Should I leave RV battery connected when plugged in?

When your RV is plugged into shore power, keeping the battery connected is generally safe if the RV’s converter/charger is functioning properly. Modern systems are designed to maintain optimal charge levels without overcharging. However, lead-acid batteries benefit from periodic equalization charges, while lithium batteries (LiFePO4) tolerate continuous charging better. Always verify your charger’s float voltage (13.6V for lithium vs. 13.4V for AGM) to prevent electrolyte loss or cell stress.

Best Battery Tender for RV Maintenance

Why do some RVers disconnect batteries when plugged in?

Parasitic loads from CO detectors and LP gas alarms (3-15W daily) can slowly drain batteries even when shore-powered. Older chargers without smart staging may overcharge, boiling electrolyte in flooded lead-acid batteries. Pro Tip: Use a multimeter to confirm charging voltage stays within 13.2-14.6V for lead-acid or 14.2-14.6V for lithium systems.

While modern converters typically switch to float mode, legacy models might trickle-charge indefinitely. For example, a 1990s-era charger pushing 14.8V continuously could reduce a lead-acid battery’s lifespan by 40% through grid corrosion. Practically speaking, if your RV has pre-2010 electrical systems, periodic disconnection prevents cumulative damage. But how do you know your system’s age? Check the converter label – modern units specify “smart charging” or list lithium compatibility.

What charging phases matter for connected batteries?

Quality chargers use three-stage charging: bulk (80% capacity), absorption (voltage hold), and float (maintenance). Lithium systems skip absorption, charging faster. Pro Tip: Install a battery monitor (e.g., Victron BMV-712) to track state-of-charge accuracy within 1%.

Consider this scenario: A 100Ah lithium battery connected for a month with a proper charger cycles between 95-100% state-of-charge (SOC), experiencing minimal degradation. Comparatively, an AGM battery kept at 100% SOC develops sulfation, losing 2-3% capacity monthly. Why the difference? Lithium’s electrochemical stability allows partial SOC storage, while lead-acid requires full cycles. Transitional phrase: Beyond chemistry differences…

Fasta Power Expert Insight

FAQs

Best RV Battery for Solar Power Systems