battery charging> which is best

gocamping14 wrote:
which method of charging a battery would be the fastest and most efficient when off the grid.

a. plugging the camper into a generator, running of course. (110v line)

b. plugging camper into the drive vehicle and running the engine.
(reg. 7 pin connection)

c. using a battery charger accessory on a generator running.

your thoughts, thanks............

ss

a) if you mean charging with the rig's on-board converter, then Abs voltage is everything. For example, at 14.6v (boost), my pm4b-45 would be putting out it's 45a limit, but when it dropped to 13.6 Vabs, current would drop to about 19a, and taper from there... thus adding several hours to the charge time.

b) charging via the vehicles alternator requires heavy cabling, otherwise excessive voltage drop will have the same effect as mentioned above, in a).

c) generators are very limited in their charging-amperage abilities, compared to the size of ac-dc charger they can support. I think someone said an eu2000i charges at 8a... compare that to running a 60a, or even a 75a(pfc) charger... 2-3 hrs vs. a day or two.

The problem is, there's not much available in the way of chargers, in the 50-100a range, so converter-chargers are usually the least expensive way to go. But you need one that holds a decent Abs Voltage (say 14.4-15.0v). On the flip side, there are lots of adjustable voltage bench power supplies available in the say 10-36a range, at very reasonable prices. And a good, reliable 40a portable is hard to find... the vec1093dbd being the leader of its class, it seems.