Recommended Vehicle to Trailer Battery Charger for Trailer Battery

Published 06/18/2018

Products Featured in This Question

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

(91)

$485.19

10 Gauge Wire - Blue Primary - Per Foot

(109)

$1.91

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

(91)

$620.00

40-Amp MIDI Fuse Kit for Redarc In-Vehicle 25-Amp BCDC Battery Charger

(18)

$90.00

Question:

Do I need to purchase the 6ga wire separately? The orange and black wire and plugs from the video? Or would it simply be wired to the orange wire in the 7 pole junction box?

asked by: Keith

Expert Reply:

Without hesitation, I recommend using a 7-way trailer connector and using the 12V charge line you find at the 1 o'clock position to run to a battery charger and then your trailer battery. Most charge lines only take whatever amperage is not being used by the vehicle and sends it to the trailer battery providing a maintenance charge. Your trailer clearance lights will run without issue using either plug and drawing power from your vehicle, so the 7-way will serve you well for that function without any changes. I've attached a wiring diagram to assist.

I recommend using the Redarc BCDC # 331-BCDC1225D to give you a 25 amp battery charge and maintainer that will also allow you to add solar if you so desire. This will allow you to run whatever camping appliances you desire as you travel. This is for 75 amp-hours - 200 amp-hour batteries. If your trailer battery is over 200 amp-hours then you will want to upgrade to the 40 amp # 331-BCDC1240D. You will also want to use the inline fuse kit # 331-FK40. This will give you the go anywhere power you desire.

expert reply by: Jason S

click to enlarge

Keith

6/18/2018

Do I need to purchase the 6ga wire separately? The orange and black wire and plugs from the video? Or would it simply be wired to the orange wire in the 7 pole junction box?

Jason S.

6/18/2018

Great question. The 6mm2 wire referenced is equivalent to about 10 gauge wire. Most 12V systems will have either 10 or 12 gauge wire to the 7-way 12V power. If you have 12 gauge, I recommend swapping it to 10 gauge using # 10-1-1. If you don't need to replace the wire, then you will simply add the fuse kit in line. If you need to replace the wire, then you will run the # 10-1-1 wire from the positive battery terminal on your vehicle to the fuse and then to the 1 o'clock position on your 7-way. Then you will use that same wire on your trailer side from the corresponding location to the other fuse and then to red wire of the charging BCDC. The orange wire will be installed differently depending on the charge profile desired. I've attached a photo to assist. I've also attached the installation details to assist.