The battery this guide is built around: the Eco-Worthy 12V 280Ah metal-case LiFePO4 — metal enclosure, mounting feet, one-touch safety switch, no battery box needed. Free U.S. shipping & free 30-day returns; 10% off your order with code RVSAFE10.
Swapping a lead-acid bank for one high-capacity lithium battery is one of the most satisfying DIY upgrades in RV ownership — a morning's work for most travel trailers. Here's the sequence, including the two steps people most often get wrong (converter profile and cable sizing).
1. Choose the location
A metal-case battery with mounting feet can bolt straight into a front tongue box, a pass-through bay, or under a dinette seat — no vented battery box required (LiFePO4 doesn't off-gas like lead-acid). Mind three things: the 68.5 lb weight (get a helper), cable run length to the DC panel, and temperature — an interior or enclosed bay location helps in winter because lithium must not be charged below freezing. The Eco-Worthy's BMS pauses charging in the cold to protect itself; an inside mount means that protection rarely has to trigger.
2. Size the cables and fusing
A 200A BMS can deliver 200A continuously — your wiring must match. For inverter setups: 2/0 AWG cable for runs up to about 6 feet, with a 250A Class T or MRBF fuse as close to the positive terminal as possible. For modest 12V-only rigs (no big inverter), 4 AWG with a 100–150A fuse is typical. Torque the terminal bolts properly — loose lugs, not cells, cause most "bad battery" complaints.
3. Check your converter — the step everyone skips
Your RV's converter must have a LiFePO4 charge profile (14.4–14.6V absorption). Many factory converters are lead-acid only (13.6V float) and will leave a lithium battery perpetually at 80–85% — you'll never see the capacity you paid for. Options: switch the converter's jumper to lithium mode if it has one, replace the converter section with a lithium-ready unit, or add a DC-DC/AC charger with a lithium profile. Our Victron charger lineup covers both routes.
4. Add solar if you boondock
A 280Ah battery pairs naturally with 300–500W of panels. A properly sized MPPT controller harvests 20–30% more than PWM from the same panels — worth it at this battery size. Browse our solar power collection for panels, controllers, and mounting hardware.
5. First power-up
- With the safety switch OFF, connect negative first, then positive, then accessories.
- Switch the battery output ON and pair the Bluetooth app — confirm state of charge and cell voltage look sane.
- Run a load test: pump, lights, fan. Then plug into shore power and confirm the app shows charging current and a proper 14.4V+ absorption voltage.
- Label the fuse and switch location for whoever services the rig next.
Common questions
Can I keep my existing battery monitor?
Voltage-based monitors read lithium poorly (the discharge curve is flat). Use the built-in Bluetooth app, or add a shunt-based monitor for a permanent display.
Do I need to disconnect it for storage?
The one-touch safety switch makes this easy: switch output off, and self-discharge is minimal over a winter. Store at 50–80% charge, not full.
Can my tow vehicle charge it through the 7-way plug?
Only at a trickle — the 7-way charge line is thin-gauge. For meaningful drive charging, add a DC-DC charger rated 20–50A.
New to lithium? Start with our sizing guide and the 280Ah brand comparison — or go straight to the Eco-Worthy 280Ah product page.