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pianotuna
Regina, SK, Canada
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Joined: 12/18/2004
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Reisender wrote:I’m not sure what the source is here. Is it the trucks 12 volt system you want to use to charge the truck campers battery? Why would you need a DC to DC converter for that. That is what the trucks charge line is for on the 7 pin. What am I missing?
We use a DC to DC converter but it is from one static battery bank to another. So no alternator etc.
My oem and additional charging circuits worked well for lead acid. But when I changed to telcom, I got no charging from the alternator unless something such as the microwave was running.
I've added a dc to DC 20 amp charger, and I'm seeing up to 19.6 amps going into the house bank. I started a thread with my observations.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.
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Reisender
NA
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Joined: 12/09/2018
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pianotuna wrote:Reisender wrote:I’m not sure what the source is here. Is it the trucks 12 volt system you want to use to charge the truck campers battery? Why would you need a DC to DC converter for that. That is what the trucks charge line is for on the 7 pin. What am I missing?
We use a DC to DC converter but it is from one static battery bank to another. So no alternator etc.
My oem and additional charging circuits worked well for lead acid. But when I changed to telcom, I got no charging from the alternator unless something such as the microwave was running.
I've added a dc to DC 20 amp charger, and I'm seeing up to 19.6 amps going into the house bank. I started a thread with my observations.
Interesting. Thanks Don.
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Hemi Joel
Minnesota
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Joined: 07/24/2014
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I just use a pair of 8 gauge wires from the truck battery to the camper batteries. That eliminates the voltage drop of the 7 pin and puts a nice charge into the camper batteries whenever I drive. I use a 200 amp blade switch that is mounted on the truck battery to isolate the truck battery when the situation calls for it, but that is rare.
2018 Eagle Cap 1163 triple slide, 400W solar, MPPT, on a 93 Dodge D350 Cummins, DTT 89 torque converter, big turbo, 3 extra main leafs, Rancho 9000s rear, Monroe gas magnums front, upper overloads removed, home made stableloads, bags.
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pianotuna
Regina, SK, Canada
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Hemi Joel wrote:I just use a pair of 8 gauge wires from the truck battery to the camper batteries. That eliminates the voltage drop of the 7 pin and puts a nice charge into the camper batteries whenever I drive. I use a 200 amp blade switch that is mounted on the truck battery to isolate the truck battery when the situation calls for it, but that is rare.
I added dual #8 wires. When I switch to telcom jars--no more charging. I do have manual control over the 200 amp solenoids I added. The dc to DC charger was, for me, a huge improvement.
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deltabravo
Spokane, WA
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Joined: 09/08/2003
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I mounted my Victron Orion in the camper as shown here
I already did a cable upgrade between the truck can camper back in 2015. Here's that project
2009 Silverado 3500HD Dually, D/A, CCLB 4x4 (bought new 8/30/09)
2018 Arctic Fox 992 with an Onan 2500i "quiet" model generator
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theoldwizard1
SE MI
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Hemi Joel wrote:I just use a pair of 8 gauge wires from the truck battery to the camper batteries. That eliminates the voltage drop of the 7 pin and puts a nice charge into the camper batteries whenever I drive.
It has been proven 100s of times, that with modern vehicles, large gauge wires will NOT give you a 100% charge on your auxillary battery bank.
Some charge, yes. Just not 100%.
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theoldwizard1
SE MI
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deltabravo wrote:I mounted my Victron Orion in the camper as shown here
I already did a cable upgrade between the truck can camper back in 2015. Here's that project
Of course, you now know that wiring upgrade is not required when you get a new truck !
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deltabravo
Spokane, WA
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theoldwizard1 wrote:Of course, you now know that wiring upgrade is not required when you get a new truck !
No, I don't know that.
I can't envision how the excessively long wire run of smaller gauge wiring of the stock truck wiring (on a new truck) will provide the amperage I see with my upgraded system
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Hemi Joel
Minnesota
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theoldwizard1 wrote:Hemi Joel wrote:I just use a pair of 8 gauge wires from the truck battery to the camper batteries. That eliminates the voltage drop of the 7 pin and puts a nice charge into the camper batteries whenever I drive.
It has been proven 100s of times, that with modern vehicles, large gauge wires will NOT give you a 100% charge on your auxillary battery bank.
Some charge, yes. Just not 100%.
That makes no sense at all. The alternator doesn't know how many batteries are connected to it. It senses voltage. Batteries that are connected equalize over time.
Regardless, it has been working for me for over 10 years. If you want to buy a device to charge your 12 volt batteries better than a 12 alternator that was designed to charge 12 volt batteries, that's your call.
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HMS Beagle
Napa, California
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Joined: 08/22/2003
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With a modern vehicle the charge voltage will be at least 13.5 volts, probably more. That will charge the house batteries 100%, though it may take a long time, and only if the charge wire to the camper is large enough to service the house loads. If you have your refer on DC for example, it is drawing around 30 amps. The #10 typical of a 7 pin harness will be dropping about 1.8V in the 60' round trip on the wire. Now your 13.5V is only 11.7 and, yeah, no charge, in fact it will drain the house. May burn up the 7 pin too. Change that wire out to #6 with a proper connector, and even at the same length and amperage, you will have a 0.7V drop, your 13.5 volts is now 12.8, almost no charge but at least not draining the house battery
A DC to DC charger placed near the alternator, without remote sense, does not solve this wiring problem, voltage will still be low. Placed near the load, or with remote sense near the load, it band-aids the problem: It will boost the voltage back to where is it supposed to be, at the cost of drawing even more current through the inadequate wires.
You need to address the wiring problem first, then consider a DC to DC charger. Or don't run large house loads (like the refer) on DC.
Bigfoot 10.4E, 2015 F350 6.7L DRW 2WD, Autoflex Ultra Air Ride rear suspension, Hellwig Bigwig sway bars front and rear
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