Double Alternators
Would most agree that on a Diesel, the option to have double alternators is a good idea if the option is available? Your thoughts please.
Forum Discussion
- Got to be a bit pedantic about this.
-- Do you mean two alternators in parallel, which is what most manufacturers do, or,
-- Do you mean two independent alternators?
Two alternators in parallel basically act like one bigger alternator and this may be all you need. (This is what I have on my truck to charge 150Ah of starter and 600Ah of camper. The advantage of this set up is that all all of the amps produced by the two alternators are available to all of the batteries. (Assuming, and this is important, proper wiring.)
With two, separate alternators you may have less total amperage available, but you have the possible advantage that the second alternator/regulator can have a different charging profile. (This may or may not be important.) This thread may be useful: http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/19027379/gotomsg/19029509.cfm#19029509 User Mike Tassinari has a very nice dual alternator set up. Do note that is is using cables that are MUCH larger than any standard tailer connector.
It is worth noting that with a large camper battery bank, say 200+ Ah, you may never drive long enough to achieve a full charge with any alternator(s) and you will probably need a secondary charge source - solar or shore power. As this secondary charge source is the one that will take the batteries from bulk through acceptance charge, to float, is is important that this charger have the proper profile to match the camper batteries. - Yes, I have a dual alternator setup. Second alternator charges my house batteries (which are AGM and require a different charging profile)
- Because I almost always dry camp and I have a total of 4 RV batteries. I most certainly recommend it.
It also has another benefit. Because the batteries are on a completely different circuit. In the case of your engine circuit alternator failure. You can use the RV battery circuit batteries to jump start the engine. I do have a overhead camper so this becomes more apparent. Two RV batteries are under the hood connected to one RV battery in the camper and one in the trailer. I use the slide in type connectors from the ends of two jumper cables to connect the trailer to the Camper. Forgot the size of the wire, but they are thick, connecting the two under the hood with the other RV batteries. I have a 100 amp fuse on that lead at the batteries.
I did use this once. While out in the middle of nowhere. Just make sure you have a set of jumper cables as part of your tool kit.
If you have a overhead camper. I certainly would recommend the dual alternators no mater what engine you have. - That is a yes/no answer in reality. Same could be said from a gas motor standpoint too.
If you are charging a LOT of batteries tween the truck starting setup, along with a house bank, MANY added running lights etc that use more power than a standard alternator can or can not charge in a reasonable time a larger or multiple alternator setup would be good.
Otherwise, not real sure it is something I would do to have this unless needed, as having multiple or a single larger alternator will use HP of the motor to run, causing lower mpg's, slower acceleration, overall top speed etc.
At the end of the day, no real right or wrong, more depends upon circumstance of your useage etc.
Marty
