AGM DC-Only Minimal (100W / 100Ah AGM)
The lowest-upfront-cost way to add a little solar to an older RV that still runs lead-acid/AGM. DC loads only. Shown mostly to make the AGM-vs-lithium trade-off concrete — you pay less now but get half the usable capacity and far more weight.
Parts list
| Part | Qty | Price | Why this pick | |
|---|---|---|---|---|
| panel Rich Solar Rich Solar MEGA 100W 12V Monocrystalline Solar Panel | 1× | $95 | Direct Renogy alternative at a slightly lower price, useful when matching an existing Rich Solar array. | View Rich Solar listing ↗ |
| charge controller EPEVER EPEVER Tracer 2210AN MPPT 20A | 1× | $75 | Lowest-cost true MPPT for small 100-260W builds; strong price-per-amp value. | View EPEVER listing ↗ |
| battery Renogy Renogy 12V 100Ah Deep-Cycle AGM | 1× | $210 | Included as the lead-acid baseline so the planner can contrast AGM economics against lithium options. | Buy at Renogy → |
| System total | $380 | Parts only — wire, fuses, mounts and breakers extra. | ||
Affiliate disclosure: Some links here (Renogy) are affiliate links — if you buy through them we may earn a commission at no extra cost to you. It never changes which part we recommend: picks are ranked by spec fit across every brand, and non-Renogy parts are listed with neutral source links. Sizing and wiring output is guidance, not an electrical sign-off — verify before buying or wiring.
Compatibility checks
Wire & fuse starting point
| Run | Max current | Wire (AWG) | Fuse / breaker |
|---|---|---|---|
| Solar array → Charge controller | 5A | 16 AWG | 10A |
| Charge controller → Battery | 20A | 12 AWG | 25A |
Wire and fuse sizes are a conservative starting point from each run's max current (×1.25). Run length, temperature and local code can change them — confirm with an electrician. Off-grid DC carries real fire and shock risk.
Deliberate teaching build: AGM at 50% depth and ~50A continuous limits what you can bolt on. Kept DC-only and single-voltage for a clean, safe minimal system.
Tune this build in the planner →
FAQ
Why is the usable capacity only ~600Wh from a 100Ah battery?
AGM should only be discharged to about 50% to avoid killing its lifespan, so a 100Ah AGM gives ~600Wh usable versus ~1,200Wh from a 100Ah LiFePO4. That's the core AGM trade-off.
Should I just buy lithium instead?
For most new builds, yes — LiFePO4 has dropped enough that the cost-per-usable-Wh now favors it, and it's half the weight. AGM still makes sense if your budget is tight today or you're extending an existing lead-acid system.
Why no inverter?
AGM's lower continuous-discharge rating makes it a poor match for a big inverter, and this build targets simple DC loads. If you need 120V, move to a lithium build sized for the inverter's current draw.
Build vetted 2026-06-21 · confidence: high. Prices and specs from each part's linked sources.