Review of the Renogy DC50s Combi Battery Charger

Truck camper owners typically rely on several devices to keep their batteries charged and maintained. Aside from the standard 120 volt converter-charger or inverter-charger, these can include a DC solar charge controller and a DC-to-DC charger to handle charging from the truck’s alternator. These devices are usually manufactured and sold individually, but this is changing as needs in the industry grows. Renogy is now offering a combination battery charger it’s calling the DC50s that performs the functions of a MPPT solar charge controller while at the same controlling the charge from the truck’s alternator. One of our readers, Alex Blasingame, recently installed this unit in his camper. This is his review.

Earlier this year, I decided to upgrade the lithium battery setup solar power system in my Lance 815 truck camper. From everything I read, a controller/charger would be needed to manage the new lithium ion battery system for my camper. This is because lithium batteries operate at higher voltages (a maximum of 13.2 volts) and require a higher voltage to charge, typically 14.6 volts. During my research I came across three products that combine the function of a solar charge controller and a DC to DC charger for vehicle alternators. One of these controllers was made in Australia and didn’t export to the USA, while the other two were made in the USA. Unfortunately, one of the two controllers was very expensive, and not with in my budget, while the third combination controller, called the DC50s Onboard Battery Charger, was new on the market by Renogy and had very few reviews on it, hence, the reason for this review.

What exactly can the Renogy DC50s do? The charger blends the two inputs from the alternator and solar to achieve maximum amperage while the engine is running, 25 amps from the vehicle and 25 amps from the solar system, 50 amps max. It provides over and under current protection for both house batteries and vehicle battery, and provides low temperature cut-out (32 degrees F) and cut-in for lithium batteries, a huge plus for lithium ion batteries. It limits MPPT solar charging to a maximum of 50 amps and up to 660 watts of solar input. The unit acts as a DC to DC charger and a battery isolator for the truck’s starting battery. Finally, the unit trickle charges the vehicle battery after the house battery is fully charged when the engine is off.

The Renogy 50s Combi Charger comes with everything you need to install the unit. It comes with three cables: a battery temperature sensor, an IGN signal wire for the Smart alternator, and a RS485 communications cable to connect the monitor. The maximum power point tracking (MPPT) solar charge controller portion of the Renogy DC50s is compatible with the four major battery types: AGM, gel, lead-acid flooded, and lithium with it’s programmed parameters, so you’ll need to select the right one for your camper. The MPPT charger includes four stages of charging to protect your batteries: bulk, boost, float, and equalization, which is carried out automatically every 28 days. The unit’s design incorporates a number of heat sink fins that provide adequate ventilation. At $256, the Renogy DC50s is very affordable.

Renogy DC50s Installation

Renogy DC50s Combi Charger Wiring Diagram

Installing the Renogy DC50s was simple and only took a few hours. Surface mounting is accomplished by using four screws with the unit capable of being mounted in any position. The positive and negative connections are on opposite sides of the unit making the installation process easy and quick. Anyone with a basic DC electrical background can wire this unit up with no problem.

As called for in the instructions, in-line fuses on the positive wiring is required. I used a 50 amp fuse on the starting battery side and a 50 amp fuse between the charger and my camper batteries. The solar power system is protected with a 30 amp fuse as well. And speaking of wiring, don’t skimp on the size of the cabling connecting the alternator to the Renogy DC50s, the larger the cable the better. I used 4 AWG cable to connect the starter battery to the charger while 8 AWG wiring was used for solar. The Renogy DC50s is monitored using a Victron BMV 700 Smart Battery Monitor, which is connected using the included RS485 communications cable.

After getting everything connected, I turned on all the main electrical loads which consists of a Dometic CR110s DC refrigerator, all the ceiling lights, and the heater. At the time, only one BattleBorn 100 amp hour battery was being used to store the charge, and with all these loads and only the solar to do the charging of the battery, it never once dropped below 60 percent discharged. Of course, living in Southern California helps when it comes to solar.

Renogy DC50s showing the heat sink fins to facilitate cooling.

How it Works

The solar power system provides plenty of power to the solar charger during daylight hours and would have the battery fully recharged within a few hours. The DC to DC power input side of this charger works very well in managing the power input from the truck. Another feature I like is that the DC to DC charger acts as a battery isolator, insuring that my truck’s two diesel batteries will never be drained when connected to the camper. This is a very important function when using lithium ion batteries; otherwise, the lithium batteries in the camper will try and charge the starting batteries in the truck. In fact, I like the Renogy DC50s so much I decided to keep it after selling my Lance. It now serves an important function in charging my two lithium ion batteries in my brand new Bundutec BunduVry hard-side truck camper.

Final Thoughts on the Renogy DC50s

The Renogy DC50s Combi Charger has performed very well and has done everything that it supposed to do in keeping my lithium batteries charged. Being a combination unit, it saved me money since I needed only one charging device rather than two. The installation was easier as well. Of course, the Renogy DC50s is powerful too. When you think about it, the 50 amps it puts out is a lot of amperage, much higher than what you’ll typically find with today’s truck camper solar charge controllers like the popular Zamp ZS-30A. Indeed, having the Renogy DC50s in your camper increases the likelihood of your batteries arriving at close to a full charge when you arrive at camp. I highly recommend this unit and give it a rating of 5 stars.


  1. Hi sirisophie, the above article is my unit. The Renogy dc to dc MPPT unit has several presets for different batteries and the settings are fixed. I write here are for my lithium batteries in my camper. Victron BMV 700…. charge 14.4 Vdc….tail current 4.oo%….Peukert exponent 1.05.
    I did make a call to Battle Born Battery when setting up the Victron BMV 700 at Toll Free: 855-292-2831, they were very helpful.

  2. Hi! I am wondering if you could share the parameter settings you have set on your Victron BMV 700 with relation to the Renogy DC-DC charger/MPPT (i.e. charged voltage, tail current, all those important things…) I have the same Renogy charger/MPPT product but have had some issues nailing the Victron settings to get an accurate read on the battery. Thanks for any advice!

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