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Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp

Item # 331-BCDC1240D
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331-BCDC1240D - 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. Call 800-298-1624 to order Redarc battery charger part number 331-BCDC1240D or order online at Free expert support on all Redarc products. Guaranteed Lowest Price and Fastest Shipping for Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp. Battery Charger reviews from real customers.
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  • Reviews (69)
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Redarc Battery Charger - 331-BCDC1240D

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

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 larger battery banks rated 200 amp-hours and higher
  • 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-FK60 - 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 led acid, calcium, and Lithium ion (LiFePO4) batteries
  • Overall dimensions: 6" long x 4-3/4" wide x 1-1/2" tall
  • Battery capacity range: 200 amp-hours and greater
  • Maximum charging voltage: 15.3V
  • Output voltage: 12V DC
  • Output power: 600 watts
  • Output current rating (continuous): 40 amps
  • Input current (maximum): 40 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 40 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-FK60 - 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

BCDC1240D REDARC In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp

Installation Details 331-BCDC1240D Installation instructions

California residents: click here

Customer Reviews

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp - 331-BCDC1240D

Average Customer Rating:  4.9 out of 5 stars   (69 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.

- 331-BCDC1240D

This unit has performed as expected. My batteries are mounted inside a plywood box in the back of my van. All the connections for the Redarc are inside the box so it has a very clean install on the exterior of the box. The two DC switches in the picture allow me to disconnect the input line to the Redarc from the vehicle's electrical system and the second disconnects my Battle Born batteries from everything. I only shut off the system when I take it into the van dealership for maintenance, and that is only precautionary.

It still works great. In fact, last week I got the solar connected and it worked without a problem.
Bill A - 07/03/2021

- 331-BCDC1240D

This is a fantastic unit. Very easy to hook to the camper batteries, using both the solar and alternator charging functionality. Used this without any issues on a 14 day trip. The instruction manual is well written and very clear. No more worries about the state of charge of my batteries even after a long day of driving with the camper because the battery charge level will be greater than 90% when arriving at campsite despite having a refrigerator running in the camper. Will now be able to leave solar panels at home for a short 2 day camping trip. A few times, the battery level was in the 60%-65% charge level and it was charged back to 80+% within a few hours of driving. Just be aware that getting the lead-acid batteries from 90% to 100% takes a much long time because it has to be a constant low current. Purchasing from etrailer was an excellent experience - received it in Canada within 2 days or order.

- 331-BCDC1240D

I installed a BCDC1240D (with optional fuse kit) in my Winnebago Revel (Mercedes Sprinter). The instructions are clear and I was able to figure out the wiring requirements pretty easily. I wired the Redarc with a switch to change between profile C (winter) and B (summer). The batteries are mounted below the vehicle so I probably need profile B at higher temperatures in the summer. I have included a picture of the Redarc installed in the passenger's seat pedestal in the van. Most of the wiring in there is Mercedes and Winnebago. You should be able to identify the Redarc (bottom center), and the two fuse holders (fuses not yet install) near the blue tape.

- 331-BCDC1240D

I have 300ah Lifepo4 batteries from Renogy.. 300 watt solar.. this unit will charge via solar or vehicle.. one or the other .. whichever has more power.. I see the lights on and see it working.. the reason I like this unit is because my batteries are only being charged from one charging source. This is safer and will improve battery life. I just wish it could have a battery and voltage meter.. I guess I need to buy a battery monitor.. This is almost the perfect device.. it needs a display for battery life and voltage.. I would love to know what it is doing.

- 331-BCDC1240D

This thing is just great. It is rock solid in construction and function. Everywhere I go now in my Arctic Fox slide in and F350, bu two 100AH LiFePo4 batteries are charging at 45 amps along the way. The fact that the Redarc is weather proof allowed me to mount it outside under the camper skirt running my 4awg battery cables along the bottom of the camper right to it.

- 331-BCDC1240D

Brilliant product! Charges trailer battery while you drive! When full-timing (almost always dry camping) we frequently found it necessary to run the generator *after* arriving at a new campsite because the “charge” line on the 7 blade RV connector delivered so little power. This fixes that: It delivers a full 40 amps to our two ~100AH flooded batteries (Walmart 29DC), which will take them from 50% to 80+% charge in less than 2 hours, our usual travel time between sites, eliminating the need to run the generator completely on most days (and we don’t skimp much on electricity, using the microwave and watching movies most evenings and a forced air heater all night). A few tips: 1) It draws 43 amps from the vehicle, so you really need the 4 awg wire to the trailer and a heavy-duty disconnect (we used a 150 amp which works well with 4 awg). 2) At full draw the vehicle battery was at 12.8 volts at idle, so it’s right at the limit: You definitely don’t want to be drawing down the starting battery. This is on a Nissan Frontier with a 130 amp alternator, meaning you also wouldn’t want to use it on a vehicle with a smaller alternator unless you’re sure you’ll always be running it above idle and/or without lights/AC/etc. on. 3) A hydraulic crimper would of course be preferred but I used a hammer crimper which worked fine. Just be sure you shrink-tube the connection since hammer crimpers can penetrate the lugs. To get full thickness into the lugs, either fold the wire in half, run the wires (8 awg from the unit, 4 awg from the line) past each other when making a butt splice, or half-fill the lug with strands cut from your 4 awg wire and then push the line in around them. I connected it to the lugs on our inverter since there were already 4 awg lines running from that to the batteries. 4) Hookup was easy, running a 4 awg line from the truck battery to the bed not so much. I fused it of course, but it’s definitely not something you want to chafe or real drama could ensue. The maximum usable distance from the vehicle to the unit is much longer than what the manual says (e.g., if your batteries are in the back of your trailer), but you must ensure that it’s at least 4 awg all the way. Using vehicle and trailer chassis grounds are fine: You don’t need to run a negative line except for a short one between the truck and trailer frames (i.e., don’t use the hitch as a ground connection). 5) Be sure you disconnect the charging line on the trailer plug. The manual doesn’t mention this, but if you don’t you’ll lose charging capacity because some of your power will feed back through that wire. 6) I used the 15V setting to maximize charging time efficiency. It quickly trips back to 13.6 volts once reaching that (much quicker than our equalizing multistage charger, for example) so no worries about overcharging. With the standard 14.6 volt cutoff you’re giving up significant amount of charging if you only drive a short time. 7) It’s 93% efficient (according to tech support) but does run pretty warm when at full output for a long time. It should be installed in area with ventilation and definitely not in an engine compartment. 8) Redarc tech support was awesome when I had questions about the installation.

Still working great. Sometimes after a long drive our volt meter stays above 12.6 volts full charge until the next morning, something we never saw when using a generator because we never were willing to run that long enough to get a full charge.
Scott R - 07/04/2020

- 331-BCDC1240D

Excellent product, easy install. If you want the option to charge and maintain an Auxiliary Battery from main battery or solar, this is an excellent compact unit. Installed this unit a year ago for a Four wheel camper. Maintain a charge on the road and camping off road, still working strong, no longer need to charge battery in the off season using solar switching, awesome for camping and maintain healthy battery. Thanks to etrailer for offering Redarc products, ease online ordering, support and on time delivery, outstanding. Highly recommend doing business with etrailer and buying this product and the Bulldog connectors!

Redarc unit still performing strong from the day I installed it, no issues. Recently installed Blue tooth battery monitor, no more need to go into the camper and check my digital gauges. During off season camper is stored in the garage connected to solar keep my battery strong and healthy. Pretty awesome feedback from other etrailer customers. Etrailer provided quality products like the Redarc battery charger, still highly recommend doing business with etrailer and zredarc product.
Bill K - 04/15/2020

- 331-BCDC1240D

Have owned this charger for a year and has not failed me yet. It is built well and don’t foresee having any issues with it anytime soon. I’m glad I chose this brand.

- 331-BCDC1240D

This battery charger is awesome. Delivers 40 amps of power for my lithium batteries while driving. So far, no problems with my 125 amp alternator using this device. Used it on a two month Utah trip. Would by this again.

- 331-BCDC1240D

One year later: Installed this to charge 2 - 100Ah Lithium Batteries from 160 Amp Alternator - It does a much better job than just the alternator itself - the boost speeds up charging by a x4 factor - worth every penny. Highly recommend - easy install with clear instructions.

After a year of traveling full time the Radarc has proven to be one of the best investments we made. It is so reliable. Would not hesitate to buy another if this one crapped out.
John B - 02/07/2020

- 331-BCDC1240D

Great product(BCDC1240D) Truck:2017 Chevy Silverado 1500 with a variable voltage alternator Trailer:2006 HiLo Towlite 22 foot camper with a 3 way refrigerator ( because of the hard sided trailer lowers for towing to 5 1/2 feet tall it closes off the propane gas vent to the refrigerator so you must run the refrigerator on 12volts while towing which pulls 15 amps. This was the answer for me to charge batteries and run the refrigerator Installed in my travel trailer oversized custom hand made battery box which is vented for cooling of the unit and the unit is also mounted to the frame of the trailer as a heat sink I hooked it up to my solar panel to keep my batteries topped off while camping or in storage. Because of the length of wire from my start battery to the travel trailer batteries (35 feet) I used 4 gauge wire and an Anderson 175 amp plug at my rear bumper as a disconnect .For the trigger wire to a ignition circuit on the truck I used the center pin on the 7 blade pigtail of the trailer plug since I don’t have reverse lights on the trailer I would give it 10 stars if I could

- 331-BCDC1240D

Is working great in my Silverado to keep auxiliary battery charged for the bed accessories. Just added a solar suitcase to it for charging and using electrical without engine. Thinking about installing the jump circuit just for safety

- 331-BCDC1240D

Using it to charge the Sprinter van house battery from the vehicle auxiliary battery. The yellow wire for the solar input is not in use right now.

- 331-BCDC1240D

We installed this product in our diy camper van conversion a year ago. Installation was not difficult. We have made a few trips in our van and the unit is working well so far.

- 331-BCDC1240D

Install took a little time. You will need a hydraulic connector press and then you will have to solder connectors. I ordered connectors off of the internet

- 331-BCDC1240D
by: 06/16/2021

good product, good customer service and speedy shipping.

- 331-BCDC1240D

Money wisely spent - for this casual ca mper.

- 331-BCDC1240D

Have not installed the Redarc in my camper yet, but really appreciated the quick turnaround on my order. Quick shipping was better than Amazon.

- 331-BCDC1240D

Keeps my house batteries charged on my boat while my engines are running. I hope to install solar panels someday to assist with charging when I’m not underway.

- 331-BCDC1240D

- 331-BCDC1240D

- 331-BCDC1240D

- 331-BCDC1225D

Review from a similar BCDC in Battery Charger

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.

- 331-BCDC1225D

Review from a similar BCDC in Battery Charger

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


Review from a similar BCDC in Battery Charger

I installed this in a 2017 Oliver Legacy Elite II travel trailer, because I had installed Battle Born lithium batteries and there was no way my truck was going to charge them properly. The actual installation was fairly painless, but I had to run bigger wires from the front of the trailer back to the batteries, which are located over the axles. I get a solid 10.5 amps continuously now, even though my Land Cruiser is only putting out 13.5 volts when connected. It works as advertised and I do recommend it. I took one star off because I think it is over priced, but that is be expected for an Australian import.

Show More Reviews

Ask the Experts about this Redarc Battery Charger

  • RV Battery Charger and Portable Solar Panel System for Boondocking
    Yes, Redarc DC to DC battery charger # 331-BCDC1240D is the right choice for charging your trailer's 540-amp battery bank. This unit can mount in the cabin of your vehicle, along a chassis frame rail, or in the engine compartment and it will connect to the vehicle's battery for input power, not to your 7-way. Use the heaviest gauge wire you can for all connections. Redarc recommends 6-gauge for runs up to 16-feet and 4-gauge for longer runs; this applies to battery input power, solar...
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  • Should I Use 25 amp or 40 amp Redarc BCDC Battery Charger For 200 ah Battery
    The Redarc In-Vehicle BCDC Battery Charger - Dual Input part # 331-BCDC1225D will work fine to replenish the 200 amp hour battery but I do recommend to the use the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D to replinesh the battery faster. The Redarc 40 amp charger is designed for battery banks 200 ah and higher and has a 600 watt power output. All of the Redarc chargers are safe for your system, the setup includes an effective battery isolation to prevent any feedback....
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  • Redarc BCDC Battery Charger Compatibility for 2019 F-350 Chassis Class C
    The Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D will work well on a Class C vehicle. The unit will charge your secondary battery and allow you to use solar panels for charging as well. It works on a wide variety of battery styles and the installation instructions will help you with installation. I do recommend using the 60-Amp MIDI Fuse Kit for Redarc In-Vehicle 40-Amp BCDC Battery Charger # 331-FK60. Redarc does recommend using...
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  • Best Way to Charge Auxiliary Lithium Ion Battery on 2019 Ram ProMaster
    The best way to charge your auxiliary LiFePO4 Deep Cycle Battery from the main battery of your 2019 Ram ProMaster is with the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D. This was designed for larger batteries and it has a built-in smart charging system that reads what kind of battery is being charged and then it adjusts the amount of power output so that the battery isn't damaged and that it gets the most efficient charge possible. Redarc recommends using the 60-Amp MIDI...
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  • How to Pick Out Redarc DC to DC Battery Charger for 450 Amp Hour Battery Bank
    The only difference between the Redarc # 331-BCDC1240D and # 331-BCDC1250D is the maximum output rating of 40 amps and 50 amps, respectively. Both of these charging units are designed for battery banks above 200 amp-hours. The difference in output means that the 50 amp version will charge your battery from dead to 100% charge faster than the 40 amp version. Overall, I recommend the 50 amp version as it would be able to charge a dead battery faster than the 40 amp version.
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  • What Is Actually Required to Install the Redarc In-Vehicle BCDC Battery Charger
    In regards to the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D, there are indeed a bunch of add-on's as the battery charger can be used in conjunction with other Redarc products such as the Manager 30 and RedVision. That said, all you really need to get setup and charging your battery/batteries would be the 60-Amp MIDI Fuse Kit part # 331-FK60 (For 40 Amp Models) and some misc. primary wire for power and ground etc. which you can pick up locally. The rest of the stuff you...
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  • Recommendation for Installing the Redarc BCDC Battery Charger for Truck Bed Camper
    For your 2014 GMC 3500 the second battery does require a charger like the Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D which is a great option. This is a customer favorite as well as a personal favorite but it does require cables, fuses # 331-FK60, and connectors sold separately. I recommend using the Bulldog Winch Wiring Kit for ATV/UTV Winches - 120" Long Power Lead # BDW20307 which does have the connectors as well. I've attached...
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  • How To Attach Goal Zero Solar Panel To a Redarc In-Vehicle BCDC Battery Charger
    Correct, in order to attach to a Goal Zero Boulder Solar Panel like part # 287-32406 to the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D you will need to remove the 8mm adapter plug and hardware the leads directly to the battery charger.
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  • How To Jump Start Battery Using Redarc In-Vehicle BCDC Battery Charger
    The Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D is a great option for charging a trailer battery. It sounds like you are concerned with the status of the starter battery and if that is case there is no need to worry as there are built-in safeguards to prevent puling power from the start battery when it gets below a certain voltage. If for some reason the start battery does die, you can use the auxiliary battery to jump start this with the Redarc Smart Start Battery Isolator...
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  • What Gauge Wire Should be Used with Redarc In-Vehicle BCDC Battery Charger
    Since the estimated length of the wire run you'll have with the part # 331-BCDC1240D is between 18 and 20 feet you'd want to use 4 gauge wire. If the run was less than 16 feet you could use 6 gauge. The two relay kits you mentioned actually provide different purposes. The part # 331-SBI12KIT is for allowing the charger to charge two batteries in the best way possible whereas the # 331-RK1260 is for connecting to a vehicle that has a smart alternator. These come with all needed circuit...
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  • Fuse Kit to Use with Redarc BCDC Charger part # 331-BCDC1240D
    With the Redarc BCDC Charger part # 331-BCDC1240D you want to use 60 amp MIDI fuses for both connections which we actually have as a kit with part number # 331-FK60.
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  • RedArc BCDC Battery Charger Compatibility with Variable Voltage System and AGM Batteries
    The Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D is designed to work with smart alternators like yours when you use the 60-Amp Relay Kit for Redarc In-Vehicle BCDC Battery Charger # 331-RK1260. You will also need to use the 60-Amp MIDI Fuse Kit for Redarc In-Vehicle 40-Amp BCDC Battery Charger # 331-FK60. This prevents your alternator being overloaded and it won't back-feed your alternator either. This system is rated for AGM or Lithium...
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  • How to Charge Trailer Batteries with the Vehicle's Alternator and Shore Power
    I do have options for you but the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D would not accept AC current from shore power and then use that to charge your two AGM batteries while disconnected from the tow vehicle. The Redarc In-Vehicle BCDC Battery Charger would still be needed while driving but when parked you would need to install a power converter to charge the batteries using shore power. The correct power converter will vary depending on the A/h of your batteries...
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  • How To Charge Trailer Battery with Tow Vehicle Battery
    The best option to provide an actual charge to the trailer batteries while in tow would be a DC to DC battery charger, the Redarc In-Vehicle BCDC Battery Charger part # 331-BCDC1240D is pretty much the best option out there for this. This system will then ensure you have the batteries fully charged each time you get setup to camp. There is an option of running a battery charge line from the vehicle battery to the to the trailer battery with something like the Roadmaster Battery Charge...
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  • Will 130A Alternator in 2019 Toyota 4Runner be Enough to Work with a 40A Charger
    It sounds like you're referring to the 40A Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D for use with your setup. When it comes to chargers it's a little more about what kind of battery bank you're trying to charge up than how much output the alternator has. With that being said, I reached out to my contact at Redarc and he said that you can typically count on about half of your alternator power being able to switch over to their charger systems so your 130A is definitely high...
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  • Where Should Redarc In-Vehicle Battery Charger be Grounded?
    When wiring the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D along with connectors # PK12801 and # PK12800 you will want to ground to the tow vehicle chassis. The linked instructions specifically state that "all ground points must be connected to chassis earth". You can see this in the diagram I've added for you to take a look at.
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  • Using Redarc In-Vehicle BCDC Battery Charger to Charge Lithium Ion Battery
    The wire that is going to the 12V pin on your Silverado's 7-Way connector is connected to the truck's battery. You should be getting 12 volts of power at the this pin (1 o'clock position) on the connector. The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D referenced in your question is a great option for charging your Lithium ion battery. When hooked up to the truck's battery or alternator, it will do a nice job of maintaining the battery's charge, but to actually charge it...
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  • Solar Panel Option for Use with Redarc In-Vehicle Battery Charger # 331-BCDC1240D
    We have a few solar panels that could be used with the Redarc In-Vehicle Battery Charger # 331-BCDC1240D. We have the part # 287-32406 which is capable of 50 watts, the part # 287-32408 which is capable of 100 watts.. No other hardware or install wiring would be needed.
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  • Recommended Wiring for RedArc BCDC Charger Used for Auxiliary Battery to Power Inverter
    To connect your Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D, you will need the 60-Amp MIDI Fuse Kit for Redarc In-Vehicle 40-Amp BCDC Battery Charger # 331-FK60. This will protect your vehicle and battery from potentially damaging overcurrent from short circuits or overloads. You will run the Red Wire from your RedArc unit to the fuse, and then from the fuse to the positive battery terminal on your vehicle start battery. I've...
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  • Does Solar Panel Controller Get Ran to Redarc BCDC Battery Charger
    If the solar panel has it's own controller setup you would bypass it and run it straight to the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D that you referenced as it is designed for unregulated solar panel power. To answer your second question a conflict is not created in the scenario you described. Having the voltage changed twice like you mentioned would not be an issue.
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  • Solution for Charging Auxiliary Trailer Battery Through Truck's 7-Way Connector
    In order to activate the 12V circuit on your truck's 7-Way so that you can maintain the charge on the trailer's auxiliary battery, you just need to run a length of 10 gauge wiring like # 10-1-1 (sold by the foot) through a breaker like # 9510 from the truck battery's positive post to the 12V pin on the 7-Way. This is the pin located at the 1 o'clock position (or 11 o'clock when looking at the backside/inside of the connector). Then from there you would wire the corresponding pin on the...
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  • Installing Redarc 331-BCDC1240D DC to DC Battery Charger For Charging Trailer Mounted Winch Battery
    The small gauge wire feeding the 12-v supply feed to the 7-way wouldn't have enough capacity to power the charger, the charger would need to connect directly to the tow vehicle battery using 4 gauge wire, according to the instructions I've linked to and the installation diagrams I've provided. You'll also need a fuse kit like # 331-FK60. I've also linked to an installation video and a help article.
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  • Compatibility of Redarc In-Vehicle BCDC Battery Charger with 24V Solar Panels
    I reached out to my tech contact at Redarc and the Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D solar input is only compatible with unregulated 12V nominal solar panels which means the open circuit voltage specification must not exceed 32V.
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  • Redarc Charger for 2018 Chevy Colorado ZR2 with Dual Battery Setup
    The Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D that you referenced is the correct charger setup you'd need. It can put out up to 40 amps and is compatible with smart alternators like you have as well. I attached an install diagram that shows how it will wire up (without the solar panel you see pictured) as well as a link to the install instructions as well.
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  • Recommended Vehicle To Trailer DC to DC Charger for Multiple Trailer Batteries
    Your auxiliary power wire gauge at your 7-way along with the discontinued CTEK40186 will be sufficient to charge your trailer batteries. The CTEK D250S will amplify the signal from your auxiliary power to boost it to 20 amps versus the 2-3 amps of a system without the CTEK unit. Changing your gauge of wire to 8 and adding the # DL24086 connections will help slightly but if you are wanting to charge multiple batteries well and more quickly/efficiently, you really will want the discontinued...
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  • Will 40 Amp Redarc In-Vehicle BCDC Battery Charger Interfere With 7-Way
    The 40 amp Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D will not interfere with the 7-way on your vehicle, though it is recommended to route separate wiring to the charger so that enough power gets to it, as a 7-way uses smaller gauge wire. So due to this you can use both at the same time if you'd like, though a 7-way will only maintain smaller batteries instead of charging them. So for charging batteries you will want to use the 40 amp Redarc In-Vehicle BCDC Battery Charger #...
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  • Solar Voltage Input of Redarc In-Vehicle BCDC Battery Charger
    I reached out to a representative of Redarc who told me the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1240D can accept unlimited current though will have an output only of 40 amps which is what it is rated for. Additionally, it will only work with 12V nominal solar panels so they cannot be connected in series to the charger.
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  • Can Redarc In-Vehicle BCDC Battery Charger Work With 160 Watt Solar Panel and 120 Watt Solar Blanket
    I reached out to Redarc and you will have no issues using both your 120 watt solar blanket and a 160 watt solar panel at the same time with the Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D as long as the solar panel and blanket are wired in parallel meaning the both positive wires are connected together, and both negative wires are connected together. The reason for this is the # 331-BCDC1240D will only draw the power that it can take,...
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