Using 7-Way Trailer Connector 12-Volt Accessory Circuit to Maintain Trailer Mounted Battery
Question:
I have an 06 Toyota Highlander Hybrid and an 06 Cruiser RV Funfinder-x trailer. I purchased a Draw-Tite 5100 brake controller and have wired it up per your video. The video shows a +12V contstant power going from the tow vehicle battery to the black wire on the 7 pin connector. When the trailer battery is connected it also shows +12V to the corresponding pin on the 7 pin connector. It appears to me, that the tow vehicle battery and the trailer battery will then be connected in parallel. - Does this mean that when im driving, both batteries will be charged via the cars alternator? If so, will this put too much straiin on the alternator? - When parked, will the trailer be draining both batteries? Should I make sure to disconnect the 7 pin when not driving? - If left alone, will the higher charged battery discharge into the lower charged battery?
asked by: Henry C
Expert Reply:
That is a great question. The 12-volt accessory feed from the 7-way CAN be used to maintain your trailer-mounted battery during travel, but it will NOT recharge a battery from a depleted state. To charge a depleted battery, a charger like the # CTEK56353 CTEK Universal Battery Charger can be used. The 10 or 12 gauge wire used in the accessory circuit will prevent enough current from going through to worry about overtaxing or damaging the alternator.
To prevent the trailer mounted battery from depleting the battery in the tow vehicle, we typically recommend disconnecting the 7-way when the vehicle is parked for more than a short period. If you are concerned about your tow vehicle battery becoming depleted, you should consider installing a battery isolator like part # PK5231201. The isolator will cut power to the accessory feed once ignition of the tow vehicle is shut off.

Products Referenced in This Question
CTEK MULTI US 7002 12-Volt Universal Battery Charger w/ Pulse Maintenance and Backup Power
- Battery Charger
- Battery Charger
- Car/Truck/SUV
- Motorcycle
- Trailer
- Lawn Mower
- Jet Ski
- 150 Ah
- Charges/Maintains
- AC to DC
- 12V
- Wall Outlet to Vehicle Battery
- CTEK Power Inc
more information >
Product Page this Question was Asked From
Starter Solenoid - SPST - 12 Volt - 100 Amp - Continuous Duty - Grounded
- Accessories and Parts
- Battery Boxes
- Switches and Solenoids
- 100 Amp
- Pollak
more information >
Featured Help Information
Instructions
Continue Researching
- Shop: Progressive Dynamics 4000 Series Mini RV Converter w/ Charge Wizard and AC/DC Distribution Panel
- Shop: Replacement Converter Section for Progressive Dynamics Inteli-Power 4000 Series 45 Amp Power Center
- Shop: Progressive Dynamics 4000 Series RV Converter w/ Charge Wizard and AC/DC Distribution Panel - 60 Amp
- Search Results: pd4135k
- Shop: Furrion Dual USB Charger and 12 Volt Receptacle - LED Indicator
- Shop: CTEK MULTI US 7002 12-Volt Universal Battery Charger w/ Pulse Maintenance and Backup Power
- Shop: Multi Device RV Charging Station - 12V Socket - 2 USB Ports - Hardwire - Black
- Shop: Bulldog Winch Dual USB Ports w/ Cover - 3 Mounting Brackets
- Video: Review of Progressive Dynamics RV Converters - Replacement Converter Section - PD4045CSV
- Search Results: power center
- Search Results: rv converters
- Search Results: pd4135kw2bv
- Search Results: rv converter
- Search Results: usb outlet
- Search Results: pd4100
- Video: Feature Review etrailer Trailer Coupler Lock for Flat Lip 1-7/8" and 2" Ball Couplers
- Video: Comprehensive Review: Ultimate Trailer Jack
- Q&A: Locking Positions for Ark Drop Down Corner RV Stabilizer Jacks
- Q&A: Can Progressive Dynamics PD4135K Power Control Center Replace Centurion CS2000
- Q&A: Are The Ark # ARK77FR The Same As Ark Part Number XODDS850BUS
- Q&A: Availability Of 33" Ark Stabilizer Jack And Dimensional Diagrams Of Similar Ark Corner Steadies
- Q&A: How To Charge 12v Batteries Wired in Parallel
- Q&A: Why Do Some Vehicles Need a Converter to Add Trailer Wiring Like a 2001 Chrysler Town & Country
- Q&A: Recommended Replacement Converter for a Elixir ELX-45
- Shop: Camper Tie-Downs
- Video: Progressive Dynamics Lithium Converter Review
- Video: Review of Progressive Dynamics RV Converters - Replacement Lithium Converter - PD4575LICSV
- Video: Review of Progressive Dynamics - RV Converters - PD4590CSV
- Video: Review of Progressive Dynamics RV Converters - Power Converter W Charge System - PD4045KA
- Shop: RV Camera