover. Designed for modular expansion from 5kWh to 20kWh.

Target System Specs

Spec	Value
Chemistry	LiFePO4 (LFP)
Cell	EVE C40 (40135 cylindrical, 3.2V 20Ah)
Configuration	16S5P per 5kWh pack
Nominal Voltage	51.2V (48V system)
Pack Capacity	5.12kWh per pack
Target Total	20kWh (4 packs)
Inverter	Victron MultiPlus II 48/5000
BMS	JK BMS B2A8S20P 150A (recommended)
GX Device	Cerbo GX
Existing Solar	Fronius IG Plus (grid-tie string inverter)

Design Goals

Seamless switchover when grid drops (<20ms, UPS-grade)
Zero grid backfeed (physical relay disconnect)
Generator input for extended outages
Modular expansion (build one 5kWh pack at a time)
Fronius solar continues working during outages via Victron micro-grid

Architecture

                    NORMAL OPERATION
Grid -----> [Victron MultiPlus II] -----> House Panel
                    |
              [48V Battery]
              (EVE C40 packs)

Generator ---> [AC Input 2]

                    GRID DOWN
Grid --X    [Victron MultiPlus II] -----> House Panel
             (relay OPENS, no backfeed)
                    |
              [48V Battery] (discharging)

Generator ---> [AC Input] (if battery low)

Files

Documentation

File	Description
`documentation/system-design.md`	Full system architecture and component specs
`documentation/bms-comparison.md`	BMS models compatible with Victron CAN bus
`documentation/ev-salvage-analysis.md`	Analysis of salvaged EV packs vs new cells
`documentation/parts-list.md`	Bill of materials and estimated costs

Session Logs

File	Description
`session-logs/2026-02-09-session.md`	Initial research and planning session

Budget Estimate

Phase 1 (5kWh + Victron System)

Component	Est. Cost
Victron MultiPlus II 48/5000	$1,400-1,800
Cerbo GX	$320-350
JK BMS B2A8S20P 150A	$80-150
80x EVE C40 cells	$240-400
USB-UART cable	$15
Cell holders, bus bars, wiring	$60-120
Fuses, breaker, enclosure	$60-110
Phase 1 Total	$2,175-2,945

Phases 2-4 (Additional 15kWh)

Component	Est. Cost
3x additional 5kWh packs (cells + BMS + hardware)	$1,140-2,010
Full 20kWh System Total	$3,315-4,955

Decision Log

Date	Decision	Rationale
2026-02-09	EVE C40 cells over salvaged EV packs	Lower $/kWh ($190-282 vs $365-780), longer life, LFP safety, simpler build
2026-02-09	5kWh modular packs (not 10kWh)	Spread cost, manageable builds, fault isolation, one-person liftable
2026-02-09	Victron MultiPlus II for inverter	<20ms UPS switchover, physical relay anti-backfeed, generator support, micro-grid for Fronius
2026-02-09	JK BMS B2A8S20P (recommended)	2A active balancing critical for cylindrical cells, best value, huge community
2026-02-09	Keep Fronius IG Plus	Still functional; AC-couple via Victron micro-grid during outages

Next Steps

Finalize BMS selection (JK BMS vs REC BMS vs SEPLOS)
Source EVE C40 cells (Grade A, matched, with test data)
Order Victron MultiPlus II 48/5000 + Cerbo GX
Design cell holder / bus bar layout for 16S5P cylindrical pack
Plan sub-panel / transfer switch wiring
Build Pack 1, test for 1 month before expanding

3.7 KiB Raw Blame History