RedArc BCDC Battery Charger Compatibility with Variable Voltage System and AGM Batteries

Question:

Ive got a 2017 GMC Savana with 105 amp alternator that will be charging a pair of FullRiver brand AGM 6v 220ah deep cycle batteries located in my camper van conversion. This is a variable voltage charging system. FullRiver recommends a 44amp initial charge current. Will my 105amp alternator be overloaded supplying 400amps initially for aux battery charging? The batteries at 50 DOD would probably draw the full 40 amps for up to 2 hours before tapering down. The FullRivers also require higher voltage for boost and absorption than most AGMs. They agree that they require closer to Li charge voltages. Is the BCDC Li charge profile also suitable for AGMs as long as the batteries are rated for those voltages? Is the charge curve different or anything like that that would cause improper AGM charging? Thanks for your assist!

asked by: Glen D

Helpful Expert Reply:

The Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp # 331-BCDC1240D is designed to work with smart alternators like yours when you use the 60-Amp Relay Kit for Redarc In-Vehicle BCDC Battery Charger # 331-RK1260. You will also need to use the 60-Amp MIDI Fuse Kit for Redarc In-Vehicle 40-Amp BCDC Battery Charger # 331-FK60. This prevents your alternator being overloaded and it won't back-feed your alternator either. This system is rated for AGM or Lithium Battery use and there really is only one change for the lithium connection in connecting the green and orange wires for that feature. With your AGM batteries you won't connect them so you will use the top diagram on the attached photo. You don't need solar panels, that is just an optional feature that the charger is designed to be able to utilize.

expert reply by: Jason S