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Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp

Our Price: $439.00
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Battery Charger
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331-BCDC1225D - Solar Panels to Auxiliary Battery,Vehicle Battery to Auxiliary Battery Redarc Battery Charger
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Maintain the charge on your RV's battery with this dual-input, DC-to-DC smart charger. Unit installs in your vehicle or trailer and pulls power from your solar panels before tapping into the vehicle battery. Great for boondocking and dry camping. 1-800-940-8924 to order Redarc battery charger part number 331-BCDC1225D or order online at Free expert support on all Redarc products. Great prices and Fastest Shipping for Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp. Battery Charger reviews from real customers.
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  • Reviews (84)
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Redarc Battery Charger

  • RV/Camper
  • Trailer
  • Battery Charger
  • 12V
  • Redarc
  • Solar Panels to Auxiliary Battery
  • Vehicle Battery to Auxiliary Battery
  • 75 Ah
  • 200 Ah
  • Charges/Maintains

Maintain the charge on your RV's battery with this dual-input, DC-to-DC smart charger. Unit installs in your vehicle or trailer and pulls power from your solar panels before tapping into the vehicle battery. Great for boondocking and dry camping.


  • DC-to-DC battery charger draws power from your vehicle to provide power to an auxiliary battery on your trailer or RV
    • Ideal for battery banks rated between 75 and 200 amp-hours
  • Dual-input device can pull power from 2 sources
    • Connect yellow wire to solar panels (sold separately)
    • Connect red wire to 12V or 24V start battery
  • Multi-stage charging algorithm ensures a complete charge on secondary battery without overcharging
    • Boost stage - provides a constant charge while monitoring auxiliary battery voltage
    • Absorption stage - keeps voltage stable to avoid overcharging while bringing battery up to 100-percent charge
    • Float stage - maintains charge on auxiliary battery
  • Solar power capable - solar panels sold separately
    • Charger automatically draws power from panels before tapping into vehicle battery
    • Built-in MPPT regulator ensures most efficient power transfer possible in all conditions
  • Fully sealed construction with fan-free operation ensures durable performance under harsh conditions
    • Tested to ensure operation in temperatures as high as 176 F
    • Protects sensitive electronics from water, dust, and shock
  • Fault recognition technology prevents damage to batteries from voltage spikes, overheating, and reverse polarity connection
  • Battery isolator function prevents charger from pulling power from start battery when vehicle is off
  • Multiple mounting options for convenient installation
    • Secure the unit in the cabin of the vehicle, along a chassis frame rail, in the engine compartment, or on your trailer
    • Cables, fuses (331-FK40 - sold separately), and connectors sold separately
  • Made in Australia


  • Application: 12V or 24V vehicle systems with standard or smart alternators
    • Battery types supported: AGM, gel, standard lead acid, calcium, and Lithium ion (LiFePO4) batteries
  • Overall dimensions: 4-3/4" long x 4" wide x 1-1/2" tall
  • Battery capacity range: 75 amp-hours - 200 amp-hours
  • Maximum charging voltage: 15.3V
  • Output voltage: 12V DC
  • Output power: 375 watts
  • Output current rating (continuous): 25 amps
  • Input current (maximum): 25 amps
  • 2-Year warranty

The Redarc BCDC dual-input battery charger allows for easy charging of a DC battery while you're on the move. Most battery chargers require that you plug into an AC outlet, but this DC-to-DC charger pulls power from your vehicle's start battery instead. The BCDC also has solar power capability so that you can keep your secondary battery charged while you're parked at a remote campsite. This means that you can go off the grid without worrying about being without power.

This charger connects directly to your battery, rather than pulling power from your vehicle via the trailer connector. This is to ensure that it's able to fully charge your auxiliary battery. A standard 7-way trailer connector is limited to 10 or 15 amps of current, which will not be able to fully restore a battery for use. But this charger can transfer up to 25 amps of current to both charge and maintain your auxiliary battery.

Solar Power Compatible with MPPT Regulator

This charger can pull power from 2 different sources. The first input accepts charge from your vehicle's battery. The second input on this dual-input unit is designed to receive power from solar panels (sold separately). The built-in maximum power point tracking (MPPT) regulator on this unit ensures that the charger will get the most power possible from your panels at any given time. An MPPT regulator is able to determine the point at which your solar panels reach their maximum output. Then the regulator can simulate that load on the panels to effectively draw the most power possible. This type of regulator is more effective than traditional ones at gathering power from solar panels and at drawing power in low-light conditions.

Built-in Green Power Priority, or primary solar selection, ensures that power is pulled from your solar panels first. The BCDC will only tap into your vehicle's battery when necessary. This will save your vehicle battery from unneeded stress. It also has a built-in battery isolator function to prevent the charger from pulling power from the start battery when the vehicle is off.

3-Stage Smart Charger

REDARC BCDC Battery Charger LED Indicators

The BCDC battery charger can be used to charge AGM, gel, standard lead acid, calcium, and Lithium ion (LiFePO4) batteries. An LED on the front panel of the unit will illuminate to show the charge profile, confirming that you've wired the charger correctly based on your auxiliary battery type. This LED will be solid while the unit is charging, and it will flash when the unit is in standby mode. Additional LEDs on this panel indicate where the charger is pulling power from, and what stage of the charging process the unit is in.

This smart charger completely and efficiently charges your auxiliary battery in 3 separate stages. This ensures that the battery reaches maximum capacity without being overcharged.

The first stage of the process, the boost stage, begins when you start up your vehicle. In this mode the charger will maintain a constant current to the auxiliary battery to quickly help it regain power.

Once the unit detects that your auxiliary battery is nearing its maximum charge, the charger will move into the absorption stage. In this stage it will slowly supply the needed current to safely reach 100-percent capacity on the auxiliary battery.

The final stage is known as the float stage. In this stage the unit monitors your auxiliary battery for drops in power and supplies the needed current to keep it fully charged. If a drop in power is detected, it will revert back to the first stage and begin the charging cycle over.

Compatible with Smart Alternators

A number of newer vehicles on the market have ECU-controlled, variable-voltage alternators designed to reduce emissions and boost performance. This type of alternator varies its voltage based on the driving conditions. When the alternator voltage is low, the system can drop below 12.7V, which would deactivate a standard isolator or battery charger. However, with the Redarc BCDC battery charger, this is not an issue. Simply connect the blue override wire to the vehicle ignition and the charger will recognize that the car battery is still receiving a charge from the alternator, even if the voltage has dropped. The charger will modify its voltage requirements so that it can continue to pull power until the start battery drops to 12V, as opposed to the standard 13.2V.

Versatile Mounting

This unit can be mounted in a variety of places to best suit your application. Use the 4 mounting tabs to secure the unit in the cabin of your vehicle, along a chassis frame rail, in the engine compartment, or on your trailer. The charger should be mounted as close as possible to the auxiliary battery being charged to prevent current loss. The farther the current has to travel, the more amperage is lost. A larger diameter wire will allow more current to flow through it, which can offset the current loss that occurs with longer lengths of wire. As a result, it is recommended that you use a heavier gauge wire to cover longer distances. The table below outlines the recommended wire size for a given length of cable:

Redarc BCDC Dual Battery Charger Wiring Guide

To ensure a low-resistance connection, you will want to use MIDI fuses (331-FK40 - sold separately) when connecting the BCDC to your batteries.

For a typical lead acid battery setup, refer to the wiring diagram (shown with fuses and optional LED and solar panel - sold separately) below:

Redarc BCDC Dual Battery Charger Standard Lead Battery Wiring Diagram

For a typical Lithium ion (LiFePO4) battery setup, refer to the wiring diagram (shown with fuses and optional LED and solar panel - sold separately) below:

Redarc BCDC Dual Battery Charger Lithium Battery Wiring Diagram

BCDC1225D REDARC In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp

Item # 331-BCDC1225D

Installation Details 331-BCDC1225D Installation instructions

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp - 331-BCDC1225D

Average Customer Rating:  4.8 out of 5 stars   (84 Customer Reviews)

Maintain the charge on your RV's battery with this dual-input, DC-to-DC smart charger. Unit installs in your vehicle or trailer and pulls power from your solar panels before tapping into the vehicle battery. Great for boondocking and dry camping.


This unit has worked fine for me. Once wired up I can pretty much forget about it and know that it's charging my house battery whenever I start my vehicle. Probably more important is the automatic disconnection it makes from my starting battery & vehicles charging system when I shut down the vehicle. As well the convenience of adding a solar panel to the system to charge the house battery while the unit still AUTOMATICALLY chooses the best option to charge and disconnects anytime I shut down the vehicle. There are a LOT of different devices/ electronics to accomplish this but the Redarc seems to combine many features/connections in one convenient unit. I have not had the solar portion hooked up yet BUT my understanding is that when I get ready to do so I will NOT need to order a separate MPPT charge controller as that is a built in feature of the unit. These units are a bit pricy for up front cost but seems to provide a lot of features all in one compact unit with a fairly simple wire connection to get it up and charging.

A year later and Redarc is still working flawlessly! BatteryLifeline brand seems to be maintained in a strong state of charge. So far this seems to be a high quality and proven unit to do what its advertised to do. And if you have any questions, the guys Down Under in Australia are right on the line to happily help you. Thanks Mates for a great product. Goodayh Mate
Dusty - 04/23/2022


Thanks etrailer for bringing this product to the USA market. I found the REDARC chargt talked about on Australian “caravan” blogs before etrailer had it for sale and considered trying to buy it from an Australian vendor. I use the BCDC1225D to charge my 200 amp hour lithium battery in my truck camper. I have 350 watts of rooftop solar and ran 8gauge wiring from the truck battery through a bed mounted Andersen connector. The very compact size of the unit allowed me to tuck it away in a small space in my camper. I wired it up just as suggested in the instructions and it worked perfectly. I’m getting the full 25 amp charge that the solar panels will provide at midday and get the added benefit of being able to charge at the same rate while driving in the dark. The thing works great. Thanks again etrailer for bringing this product to the USA market

I’m still loving my Redarc. Five Stars!
Chris J - 08/01/2020


I highly recommend it. Adding a dual battery setup and using the Redarc BCDC1225D to charge it was the best addition to my rig. Very simple to install and customer service is Tier 1.


The charger works great. Here is a picture of the system I built for it. The battery is a Battle Born 100 amp hour LiFePo, it’s also charged by (2) 100 watt flexible solar panels. It has (2)- 12 volt receptacles, (2)-dual USB receptacles, and a 750 watt modified sine wave inverter. It runs a small refrigerator, led lights, and various other electronic devices flawlessly. I’m very satisfied with the Redarc unit.


"Great piece of kit!" Seriously well worth the beans. The REDARC allows me to charge my trailer battery while towing. The trailer's converter supplies 13.6 VDC, which is not sufficient to charge my on board battery. The REDARC brings this DC voltage up to approximately 14.7 VDC. So my Truck charging system provides the trailer battery while travelling, and the on board trailer converter,(while AC CONNECTED at the site), sends DC voltage to the REDARC via the Solar Panel Input side of the unit, as I do not have a solar panel. I called Australian support number, and asked if this was an acceptable means of connection. They were most helpful and knowledgeable.

Two camping seasons and ZERO SNAGS with the REDARC BCDC unit! Real nice
Chas. B - 05/02/2021


The right product for new Ranger with a Four Wheel Camper.Install was easy, compact , maintains two deep cycle agm batteries and monitors 100 amp solar for a complete package. Was able replace my 3 way fridge with a 2 way for better service.


Works well, good hardware solution for second battery charging- only wish it could use the second bat as a jumper for primary- solar charge is a nice feature.


I am looking forward to installing this product. My research showed that this is the optimal DC to DC charger for our needs. I don't know if we will make use of the dual input option but I specifically ordered this model in case we decide to add a solar panel in the future.

This unit will be installed in our small vintage Aladdin travel trailer for use during dry-camping trips so that the accessory battery will be charged between campsites where we will have shorter stays and travel frequently between camps.


This redarc unit us excellent. I use it in my fire transit to charge a 100ah lithium battery. I’m not currently using solar so this is b2b charging only but it works great. Voltage sensing turns the unit on and off quickly, the low profile form factor makes it convenient to install and it doesn’t seem to get particularly warm in operation. Couldn’t be happier.


Easy to install. Instructions that come with all Redarc products are straightforward. It's working great so far charging a 105 Ah battery that is running a fridge/freezer, some lights, and assorted other gadgets.


This works as advertised. I charge a battery in my truck camper with the solar input and from the truck alternator. You really need to run large gauge wires from the truck battery to the camper battery though.


I bought this to help manage an auxiliary battery I'm installing in my F150 to run CB and ham radios and other 12VDC gizmos. I bought the 25A unit because I wanted the solar MPPT controller for a small 130W foldup panel I keep in my truck for emergencies. The 12A Redarc unit doesn't have the MPPT controller. I also favored the Redarc unit over a similar Renogy unit because the Redarc unit is much smaller and seems designed to fit into much smaller space. Not knocking the Renogy unit. It just seems designed to fit into a cabinet or closet in an RV. As I won't be installing this for a few weeks, I'll give my initial impressions then update later if can. First, etrailer slapped the postal sticker on the original product packaging. It's bad enough with porch pirates stealing packages when they can't see what's inside. This was just advertising "please steal me". Second, the Redarc unit looks well constructed and designed. The power wires are larger than required for the amperage and are tin-plated for corrosion resistance. However, the three (3) signal wires (orange, blue, and greed) are bare copper. Yes, they aren't carrying current or aren't carrying much current, but they are still susceptible to corrosion, especially if you choose a frame or rail mount outside of the cabin. Third, I disagree with Redarc's suggestion to crimp then solder the power wires. No OEM car manufacturer in the world solders. Anything that vibrates like a car or airplane should only use crimp connections. Vibration will ultimately cause solder joints to fail. Crimping done correctly is gas tight and provides its own strain relief. Finally, I think you can add a switch to the blue wire to manually turn off the alternator input if you so desire. The details vary depending on the alternator type, and I need to experiment with the setup first before giving out wrong information. When/if I post an update, I will provide instructions for the switch.


Work great. Charges from the trailer plug and a 100 watt solar panel on the roof. Never have to charge the winch battery. No worries all winter when the trailer just sits. Would buy again.

Works great. Don’t have to worry about the trailer battery freezing during the winter.
Bob H - 01/19/2021


Works as advertised. It bumps the charging voltage from my Tacoma up to where I can get 20 amps charging current into the trailer battery even while the engine idles. The unit makes up for the voltage drop through the trailer 7 pin connector and about 35 feet of wire plus the ground circuit.. The integrated solar controller works as well as the separate controller the REDARC replaced. Installation could be easier, the REDARC unit has large wire pigtails that must be butt spliced. It would be easier if the unit used a clamp style terminal block.


Fantastic product.! I mounted it on the outside of my power supply box connected to the auxiliary battery on my camp trailer. It’s seen sun, rain, snow, mud and dirt, keeps my battery charged and handles all the switching between solar panel and alternator charging. Made in Australia which is the next best thing to made in the USA.


This thing is amazing and is the solution for anyone who wants to charge a battery more than a few feet from the alternator. I have a truck with a bed mounted battery which is about 22 feet of wiring from the main battery and it charges perfectly. My Dometic fridge in the bed has been running non stop for a year with one small solar panel a marine battery and this charger connected to the alternator and solar


Too easy. Does what it is deaigned to do.
to modify a Law Enforcement Vehicle with limited space.

Voltage and charge test Alesha’s proved “solid”.


I recieved the Redarc bcdc 1225d charger today. This will not be installed for awhile but after looking the unit over, seems to be of high quality. Small but somewhat heavy for the size l would think very good internal components. I chose this over others due to what appears as a better water proof unit. Also the wiring is heavier. Im hoping this unit will last yrs in my setup. I gave 4 stars due to non install yet and packaging.


I have used this in my custom camper for one year. It is connected to a Size D gel cell enology battery that drives an inverter to power fridge, micorwave, tv and lights. I have never had an issue with vehicle battery or the gel cell even when used overnight. Works as advertised.


I ordered the BCDC1225 on Friday and received it on Monday, before noon ... how great is that! Everything appears to be in order. I'm looking forward to getting this charger hooked up to run the fans in the trailer that I carry my dogs in (it's a specially designed trailer which remains cool, but moving air keeps them even more comfortable). Notably, the help that I've received even BEFORE ORDERING has been outstanding. I will turn to for all future trailer-related needs.
(Once installed, I'll post a performance review.)


After one year of working with the charger, it performed perfectly with solar or managing the duel battery set up. A no brainer charger.


The product works great - I currently use it in the back of my truck to charge a 100 AH LI battery. My next step is to use the solar charging feature and see how it works swapping back and forth between truck / solar recharge.


I haven't installed yet, but have heard good things about the product. I have a 4x4 that sits at the airport for 6 months, currently being charged by a 170 w solar panel, feeding both battery's, so the redark will provide charging to the second battery when the car is run. With fridge load, solar not enough.


What a difference this makes. Installing this means I have a fully charged battery when I get to camp


Good quality. Is holding up after a year of use. My trailer stays in the garage most of the time, so this only gets used when I am out camping or leaving it in the drive way on occasion.

Show More Reviews

See what our Experts say about this Redarc Battery Charger

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    There are solar options for charging a 12V5AH breakaway battery. You could use the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D. This charger includes an input for connecting a solar panel without the need of a regulator. The attached photo shows how to connect a solar panel and how to connect the charger to the battery. The yellow input wire is for the solar panel. I've attached a video to help with the installation to make it easy.
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  • Mounting Locations For Redarc BCDC Battery Charger
    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D can be installed in several different places, depending on what you plan to use it on. It is designed to connect to an alternator, a solar panel, or both. If you plan on using it for a vehicle, you should install it in an area under the hood that has sufficient room, and free of moving parts on the vehicle like the fan or belts, etc. If it is to be used on a boat, or any other application, it should be mounted in a ventilated area....
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  • Can Redarc In-Vehicle BCDC Battery Charger be Used with 7-Way 12 Volt Circuit
    Yes you can use a # 331-BCDC1225D with the 12 volt accessory circuit of your 7-way for charging your trailer battery. The input current max for this is 25 amps which would be right around what a 7-way accessory circuit could provide.
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    To connect your solar panel to the Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp # 331-BCDC1225D you will simply connect the power output wire from the panel to the yellow wire on the BCDC you stated. The other wire of the solar panel will simply be the ground wire connection. You will connect that to the frame if your vehicle or trailer.
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  • Using the Redarc BCDC1225D Charger to Charge Two Different Batteries
    There is a way to use the Redarc # 331-BCDC1225D charger to individually charge both of your batteries in two locations. First, I would not connect dissimilar batteries together for use or charging. I would complete your truck/refrigerator install as normal except I would put Anderson quick connectors on the black and brown power output. In this way you could connect to either the 110Ah battery in the truck bed, or the 80Ah battery in the trailer. The attached product page has a wiring...
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  • How To Charge a Trailer Battery Used for Winch On a Car Trailer
    In order to charge the trailer battery via the vehicle battery/alternator you are going to need a bit more than just a voltage regulator because there needs to be a system in place that can sense when the vehicle battery is getting low so it can then stop the charge, prevent the trailer battery from being overcharged, and stop the charge when the vehicle is then turned off as the vehicle battery is no longer receiving a charge from the alternator. These features can be obtain with the Redarc...
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  • Best Way to Charge Trailer Battery From Tow Vehicle
    The 12V circuit from a tow vehicle's 7-Way connector does a nice job of providing a maintenance charge for the trailer battery but it's not going to send enough power to actually fully charge it. You have ruled out the tow vehicle as being an issue on your setup and you're fairly certain all the wiring is sound on the trailer. What you are experiencing is simply the limitations of this particular setup. The distance between the battery/alternator on the tow vehicle and the trailer's battery...
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  • How To Charge a Trailer Battery Without Killing the Tow Vehicle Battery
    I know this may be more than you are looking to spend but the 7-way circuit on your tow vehicle is not going to have all the functions are you looking for so your only option to obtain these would be with an actual battery charger, the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1225D . The BCDC uses power from the vehicle's alternator so you don't have to worry about it killing the tow vehicle's battery. The BCDC will also provide an actual charge for the trailer battery whereas...
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  • Will Redarc In-Vehicle BCDC Battery Charger Drain Vehicle Start Battery
    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D has a mechanism built in so that when connected it wouldn't drain the starter battery. If you check out the diagram I attached you can see that the blue wire runs to vehicle ignition and is a low voltage trigger which would cut off charging the auxiliary battery if the starter batter got too low. This means you don't have to worry about your vehicle battery being dead and leaving you stranded.
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  • Why Must the RedArc Be Grounded to The Battery Rather than Grounding to Chassis?
    I understand the reasoning behind this and I actually installed the first one that way and didn't get the results we wanted. It makes sense to save the expense of the wire and use the chassis. The reason you must run the wire full length is so the current can free flow and give accurate readings to the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1225D. The RedArc products are the best in the industry at making these work everytime and to do that the BCDC needs to have dead accurate...
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  • How To Charge a Trailer Battery For Refrigerator While Driving Down the Road
    In order to charge a trailer battery while driving you really only have one option which is to use the vehicle's alternator. In order to do this you need a device sophisticated enough to take the correct amount of charge without causing issues to the vehicle's battery while also ensuing your are not overcharging the trailer's battery. Furthermore, you will need to isolate the two batteries so there aren't any issues with shorts. For this, we have the Redarc In-Vehicle BCDC Battery Charger...
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  • Can Redarc BCDC Battery Charger Be Installed on 2014 Silverado with Smart Alternator
    I reached out to my contact at Redarc, who ensured the # 331-BCDC1225D is indeed compatible with all makes of vehicle including the latest GM models with smart alternators, like your 2014 Silverado. There have been no reports of newer GM vehicles displaying error codes after installing it. On the newer GM vehicles, they often now feature a current shunt or Hall Effect Sensor on the negative terminal of the main battery to measure various loads and information from the vehicle. Simply follow...
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  • Charger that Can Draw Power From Alternator and Solar Panel for Charging AUX Battery
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  • Installation and Operation of Solar Panel Connected to Redarc BCDC Dual Input Battery Charger
    The Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 25 Amp # 331-BCDC1225D does utilize the yellow wire as you stated to connect the solar panel. There does not need to be an inline fuse on that input and the solar panel is grounded to the vehicle chassis as you stated. The solar panel will be able to continue to charge your auxiliary battery and provide power even when the ignition is off and is designed for that purpose. It is a smart charger so it will not...
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    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D that you referenced would not allow amperage or voltage to backfeed onto the vehicle trailer wiring to the point of causing any issues. With DC power it's okay to have more than one power source connected on the same circuit and there won't be any problems. AC power is a different story but that's not something you'd need to worry about.
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  • Installation Questions About Redarc 331-BCDC1225D In-Vehicle DC to DC Battery Charger
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    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D can work with basically any 12 volt solar panel type setup and has a max input amperage of 25 amps so nearly all solar panels you'd find in RV applications would easily work well. I am not sure exactly what type of solar panel needs you have so I attached a link to this page that has all of the options we carry as well as a review video for the charger.
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  • How do I Know if I Have a Smart Alternator?
    The best way to tell is to look for the sensor on the battery. Variable Voltage Alternators require some sort of battery sensing technology to determine load coming from the battery and this is done by a battery sensor which is found on one of the battery terminals (usually the battery negative).
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    To keep your XS Power XP950 charged I recommend using the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D. The BCDC will actually use the vehicle's alternator to keep the auxiliary battery charged. When the auxiliary battery is fully charged, the unit will automatically redirect maintenance charge power to the starter battery. I have attached a review video on the charger for you as well.
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    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D is designed to charge a battery with either an alternator or solar panel power source like what you have. This would work well for what you need. The only way to switch the power source from your van battery to the aux batteries would be with a switch setup for each circuit.
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  • How to Charge Two 6 Volt Batteries Connected In Series with Solar Panel
    To charge your two 6 volt batteries connected in series with your solar panel, I recommend using the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D. This will give you a clear input for your solar panel and alternator as well as a clear positive output to your two 6 volt batteries. I have included a diagram that shows how the connections should be made.
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  • Does the Redarc BCDC Battery Charger # 331-BCDC1225D Come With A Solar Input
    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D does come with an auxiliary input for connecting to a solar panel without the need for a regulator. I've attached a video to show you the installation and how this will be connected to the yellow wire for power input and then the solar panel will have it's own ground wire.
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  • What Is The Benefit Of Connecting To Alternator Versus Directly to Battery Terminal
    I reached out to my contact at Redarc and confirmed that when using the In-Vehicle BCDC Battery Charger # 331-BCDC1225D the only benefit is the increased amperage when you connect the unit to the alternator versus the battery directly. This is a big help in charging versuses maintaining a secondary battery and maintaining the use originally designed in the system for the starter battery. The alternator will increase the amperage the unit will receive and charge the additional battery...
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  • Best Battery Charger for Two Interstate SRM-24 Batteries on a Trailer
    The Battery Life Solar Battery Charger and Maintainer part 329-BLSOLAR5 is a great option for a smaller battery but won't do much at all for your two Interstate SRM-24 batteries.The most important aspect in choosing the correct battery charger is Ah (amp hours). The Battery Life Solar Battery Charger and Maintainer is rated for use on batteries between 1.2 - 20Ah (amp hours). The Interstate SRM-24 batteries you have are each rated at 84Ah each which means this battery charger will not be...
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