Anyone add a DC/DC Charger for chargin house batteries in an RV?

[ppine]

Adding a Renogy 50 amp charger to take advantage of the 220 amp alternator on my Ram diesel. It will charge lithium batteries going down the road. It is has a built in MTTP solar charger for when the rig is stopped.
There is a lot of protection built into this device. Anyone else using one?

 

[jsalbre]

I’ve installed a Renogy 60A DCDC in my last two trailers. I run 2Ga from the truck battery, through a 300A continuous duty solenoid switched by ignition hot, and to an Anderson connector at the bumper.

My control system (Victron Cerbo GX) disables it if the batteries are above 90% and the load is less than 60A.

Works great.

 

[AH64ID]

I’m planning to install the Victron 18A DC-DC charger in my 5th wheel next spring. It’s small enough I can use the existing wiring, and will still provide a better charge than the 7-pin alone.

 

[ammdrew]

I have a victron 18a dc/dc and it works perfect through the 7 pin.. charges the battery and keeps up with our 12v fridge. Much better then just the direct hook that was wired.. I have a victron shunt so I can see whats going in and out of the battery and we would barley sustain a charge before and now we easily charge to 100% while driving and it disconnects from the truck once we shut the truck off so no threat of draining the truck batteries at the Walmart overnights

 

[CdnHO]

I have a victron 18a dc/dc and it works perfect through the 7 pin.. charges the battery and keeps up with our 12v fridge. Much better then just the direct hook that was wired.. I have a victron shunt so I can see whats going in and out of the battery and we would barley sustain a charge before and now we easily charge to 100% while driving and it disconnects from the truck once we shut the truck off so no threat of draining the truck batteries at the Walmart overnights

Did you just wire it into the 7 pin cable where it connects to the trailer? My fridge is a 120 volt compressor conversion running on an inverter in the trailer and my batteries are pretty well dead at the end of a day on the road. Which model Victron are you using. I see several models on their website. Thanks.

 

[ammdrew]

18 amp dc/dc yes just disconnected the 7 pin hot wire at the junction box on the trailer and wired to the dc/dc. This was fairly easy on my flasgstaff.

Not sure how well you will do with a inverter pulling amps from the 12v but it should reduce the amount you lose on the road. really depends on amp use. I have a shunt so was more then comfortable we only lose 3-5 amps to the 12v fridge on average.

If you go with a larger dc/dc you may pull more then factory wiring can handle and need to run a separate hot lead from the batteries.

 

[AH64ID]

Did you just wire it into the 7 pin cable where it connects to the trailer? My fridge is a 120 volt compressor conversion running on an inverter in the trailer and my batteries are pretty well dead at the end of a day on the road. Which model Victron are you using. I see several models on their website. Thanks.

What is your DC amp draw with the inverter running the fridge?

 

[CdnHO]

What is your DC amp draw with the inverter running the fridge?

When both compressors are running, around 25 amps. It is a Norcold four door and I installed a 120 volt compressor conversion in it when the original cooling unit failed. It draws around 2.5 amps AC. I could have gone with 12 volt compressors but that would have meant running 8 gauge wiring to the slide which was going to be a real bear to do.

 

[AH64ID]

When both compressors are running, around 25 amps. It is a Norcold four door and I installed a 120 volt compressor conversion in it when the original cooling unit failed. It draws around 2.5 amps AC. I could have gone with 12 volt compressors but that would have meant running 8 gauge wiring to the slide which was going to be a real bear to do.

So you could probably get away with the 18A version, unless you have a lot of compressor on time. It wouldn't hurt to run separate wiring and get a 12/12-30 either.

 

[CdnHO]

So you could probably get away with the 18A version, unless you have a lot of compressor on time. It wouldn't hurt to run separate wiring and get a 12/12-30 either.

Compressor run time is depending on temperature of course but if I can arrive at the end of the day with more battery left is all I am looking for. Stopping for the night we always have shore power.

 

[CdnHO]

18 amp dc/dc yes just disconnected the 7 pin hot wire at the junction box on the trailer and wired to the dc/dc. This was fairly easy on my flasgstaff.

Not sure how well you will do with a inverter pulling amps from the 12v but it should reduce the amount you lose on the road. really depends on amp use. I have a shunt so was more then comfortable we only lose 3-5 amps to the 12v fridge on average.

If you go with a larger dc/dc you may pull more then factory wiring can handle and need to run a separate hot lead from the batteries.

Do you have a link to the one you bought? Thanks for the response.

 

[AH64ID]

Compressor run time is depending on temperature of course but if I can arrive at the end of the day with more battery left is all I am looking for. Stopping for the night we always have shore power.

The 12/12-18 is probably plenty.

https://www.amazon.com/Victron-Orion-TR-Isolated-Charger-Supply/dp/B0851TPKV7/ref=sr_1_3?crid=3AZ7SSNH1C8QS&keywords=Victron+12%2F12-18&qid=1697045256&sprefix=victron12%2F12-18%2Caps%2C267&sr=8-3&ufe=app_do%3Aamzn1.fos.18630bbb-fcbb-42f8-9767-857e17e03685

 

[ammdrew]

https://www.amazon.com/dp/B0851TPKV7?psc=1&ref=ppx_yo2ov_dt_b_product_details

Should be plenty and should actually be able to get your battery fairly charged as I would expect the compressor only runs part of the time. You can also watch what is happening on the bluetooth app while driving and really know what is happening with the current and the charge.