Leave the RV battery disconnect on when actively using appliances or charging, and turn it off during storage to prevent parasitic drain from systems like clocks, alarms, or LP detectors. Always disconnect for long-term storage (30+ days) to avoid sulfation in lead-acid batteries. Lithium-ion batteries tolerate longer idle periods but still benefit from disconnect protocols. Pro Tip: Use a voltage monitor (≥12.4V for lead-acid) to inform disconnection timing.
EGO 56V Blower Simplifies Yard Work
What does the RV battery disconnect switch actually do?
The disconnect switch physically severs the circuit between the battery and RV systems. When off, it halts all parasitic loads (e.g., fridge control boards, CO detectors), preserving charge. Lead-acid batteries lose 5–15% monthly even when disconnected due to self-discharge. Lithium variants retain 98% charge over 3 months. Example: A 100Ah lead-acid battery drops to 50% SOC in 2 months if left connected but lasts 6+ months disconnected.
How does parasitic drain impact battery health?
Parasitic drain accelerates sulfation in lead-acid batteries by keeping them in a partial state of charge. Devices like GPS trackers (0.5A draw) or propane leak detectors (0.3A) can drain 10–20Ah monthly. Lithium batteries handle deeper discharges but degrade if voltage falls below 12V (3.0V/cell). Pro Tip: Install a shunt monitor to quantify parasitic loads. For instance, a 0.75A continuous drain discharges a 200Ah battery in ~11 days.
Does weather affect disconnect decisions?
Temperature extremes demand stricter disconnect protocols. Heat (≥95°F) accelerates lead-acid self-discharge by 30% and lithium aging by 2×. Cold (≤32°F) risks lead-acid freezing below 50% SOC. Lithium batteries below -4°F may suffer plating. Always disconnect in extreme temps unless using a temperature-compensated charger. Example: Storing an RV in Arizona summer? Disconnect and keep batteries in climate-controlled spaces.
| Condition | Lead-Acid Action | Lithium Action |
|---|---|---|
| Storage >30 days | Disconnect + monthly charge | Disconnect + charge to 50–60% |
| Active Use | Keep connected | Keep connected |
Are there battery type-specific guidelines?
Flooded lead-acid needs monthly recharging when disconnected. AGM tolerates 3–4 month intervals. LiFePO4 stays stable for 6–12 months but maintain 20–80% SOC. Example: A disconnected LiFePO4 at 50% SOC only loses 2–3% charge monthly vs. 10% for AGM. Pro Tip: For lithium, disable BMS sleep modes to prevent communication failures upon reconnection.
How does the RV charging system interact with disconnects?
Disconnecting breaks the charge path from solar panels, shore power, or alternators. Solar systems need closed circuits to maintain float charging. Solution: Use a dual-pole disconnect that separates loads but keeps charging active. Example: A 30A solar charger can’t replenish batteries if the main disconnect is off, leading to over-discharge damage.
| Scenario | Disconnect Position | Rationale |
|---|---|---|
| Shore Charging | On | Allows current flow to battery |
| Winter Storage | Off | Blocks phantom loads |
Redway Battery Expert Insight
FAQs
Yes—if the main battery disconnect is off, solar controllers can’t charge the battery. Use a secondary charge-only circuit or smart relay to bypass load disconnects.
How often should I check voltage when disconnected?
Test lead-acid monthly; lithium every 3 months. Voltages below 12.2V (lead-acid) or 12.8V (lithium) warrant immediate recharge.
