If you’re like me, you enjoy using your RV throughout the year, including winter when there are many activities to enjoy.
However, more often than not, electrical hook-ups in a campground aren’t available when winter camping. This leaves your batteries to power your off-season adventure.
Winter camping and your RV batteries
Preparing for winter camping takes a bit of thought, especially when it comes to figuring out how to power up everything you need.
In the instance where you only have one house battery, forget about winter camping (if an electrical hook-up is not available). As a result, you won’t have enough reserve capacity to keep the systems in your RV operating.
Two winter battery basics:
- A charged battery has a higher percentage of sulfuric acid than a discharged battery. This means there is less water in the battery’s electrolyte and it’s less likely to freeze. It’s worth noting that a fully-charged battery will freeze if the temperature drops to 55 °F or more. A discharged battery may freeze around 20 °F. For coach owners, verify that the converter/charger charges the house and start battery. Otherwise, your engine battery may not start your rig at the end of your trip.
- Never let your batteries discharge below 50% of the rated capacity. If you do, recharge them. If you let them discharge to lower than 20% capacity, they’ll never charge to full capacity again.
Here’s what you can do to maximize power:
Battery usage is all about amps out and amps in. So, if you draw six amps out, say, running a furnace, you need a way to put those six amps back in. Or, you’ll have to head home when your battery bank is at 50% of its rated amperage capacity.
There are several ways to put amps back in your battery bank, including:
- You can charge them via your tow vehicle or alternator on your motor. This is typically the least efficient, but it is an option.
- Use your solar system if you have one.
- Use a generator to charge your batteries. This can be done via the RVs converter/charger by plugging in the RVs electrical shore power cord to the generators 120 volt AC outlet. Or, if the generator has a 12 volt DC output, hook straight up to the batteries.
To determine the best option, find out what the charge rate is of your converter/charger compared to the DC output of the generator. Then, utilize whatever puts out more amps. Three-stage chargers are also ideal to use.
How to minimize amps:
Now, let’s look at minimizing the amps that are taken out.
The biggest amp draw will be from your furnace. Determine the amperage draw, and then note how long it runs. You can then estimate how many amps were drawn out and how long your charging source will need to replenish those amps.
As an example: If your furnace draws six amps for every hour it runs (and if it runs about 30 minutes out of every hour) you will need 72 amps/day to recharge your batteries (i.e. six amps per .5 hours x 24 hours in a day = 72amps / day).
If you have a good three-stage charger it can charge at upwards of 40 amps per hour or more. So, to put those amps back in you would have to plug your RV into your generator and run it approximately 1.8 hours (72 amps divided by 40 amps per hour = 1.8 hours)
Other sources of battery drain include 12V lights. You reduce the drain by using LEDs, as incandescent bulbs draw about 1.5 amps while LEDs pull about .15 amps.
Other battery-draining sources include gas leak detectors, TV antenna power boosters, stereos, appliance circuit boards, or refrigerators with heat strips that reduce condensation.
Most are negligible but they can add up to an amp or two per hour. An easy way to determine the amp draw of these items is to pull the fuse in the converter and measure the amp draw between the fuse terminals with a volt-ohm meter. Also, decide if you can eliminate any of these loads safely.
With a little research and practice, you will soon be able to maximize your RV’s batteries while camping. So, be sure to enjoy winter RV fun and everything that goes along with it on your next adventure!