Renogy DC-DC Charger / Solar Controller

There's a lot going on in this charger, and that's the best thing about it! Here's a more in-depth run down of how all these features are integrated:

Isolation: Battery isolators (like our Aux Battery kits) allow you to discharge your auxiliary (also called coach or house) battery without draining your main (also called starter) battery. This is the whole point of having a second battery, enabling you to run a fridge, heater, lights, etc. and still know that you've got juice to start the van the next morning. This Renogy unit senses the voltage of the main battery, watching for alternator voltage to isolate the auxiliary battery automatically, and has status lights to tell you when it's charging. Crucially, this charger can unlatch the BMS on a LiFePo4 battery if it goes into a disconnected mode, so you can recharge it after you fully draining, freezing, or overheating your battery.

DC-DC Charging: A battery isolator supplies alternator voltage to the auxiliary battery while the vehicle is running. For many Vanagon owners, a simple isolator or solar panel is adequate to keep an aux battery topped off. But for those that want to take advantage of fast charging with LiFePo4 batteries, those with large battery banks, or Eurovan owners that need to charge LiFePo4 batteries off of their "smart" alternators, a DC-DC charger is really the only way to go. This Renogy DC-DC charger, unlike a simple isolator, can independently adjust the charge voltage of the auxiliary battery to a higher voltage than the alternator puts out. The charge profile can be varied to work with any common aux battery so that the charge voltage can be optimized for any type of battery and its state of charge. This allows for rapid battery charging at as much as 30A. With this Renogy charger, two hours of driving can fully recharge a GoWesty LiFePo4 battery!

MPPT Solar Charge Controller: Most important for the typical camper with a single 100W panel: this MPPT controller is much more efficient than a typical PWM controller. Using an MPPT controller under common conditions, your solar panel will supply 25% more power to your battery than it could with a PWM controller. That difference is huge if you only want to store one solar panel in your van. The integration of both an MPPT and a DC-DC charger into one unit also allows for a lot of clever operational features. The MPPT solar controller alone can charge at up to 30A if you have a large array of panels. Solar and alternator power can be used at the same time if you have a fixed solar panel on your van, resulting in a combined maximum of 30A charging with less load on your alternator. You can also use the solar input to charge your main battery in addition to your aux battery. This main battery float charge is only enabled when the auxiliary battery is fully charged so that no solar power is wasted.