Best additional 12V plug

[kipper]

So I am looking to install a renogy DC-DC converter in my setup for safe charging while driving from TV to Trailer.

The 7 pin connector ampacity is a little low to use and the renogy also needs a + signal to start the charge (typically from the ignition on). I could leave the charger in the TV and then only need the 2 wires to my battery but I am not settled on either way yet.

What is the best additional connector system? need possibly 3 wires and 2 of them need to handle 20A (I am looking at the renogy 20A unit).

Thanks!

[Raspy]

I just installed an Anderson plug on the back of my truck, next to the seven pin plug. It is a 50 amp style and is fed by #6 wires. I installed a 60 amp breaker/disconnect next to the battery, and routed the wires to the back of the truck. These breakers are cheap, resettable, small, can be used as a disconnect and are waterproof.

Mine is not an automatic disconnect, but that can be easily done with a relay.

When hooking up, I plug in the seven pin and the Anderson plug. The trailer side of the Anderson has its own pigtail that is wired with #6 wires back to the batteries and through another breaker on that circuit.

This arrangement supplies a lot of power to the trailer and gives me a place, while camped, to plug my suitcase solar into the trailer. No more wondering if I'll get enough power to charge the batteries while driving and I can confidently run the fridge on 12 volts. A huge improvement.

[kipper]

Thanks Raspy it does seem like the Anderson style is the ticket after looking at them. Made for this kind of usage.

Sounds like you have a sweet setup. I was going down the DC-DC converter path after reading the stories of people forgetting to unplug or just going shopping for a few hours and then not being able to start their vehicle.As you mentioned that could be solved with a relay circuit tied to the ignition to pull in / drop out automatically and then you get full power to the trailer batteries for charging and running the fridge while driving.

I think both methods are fine as the dc-dc has some extra protections built in and they state the output will remain steady even if the input drops due to voltage drop on the wires. I am not certain its worth it but e-trailer seemed to think so in the article that got me onto it first.

[Raspy]

Andrew,

I don't know about the strategy of a dc-dc converter, but battery charging is not done correctly at a steady output. Three stages are nice to have. The typical automotive strategy is to take them up to 14.1-14.5 with full alternator output. That works while driving, but not as a steady diet.

If the battery is low, high output is best to bring it up fast. That would be bulk. Then the amps are reduced to not drive the battery past 14.5 volts. And then, at a pre-determined output, a drop to just over 13 volts for the duration of the run. I've discovered that my Ram charges somewhere north of 14 volts first, and then drops to around 13 for longer term running, after the batteries are up to some charge level. I haven't measured the exact voltages, but they are displayed on the dash. This means you get full power to bring low batteries up fast, but a lower running voltage to "float" them during longer run times. In my case it can take two hours or so to drop to 13 when connected to the four 200 AH AGMs in the trailer. I arrive fully charged, even if running the fridge, as long as it has had enough time.

Compare the difference between the typical trickle charge from the seven pin, and the ability to bring four 200 amp hour batteries up, while running the fridge. Or charge them at camp while idling the truck for a little while. The Anderson plug and wiring is a significant improvement. Further, this is how the Australian caravans do it, and they are set up that way from the factory. Mine came from the factory with an Anderson plug at the tongue, pre-wired with #6 wires straight to the batteries.

This would also be handy if you did not have solar, or a generator, and needed to charge the batteries while at camp. Just plug in the Anderson plug, and idle the truck. I used to use jumper cables on my Oliver, from the truck battery to the Oliver batteries, and it charged the batteries faster than my 2000 watt generator. Now, I can simply plug in if needed.

Here's a pic of the simple plug:

[kipper]

Thanks for the info sounds like your Ram does automatically what the DC-DC converter is meant to do. Since I am towing with an older Sienna I am not sure it is quite as setup from the factory but would be worth a test as it has to manage its battery somehow. With the 20A limit for bulk on the Renogy I am looking at it might take a bit more driving time to charge but my needs are low, or at least I think so at this point (still a greenhorn here..) there is a 40A unit available however.

My thought was to run the fridge on propane most of the time, other than driving, and then the battery is mostly saved for running the fantastic fan and led lights which are low wattage in my 14' surfside. I also have a 80W portable solar setup for during the day to help out. Then I can plug in at times also to top it up with the built in AC to DC charger

Never thought about idling the vehicle to charge up the battery in a pinch but it is a great solution. Cant pollute anymore than the generators really.

So yeah anderson plug it is thanks for the pictures, and will investigate further if the DC-DC is necessary.

[minke]

Originally Posted by Raspy

Andrew,

I don't know about the strategy of a dc-dc converter, but battery charging is not done correctly at a steady output. Three stages are nice to have. The typical automotive strategy is to take them up to 14.1-14.5 with full alternator output. That works while driving, but not as a steady diet.

If the battery is low, high output is best to bring it up fast. That would be bulk. Then the amps are reduced to not drive the battery past 14.5 volts. And then, at a pre-determined output, a drop to just over 13 volts for the duration of the run. I've discovered that my Ram charges somewhere north of 14 volts first, and then drops to around 13 for longer term running, after the batteries are up to some charge level. I haven't measured the exact voltages, but they are displayed on the dash. This means you get full power to bring low batteries up fast, but a lower running voltage to "float" them during longer run times. In my case it can take two hours or so to drop to 13 when connected to the four 200 AH AGMs in the trailer. I arrive fully charged, even if running the fridge, as long as it has had enough time.

Compare the difference between the typical trickle charge from the seven pin, and the ability to bring four 200 amp hour batteries up, while running the fridge. Or charge them at camp while idling the truck for a little while. The Anderson plug and wiring is a significant improvement. Further, this is how the Australian caravans do it, and they are set up that way from the factory. Mine came from the factory with an Anderson plug at the tongue, pre-wired with #6 wires straight to the batteries.

This would also be handy if you did not have solar, or a generator, and needed to charge the batteries while at camp. Just plug in the Anderson plug, and idle the truck. I used to use jumper cables on my Oliver, from the truck battery to the Oliver batteries, and it charged the batteries faster than my 2000 watt generator. Now, I can simply plug in if needed.

Here's a pic of the simple plug:

Do you do anything to weather protect the Powerpoles?

[Raspy]

An added benefit to this is not running a propane flame while driving. I have never worried about that, but it has come up here a number of times, and the concern has merit. Gas stations and tunnels, etc. The hassle of turning off the propane and then turning it back on after fueling. Regardless of that potential issue, it's nice to save a bit of propane by not running it at all during the many hours spent actually driving.

While at North Rim, a ranger came by and noticed my hood up, the engine running and jumper cables going to the trailer battery. She immediately came over and told me they don't allow that. I commented that idling the truck is quieter than a generator, our spot was completely shaded, I had no generator, and my batteries were way down. I told her she was essentially throwing us out. She suggested we move to a sunny spot near the entrance gate temporarily to get some solar. Meanwhile a ridiculously loud generator was struggling along, a hundred yards away, and very annoying. No problem with that. So, with this new method, nobody would even notice if we were charging. A stealth charge with merely and idling truck. If we have sun, the suitcase plugs into the same spot.

A week and a half ago, at Valley of Fire, I was reminded of how annoying generators are. Even quiet ones, run by polite campers, during allowed hours. I decided sometime ago to not bring my delightful little Yamaha generator along at all. Three weeks ago, at Death Valley, the place sounded like a construction site with a larger genny powering loud music and a flood light that turned night into day. The only thing that offset that irritation was the spectacle of the gall at disrupting an entire camping area and the reactions of other campers that made it abundantly clear what an assault it was. The idea that a group could be so clueless was, in itself, a show. The disruption was so bad the rangers were called and had to drive out there from about 60 miles away to restore peace. The next night, it was back on. I'm still laughing.

[Raspy]

Originally Posted by minke

Do you do anything to weather protect the Powerpoles?

The back of the plug, where the wires enter, is filled with E6000 glue that seals it completely. The front has a rubber weather cap that goes on when unplugged. I think a bit of rain won't bother it, but salt spray might. I rinse it out with windex from a spray bottle and can shoot in some WD 40 as needed. I can also shut off that circuit under the hood with the circuit breaker/disconnect. The trailer side plug is also filled with sealant and has shrink tube protecting it. Not a perfect water tight solution, but entirely adequate. The glue and the shrink tube also give it strength so it can fly across from the trailer to the truck alongside the umbilical. They are taped together to help with the strain.

[charlsara]

Originally Posted by Raspy

I just installed an Anderson plug on the back of my truck, next to the seven pin plug. It is a 50 amp style and is fed by #6 wires. I installed a 60 amp breaker/disconnect next to the battery, and routed the wires to the back of the truck. These breakers are cheap, resettable, small, can be used as a disconnect and are waterproof.

Mine is not an automatic disconnect, but that can be easily done with a relay.

When hooking up, I plug in the seven pin and the Anderson plug. The trailer side of the Anderson has its own pigtail that is wired with #6 wires back to the batteries and through another breaker on that circuit.

This arrangement supplies a lot of power to the trailer and gives me a place, while camped, to plug my suitcase solar into the trailer. No more wondering if I'll get enough power to charge the batteries while driving and I can confidently run the fridge on 12 volts. A huge improvement.

My setup is the same except I don’t have solar. With my Truckfridge I can be off grid for three days. When the vehicle is hooked up I can have full batteries in 30 minutes. I can’t see the need for solar unless your camped without power for weeks.

[CarlD]

A word of caution. A DC-DC converter is not a battery charger. If used with lead acid batteries there is potential to damage your batteries from overcharging.

However a DC-DC converter works well with a LFP battery (Battle born type) and will not cause damage if the output voltage is set properly.

[Lynn Eberhardt]

Using a voltage sensing relay is an easy way to make sure the trailer is connected only when the tow vehicle is running.

[minke]

Originally Posted by Raspy

The back of the plug, where the wires enter, is filled with E6000 glue that seals it completely. The front has a rubber weather cap that goes on when unplugged. I think a bit of rain won't bother it, but salt spray might. I rinse it out with windex from a spray bottle and can shoot in some WD 40 as needed. I can also shut off that circuit under the hood with the circuit breaker/disconnect. The trailer side plug is also filled with sealant and has shrink tube protecting it. Not a perfect water tight solution, but entirely adequate. The glue and the shrink tube also give it strength so it can fly across from the trailer to the truck alongside the umbilical. They are taped together to help with the strain.

Thanks.

[kipper]

Originally Posted by CarlD

A word of caution. A DC-DC converter is not a battery charger. If used with lead acid batteries there is potential to damage your batteries from overcharging.

However a DC-DC converter works well with a LFP battery (Battle born type) and will not cause damage if the output voltage is set properly.

The Renogy has specific modes for Lead Acid and Lithium with adjustments for float voltage and such so I think it would be protected. The converter is sold as a charger, just happens to use DC-DC as the base technology.

[CarlD]

In my former life, a DC-DC converter is a current limited power supply with a maximum (setpoint) voltage which is not ideal for a lead acid battery charger. The Renogy is much more and looks like a nice solution.

[jhilley]

Originally Posted by CarlD

A word of caution. A DC-DC converter is not a battery charger. If used with lead acid batteries there is potential to damage your batteries from overcharging.

However a DC-DC converter works well with a LFP battery (Battle born type) and will not cause damage if the output voltage is set properly.

The Renogy DC to DC charger uses Three Stage Charging

"Smart Protection Features ( Battery Isolation, Over-voltage safety, Overheat protection, and Reverse polarity protection)

S3-phase Charging (Bulk, Boost, and Float)"

They call it a DC to DC Charger rather than Converter

[Juggledude]

Originally Posted by Raspy

The back of the plug, where the wires enter, is filled with E6000 glue that seals it completely. The front has a rubber weather cap that goes on when unplugged. I think a bit of rain won't bother it, but salt spray might. I rinse it out with windex from a spray bottle and can shoot in some WD 40 as needed. I can also shut off that circuit under the hood with the circuit breaker/disconnect. The trailer side plug is also filled with sealant and has shrink tube protecting it. Not a perfect water tight solution, but entirely adequate. The glue and the shrink tube also give it strength so it can fly across from the trailer to the truck alongside the umbilical. They are taped together to help with the strain.

Raspy,

The previous owner of my Casita had a similar setup.. i'm left with a very nice set of 6g wires and an anderson connector at my tongue. I intend to add the wire to my Toyota Tundra, but am not perfectly clear on the under the hood setup.. would you be willing to post a pic?

Thanks,

Royce

[Raspy]

Royce,

Yes, later today I can post a pic.

It's a very simple setup though. The plus wire goes from the battery plus, to the circuit breaker that is mounted to the truck next to the battery. Then on to the back of the truck. The neg wire goes from the battery to the rear of the truck. As they go they are routed in loom where needed and zip tied in place

[Air Doug]

For our older teardrop I used an Anderson 30 amp power pole connector at the rear of the vehicle for connecting the TV battery to the trailer battery with 10 gauge wire. They are built for 12 to 14 gauge wire but if you spread the connector just a tiny bit with something like one half of a needle nose plier end, you can easily insert 10 ga wire. Of course, use the correct Anderson crimper.

I never did anything to weather proof it and never had a problem. I used a battery isolator tucked into the quarter panel. Trailer had an AGM battery that came with our Lil Snoozy. I'm still using that battery, but now using a Genius charger in our new TC Teardrop.

[Raspy]

Originally Posted by Juggledude

Raspy,

would you be willing to post a pic?

Thanks,

Royce

Oooops, it got dark before I got a picture. Tomorrow.

John

[Juggledude]

Originally Posted by Raspy

Oooops, it got dark before I got a picture. Tomorrow.

John

No worries. I've been shopping on Amazon for this project... Is your circuit breaker something like this?

https://www.amazon.com/dp/B01F76VJKQ/ref=cm_sw_r_em_apa_i_eflzEb92S0VSQ