Oct-07-2020 04:59 PM
Oct-10-2020 06:33 PM
Oct-10-2020 05:31 PM
3 tons wrote:srschang wrote:StirCrazy wrote:
why is this an issue at all? If you have a proper solar set up do you need power from the truck? I disconected that part of my wiring so I only have the solar set up powering the camper when I am not pluged into power.
Steve
Same here, BUT I have 4 panels installed to charge my 2 100ah Battle Borns. We've never run out of power, but there have been rainy days where the batteries only get back up to 90% charged.
I wasn't sure if it would be OK to have the 14.6v from the camper converter backfeeding into the truck batteries / electrical system, so I disconnected the 12v cable from the truck.
Exactly, with the exception if running a compressor refrigerator during inclement weather...
Oct-10-2020 11:15 AM
J.Duncan wrote:
Would you mind providing pictures and descriptions of equipment procured and set up, it sounds like you have it dialed in for what I’m looking to do.
Oct-10-2020 10:47 AM
3 tons wrote:
Exactly, with the exception if running a compressor refrigerator during inclement weather...
Oct-09-2020 03:37 PM
srschang wrote:
I wasn't sure if it would be OK to have the 14.6v from the camper converter backfeeding into the truck batteries / electrical system, so I disconnected the 12v cable from the truck.
Oct-09-2020 10:59 AM
srschang wrote:StirCrazy wrote:
why is this an issue at all? If you have a proper solar set up do you need power from the truck? I disconected that part of my wiring so I only have the solar set up powering the camper when I am not pluged into power.
Steve
Same here, BUT I have 4 panels installed to charge my 2 100ah Battle Borns. We've never run out of power, but there have been rainy days where the batteries only get back up to 90% charged.
I wasn't sure if it would be OK to have the 14.6v from the camper converter backfeeding into the truck batteries / electrical system, so I disconnected the 12v cable from the truck.
Oct-09-2020 05:53 AM
StirCrazy wrote:
why is this an issue at all? If you have a proper solar set up do you need power from the truck? I disconected that part of my wiring so I only have the solar set up powering the camper when I am not pluged into power.
Steve
Oct-09-2020 05:33 AM
Oct-08-2020 11:57 AM
Siletzspey wrote:Bert the Welder wrote:
use of the second alt ... big ga. wire ... 7-pin
The challenge is battling "voltage drop" over long lengths of charger wires.
Though a typical alternator puts out ~14.4V, that voltage drops to 13.some volts over a typical 7-pin setup where the NEG and POS wires are typically 10-12ga. My 2015 F350 has 10ga for NEG/POS, and be warned some umbilical cords use down to 16ga for POS/NEG. Below 13.6V delivered volts, a LiFePO4 won't really pull current and thus charge. Ideally you want 14.4V+ delivered volts for a LiFePO4 battery to quickly and fully charge, and to enable the LiFePO4 BMS to do cell balancing.
For lead acid batteries, most people report getting 5-10A of anemic charging off the 7-pin, and I believe the 7-pin connectors themselves are only rated for ~30A, and truck manufacturers usually fuse the POS wire at 30-40A.
Some people run LARGE (1/0AWG+) dedicated copper wires thru say Anderson Connectors, but don't under-estimate the weight and EXPENSE of such a setup, and you'll often still be getting suboptimal voltages. At 45' one-way of 1/0AWG wire, 14.4V drops to 13.9V under a hypothetical 60A load.
The increasingly common approach is to install a DC-to-DC charger that can boost the voltage coming off your wiring into what the LiFePO4s want for optimal charging, and it can limit the current draw on your alternator.
Speaking of a second alternator... picking on a 100Ah BattleBorn, the max-max charge rate is 100A, and the recommended max charge rate is 50A, and the longevity of the battery can be further increased by not even pushing 50A.
It begs the question, how big will your battery bank be? Two or eight 100Ah batteries? How fast do you want to charge?
With my 2 100Ah BattleBorns, I went with a 60A DC-to-DC charger so that each gets 30A, and if a battery BMS happens to shut off, dumping all 60A into a single battery won't be fatal. 60A into the batteries translates into a load of 60-80A on the alternator, which is well within the ability of a single and typical 200A truck alternator to deliver. With just 60A of charging for a 200Ah bank, I don't need to drive much to recharge from empty.
--tg
Oct-08-2020 11:20 AM
Bert the Welder wrote:
use of the second alt ... big ga. wire ... 7-pin
Oct-08-2020 11:02 AM
Bert the Welder wrote:
Does the second alt still need some connection to the truck "brain" so charging is disconnected when the truck is turned off, so doesn't drain the truck batt. or is it not hooked up to the trucks "brain" at all and a stand alone automatic or manual on/off switch installed in-line?
Oct-08-2020 10:22 AM
Bert the Welder wrote:Kayteg1 wrote:J.Duncan wrote:
B2B charger could you elaborate?
Battery 2 Battery charger.
Lithium batteries operate with higher voltage than truck alternator provides, so you need B2B charger and also solar charger + converter who can adjust the voltage.
Some RV owners have power obsession and Sprinters owner are generally willing to spend more money on gadgets, than TC owners.
Cover your roof with solar panels, add lithium battery bank, replace chargers with computerized system and you can easy spend 5 grands on the project.
Some owners make 2nd alternator just for lithium charging.
This use of the second alt. as a charger is interesting, especially being in the market for a new truck. So for those of us in the cheap seats and if you don't mind expanding on it:
Does the second alt get disconnected completely from the trucks systems?
Does a big ga. wire from it replace the existing charge wire from the primary alt. running back to the truck bed plug that the camper plugs into, like the standard 7-pin or is it run to a separate connector and is in addition to the stock 7-pin charging wire?
Does the second alt still need some connection to the truck "brain" so charging is disconnected when the truck is turned off, so doesn't drain the truck batt. or is it not hooked up to the trucks "brain" at all and a stand alone automatic or manual on/off switch installed in-line?
Thanks for the info. 🙂
Oct-08-2020 09:09 AM
Kayteg1 wrote:J.Duncan wrote:
B2B charger could you elaborate?
Battery 2 Battery charger.
Lithium batteries operate with higher voltage than truck alternator provides, so you need B2B charger and also solar charger + converter who can adjust the voltage.
Some RV owners have power obsession and Sprinters owner are generally willing to spend more money on gadgets, than TC owners.
Cover your roof with solar panels, add lithium battery bank, replace chargers with computerized system and you can easy spend 5 grands on the project.
Some owners make 2nd alternator just for lithium charging.
Oct-08-2020 08:48 AM
J.Duncan wrote:
B2B charger could you elaborate?