Battery Charger Recommendation for Trailer with 2 Batteries

Question:

I have an aux battery in my 85 Westy with the Hella single relay kit. This doesnt really keep my aux battery fully charged. The main battery runs at about 12.59 volts or so but the aux wont get about 11.57. Is there some other way I can get the aux to fully charge?

asked by: Andy

Expert Reply:

It's really pretty hard to charge a set of trailer batteries efficiently while the trailer is being towed. The 12 volt wiring that leads to trailer batteries just doesn't have the thickness to carry enough amperage. We recommend people use wall outlet chargers like the NOCO Genius Battery Charger and Maintainer # 329-GENIUS5 to charge the battery when parked and then let the trailer's wiring put a maintenance charge on the batteries.

expert reply by: Jameson C