This four-part mini-series will review the main types of battery chargers: AC-to-DC, DC-to-DC, and Solar. This article isn't a product review or a scholarly journal... it's an overview intended to help you identify the best charging system for your application.
For this review's purpose, we will look at 12v systems used in an off-grid setting because...we like camping.
DC-to-DC chargers are the unsung heroes of mobile power applications. I feel like I'm leading with the conclusion with a statement like that right outa the gate, but it's true. AC-to-DC systems are practical. Solar systems are sexy. DC-to-DC gets it done by just doing what you'd usually be doing and not having to be intentional about it.
Basically, a DC-to-DC charger works by taking power generated by your vehicle's alternator and modifying it so it will correctly charge your house battery. There's a whole nother Ramble here with the specifics, but that's a separate post.
In short, modern vehicle alternators can output between 13.5v and 14.5v. Typically they will start at 14.5v but then dip down to 13.5v when the starter battery is fully charged. 13.5v isn't enough to fully charge a Lithium battery as Lithium requires at least 14.2v - 14.5v to reach full capacity. The DC-to-DC charger monitors the voltage output to make sure the house battery receives the proper voltage to fully charge.
To be fair to other chargers, let's run through the PROs and CONs:
- You charge while your vehicle's engine is running.
- Driving to camp...Charging
- Heading into town for supplies...Charging
- House battery can be fully charged from your vehicle's alternator.
- Because it's a set-it-and-forget-it type of system, you can tuck the unit away for a clean install.
- Very efficient charging, since it's DC-to-DC, the charger is only adjusting the volts and amps.
- You can fully charge a trailer battery in transit rather than rely on the trickle charge from the 7-pin connector.
- You may be somewhat limited to the ability of your vehicle's Alternator. Not all alternators can accommodate a 40 amp per hour charger.
- These systems can be more costly than their AC-to-DC counterparts.
- Your vehicle has to be running.
In most applications I've encountered, installing a DC-to-DC charger would rate about a 3 on the 10-point difficulty scale. They're pretty straightforward. I run a Victron Orion-TR Smart 12/30 amp charger in my Jeep to keep my house battery topped off all the time. The Victron's key feature is that it can auto-sense when you start your rig. This saves the step of running another wire to sense ignition.
Bottom line, the DC-to-DC charger is my most used charger, by far. When paired with our Nicolet Power System, I have yet to run out of power while camping. Even when I basecamp and don’t move much, the ability to pump in 30+ amps per hour allows the battery to recharge while on a resupply run.
If you're unsure about your next steps for charging solutions, please let us know if we can answer any questions or help steer your decision. We genuinely appreciate your support. Be sure to tune in to the next Ramble, where we'll discuss solar charging systems.
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