Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. Today he discusses using a tow vehicle battery and jumper cables to supplement a travel trailer’s house battery.
I am traveling to Death Valley next week and staying at Furnace Creek with no hook-ups. I am staying for three nights and have a 120-amp ACOPower solar panel to charge the battery (single 12 volt). It looks like the weather is going to be unseasonably cool with lows in the mid-30s.
While the Suburban furnace runs on propane, the blower motor will be drawing off of house power. I had not anticipated putting this much load on the battery and am worried that I will be using more power than the charger can replenish.
Can I use jumper cables and the battery in my tow car to help keep the travel trailer battery charged? I know when I have jumped cars with dead batteries, there usually is a healthy spark when connecting the jumper cables. I am worried that this might cause a problem with the electrical system of the RV. Is this okay to do? I have a battery kill switch. Should I turn the power to the RV off before connecting the jumper cables from my car to it? Thanks so much. —Michael
I spent three nights in Death Valley this past April but did not dry camp; rather, we stayed at the Longstreet Inn, Casino & RV Resort in Amargosa Valley, NV. We shot footage in Furnace Creek as well as Noonday Mine.
We are developing a series of safety videos for off-roading in Death Valley, so be careful and be prepared! First thing, there’s no cell or Wi-Fi service in most parts of the area, so get a satellite phone. Make sure you have a good map and understand the roads and non-roads. There have been several cases of people taking 4-wheel-drive units that they thought were off-road and blowing tires and trying to walk out. They did not make it. If you would like more information, I can put you in touch with the host of the series that has been off-roading in Death Valley for several years.
You are correct in your assumption regarding the 120-watt solar panel not being enough to charge your battery. However, you also need to factor in the amp-hour rating of your battery as well as its current condition as to sulfation. I doubt your battery has more than 100 amp hours, and if it’s lead-acid, you will not be happy with the performance.
I would not suggest using jumper cables from the vehicle to the RV house battery. Not because of damage but, rather, it will drain the battery down fast. You could be stuck with two dead batteries in a place that does not like humans! They call it Death Valley for a reason.
Also, your truck battery is a cold-cranking amp battery and is not designed to drain and be recharged too often. It will ruin it quickly. If you have a-7 pin plug in your vehicle, you should have a charge coming from the engine alternator to the RV as you drive. You could run the vehicle with the unit plugged in, but I would only do that in case of emergency.
I would suggest getting another solar panel and possibly another battery. However, first you need to evaluate the one you already have and match it exactly. If it’s a lead-acid battery and more than two years old, I would purchase two new ones that are AGM and are less maintenance. If you only have one battery, I would assume your converter/charger is not a multi-stage charger and simply throws a 13.6-volt charge to the battery until it reaches 12.6 volts and then levels off to a maintenance charge of 13.2 volts. This does not break up sulfation. You might want to consider one lithium battery as a 100 amp-hour battery will drain down almost 100 percent and your lead acid or AGM only provides 50 percent or less. If it’s sulfated, you’ll be sitting with no battery power in less than a day.
One other consideration: How about a portable generator? Make sure it’s a generator/inverter so it’s got cleaner power (sine). I have found a few at Harbor Freight that have gotten good reviews and are much less expensive. Maybe we can get some of our readers to tell us what they have in the comments. (Readers?)
Now, let’s discuss reducing your 12-volt power consumption, as well. Instead of running your deep-cycle battery-power-devouring furnace, I like to use a catalytic heater that runs on the small propane bottles and uses no battery power.
Again, be careful, stay hydrated, and have fun. Here is the Rubber Foot Buffalo and me at the campsite.
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