Can a Trailer Battery On Dump Trailer Be Charged Using The 7-Way Trailer Connector

Updated 07/15/2014 | Published 07/12/2014

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Question:

REGARDING: How To Charge Trailer Battery On Dump Trailer Using The 7-Way Trailer Connector Question: how can i get my dump trailer battery to charge off of my tow vehicle? as of now there is no wires going from 7 wire 6/14-1/12 cable in trailer to battery. asked by: J.R.M. Expert Reply: You will want to use a circuit tester like the Quickee Tester, # 3808, and check the # 4 terminal on the back the 7-way trailer connector on your trailer for power. This is the 12 volt power terminal so there should be power to that terminal. You will need to run a 10 gauge power wire like the, # 10-1-1, from the # 4 terminal 12 volt on the 7-way trailer connector on the trailer to the positive terminal on the trailer battery. This will allow you to maintain a charge on your trailer battery, it will not charge the battery from a discharged state. To be able to fully charge the trailer battery from a discharged state you would have to use the CTEK Multi US 3300 12-Volt Universal Battery Charger, # CTEK56158. This charger can be used to fully charge the battery and then you can maintain that charge with the vehicles charging system. I am sending a link to a picture of the 7-way trailer connector that will show the 12 volt power terminal. expert reply by: Jeff D I have the same question as J.R.M., but Im a little confused by your answer. 1. You mentioned above This will allow you to maintain a charge on your trailer battery, it will not charge the battery from a discharged state.inch My questions: Does this mean I can charge from my trucks 12-volt harness wire as long as the battery is not fully discharged?? Is there the possibility of overcharging on long trips?? If so, should I install a battery tender/charger in the circuit to prevent overcharging of the trailer battery??

asked by: DeWane

Expert Reply:

The issue is that trailer wiring is too small and vehicle alternators are rarely strong enough to push back the amperage needed to charge up a trailer mounted battery (unless it is a small breakaway system battery). The amount of power sent back is only enough to keep the battery at the level of charge it is currently at.

Having the 12 volt circuit connected to a 12 volt trailer battery will not over charge it because it cannot charge it up so no worries there.

When you have access to shore power (AC power) you would want to charge the trailer battery using a charger such as # CTEK56353. I own this charge as do several co-workers and it works beautifully. It will not over charge a battery like old trickle chargers and it can help recondition a battery for a longer life.

expert reply by: Michael H