Words and Images by: Michael Tyrrell

Portable panels are easy to adjust and arrange to maximise sunstrike.

When you take your RV out to remote locations, power is of critical importance. Keeping your batteries charged should stay top of mind when you’re preparing for your next trip. If you run out of power when off the grid, you could find yourself stranded in the middle of nowhere placing your safety at risk.

WHY CHARGE YOUR BATTERIES?

• To avoid an unexpected delay or need to cut your holiday short.
• The power load on your batteries can be large, so without regular charging they’ll die prematurely.
• To improve their reliability as unhealthy batteries discharge faster.
• To minimise the amount of time you run a noisy generator.
• To maximise battery capacity.

WAYS TO CHARGE YOUR BATTERIES

• Via your alternator as you drive along (without a charger). An alternator, by itself, isn’t going to fully charge your batteries.
• Via a DC-DC battery charger which will enable you to charge your batteries via your alternator (while you drive) or your solar (at camp).
• Via an AC battery charger and a generator. This can work well but generators are noisy and there are usage restrictions in some locations.
• Via an AC battery charger when you get back home. When you put your RV in storage, your batteries are going to continue to discharge. The next time you take your RV out, you may find your batteries are discharged, damaged, or dead.

HOW LONG WILL MY BATTERIES LAST?

Michael Tyrrell says the duration of your batteries depends on factors including how powerful your battery system is.

“A large battery system with two or three 120A AGM batteries will last much longer than a small battery system with one 100A battery.”

He says there are a few questions you should ask yourself to ensure  you meet your needs on the road. For example, what type of appliances do you want to run when you are away? How much power does each of these appliances draw? How long do you want to run these appliances each day? Also consider how many appliances you’ll run simultaneously.

Tyrrell says how you charge your batteries will also influence how long your batteries last.

“Solar is very helpful in offsetting some of your power usage. This means your batteries will stay charged a bit longer. As a result, you may not need to go for a drive to charge the batteries via your DC-DC charger or to run your generator as often. The more your charging solution is charging via alternator, solar and generator – the more likely your batteries will last longer.”

HOW CAN BATTERIES CONSERVE POWER BETTER?

We are so used to having 240V power at our fingers tips, yet with rising electricity costs Australians are more aware of how to reduce our energy consumption at home. However, when off the grid, it can be easy to forget we don’t have mains power on tap – or even the same level of power available to us in our DC-DC systems – even with a generator.

So, Tyrrell advises the best way to conserve power when we are away is measuring our power usage.

“It’s an adage which holds true for many things – what we measure, we control. Firstly, get a good quality monitor installed such as a Victron BMV702 which will give you more advanced information about volts, amps, percentage of energy consumed, and the amount of time you can continue to support the current load. You can also set an audible alarm for a specific battery voltage. Then, it’s becoming familiar with what your appliance are drawing.”

He says with a monitor such as the BMV702 or equivalent, turn off all appliances, and then turn one on to see what it is drawing.

If you are using an inverter you need to be particularly energy conscience.

“I’ve heard people say inverters flatten batteries. They don’t. But if you are using an inverter to run some 240V appliances, you are likely to run your batteries down faster.”

Small microwaves, fridges, and washing machines all use more power.

It’s also more popular for people to take more cooking appliances and coffee machines on the road.

“A coffee machine can be a big power consumer, requiring a 2000 watt inverter,” Tyrrell says.

“However, there is more to consider than the inverter size. Running a coffee machine can run your batteries down fast, so you may need to upgrade them.”

If high-power items are a must, you’ll need a large inverter, a large battery bank and a good DC-DC charging system.

TWO CHARGING SETUPS

The type of power you require in your RV will depend where you stay.

POWERED SITES

At a powered site, you may not need an integrated charging system because you can run your appliances from mains power. However, when you get back home and put your RV into storage, you should use an AC charger to keep your batteries charged.

UNPOWERED REMOTE LOCATIONS

If you’re running appliances at an unpowered remote location, you will need an integrated charging system.

For heavy power, you need a DC-DC charger such as the CTEK D250SA and SMARTPASS 120 to charge your batteries via your alternator and solar, as well as a generator.

Using a DC-DC charger, solar, generator and AC charger will maximise battery performance. 

All work together as follows:

• The DC-DC will charge your batteries fast on the move
• Solar will offset some power used
• A generator, used with an AC battery charger, can charge your batteries faster than solar power With an integrated charging system you won’t have to run your generator as much – perhaps every second day.

AN EXAMPLE OF A DC-DC CHARGING SYSTEM

A DC/DC Charger such as the CTEK D250SA (20A/DC-DC charger) can extend the life of batteries by as much as three times.

Many DC-DC systems such as the D250SA can charge your batteries via a smart alternator or via solar.

Combining a DC-DC charger with a power management system such as the CTEK SMARTPASS 120 can increase your charging capacity to 140 Amp. This charges batteries faster and reduces generator time.

Category: Advice
Written: Sat 01 July 2017
Printed: July, 2017
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