DC to DC charger

[jdcellarmod]

Thinking of installing a Victron charger for those days on the road when solar is not available. Can the charger be used in conjunction with an inverter (2000 watts) to run the refrigerator on electric while on the road?

Thanks, Jeff D

[Hemi_Joel]

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.

[Reisender]

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.

[pianotuna]

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.

[Reisender]

StirCrazy 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.

the 7 pin wire is small, lots of voltage drop. so if your altanator is putting out 13.5V, just to pick a number, by the time it is down at your rv batteries it could be in the 12's, also unless you buy a battery isolater the rv can suck down the truck batteries if you leave it plugged in. I believe newer vehicles may come with that but the wires are still to small.

a dc to dc charger mounts as close to the battery as you can, and you run a new wire, or use your 7 pin, directly from the truck battery to the DC to DC. the charger then turns what ever it is getting into a proper voltage for your batteries. as a bonus it also isolates your truck batteries from the rv batteries so you cannot drain your truck down.

if you use the 7 pin charge line to feed it the inlett amps will be up to 50% higher than the ouput amps, the reason to run a larger wire on a plug is to lower that difference by making less voltage drop on the feed.

so you can also set the charging profiles on the dc to dc charger so if you have deep cycle batteries it will get the best charge as aposed to what ever the starting batteries in the truck get. same goes for gel and Li.

I am installing on in my camper in the spring, this will let me have a emergency source of power for charging if I hit a ton of dark days when I am lait fall/early winter camping. my solar handles everything but last year I saw three days of rain and dark and I was hitting the 50% mark on y deep cycle from running the furnace all the time. I have a 10 day cussion now with the LiFePO4 cell I built but, with the dc tyo dc, in 1.5 hours I can recover 24 hours power use if I need to.

Thanks for the explanation. That all makes sense. I didn’t think it would be a problem with the drop from the alternator but yah. I get it.

We use ours very rarely. When we are dry camping we have a little 2000 watt propane generator we use for keeping the battery up on our little trailer if the solar conditions are bad. (Meaning shady sites etc). But we have stayed at a no generator campground a couple times. We plugged into the 12 volt receptacle in the trunk of the Tesla which kicks out 13.6 volts and then set the DC to DC converter to 14.4 volts to trickle charge the trailer battery for half a day. Got us thru the last couple of days of a camping trip. Handy devices.

Thanks again for the explanation.

[Bedlam]

I am collecting the pieces for a Renology 60A DC to DC setup. I run half worn out AGM's because they are free to me, so every once in while my solar cannot keep up and the batteries don't have sufficient capacity.

[StirCrazy]

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.

the 7 pin wire is small, lots of voltage drop. so if your altanator is putting out 13.5V, just to pick a number, by the time it is down at your rv batteries it could be in the 12's, also unless you buy a battery isolater the rv can suck down the truck batteries if you leave it plugged in. I believe newer vehicles may come with that but the wires are still to small.

a dc to dc charger mounts as close to the battery as you can, and you run a new wire, or use your 7 pin, directly from the truck battery to the DC to DC. the charger then turns what ever it is getting into a proper voltage for your batteries. as a bonus it also isolates your truck batteries from the rv batteries so you cannot drain your truck down.

if you use the 7 pin charge line to feed it the inlett amps will be up to 50% higher than the ouput amps, the reason to run a larger wire on a plug is to lower that difference by making less voltage drop on the feed.

so you can also set the charging profiles on the dc to dc charger so if you have deep cycle batteries it will get the best charge as aposed to what ever the starting batteries in the truck get. same goes for gel and Li.

I am installing on in my camper in the spring, this will let me have a emergency source of power for charging if I hit a ton of dark days when I am lait fall/early winter camping. my solar handles everything but last year I saw three days of rain and dark and I was hitting the 50% mark on y deep cycle from running the furnace all the time. I have a 10 day cussion now with the LiFePO4 cell I built but, with the dc tyo dc, in 1.5 hours I can recover 24 hours power use if I need to.

[Reisender]

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.

[terrybk]

I'm running a Renogy 40A but with dual alternators. If I unplug one alternator you can see the voltage sag for a second and then it comes back up as the PCM cranks up the alternator output. But I didn't want the alternator to run super hot with a lot of current draw (recharging both the starter and camper batteries at around 80 amps) so I installed the second alternator. The voltage doesn't blip.

[deltabravo]

I have been using a 30 amp Victron also. It works very well.

[pianotuna]

I've installed the 20 amp dc to DC charger. I love the results. I started a thread on what I've been able to glean.

[WarrenS65]

I have the Victron Orion 30 A and it's working great. I plan to add a second one as well. My truck has dual alternators so I'm not worried about overworking them.
I run my absorption fridge when parked at home, on the move, or when I have shore power. At camp I run on propane to save the batteries for other stuff.

[deltabravo]

jdcellarmod wrote:
Can the charger be used in conjunction with an inverter (2000 watts) to run the refrigerator on electric while on the road?

Yes. I do it all the time when driving to save propane.

[SoonDockin]

I have been using a 30 amp Victron also. Works well. If your vehicle has the charging capacity, you could run more than one 30 amp unit.

[Camper_Jeff___K]

I have the victron 30 amp model. Works great and puts out about 360 watts. My absorption fridge uses 325 watts. I have 400 AH lithium battery so plenty of capacity to run the fridge. I do regularly run the fridge on the TC solar electric system with great performance. The dc dc charger works great.

[Lwiddis]

My solar system produces in shade. Not a bunch but produces.