The
Renogy 40-Amp DC-to-DC battery charger had been on my Amazon wishlist for a while, and it was on sale during the holidays, so I bought one. I was planning on getting it anyway for our upcoming Lithium battery upgrade (coming soon). A DC-to-DC charger is required to limit the current draw from the alternator, particularly with Lithium batteries, which can draw a large amount of current from the alternator while charging.
According to
Mercedes Body and Equipment Guidelines for 2018 Sprinter and older, it states that the maximum charging current for the auxiliary batteries should not exceed 40-Amps. For now, our current AGM coach batteries will benefit from the DC-to-DC charger as it will receive a proper 3-stage charging (bulk, absorb, float) while driving or idling.
