Should I leave RV plugged in all the time?
Leaving your RV plugged in continuously is generally safe if using a smart charger or converter with voltage regulation to prevent battery overcharging. For lead-acid batteries, maintain float voltage at 13.2–13.8V; lithium systems tolerate indefinite charging via built-in BMS. Always prioritize battery chemistry specs—flooded batteries require monthly equalization, while AGM/LiFePO4 benefit from continuous maintenance charging during storage.
What happens when an RV stays plugged in long-term?
Continuous shore power charges the house battery bank through the RV’s converter, which can cause water electrolysis in flooded batteries or passivation layer issues in AGM if improperly regulated. Modern RVs with multi-stage chargers reduce risks by switching to float mode after bulk/absorption phases.
When voltage exceeds 14.4V for lead-acid or 14.6V for lithium, electrolyte breakdown accelerates. Pro Tip: Install a voltage monitor between the converter and batteries—sudden spikes above 14.8V indicate failing voltage regulation. For example, Trojan flooded batteries lose 3% monthly capacity when kept at 13.6V indefinitely versus 1% when cycled. Transitionally, while lithium systems handle continuous charging better, their BMS still requires periodic full discharge cycles to recalibrate capacity readings.
| Battery Type | Max Float Voltage | Overcharge Risk |
|---|---|---|
| Flooded Lead-Acid | 13.6V | High (water loss) |
| AGM | 13.8V | Moderate (grid corrosion) |
| LiFePO4 | 13.6V | Low (BMS-protected) |
How to safely maintain RV batteries when plugged in?
Use a multi-stage converter with temperature compensation and set it to your battery’s float voltage. For older RVs, add an external charge controller to prevent voltage creep. Disconnect batteries monthly for 24 hours to test self-discharge rates—healthy units lose <5% charge daily.
Lithium batteries simplify maintenance through adaptive balancing, but their lower internal resistance can trick basic converters into over-delivering current. Practically speaking, upgrading to a lithium-specific converter (like Progressive Dynamics 9145) prevents this. A real-world example: pairing Battle Born LiFePO4 batteries with a Victron IP65 charger extends cycle life by 40% compared to generic chargers. Transitionally, even advanced systems benefit from quarterly manual inspections—corroded terminals increase resistance, forcing converters to overcompensate.
Does continuous charging damage RV batteries?
Yes, if using non-automatic converters that don’t reduce voltage post-absorption. Lead-acid batteries suffer plate corrosion and water depletion, while lithium cells experience micro-dendrite growth when kept at 100% SOC. Always verify your converter’s absorption-to-float transition—older models like Parallax 7355 lack this feature.
Modern solutions involve programmable charge profiles. For instance, converting a 12V system to LiFePO4 requires setting bulk/absorption to 14.4V and float to 13.6V. But what about temporary setups? Pro Tip: Use a DC-DC isolator to separate starter and house batteries, preventing alternator overload. Transitionally, RV parks with unstable shore power (below 105VAC) strain converters, causing erratic charging—voltage stabilizers mitigate this.
| Component | Risk Level | Solution |
|---|---|---|
| Basic Converter | High | Upgrade to 3-stage |
| Lithium BMS | Low | Enable storage mode |
| Solar Controller | Moderate | Set absorption timer |
Fasta Power Expert Insight
FAQs
Indefinitely with lithium batteries and a smart converter. For lead-acid, unplug after 24–48 hours of absorption charging to allow equalization.
Will my RV battery drain if plugged in?
No—properly functioning converters prioritize shore power over batteries. However, faulty diodes can create parasitic drains up to 1.5A.
Do solar panels override shore charging?
Yes, solar controllers typically take priority, but only if panels generate sufficient wattage—otherwise, the converter supplements.