Couple of questions about DC-Dc charging
I've been thinking about adding a DC-DC charger now that I've added 400 amp hours of AGM batteries. There are lots of useful posts but I haven't run into a couple of things I'm curious about. One ...
Forum Discussion
One advantage to the DC-DC is:
If you also have solar, then the usual alternator charging would be at a lower voltage (14.1 say) than the Vabs set on the solar controller (14.6 say). So they don't add their amps very well. You get all the solar amps but only some of the "alternator" amps.
The DC-DC charger has a range of selectable voltages for Vabs, so you can choose one that is close to the solar controller's setting so they add their amps completely.
This is good if you are driving in the sunshine. If not, then all you have is the DC-DC amps, which might be less than what you would get with no DC-DC depending on all the things mentioned above in the thread. It is scenario that matters as usual.
On balance, given RVers like to camp in better weather, most likely when driving during the day for just a few hours between camp sites, there will be some sunshine. So DC-DC plus solar where they add their full amps could be the better choice most often.
If you also have solar, then the usual alternator charging would be at a lower voltage (14.1 say) than the Vabs set on the solar controller (14.6 say). So they don't add their amps very well. You get all the solar amps but only some of the "alternator" amps.
The DC-DC charger has a range of selectable voltages for Vabs, so you can choose one that is close to the solar controller's setting so they add their amps completely.
This is good if you are driving in the sunshine. If not, then all you have is the DC-DC amps, which might be less than what you would get with no DC-DC depending on all the things mentioned above in the thread. It is scenario that matters as usual.
On balance, given RVers like to camp in better weather, most likely when driving during the day for just a few hours between camp sites, there will be some sunshine. So DC-DC plus solar where they add their full amps could be the better choice most often.
