If you are looking for the best DC to DC charger money can buy, Enderdrives ePOWER EN3DC40 12v/40a DC to DC Battery Charger is our top pick. This Enerdrive ePOWER 40a/12v EN3DC40 DC to DC charger truly stands out from its competitors. Engineered to perfection and manufactured to the highest possible quality, it's easy to see why Enerdrive is quickly overtaking the market. The Enerdrive ePOWER 40a/12v EN3DC40 DC to DC charger is a fully automatic multistage, multi-input battery charger that has the capacity to charge from solar power using the integrated Maximum Power Point Tracking (MPPT) Solar Controller or from an alternator connected to a battery. The main/house battery can be charged from any of the two accessible inputs: the engine when moving, or the solar panels.  Both functions are managed internally by the device itself without the use of external relays, making it completely automatic to select between the engine or the solar power.

With the option to select GEL, AGM, Flooded, Custom Programmable, or Lithium, this dc to dc charger will perform a full charge cycle to float stage on the home battery bank during regular operation. When float stage is reached the dc to dc charger switches to a power supply mode to handle any on-board DC loads.

Dc to Dc chargers Multiple-Stage Charging Method: 

The fully automatic, set-and-forget ePOWER EN3DC40 Enerdrive dc to dc charger is made to properly and quickly recharge your specialised deep cycle batteries using charger algorithms that extend the life of your batteries.

The multistage smart charging mechanism in the ePOWER dc to dc charger enables the charger to be permanently linked to your battery bank. You can be confident that your batteries will be charged while you are moving and when the sun is shining on your solar set up thanks to the input from different sources in this dc to dc charger. Deep cycle batteries require a multistage charge sequence in accordance with the instructions provided by the battery manufacturer for flawless, quick, and precise charging. Three primary charge stages are provided by the Enerdrive ePOWER EN3DC40 40a/12v dc to dc charger.

Stage 1: Bulk or boost charging; the battery is charged at the charger's maximum rated output current until it reaches the absorption voltage, which is the battery's final charging voltage. Around 80% of the battery is restored as quickly as the dc to dc charger can in this process.

Stage 2: Absorption Charge: The remaining 20% is replenished while the charger voltage is kept constant, and as the battery gets closer to full charge, the dc to dc charger allows the current to taper down.

Stage 3: Float. The dc to dc charger voltage is decreased and maintained at a steady, safe level throughout this stage. By doing this, the battery is kept from being overcharged while yet allowing the charger to deliver enough current to compensate for the battery's self-discharge losses and support any additional loads attached to the battery (such as DC lighting and refrigerators). This phase enables the dc to dc charger to function as a DC power source.

Adaptive Charging Function:

The loads connected to your battery bank will cause the ePOWER dc to dc charger to adjust its output. Since some dc to dc battery chargers misinterpret loads for discharge and hold the batteries in the bulk or absorption stage for protracted periods of time, damaging the battery bank, this function is crucial to preserving the life of your battery bank. To make sure that your dc to dc charger transitions to float when it should, the ePOWER dc to dc charger offers two ways of load-based regulation, making it one of the most advanced battery chargers available.

Features:

• Two totally independent DC Inputs for both engine and solar regulation charging one house battery bank output
• DC M6 screw terminals that will allow for large battery cable connection between all sources
• A dedicated Maximum Power Point (MPPT) solar regulator
• The same battery algorithms as included in our AC mains ePOWER battery charger. GEL, AGM, Flooded, Lithium and the ability to create  a full custom profile
• Vehicle input allows for either 12 or 24v and a maximum solar input of 45V/800W
• 40A+ output up to 40+°C with thermo controlled fan cooling
• Fully programmable LCD display to show which source is charging the battery along with charger status, voltage and amperage
• Temperature sensor included with charger for more accurate battery charging

Maximising your Solar Harvest using the DC2DC+

The Solar Input on the DC2DC+ unit has a maximum rated INPUT current of 30amps. This means it is optimised for using higher voltage ‘grid’ type modules for best output performance. The maximum achievable output using standard 20Voc solar modules will be approx 35amps @ 14.4Vdc

* Maximum achievable output on the DC2DC+ unit when using 20Voc Solar Panels will be the approx 35amps. ** Maximum achievable output on the DC2DC+ unit when using 43Voc Solar Panels will be the approx 47amps.