Can a Trailer Mounted Battery be Charged Up Using a Breakaway Battery Charger

Question:

We currently have a small battery with charger and light to indicate power for our breakaway switch. We also have a large sorry dont know the exact size, lets say standard RV battery deep cycle battery for running our electric jack and lights when were not connected to the truck. Its hooked inline with the smaller battery so it always says charging on the small battery as the large one is always drawing current to charge itself up. Can we use 20011 charger for the large battery and do away with the small one altogether?? If we can is there an accessory light that shows the green/yellow/red charge indication that the small battery has built in??

asked by: Morgan

Expert Reply:

A charger such as # 20011 will not be able to charge up a regular battery, only small breakaway batteries. The issue is that the wiring on the trailer and vehicle is not large enough and the alternator is not strong enough (on most vehicles) to push back the amperage required to charge up a battery. At best it can only maintain the charge level of the battery.

Also, you will want to disconnect the breakaway battery from the larger battery. Otherwise it will just drain it and also shorten the life of the breakaway battery. You could split of from the power wire on the trailer side connector and run that directly to the positive battery terminal on the larger battery and that will also provide the maintenance charge without involving the smaller battery.

The best way to charge the larger battery would be to plug it up to an AC powered battery charger such as # CTEK56353 when you have access to shore power.

expert reply by: Michael H