What’s the Difference Between Renogy’s Two NEW 40A DC to DC Battery Chargers?
Ever experience one of these two off-grid charging situations?
Your solar panels do a great job of keeping your off-grid house battery for your van, RV, or boat powered up while the sun is shining, but when the weather turns cloudy or you want to hide from the sun to keep things cooler during the summertime in the shade, charging back up is a challenge.
Your DC to DC battery charger takes good advantage of the power coming from your vehicle's engine to rapidly charge up the off-grid house battery for your van, RV, or boat, whenever the engine is running. But, when you're stationary, without solar or shore power, you are left without a good power source while boondocking.
Each device has its time to shine, but also has limitations that could leave you longing for greater flexibility. What if there was a device that handled both of these off-grid charging situations? There is……read on!
What's the Difference Between Renogy's Two NEW 40A DC to DC Battery Chargers
Many tow-behind RVs, motorhomes, and motorboats claim that the house batteries trickle charge (usually around 5A) isn't enough to do more than keep them topped off. If you're going from one shore power campsite to another shore power campsite, then this solution is adequate.
However, if you intend to live off-grid – even for a few days – then this trickle will not be enough to recharge a discharged house battery. A DC to DC charger acts as a pump to increase the charging power to effectively recharge your battery, but the difference between these two styles is significant and important to understand:
- 40A DC to DC Charger is designed to boost the charge from your starting battery or alternator, making it perfect for SUVs or RVs without solar panels. It's also an excellent addition for those with a solar charge controller, ensuring seamless, interference-free charging from both solar power and your vehicle's battery.
- 40A DC to DC Charger with MPPT can accept a charge from either the engine OR a solar panel array. This eliminates the need for a solar charge controller in your system as this unit does the job of both an MPPT solar charge controller (brain of the system) and DC to DC charger (boost from the engine). The new 12V 40A model allows you to choose one or the other with a simple press of a button.
Let's compare the standard 40A DC to DC Charger with the 40A DC to DC Battery Charger with MPPT:
Specifications |
40A DC to DC Battery Charger |
40A DC to DC Battery Charger with MPPT |
System Voltage |
12V |
12V |
Battery Type |
AGM, Gel, Flooded, Lithium Iron Phosphate |
AGM, Gel, Flooded, Lithium Iron Phosphate |
Charging Source |
Engine |
Engine, Solar |
MPPT |
No |
Yes |
Dimensions |
9.3 x 6 x 2.4 inches |
7.7 x 5.6 x 1.9 inches |
Weight |
4.4 lbs. |
2.6 lbs. |
Alternator Input Voltage |
Traditional Alternator (13.2 – 16 VDC) Smart Alternator (12 – 16 VDC) |
Traditional Alternator: 13.2-16.0 VDC Smart Alternator (Euro 6): 12-16.0 VDC |
Output Current |
40A |
40A |
Output Power |
584W |
616W |
Operating Temperature |
-4℉ -122℉ /-25 ℃ - 60℃ |
-4℉ -113℉ /-20 ℃ - 45℃ |
Communication Method |
RS485 Cable |
Does not offer communication |
Charging Efficiency |
94% |
≥93% |
Simply put, the DC-DC Battery Charger with MPPT combines the best of both off-grid charging methods into one device, expanding your charging options while saving valuable space in your power cabinet. Solar charge controllers with MPPT (Maximum Power Point Tracking) are nearly 40% more efficient than older PWM (Pulse Width Modulation). The newest line of DC-DC Battery Chargers with MPPT come equipped with both of these advanced charging technologies, giving you optimal efficiency and flexibility in one compact solution!
Top Features of Renogy's NEW 40A DC to DC Battery Charger with MPPT:
- Dual Battery Charging Options – Solar or engine, but only one at a time, with engine source as the default mode. Select charging input with the press of a button.
- Enhanced Charging Safety – Standard features include reverse connection protection, overvoltage protection for your house battery, over discharging protection for your starter battery. Additionally, it includes BMS protection for Lithium Iron Phosphate (LiFePO4) batteries, along with over-temperature and charging timeout protection.
- Compact & Lightweight – At only 7.68” x 5.87” x 1.89” and 2.64 lbs, it saves valuable space/weight in your RV, SUV, van, or boat.
- Easy Installation & Operation – Labeled, and color-coded wires, makes installation simple and quick. Select the battery type with the press of a button, and real time indicator lights provide convenient updates on charging status.
- Certified Safety for Multiple Battery Types – Compatible with a multitude of alternator types, the Renogy 12V DC to DC Battery Charger with MPPT ensures optimal charging for AGM, Flooded, Gel, and LiFePO4 batteries. It is certified to meet FCC Part 15 Class B, CE, RoHS, and SAA standards.
How Does the 12V 40A DC to DC Battery Charger with MPPT Work?
This new version of DC to DC Battery Charger with MPPT has a dedicated switch to select the preferred charging source. This way, while driving, the DC to DC charger can take full advantage of the full 40A. The only downside is that you must remember to switch to solar when you stop driving and want to charge via your solar array.
When using the engine input with a standard alternator, charging begins when the starting battery voltage is greater than 13.2V. For a smart alternator, charging begins when the starting battery voltage is greater than 12V. Note: The engine charging mode will only work if the alternator is on, so there is no danger of draining the starting battery.
Using the solar charging mode, charging begins as soon as the input voltage is higher than 13V. Note: Remember to manually switch from the engine default mode in order to charge from solar power!
If you're considering installing solar to recharge your house battery on your van, RV, or boat, then it's important to increase your flexibility so that you are prepared for whatever the weather throws your way.Whether you're heading out in your off-grid RV or boat, adding a DC to DC Battery Charger with MPPT to your off-grid charging solutions is a great way to take advantage of the best charging situation now – and remember, it's like two charging devices in one small unit!
With the flip of a switch, you can keep your batteries charged using an engine source OR your solar array, all in one compact and efficient unit. Save some space, money, and headaches with the latest version of Renogy's 12V 40A DC to DC Battery Charger with MPPT.
Shari Galiardi & David Hutchison have turned their higher education backgrounds, desire for life-long learning, and thirst for adventure travel into writing, photography, video production, and public speaking tours from coast to coast. Known to their friends as simply Shari & Hutch, you can learn more about their full-time, solar powered adventures on their website at freedominacan.com. Or, follow them on Facebook, Instagram, and YouTube as "Freedom in a Can."Save an additional 10% off most products using our promo code CANLIFE - even on sale items!