Stretch your amps and watts

By Bob Difley


Electricity. We take it for granted. Plug in an appliance and turn it on. What could be simpler. But when you take up boondocking, electricity is more like opening the spigot of a water jug. When it all flows out there is no more, unless you refill the jug.

stretch bulbYour rig’s 12-volt system is sufficient for satisfying your power needs as long as you avoid excessive use of 120-volt current. An inverter — which converts 12-volt into 120-volt — consumes huge amounts of power if you run your air conditioner, toaster oven, and microwave oven. Leave your electric blanket and Mr. Coffee at home for the same reason. An extra blanket and a drip coffee maker will replace these necessities of modern living.

If you observe a few basic electricity conservation rules, you’ll be able to get the most out of your available battery power.

• Use lights only when needed and turn off when not used — even for a short time.
• Don’t leave the porch light on. Carry a flashlight in the dark.
• Use battery operated reading lights and flashlights.
• Shut off the radio or TV when no one is listening or watching.
• Avoid lengthy use of appliances requiring high wattage to operate, even if they are 12-volt, like your water pump.

The amount of 12-volt electricity in your battery/ies available to operate your systems is a limiting factor for your length of stay, or the time between recharges. A single deep cycle 12-volt house battery will produce about 105 ampere-hours of electricity. By calculating the number of amps each of your electrical appliances draws multiplied by the hours used makes for an educated guess at when you need to recharge by subtracting the ampere-hours used each day from the total available.

Only about half of these amps (about 50) are actually available to run your electrical equipment. Take voltage readings at the battery terminals with a multi-meter and when the voltage drops to 12.2 volts, start your engine or run your charger/converter off your generator to recharge the battery. Installing a second house battery or switching to a pair of 6-volt golf cart batteries will increase the total number of available amps.

Practice. Take notes. Keep a log. Soon you’ll be able to accurately judge how long you can go before your system needs rejuvenating.

You can find Bob Difley’s RVing e-books on Amazon Kindle.