The best dc to dc charger with mppt solar for campers. Feature image
Electrics

The Best DC To DC Charger With MPPT Solar For Campers 2023

Are you looking for the perfect DC to DC charger with MPPT solar charging capabilities for your campervan?

Look no further!

This post is all about the 4 best DC-DC chargers that include MPPT solar charging (DC-DC + Solar) for charging campervan leisure batteries.

With a multitude of options available, we’ve narrowed down the top 4 chargers that not only provide optimal performance but also offer compatibility and reliability for your campervan’s electrical system.

Also referred to as battery to battery and B2B battery chargers, they’re essential for keeping your campervan powered up and ready for adventure.

Portrait photograph of Jolly sipping a coffee

Trusted Review

Jolly (a self-confessed electrical geek with over 17 years of experience as a qualified electrical engineer) carried out the product comparison review.

Extensive research and honest user experiences have provided the information for this post.

Jolly’s focus now is campervan conversion electrics which started in 2019 with the birth of Vandercamp. Jolly is either building his own campervan or providing electrical help and guidance to others.

Disclaimer

The products reviewed do not sponsor this post. Therefore, the information in this article is our own honest opinion.

This post may contain Amazon affiliate links. Meaning, if you make a purchase after clicking one, we may earn some commission. This pocket money will help Vandercamp Adventures continue to grow at no extra cost to you. It’s a win win situation!! Learn More…

Our Pick For The Best DC To DC Charger With MPPT Solar 2023

Comparison Table

NameInput VoltageCharge Current (Amps)Maximum Solar Voc*Maximum Cable SizeOperating Temperature (°C)WarrantyEfficiencySmart Alternator CompatibleWeightSize (mm)PriceView
Renogy DCC30SRenogy DCC30S DC to DC charger with MPPT Solar8-16v30A25vNo limit-35 > +602 Years97%Ignition wiring required1.42kg244x145x77£View Renogy Product
Renogy DCC50SRenogy DCC50S DC to DC charger with MPPT Solar8-16v50A25vNo limit-35 > +602 Years97%Ignition wiring required1.42kg244x146x77£View Renogy Product
Redarc BCDC 1225DRedarc BCDC1225D 25A DC DC Charger MPPT Solar Controller9-32v2532vNo limit-10 > +802 YearsUnknownIgnition wiring required1kg165x120x37£££View Redarc Product
Redarc BCDC 1240DRedarc BCDC1240D 40A DC DC Charger MPPT Solar Controller9-32V4032vNo Limit-10 > +802 YearsUnknownIgnition wiring required1kg165x120x37
££££View Redarc Product
CTEK D250 SECTEK D250SE DC to DC battery charger11.5-23v20A23vNo limit-20 > +502 YearsUnknownIgnition wiring required0.7kg192x110x65££View Ctek Product
Sterling BBS1230Sterling BBS1230 battery to battery solar charger12v30A31v16mmUnknown2 years87%Yes1.4kg198x164x71££View Sterling Product

Table Definitions

Input Voltage – The voltage accepted from the alternator/starter battery. All DC to DC chargers here are compatible with 12v inputs.

Output Charge Current – The current (amps) supplied to the leisure battery under charge conditions.

Maximum Solar Voc – The open circuit voltage (Voc) is the maximum voltage that the solar panel can produce with no load on it.

Maximum Cable CSA – The maximum size of cable the charger terminations can accept.

Warranty – Manufacturer warranty. See the charger details below for their warranty details.

Efficiency – Energy efficiency of the output charge as a percentage. All electrical devices have energy wastage, usually in the form of heat. The higher the percentage the more efficient.

Smart Alternator Compatible – The charger either has built in voltage sensing software or requires an ignition circuit.

Weight – Overall weight of the unboxed charger

Size – Overall size of the DC-DC charger (See product manuals for their detailed measurements)

Cost – From £ (cheapest) to ££££ (most expensive). See product for the current price.

The Benefits Of DC to DC + Solar Chargers

  • Combination of two charging methods in a single unit, saving space and weight
  • More cost-effective than purchasing separate DC to DC charger and solar converter
  • Charges your leisure battery to 100% unlike voltage sensing relays (VSR), ensuring battery health
  • Compatible with smart alternators, unlike VSR’s
  • Suitable for charging all types of campervan leisure batteries (lead-acid, AGM, GEL, calcium, and lithium-ion) and capacities
  • Highly efficient charging method, with alternator and solar charging working together to charge the battery efficiently
  • Ideal for small electrical systems

The Downsides To DC to DC + Solar Chargers

Who Are The 4 Best DC-DC + Solar Chargers Suited To?

Renogy – Low budgets, novice installers, any size electrical system.

REDARC – High budgets, weight/space conscious, extreme conditions.

Ctek – weight-conscious, small electrical systems, lead-acid batteries.

Sterling – Electrical experience/engineer, custom battery setups, smart alternators.

The 4 Best DC to DC Charger With MPPT Solar

When it comes to finding the best DC to DC charger with MPPT solar for your campervan, there are several factors to consider. With a multitude of options available, we’ve narrowed down the top 4 DC-DC chargers that not only provide optimal performance but also offer compatibility and reliability for your campervan’s electrical system.

These DC-DC chargers are compatible with all battery types, including Lead-acid, GEL, AGM, calcium, and Lith-ion, as well as 12V systems. Additionally, they are designed to work seamlessly with smart alternators, ensuring a smooth charging experience.

Safety and efficiency are crucial, and these chargers excel in both areas by isolating the starter and leisure batteries when no charge is present, preventing the starter battery from discharging. They also maintain a steady output current, regardless of input voltage fluctuations, ensuring a consistent and efficient charging process.

Moreover, all four chargers come with a 2-year manufacturer warranty, giving you peace of mind knowing that your investment is protected.

Renogy DC-DC Charger With MPPT

Why it made the list: Low budget, Simple installation and setup, highly efficient

Renogy DCC30S & DCC50S

Renogy DCC50S DC to DC charger with MPPT Solar
Renogy DCC50S DC to DC charger with MPPT Solar

The Renogy DCC30S & DCC50S DC to DC charger with MPPT solar is the most efficient in this selection, with a solar efficiency of 99% and DC-DC efficiency of 97%. It offers multiple intelligent protections, including battery isolation and over-voltage protection. This charger features 3-way charging and is compatible with smart alternators, although ignition wiring may be more complicated for novices.

It provides trickle charging for the starter battery when the leisure battery is fully charged and has a soft-start design to protect the alternator. The Renogy charger prioritises solar power over the alternator to prolong the alternator’s life and reduce fuel consumption.

The maximum charge current is split 50/50 between solar and alternator, with the alternator able to use 100% of the capacity if the solar input is turned off. The charger is compatible with Renogy’s DC Home app, monitoring screen, and Renogy One.

Features

Input VoltageCharge Current (Amps)Maximum Solar Voc*Maximum Cable SizeEfficiencySmart Alternator CompatibleWeightSize
9-16v30A/50A25vNo limit97%Ignition wiring required1.42kg244x146x77

*Voc = Open Circuit Voltage

Go To Comparison Table

Pros

  • Solar priority charging will prolong the life of the alternator and reduce fuel consumption for traditional alternators.
  • Trickle charge your starter battery when the leisure battery is full.
  • Cheapest charger here.
  • Simple installation and setup.
  • Multiple monitoring options (DC home app, Monitor screen, Renogy one)
  • Lowest operating temperature

Cons

  • Solar and alternator charging is 50/50 split of the output current.
  • Maximum solar charging is 50% of charger capacity.
  • Ignition wiring required for smart alternators.
  • Heaviest of the 4 chargers here.

Renogy DCC30S & DCC50S Manual

Download here.

Warranty

2 Year material and workmanship

REDARC DC-DC Charger With Solar Input

Why it made the list: Lightweight, withstands extreme conditions, alternator safe feature

REDARC BDDC1225D & BCDC1240D

Redarc BCDC1240D 40A DC DC Charger MPPT Solar Controller
Redarc BCDC1240D 40A DC To DC Charger With MPPT Solar

Built for the Australian outback, the REDARC charger is designed for extreme conditions, featuring a fully sealed, water and dustproof design, and a high operating temperature of 80°C. Weighing just 1kg, this slim charger is compatible with 12V and 24V alternators, prioritising solar power for energy efficiency and longer alternator life.

The 600W MPPT charger efficiently shares output current between solar and alternator sources. The front panel displays the essential information, but without a means of wireless monitoring, the panel needs to be accessible. Customers pride REDARC for their excellent tech support. The charger operates quietly without a fan and is protected against water and dust.

However, it is the most expensive option and requires ignition wiring for smart alternators. The battery cable connections can be challenging, posing safety risks if done incorrectly. Despite these drawbacks, the REDARC charger remains a top choice for high-quality DC to DC solar battery charging in campervans.

Features

Input VoltageCharge Current (Amps)Maximum Solar Voc*Maximum Cable SizeEfficiencySmart Alternator CompatibleWeightSize (mm)
9-32v25A/40A32vNo limitUnknownIgnition wiring required1kg165x120x37

*Voc = Open Circuit Voltage

Go To Comparison Table

Pros

  • High operating temperature of 80degC
  • No fan for quiet operation
  • Fully sealed – water and dust proof
  • Slim and lightweight
  • 24v alternator compatible
  • Alternator safe feature

Cons

  • Most expensive charger here
  • Ignition wiring required for smart alternators
  • Wiring required to set output voltage (Orange wire configuration)

REDARC BCDC1225D & BCDC1240D Manual

Download manual.

PRODUCT Warranty

Defects in materials and workmanship affecting normal use for 2 years.

CTEK DC-DC Charger With Solar Input

Why it made the list: 5-stage battery charging, lightweight, splashproof and dustproof

CTEK D250SE

CTEK D250SE DC to DC battery charger
CTEK D250SE DC To DC Charger With MPPT Solar

The CTEK D250SE is a compact and lightweight DC to DC solar battery charger ideal for campervan enthusiasts seeking efficiency and reliability. Its 5-stage charging ensures optimal battery performance and longevity, while the IP65 rating provides splashproof, dustproof protection and suitability for external installation. Prioritising solar power, the charger maximises solar energy before using the alternator and can trickle charge the starter battery when needed.

However, the 20A output current may be low for some, requiring the CTEK SmartPass 120S for leisure battery capacities over 110Ah. The SmartPass 120S can be combined with the D250SE to increase output current up to 140A. Weighing just 0.7kg, it’s the lightest among our top choices and features silent, fanless operation. Unfortunate, ignition wiring is needed for smart alternators.

The CTEK D250SE offers an efficient, lightweight charging solution with 5-stage charging, solar power prioritisation, and IP65 durability, making it a reliable choice for campervan charging requirements.

Features

Input VoltageCharge Current (Amps)Maximum Solar Voc*Maximum Cable SizeEfficiencySmart Alternator CompatibleWeightSize
11.5-23v20A23vNo limitUnknownIgnition wiring required0.7kg192x110x65

*Voc = Open Circuit Voltage

Go To Comparison Table

Pros

  • 5-stage battery charging
  • IP65 rated so can be externally mounted.
  • Charges starter battery if leisure battery full.
  • Combine with SmartPass 120S to increase output charger current to 140A
  • Lightweight. Half the weight of Renogy or Sterling

Cons

  • Low 20A output current. SmartPass 120S required for battery capacity over 110Ah
  • Expensive for only 20A output current.
  • Ignition wiring required for smart alternators.

CTEK D250SE Manual

Download manual

PRODUCT Warranty

The 2 year warranty applies to manufacturing faults and material defects.

Additional Information

The SmartPass 120S can be combined with the D250SE to increase the output current up to 140A.

Sterling DC-DC Solar Charger

Why it made the list: Smart alternator compatible, regenerative braking technology, custom battery settings

Sterling BBS1230

Sterling BBS1230 battery to battery solar charger
Sterling BBS1230 DC-DC solar charger

The Sterling BBS1230 DC to DC charger with MPPT solar is a compact and advanced solution for campervan enthusiasts. Compatible with up to 350W of solar power and a maximum Voc of 31V, this 1.4kg charger is designed for optimal performance. It features alternator priority while driving, built-in voltage sensing software for traditional and smart alternators, regenerative braking technology, 4-stage battery charging, and custom battery type settings.

With a night quiet run setting, fan noise is reduced by 50%. The charger also offers temperature compensating charging using a temp sensor. However, drawbacks include a noisy fan without night mode, a complicated installation process, a complex front display, a limited maximum cable size of 16mm, no auto battery selection, and no starter battery trickle charge.

Despite these drawbacks, the Sterling BBS1230 remains a versatile and effective choice for those seeking an advanced DC to DC solar battery charger for their campervan adventures.

Features

Input VoltageCharge Current (Amps)Maximum Solar Voc*Maximum Cable SizeEfficiencySmart Alternator CompatibleWeightSize
12v30A31v16mm87%Yes1.4kg198x164x71

*Voc = Open Circuit Voltage

Go To Comparison Table

Pros

  • No ignition wiring required for traditional and smart alternators
  • 4-stage battery charging
  • Regenerative braking technology (smart alternators)
  • Custom battery type settings
  • Optional remote control shows voltage and charge stage

Cons

  • Noisy fan when not using night mode
  • Installation and user manual complicated for novices
  • Complicated front display
  • Maximum cable size 16mm
  • No auto battery selection
  • Does not trickle charge the starter battery

Sterling BBS1230 Manual

Download manual.

PRODUCT Warranty

2 years – Each product is guaranteed against defects in material or workmanship from the date of purchase.

What to look for when choosing a DC to DC MPPT charger: Key Factors and Features

Selecting the right DC to DC solar charger for your campervan is essential for maintaining optimal battery performance and health. Here are the crucial factors to consider when choosing a charger:

Input Voltage

Input voltage is a crucial factor to consider when selecting a DC-DC mppt charger for your campervan, as it refers to the supply voltage provided to the charger from the alternator or starter battery.

The majority of campervans come equipped with 12-volt alternators and starter batteries, which is the standard voltage for these components. However, it’s important to note that some campervans may feature 24-volt alternators and starter batteries instead.

Before making a decision on which DC to DC charger with MPPT solar to purchase, it’s essential to determine the voltage of your campervan’s alternator and starter battery. Testing the voltage will ensure that you choose a charger that is compatible with your campervan’s electrical system, providing optimal performance and safeguarding against potential issues.

Output Charge Current

Output charge current is the key factor that determines how quickly your leisure battery will charge. It is the current delivered by the DC-DC charger to your leisure battery, ensuring your campervan has the necessary power for all your adventures. Each DC-DC battery charger comes with an amp rating, which represents its charge current capabilities.

While a higher charge current can result in a faster charging process for your leisure battery, it’s essential to understand that selecting the highest charge current isn’t always the most practical option. Batteries have a maximum charge current specified in their technical documentation, which must not be exceeded in order to prevent damage and ensure optimal performance.

A chart showing the maximum continuous charge current for the Renogy 200 amp hour lithium battery
Example of The Renogy 200Ah Lithium Battery Maximum Charge Current

Additionally, higher currents charge faster but require larger cables and fuses, increasing costs and installation complexity. Additionally, leisure batteries have maximum rated charge currents specified in their documentation. Exceeding these limits can damage the battery. As a general guideline:

  • Sealed Lead-Acid: Max charge current = 30% of total capacity (e.g. 100Ah battery = max 30A charge current)
  • AGM: Max charge current = 30% of total capacity (e.g. 100Ah battery = max 30A charge current)
  • GEL: Max charge current = 50% of total capacity (e.g. 100Ah battery = max 50A charge current)
  • Lithium: Max charge current = 50% of total capacity (e.g. 100Ah battery = max 50A charge current)

The ideal charge current for your campervan will depend on the capacity of your leisure battery. Smaller capacity batteries typically require a lower charge current, while larger capacity batteries or setups with multiple battery banks necessitate a higher charge current.

Solar Input Voltage (Voc)

Solar input voltage, also known as the open circuit voltage (Voc), is an essential factor to consider when choosing a DC-DC mppt charger for your campervan. The open circuit voltage refers to the maximum voltage produced by a solar panel when its positive and negative terminals are not connected to any load. This voltage can be found on the solar panel’s data sheet, specifications, or the sticker located on the panel’s underside.

100 watt Renogy solar panel
100 Watt Renogy Solar Panel
Renogy 100 watt solar panel electrical data with open circuit voltage highlighted
Solar Panel Data Sheet

For instance, the Renogy 12V 100W solar panel has a Voc of 24.3V. These solar panels are compatible with the Renogy, Redarc and Sterling DC-DC solar chargers. However, the Ctek charger has a maximum Voc of 23 volts, so wouldn’t be compatible.

It’s important to note that the Voc can change depending on the configuration of your solar panels. When connecting multiple panels in parallel, the voltage remains the same while the current increases.

For example, two Renogy 100W panels connected in parallel have a combined Voc of 24.3V. On the other hand, when connecting panels in series, the voltage increases while the current stays the same. In this case, two Renogy 100W panels connected in series would have a combined Voc of 48.6V.

DC-DC solar chargers typically have a maximum solar input voltage compared to dedicated solar charge controllers. As a result, you might need to opt for a parallel solar panel array to ensure compatibility with your chosen charger.

By understanding the solar input voltage requirements and selecting the right panel configuration, you can maximise the efficiency of your campervan’s solar charging system.

Further Reading | Solar panels: Series vs Parallel

Alternator Output Amps

The alternator is a vital component in your campervan’s electrical system, generating voltage and current when the engine is running. When selecting a DC to DC charger for your vehicle, it’s essential to be aware of your alternator’s amp rating to avoid overloading and potential damage.

Overloading the alternator by choosing an unsuitable charger can lead to a burnt-out alternator, which can be costly to replace and highly inconvenient on your adventures..

It’s important to note that the input current of DC-DC chargers can be up to 50% higher than their rated output current during startup. This additional load on the alternator should be factored into your calculations when selecting a charger.

To prolong the life of your alternator and ensure efficient charging, we recommend choosing a DC-DC battery charger that does not exceed 50% of your alternator’s rated amps.

For example, our alternator is rated at 110 amps so wouldn’t exceed 55 amps (50%) charge current from a DC-DC charger. We have a Renogy 40A DC To DC battery charger that is less than 50% of the alternators capacity.

Product Documentation

Renogy DC-DC solar charger: Manual, Specification

REDARC DC-DC solar charger: Manual, Specification

CTEK DC-DC solar charger: Manual

Sterling DC-DC solar charger: Manual, Regenerative braking

Recap

When it comes to choosing a DC to DC charger with MPPT solar for your campervan, factors such as input voltage, output charge current, solar input voltage, and battery type compatibility are essential.

The Redarc BCDC1225D, Sterling BBS1230, CTEK D250SE, and Renogy DCC50S are all excellent choices, providing a combination of reliability, efficiency, and compatibility with various battery types and capacities.

By selecting the right DC-DC charger for your needs, you’ll be well on your way to enjoying a reliable power supply for your campervan adventures.

Further Reading | Discover 4 Other Ways Of Charging Your Leisure Battery Efficiently

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