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

Part Number: RED36TR

27 Reviews | 17 Questions

$260.00

Retail:$286.00

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redarc battery charger rv/camper trailer solar panels to auxiliary vehicle red36tr

redarc battery charger rv/camper trailer charges and maintains red36tr

redarc battery charger charges and maintains solar panels to auxiliary vehicle red36tr

redarc battery charger solar panels to auxiliary vehicle in-vehicle bcdc trailer - dual input dc 12v 12 amp / 40

redarc battery charger rv/camper trailer charges and maintains

redarc battery charger rv/camper trailer

redarc battery charger charges and maintains in-vehicle bcdc trailer - dual input dc to 12v 12 amp / solar 40

redarc battery charger rv/camper trailer in-vehicle bcdc - dual input dc to 12v 12 amp / solar 40

redarc battery charger charges and maintains red36tr

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Keep your trailer battery charged with this dual-input smart charger. Installs in your trailer and pulls power from your vehicle battery or rooftop solar panel to charge your auxiliary battery. Ideal for travel trailers or other enclosed models. 1-800-940-8924 to order Redarc battery charger part number RED36TR or order online at etrailer.com. Free expert support on all Redarc products. Great prices and Fastest Shipping for Redarc In-Vehicle BCDC Trailer Battery Charger - Dual Input - DC to DC - 12V - 12 Amp / Solar 40 Amp. Battery Charger reviews from real customers.

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Redarc Battery Charger - RED36TR

Features:

DC-DC charger, an MPPT solar regulator, and a smart battery isolator all packed into one compact, lightweight unit
Dual-input system combines a 12A tow vehicle charger and a 40A solar regulator for simplified, enhanced power management
40A solar regulator feeds your off-grid adventures, with a longer and more reliable charging capability
DC-to-DC battery charger draws power from your vehicle to power up the auxiliary battery on your enclosed trailer as you travel
- Ideal for smaller battery banks rated less than 75 amp-hours
- Uses your 7-way plug to pull power
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
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
Green Power Priority algorithm ensures solar is prioritized when both systems are available
Unit has profile and status LED indicators for confident set up
Combine with the Redarc Smart Battery Monitor (sold separately) and RedVision smartphone mobile app to keep an eye on battery levels
Unit must be mounted in the interior of an enclosed trailer
- Cables, fuses (RED76FR and RED86FR), and connectors sold separately
Made in Australia

Specs:

Application: 12V or 24V vehicle systems with standard or smart alternators, plus 12V, 40 amp solar input
- Battery types supported: AGM, gel, standard lead acid, calcium, and lithium ion (LiFePO4) batteries
7-Pin tow vehicle plug connector can be used
Continuous vehicle rating: 12 amps
Continuous solar rating: 40 amps
Overall dimensions: 6-1/2" long x 4-3/4" wide x 1-1/2" tall
Maximum charging voltage: 15.3V
Output voltage: 12V DC
Output power:
- 12V vehicles: 147 watts
- 24V vehicles: 294 watts
Output current rating (continuous): 11 amps
Input current (maximum): 12 amps
Weight: 2 lbs
2-Year warranty

BCDC1212S Redarc In-Vehicle BCDC Trailer Battery Charger - Multi Input - DC to DC - 12V - 12 Amp / Solar 40 Amp MPPT

Installation Details RED36TR Installation instructions

Customer Satisfaction Score:

95% were satisfied with this product

5% of customers were not satisfied

Wrong item was ordered
Defective
Did not arrive in time

5% of customers were not satisfied

Wrong item was ordered
Defective
Did not arrive in time

4.5

27 reviews

5 Stars		(19)
4 Stars		(6)
3 Stars		(0)
2 Stars		(1)
1 Star		(1)

by: Mark 09/22/2025

Works great and was easy to install

Click to Enlarge

Kate F.

9/24/2025

Wow, the install looks great Mark! Do you do a lot of Boondocking?

by: Aidan 04/05/2026

Works great I only got about 9-10 amps of charging off 7pin of truck but perfect for what I needed

by: Bruce 06/30/2026

Great surmise for a great product.

by: Todd 04/06/2025

Detailed and easy to follow instructions. Materials feel like quality stuff.

by: Troy 10/23/2025

by: Kelly 01/22/2026

by: Paul 05/28/2025

by: Ben 02/04/2025

by: Jonathan 10/08/2024

by: Don 04/02/2025 One Year Later

I absolutely love this device... I installed it on our dump trailer where the most embarrassing thing is when your battery dies while trying to dump at the recycler... (everyone hates you!) This unit keeps the trailer battery always topped off, we are in and out quicker and no more people shaking their heads because you're tying up the space. We installed it with an indicator light so we know when it's working. Easy install. The only suggestion I would make is for the unit to come with circuit breakers so the buyer doesn't have to hunt them down when doing the install. Again.. Love the unit!!

Don One Year Later

4/11/2026

Great! I had changed the battery on my dump trailer to Lithium battery and with just connecting one wire was able to access the lithium charging profile. Easy-peezee! I did have some charging issues when towing with a truck with a variable output alternator but then again... attaching one wire to the trailer lighting circuit and now the charger works with that truck. This a very flexible product... has a lot of intelligence built-in. Very happy with it!

by: John E Davies 03/10/2021

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.

Click to Enlarge

by: Matthew 07/29/2023 One Year Later

Product works as expected to maintain marine battery installed in car hauler. Battery powers winch and interior lights. Redarc charges the battery while towing without overloading charge circuit on truck. Installation was easy. Installed for one year. Very pleased.

Click to Enlarge

by: Dan 11/27/2022 One Year Later

I installed this on my 2015 Airstream with my 2020 F-150 and love it! The 96 FR will work with the 7-pin trailer harness and the F-150, so there is no need to run bigger wires. The truck has a 25 amp fuse on the charging circuit to the 7-pin trailer harness, and the 96 FR is current limited to 20 amps, which is perfect! The F-150 has a smart alternator that reduces the output voltage when the truck is under load, so without the 96 FR the truck would do very little charging of the trailer batteries while driving down on the road. I love it!

Dan One Year Later

11/28/2023

Great! The only issue so far is that the unit locks out when the temp is below 10 degrees F. I live in Wyoming and typically leave to go camping in the winter when it’s often subzero. I sometimes drive most of a day before the Redarc warms up enough to turn on. My Redarc is mounted under the bed, inside my camper.

by: MBP 03/27/2025

Easy, straightforward install. Getting 14.6 V at the dump trailer battery when charging. If it stays trouble free, would highly recommend.

Brooke M.

3/27/2025

We would definitely be interested in what you think once you have some time to use it! Keep us in mind once you've gathered some data. :)

by: Rbberfish 05/27/2021

I'm charging a house battery that powers a 12 volt refrigerator. Very simple install. Not giving this unit a 5 star rating because the 12 volt input and charging wires exiting the unit are 12 gauge wire and they get fairly warm to the touch. The instructions that come with it list 10 gauge wire as the minimum wire size to use to connect it.

Rbberfish One Year Later

5/28/2022

Still working and Im happy with the job it does.

by: Nick 02/07/2024 One Year Later

I have put close to 50k miles on my trailer after installing this unit running hotshot. It worked great for keeping the battery charged off of the truck power. I actually have another trailer I have been planing to order another one for so I'm able to hook up a batter and run utility lights in as well as battery chargers.

by: Patrick 04/14/2023

Using this as a current limiter to charge an auxiliary battery on my auto hauler. Wiring is extremely simple for a standard 14v application. Small unit that fit easily in the tongue box.

Patrick One Year Later

4/15/2024

Still works as designed.

by: Edward 06/07/2022 One Year Later

Most modern 1/2 ton pickups have "energy efficient alternator" as part of the battery management system. That means if the battery management system senses that your truck battery is fully charged, it lowers the output of the alternator. This means that the alternator voltage is insufficient to charge the camp trailer battery. This Redarc device will take the lower voltage from the alternator and boost it up to charge the camper battery. It works as intended and solved a big mystery for me as to why the camper battery didn't gain charge during long drives from one campground to another

by: Indy Fritz 06/08/2023 One Year Later

This gadget is awesome. It solves two problems. (1) How to charge your camper battery when it is at the end of a long line from car to camper with attendant voltage drop. The Redarc boost the voltage back up to a proper battery charge level. (2) When you shut the tow vehicle down, the Redarc protects the tow battery from discharge into the camper system. Has worked fine for me.

by: Ray 11/09/2022 One Year Later

Overall, I think giving the product itself 4 stars is a correct evaluation. I want another evaluation of 5 stars given to the support staff at Redarc. The charger itself has not given me the slightest issue as far as reliability goes. The fact that it came with a temperature sensor in the device that shuts off charging at its own temp of 0°C (freezing temp) on Lithium charging mode came as a complete surprise to me. By reading the documentation that came with the charger, I didn't discover it shuts off automatically at freezing temperature. When I noticed I could not charge my LifePo4 battery at below freezing. Thanks Redarc staff for telling me about this after I asked about it.

by: Rudy 08/17/2022

This worked exactly as I hoped. I needed something to limit the current coming out of a cigarette lighter so I could charge a lithium battery from that lighter. Worked perfectly.

eTrailer was helpful in showing me this solution.

by: Michael 05/14/2023

I searched long and hard to find something like this. Strangely enough its not easy to find unless you contact etrailer. In no time they recommended this charger and it was spot on for my needs. Etrailer will get my business in future

by: Dwayne 11/29/2023

Fast shipping, excellent

by: Alex 01/29/2025

Alex One Year Later

1/31/2026

I Still love this charger. It keeps the marine battery on my gooseneck fully charged for running the winch and hydraulic tilt. The 12 amp charger is great because it is able to use the 12 volt auxiliary power from the 7 blade plug.

by: Andrew 09/10/2026 One Year Later

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See what our Experts say about this Redarc Battery Charger

Do you have a question about this Battery Charger?

How to Charge Battery for Fridge Using Alternator and Solar Power
Hey Greg, thanks for reaching out to us! Hopefully I can help you get all of this figured out so you can seamlessly keep your refrigerator battery charged up. It sounds like you're needing the Redarc In-Vehicle BCDC Trailer Battery Charger # RED36TR which pulls power from your vehicle alternator to charge a separate power bank, but can also have a solar panel connected into it as well. During normal operation this system prioritizes the solar panel power, but then pulls the rest of the...
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DC to DC Charger Recommendation to Keep Lithium Battery in Casita Spirit Topped Off
Hey Tom, you'd need a DC to DC charger that has a lithium battery charging profile like the Redarc BCDC charger part # RED36TR which has dual inputs as well and can charge up to 40 amps so it would do a great job keeping your lithium battery topped off. Which charger did you watch Wild RV Life install?
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Can 12 Volt Accessory Circuit of Truck Charge Trailer's Lithium Battery
Hey Brett, this is a really great question. Basically if you don't use a DC to DC charger like the part # 331-BCDC1225D that you referenced the battery would only ever get to a charge of around 80 percent since Lithium batteries need a much higher voltage to charge. If you wanted to save some money on a charger we have the part # RED36TR as well which is a 12 amp charger instead. The one you referenced is a 25 amp charger.
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Recommended Solar Panel for a Redarc In-Vehicle BCDC Trailer Battery Charger
Hey Todd, welcome back! Glad you're enjoying the Redarc In-Vehicle BCDC Trailer Battery Charger item # RED36TR. You are correct you do not need a solar controller because the Redarc has a 40 amp one built in. For a 40 amp solar controller you can use the 200 Watt Solar Panel Go Power Overlander Expansion Kit item # 34282182. To get wired up you can install the 25' Long Go Power Solar Cable Entry Plate with Red and Black MC4 Cables item # 34273843REVA or the 10' Long item # 34273842REVA...
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Does the Redarc In-Vehicle BCDC Charger Come With a Solar Panel
Mike, no the Redarc In-Vehicle BCDC Trailer Battery Charger # RED36TR does not come with a solar panel. This can be used with a solar panel though - you'd just need to connect the power wire on the solar panel to the yellow wire on the BCDC charger, and then the other wire on your panel would be your ground.
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Can Blue Ox Towed Vehicle Battery Charge Line Be Used For Trailer Battery
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How Can Truck Charge Battery of RV
Hey David, I did some checking and the 12 volt accessory circuit of your 2017 Ram 3500 is active all the time so you can use it to charge your trailer battery. The 1:00 pin of the 7-way carries this circuit and it would need to be ran on the trailer side 7-way to the positive pin of the battery using 10 gauge wire like the part # 10-1-1. This is great for like a light maintenance charge for the battery. Now if your trailer battery is lithium you would instead need to use a BCDC charger...
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David, it sounds like you're looking for the Roadmaster Dual Hitch Receiver Adapter # RM-077-10. This dual hitch adapter can be configured in a 2" rise/drop or 10" rise/drop, has an overall length of 13", and a max towing weight of 10,000 lbs, with a max tongue weight of 400 lbs.
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Recommended Charger For Keeping Winch Battery Charged w/a Tow Vehicle
No, it will not Joe. The large draw is going to be on the batteries you connect to. The accessory circuit on your tow vehicle's 7-way connector isn't going to provide enough power. It is designed to recharge your trailer's battery but it only provides 12v. That's not going to put stress on your alternator but the 7-way won't power the winch if you kill the battery or batteries and it won't recharge them either. At best the 7-way way maintains an already charged battery. You're going to...
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Could Redarc In-Vehicle BCDC Battery Charger Power 3-Way RV Fridge
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Can I Use A Dc to DC Charger To Keep My Trailer Battery From Draining?
Hello Jeramie, thanks for reaching out. Using a DC to DC charger will absolutely help with this. The Redarc In-Vehicle BCDC Trailer Battery Charger # RED36TR is what I recommend for keeping the trailer battery charged. You could add a second battery but those can be expensive. Adding the charger is a much more affordable solution. What type of battery do you have? Just curious
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How do I Trickle Charge a Battery on my Trailer
Hey Robert, this is a really great question. In short, you can use the Redarc In-Vehicle BCDC Trailer Battery Charger part # RED36TR to charge your battery on your trailer. There are some extra parts you will want to pick up as well. 60-Amp MIDI Fuse Kit Part # 331-FK60 (need this between the charger and the battery) Battery to Fuse Holder Cable for Part # RED66FR (need this to go from the MIDI fuse to the battery) I also included some pictures showing a diagram. Redarc is really good...
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Hey Andrew, you would want the Redacr In Vehicle BCDC part # RED36TR which is compatible with the setup you have. This can use solar power as an input as well as is compatible with lithium and AGM batteries. How many solar panels do you have?
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Can Redarc In-Vehicle BCDC Trailer Battery Charger Charge Two 100 Amp-Hour Batteries
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