How to Charge Your 12V Battery While Driving

If you've ever rocked up to camp and realized your fridge has turned off, the beers are warm, and the lights won’t flick on — you’ll know exactly why charging your 12V battery while you drive is a game-changer.

I’ve had this happen to me before — thought I had everything sorted, only to find out the battery wasn’t charging properly between stops. Lesson learned: your 12V setup needs more than just a fridge and hope.

Here’s what I’ve learned about keeping your battery charged on the move — simple gear, real talk, and no fluff.

🚙 Why Bother Charging While Driving?

Let’s be honest — even if your battery is fully charged when you leave home, it doesn’t take long for it to start draining. Running a fridge, charging devices, maybe a few lights or a water pump… it adds up. Charging while driving just makes sense.

It means:

• You’re topping up the battery as you go
• You’re not stressing about flat batteries when you pull into camp
• You’re not relying purely on solar (especially on cloudy days)
  

🔋 1. Get Yourself a DC-DC Charger (Just Do It)

• This is one of the best upgrades I’ve made. A DC-DC charger (I’ve got a REDARC in my setup) basically makes sure your second battery charges properly from your alternator — and doesn’t mess with your vehicle’s smart alternator if you’ve got a newer 4WD.
• Even better, most of them let you plug in a solar panel as well. So you’re charging while you drive and when you’re parked.

🔄 2. Dual Battery Setup Is the Backbone

• If you're running a fridge or any gear off-grid, a dual battery system is a no-brainer. Your starter battery powers your car. Your auxiliary battery powers your gear. Simple.
• Just don’t skimp on the gear — if you’re going lithium, a 200Ah lithium battery gives you heaps of capacity without the weight.

⚡ 3. Anderson Plugs — Underrated but Bloody Handy

• Anderson plugs are what keep everything connected — especially if you’ve got a canopy or camper trailer. I’ve got one running from the ute to my canopy batteries, and it works great for charging while driving. Just make sure everything’s fused properly and wired with thick enough cable so you’re not losing voltage along the way.

☀️ 4. Solar + Driving = Perfect Combo

• Solar panels are awesome when you’re at camp, but combining them with your DC-DC charger is where the magic happens. I use a KT solar panel — easy to set up, and great for keeping things topped up during the day.
• Quick tip: Always park so your panels get the most sun (obvious, but easy to forget when you’re chasing shade).

🧠 5. Keep Tabs on Everything (Volt Meters or Smart Shunt)

• This is a small one that makes a big difference — having a volt meter or smart shunt installed means you can actually see how your battery is doing. No more guessing. You’ll know if it’s charging properly while you’re driving and whether you’re draining too fast at camp.

🛠️ What You’ll Need in Your Setup

Here’s what I personally recommend if you want things to work right:

• DC-DC charger (REDARC’s been bulletproof for me)
• 200Ah lithium battery (great balance of capacity & weight)
• Dual battery system
• Anderson plugs and quality cabling
• KT solar panel (roof or portable)
• Voltmeter or smart shunt to monitor

Need a Hand?

If you're not sure where to start or want to build out your 12V setup, we’ve got all the gear at Perth Pro Bayswater, WA — REDARC chargers, lithium batteries, KT solar gear, Anderson plugs, and more.

Reach out to us with a message if you want advice that’s actually helpful (and not just techy mumbo jumbo).