Had it with losing power while boondocking? Try these tips to extend the life of RV batteries
RV batteries are one of those things that you really should know about. But in truth, all you care about is turning on your hairdryer, coffee maker, or toaster without thinking about where the power comes from.
Talking about watts, amperage, voltage and things like sine waves, inverters and parasitic drain is just too geeky for most people.
I get it.
So I am going to keep this super simple. The gearheads and armchair electricians are not going to like this.
But my intent is just to help you extend the life of RV batteries and thus let you have the power you need when running on them.
Types of RV batteries
There are wet cells, AGM and lithium batteries found in RVs today. In terms of efficiency, wet cells are the worse. AGMs are better and used to be the standard. But lithium is now the best. Lithium RV batteries last longer, charge faster, discharge more (that’s good, meaning you get more use) and they weigh about half as much as AGMs.
Lithium batteries are expensive, though. Figure about $1,000 bucks for a 100 amp battery. Your RV should have at least two of them if you plan to do a lot of boondocking.
When we talk RV batteries, we need to distinguish between the batteries that power the engine of your motorhome (if that’s the kind of RV you have) and those batteries just for the RV appliances. The engine batteries are called the chassis batteries. They provide 12-volt power to your RV. Your RV lights are run off them. The USB power receptacles in the RV run off them. So does the TV antenna booster. Sometimes TVs, too.
But except for a tip a little later, we’re not so much interested in them.
We’re interested in the coach batteries, also called the house batteries. Those power up your RV. They also provide 12 volts. Or 24 volts in some RVs. But don’t get confused. To explain messes up my plan to be simple. Just know there are two kinds of batteries – chassis and house.
And I don’t care what kind of RV batteries you use (though I do recommend you at least consider lithium because it will let you stay out there longer).
We’re just going to talk about how to save power or extend the life of your RV batteries.
But we need to also mention the RV Inverter
Your batteries run through an inverter. It changes DC power that comes from the battery to AC and turns 12 volts into the 110 volts RV appliances like, such as the microwave, the coffee maker, and the hairdryer. Inverters come in different sizes, or more accurately power capacities. Many older or cheaper RVs have 1,000-watt inverters. Frankly, that is so miserly to be almost useless.
Next up are 1,500-watt inverters. That’s a bit better but still marginal in our book (you’ll see why when you scan the chart we include below).
A 2,000-watt inverter, in our mind, is workable. That’s the minimum you should have. A 3,000-watt inverter is even better.
Think of the inverter as taking the power from your RV batteries, dong it’s conversion of DC to AC magic, and making it available for the accessories you want to run.
One example (again, there’s a chart below): Most RV microwaves draw 1,500 watts of power. Your 1,000-watt inverter won’t handle it. That 1,500-watt inverter may, though if anything else – even something minor like maybe a cell phone charger – is also plugged into a 110-volt outlet, you’re going to blow fuses or trip a circuit breaker.
I’m not going to get into all the numbers and formulas on how you use wattage and current (voltage) to calculate how many amps are required from the RV batteries. Way too much geek-speak. We want to talk about how to extend the life of RV batteries.
Let me just say that the higher the wattage required to run an appliance, the faster that appliance will drain your RV batteries.
So then, how do we extend the life if RV batteries?
Here are 10 tips:
Don’t use your Inverter all the time – Just having the inverter on is a draw of your RV batteries. So, when you are boondocking and powering all the stuff inside your RV with those coach batteries, turn it off when you don’t need it. The inverter all by itself, without any appliances operating, will eventually drain your RV batteries all by themselves. How fast depends on how big the inverter is. You can do all those electrical formulas to come up with an answer but just trust me, turn it off unless you need it. That will help extend the life of RV batteries
If you’re driving down the road and want to run it to, say, charge batteries or run a crockpot to cook dinner as you drive, no problem. The chassis batteries are charging both themselves and the RV batteries from the engine alternator and there’s no loss.
If you are in a campground and plugged into shore power, that power passes through the inverter and doesn’t take any juice from the RV batteries.
But if you are boondocking. turn the inverter on only when you need to run a 110-volt appliance. Then turn it off again.
Unplug the Vampires – The vampires are the devices that are plugged into an inverted outlet (a 110 outlet) and sneakily suck power even when they are off. They cause what is called a parasitic load or a parasitic drain. I prefer calling them vampires. Even if those appliances re not on, just being plugged in draws RV battery power.
Your cellphone, computer, and camera chargers have a parasitic drain. So does your cell phone booster. Basically any appliance plugged into a circuit powered by the inverter will take power from the RV batteries whether it is turned on or not.
Use power the 12-volt chassis batteries when possible – I bought cables to connect our laptops, tablets, cell phones, watches and many of my camera battery chargers to the 12-volt USB plugs that are powered by the chassis batteries. I charge my small electronic gadgets that way, instead of turning on the big inverter to get 110-volt power.
For those little things, the 12-volt drain is minimal on my chassis batteries. When they go through the inverter, they suck juice from the RV batteries and consume power from the inverter, which has to power up itself first, then convert DC to AC and then distribute it to all the outlets in the RV.
Running those little gizmos off the inverter is overkill and ends consuming more energy.
Ask your dealer or serve shop to power your TV from 12 volts – Its not that hard for them to do. It will save you even more RV battery power. Many of the newer RVs already are wired that way. If yours isn’t, consider doing so.
Run your fridge off LP gas, if you have it – Lots of RV refrigerators can run on 3 types of power: 12 volts from the chassis batteries, AC from the inverter, or LP gas. The only time I run my fridge off of 12 volts is when the engine is running and we’re driving. Otherwise, being a much larger appliance, the fridge can drain a chassis battery over prolonged use.
It will also drain an RV battery.
So if you can run it on LP when boondocking, do so
Consider a portable refrigerator – In recent years, we’ve seen several companies offering portable battery-powered refrigerators. These refrigerators are very effective and the batteries are built into them. Some use lithium batteries, which, as said earlier, last longer. Using a portable, battery power refrigerator will indeed extend the life of RV batteries.
Get a battery pack for your CPAP machine – CPAP machines, because they are on for 8 solid hours, consume hefty amounts of power. Check with your supplier and see if yours can be powered by an optional battery pack.
Temporarily use your generator for the heavy lifting – Do you use a griddle for pancakes? An electric frypan for bacon? A hairdryer? The microwave? While yes, you could run them off your RV batteries via the inverter, consider running your RV generator for a half hour or so. You can use those energy-sucking appliances with generator power and extend the life of RV batteries.
Use a kettle to boil water for coffee instead of a coffee maker – I use a cheap little french press like device that makes me great coffee with boiling water. No more coffee maker for our RV
Use solar – I hesitate to mention this as solar has been oversold to many RVers. But it does help. But you need more than one 100 watt panel. Solar helps to top off your RV batteries. But it takes a long time. We have 400 watts of solar panels atop our RV. With full, direct overhead sun they can pretty much charge up my RV batteries each day by nightfall, assuming I haven’t drawn them down too much over the previous night. If you really like to boondock, solar is a great option that will also extend the life of RV batteries.
Extend the life of RV batteries: Check out the chart
Okay. Time now for the promised chart. I show you this so you can see what conveniences draw the most power. This shows how much power consumption is in watts. The longer it is on, the more watts it gobbles up, and the faster it will drain your RV batteries.
- Blender- 500 watts
- Coffee machine – 1000 watts
- Refrigerator 8 cu.ft.- 600 watts for the whole day
- Toaster – 850 watts
- Box fan – 200 watts
- TV – 150 watts
- Video game console – 150 watts
- Laptop – 100 watts
- Smart phone – 6 watts
- Curling Iron – 150 watts
- Electric shaver – 15 watts
- Hairdryer – 1500 watts
- Small electric heater – 1,000 watts
Get the picture?
Two final tips to extend the life of RV batteries
Prolonged exposure to very cold (below freezing) temperatures can drain your RV batteries. Lithium batteries hate the cld. Some come with their own heaters but they stop charging and discharging when it gets really cold.
Sitting unused for too long is not good. Think about a slow charger if in storage.
Remember, I promised simple here.
Hope these tips helped!
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