One common concern for RVers during the off-season is “is it bad to leave your RV plugged in all the time?”, when your motorhome is put in storage. While the battery is expensive to replace, charging your RV battery improperly would shorten its lifespan, not to mention the disasters that can happen when you’re traveling with a damaged battery.
Read on to find out the possible consequences of leaving your RV plugged in all the time and how to avoid these problems. There are times when you might want to plug your RV into shore power for an extended period of time, but there are safer, less energy-consuming ways, which RVing Trends will also discuss in this article.
Is It Bad To Leave Your RV Plugged In All The Time?
The first concern is your RV electricity consumption. The dollar number of course depends on the utility rates in your area, plus how often you are plugging your motorhome into shore power during storage. As a ballpark figure, you can expect your utility costs to increase by $10 to $40 per month. This also means more pressure on our Mother Earth, in case you’re an environmentally conscious camper.
Is it bad to leave your RV plugged in all the time, if utility costs are not a concern? Up to $40/month might not be substantial, but more important than your energy bills is the possible damage to your expensive RV batteries when you leave it plugged in all the time during storage. For RV rentals, when you’re out on the road, or for any short term battery usage, you should have no problem leaving your RV plugged in 24/7. However, if you own an RV, battery charging and maintenance during storage require some due attention.
If you have a modern converter or smart charger that slows to a trickle charge after the batteries reach full charge, all is well and you just need to check once in a while to make sure your battery is charging normally (more on this right below). Otherwise, you might risk overcharge and overheat your battery bank, thus making it depreciate faster:
Overcharged Battery House
If your RV is left plugged in for too long after the batteries have reached full charge, continued charging means the batteries have to continue enduring more heat and current, and the heat and current can start to deplete the electrolyte levels inside the battery cells. This directly translates to shortened battery life.
In more severe cases, depleted electrolyte levels can cause failures in the lead-acid battery’s protective case, causing battery acid to spill out of the case, damaging wiring and other surrounding parts. This is also a dangerous hassle to clean up.
You might have heard that you might be able to restore the electrolyte levels by adding a bit of distilled water. However, you can only do this once or twice over the lifespan of an RV’s lead-acid battery.
How To Avoid Overcharging Your RV Battery
Is it bad to leave your RV plugged in all the time? Yes. One of the best ways to prevent RV battery overcharging and premature replacement is to invest in a proper charger specifically used for charging an RV deep-cycle battery. It’s called a smart charger, a three-stage charger or an RV deep cycle battery charger. These chargers use a three or four-stage process for optimal charging—bulk, absorb, and float—without overcharging your precious batteries.
At each stage, the charger charges at a specific voltage for efficiency:
- Bulk stage: In this stage, a depleted battery will be recharged up to 80% of its capacity. The charger charges at a faster rate or high current to bring voltage up fast, so that a depleted battery will be topped off quickly.
- Absorb stage: After the battery has been sufficiently restored, the charger will continue with a slower charge rate to replenish the battery to its full state of charge.
- Float stage: After the battery reaches 100% capacity, it will receive a “trickle charge”, the rate of which is equal to the battery’s natural self-discharge rate, in order to maintain this full state of charge. (Self-discharging: All deep-cycle batteries lose a bit of charge over time even when not in use.)
In addition, even if you forget to unplug after the battery has reached full charge, you can leave the charger plugged in 24/7 without worry of damaging the battery, since modern deep cycle battery chargers these days often have an auto-stop feature that will stop charging when the battery reaches 100% capacity. Is it bad to leave your RV plugged in all the time? Not if you have the right charger, but do check once in a while to make sure everything is well.
When You Might Want To Leave Your RV Plugged In
When you are at a campground and want to run any necessary appliances, there are times when it’s convenient to run the appliance via a common extension cord when you need to instead of leaving your RV plugged in all the time. This way, you can then leave the rest of the electrical system disconnected.
When your RV is in storage, however, there might be times when you want to plug your RV into shore power for an extended period of time. But there are safer, greener and cheaper alternatives:
Protecting your RV from humidity during storage
If you store your RV in hot and humid climates, you might want to plug in your RV to keep the A/C running from time to time, so that your upholstery and other interior parts will not be damaged by excess moisture.
Alternative Option – Dehumidifier(s):
This might sound legit, as replacement might cost $250 to $500 for replacement per item. That said, this might be a lot of stress on the RV’s rooftop A/C, causing premature wear and tear. An easy and more affordable option is to place a home dehumidifier inside your RV during the hottest and most humid months of the year. You might need to run the RV’s A/C in conjunction from time to time, but the dehumidifier would allow you to run the A/C at a lower setting and in shorter periods.
Using the RV as a guest house
If you often have guests staying over during the holiday seasons, for example, you might want to use your RV as a guest house, so that your guests and you both have more space and privacy.
Alternative Option: While it’s less work to just leave the rig plugged in all the time, it’s not exactly a hassle to plug it in the night before your guests arrive. This is more than enough time to let the batteries charge without wasting energy.
When You Don’t Have Time To Winterize Your RV
You might not want to spend all that time to fully winterize your rig, so leaving the RV plugged in might be easier to keep the thermostat and the heating system running, so that your water lines and storage tanks would not freeze over. Many campers living in extreme cold climates claim that the extra utility costs outweigh the potential damage from a long, cold winter, since winterizing might not resolve all the issues.
Alternative Option – Radiators: If you are wondering “should i leave my rv plugged in all winter”, know that another option is to install one or two oil-filled radiators to keep the interior of your motorhome warm during winter storage. These don’t come with the fire risks of a traditional space heater and are also low-wattage, thus are much more energy efficient than running the RV’s furnace. When the temperature drops below the specific temperature range that you set the appliance to, an internal heating element warms a special type of oil inside. This ambient heat then exudes to the surrounding air to warm the space.
Charging Your RV Fast and Properly: FAQs
1. How often should I charge my RV battery?
Your RV’s house batteries are deep cycle batteries, which are lead-acid batteries. All batteries of this type run the risk of rapid sulfation if left uncharged for too long. Sulfation is a natural process of lead sulfate crystals building up on a battery cell, but when rapid sulfation happens, the battery will accept far less current than normal.
You should use a multimeter or a voltmeter to check your RV battery’s state of discharge to recharge them in time. The best practice for optimal lifespan is to charge deep cycle batteries when they drop to 45-50% capacity, although deep cycle batteries are technically designed to discharge down to 20%. Over time, you should be able to estimate how long it takes your rig to get down to 45-50% depth of discharge, given your energy consumption.
2. How long does it take to fully charge an RV using a charger?
Experts generally recommend charging your house battery slowly using a smart charger at a room temperature of around 70°F or 21°C in up to 20 hours. A smart charger usually has damage protections and can be safely plugged in 24/7. This long charging process allows the acid inside the battery enough time to penetrate the thicker active plates, all the while minimizing stress on the plates, thus prolonging battery life.
Charging time can be estimated by dividing the battery’s capacity by the charger’s rating for amps-per-bank. For example, you have a dead 100 ampere-hour deep cycle battery and a 10-amp charger. A good rule of thumb is to add about 10% for the extra time to totally top off the battery, so you would need about 11 hours to restore your battery to full charge at room temperature: 100AH ÷ 10A × 110% = 11 hours.
Sometimes, when you need to charge your rig in a hurry, you can charge the battery only up to 90%, since getting from 90% to 100% takes considerably longer than getting from 80% to 90%. However, do note that recharging to full charge each time is best for your battery lifespan.