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 > Anyone made the dive to Lithium and had it in four seasons?

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Kayteg1

California > Nevada

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Posted: 10/08/20 12:02pm Link  |  Quote  |  Print  |  Notify Moderator

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?


My 2017 Ford has dual alternators as that was required for electric cabin heater, but from my research the 2nd alternator is integrated part of the system and not easy separable.
My Sprinter has electric cabin heater as well, but 250 amp alternator solves the need for more charging.
What I mentioned is that on Sprinters - owners who go that far add 2nd alternator with independent house charging system.
Again - this is for people who don't mind to spend few thousand$$ on the projects and no offence, but average Sprinter owner seems to be well better educated than average TC owner.
Bottom line - such project is not for just anybody.





Siletzspey

Shedd, OR

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Posted: 10/08/20 12:20pm Link  |  Quote  |  Print  |  Notify Moderator

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

J.Duncan

Florida

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Posted: 10/08/20 12:57pm Link  |  Quote  |  Print  |  Notify Moderator

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


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.

StirCrazy

Kamloops, BC, Canada

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Posted: 10/09/20 06:33am Link  |  Quote  |  Print  |  Notify Moderator

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


2014 F350 6.7 Platinum
2016 Cougar 330RBK

srschang

Western NY

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Posted: 10/09/20 06:53am Link  |  Quote  |  Print  |  Notify Moderator

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.


2020 Ram 3500 SRW Crewcab Longbed Cummins, 2019 Northstar 12 STC

3 tons

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Posted: 10/09/20 11:59am Link  |  Quote  |  Print  |  Notify Moderator

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...

Kayteg1

California > Nevada

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Posted: 10/09/20 04:37pm Link  |  Quote  |  Print  |  Notify Moderator

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.


You must drive Dodge, as Ford has trailer charging relay?
But regardless, B2B charger should prevent it.
This is leading us into higher end technology, where battery monitors can be $300 units, who have artificial intelligence.
Beside the high cost, ask yourself if you are educated enough to troubleshoot the system when something goes wrong?
And being that new technology, with limited demand - baby teeth are expected.

toddb

az

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Posted: 10/10/20 11:47am Link  |  Quote  |  Print  |  Notify Moderator

3 tons wrote:



Exactly, with the exception if running a compressor refrigerator during inclement weather...


I put in a 110w dc-dc charger to keep up with my compressor fridge. I have been shutting the solar off on the drive home. It's worked out well with the battery drawn down to ~50-60% when we get back so I can just disconnect.

Siletzspey

Shedd, OR

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Posted: 10/10/20 12:15pm Link  |  Quote  |  Print  |  Notify Moderator

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.


Attached are two diagrams with embedded comments.

I personally felt 60A of alternator charging into 2 x 100Ah batteries was adequate, and that I was avoiding some safety, longevity and cost issues by NOT pushing for 100A+ of charging. I was shooting for a happy medium.

While the 2AWG wire and Sterling charger are mostly installed, I have not yet turned that part of the system on. I have been stunned at how well 300W of solar into 200Ah of LiFePO4 has been working.

http://www.barbless.com/share/www-rv-net/201010-NL-LiFePO4-Overview.png
http://www.barbless.com/share/www-rv-net/201010-NL-LiFePO4-Wiring.png
http://www.barbless.com/share/www-rv-net/201010-NL-LiFePO4-Picture.jpg
http://www.barbless.com/share/www-rv-net/201010-NL-LiFePO4-Picture2.jpg
http://www.barbless.com/share/www-rv-net/201010-NL-LiFePO4-Picture3.jpg

--tg

* This post was edited 10/10/20 12:29pm by Siletzspey *

StirCrazy

Kamloops, BC, Canada

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Posted: 10/10/20 06:31pm Link  |  Quote  |  Print  |  Notify Moderator

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...


yess that would be a reason to have 12V available if your driving at night. I use propane for the fridge, but I didnt want to take the chance that something would suck the truck batteries down while I was camping.

Steve

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