GarryandKristi

Goal: Eliminate house battery drain due to DC fridge while traveling to arrive at dry camping sites with a fully charged battery. Hybrid to refers to keeping existing charge wire when adding another charge line of heavier gage. After upgrading to a lithium battery (300 AH Epoch) I wanted to be able to negate the amp draw from our 3-way fridge (dometic RM2454) and other small loads that total about 16-17 amps. That fridge used a 100% or nearly duty cycle on DC. I purchased a Renogy 20 amp DC-DC charger. Initially I replaced the 14 awg gage wire Oliver spliced from the 12 awg pigtail power wire terminus to the charger with 10 awg. Why Oliver went to a smaller gage than the pigtail is beyond me although this was back in 2018. I also spliced a 10 gage wire to the pigtail common 10 gage that Oliver in its wisdom had also spliced to a smaller gage wire. This worked fine if I triggered the current limiting feature that reduce the charging current to half (10 amps) of the rated. When I tried to charge at 20 amps it only produced about 14 amps and resulted in a very warm pigtail plug as you might suspect. So I relented and decided to run 8awg wire through my pickup (2015 RAM 1500) and Oliver E2 - but with the intent of also using the pigtail charge wire to carry some amperage. Doing some calculations using the wire resistance of 10 and 8 awg and knowing that the voltage would be the same at the junction I planned near the charger input I figured about 2/3 of the amperage would be carried by the new 8 awg line but after installation found that it actually carried 3/4 of the amperage probably in part by neglecting the loss through the tiny 12 v wire pin in the 7-pin socket on the pickup. The ground pin has about 3x the surface area of all the other wire pins in the socket Fiberglass rods that I had were helpful in running wire and I only used a 2 or 3 foot ground leg to the chassis frame rail near the bumper so essential just ran the positive wire under the truck. I had to remove the front of the bathroom sink to pull site into the trailer. I have read that some have run wire without messing with the sink but they must be magicians! I tap into the trailer running light wire (green) to activate the charger. First results after an initial camping trip were good. When testing at idle I measure 25 amps in to get 20 out and a voltage drop of 1.1 volt from about 14.0 at the battery (I had calculated a 1 volt drop and I guess got lucky. So I wasn’t going after the big amps as my objective and figured I could run smaller gage wire in tandem with the existing pigtail to meet my needs. 30 amp fuse off positive battery terminal Andersen-type plug with t-handle above bumper entrance gland/strain relief (1/2 inch) behind propane tanks on left input on right (8awg after junction of 8 and 10 awg) and output on left (10 awg). I rummaged an old DPDT switch and used one side of it to activate the current limiting feature that should not be needed after running the 8 gage wire.

I have a 300 AH epoch battery and just kept my PD converter charger (2018 Oliver) and moved the jumper to the Li position. I believe it charges at 14.8 volts constantly but I don’t see a problem with this. The Epoch has overcharge protection with its BMS and you can switch off the MOS “charge” toggle switch via the epoch app so it won’t charge after you have topped it off and are on shore power. Others have said they trip the AC charge breaker when fully charged on shore power. I have not had any issues with just using the old PD converter/charger since I bought the battery over a year ago. I do not have solar.

I just installed an Epoch 300 AH battery to replace our original 4-6 volt trojan agms. I have a victron shunt so I can monitor things. I did not disconnect the charge wire. So far I can only get 2.5 amps or so through the 7 pin depending on voltage difference of TV battery and smart alternator and TT. I went to the trouble of installing a normally open relay in the Oliver to isolate the batteries, and can attempt charging by turning on lights (trigger for relay). The black wire on the far right stud between the relay and the circuit breaker is the charge line from the 7 pin. Left studs are for trigger off green lights wire and ground. So, right now not much difference from just disconnecting although I need to make sure the charge and ground wires off the umbilical weren’t spliced to a smaller gage wires and test disconnecting the feedback to the smart alternator and see if it will output a constant high voltage.

I’d be very surprised if your Oliver has 10 awg wire for both charge and ground wire. Ours (2018 elite 2) has 12 awg charge and 14 awg ground. However as @John E Davies mentioned (I think in another post) he noticed a splice inside the trailer in which the wire gage was reduced. I need to check this myself in hopes of getting a tad more amperage. You may have already completed your charge modifications, but I can vouch that with the existing 7 pin and wiring, and especially with Lithium hose batteries you’ll be lucky to get any charging. I only get 2 or 3 amps. I like John’s idea of not having to mess with TV and TT wiring and just being satisfied with somewhere in the range of 11 to 18 amps. In our case that would at least offset the adsorption fridge draw of about 15 amps. I added a relay in our oliver that is triggered by the taillight (green) 7 pin wire so at least I could isolate the batteries and only attempt to charge (turn lights on) when the conditions are good. With the newer “smart” alternators sufficient voltage to charge with the existing 7 pin setup is dubious. There is no way that a 7-pin system can cause overcharging and too much lithium house battery draw as the voltage potential difference is just not there and much amp draw would increase the voltage drop and lessen the voltage potential difference. I am considering unplugging the wire from the shunt on the negative post of our truck battery to get a constant higher voltage from the alternator - at least for a test. If it seems ok I would only disconnect for times were were both traveling quite a distance and then dry camping. I am just not sure of what other electrical systems might do with the smart alternator feedback interrupted.

and much easier to “fabricate”.

Agreed. We actually exhausted our nearly 6 year old agms with 2 days of dry camping and to get the front jack lifted I had to plug in the 7 pin cable. That did the trick and was easier than dragging out the generator. It certainly offsets the refrigerator drain on DC setting while traveling between sites. Very glad we have the 3-way fridge to operate on propane while Dry camping. Also glad we have a separate inverter and not the new inverter/charger in which everything has to be run through the inverter. Ours is a 2018 model.

I had the same issue with the remote not working about 2 years ago. I removed the control board and thoroughly cleaned it (I believe with isopropyl alcohol and or vinegar as a mild acid). Reinstalled and it resumed working. Wish I had coated the board at that time. Issue has just reappeared after I entered the traIler and the fan was spontaneously running at max speed and the operator was in a dozen pieces. Original operator appeared to be cheap pot metal and replacement from etrailer doesn’t appear to be a whole lot better. Fan still works using the button board. Am thinking about pulling the control board again and cleaning and coating. May also install a voltage regulator. By the way, our fan fuse is in the sub-panel in the attic (7.5 amp). Hull number is 372 (2018).

The resistance of the factory 7-pin small gage wire would limit current draw so shouldn’t damage your alternator. Don’t know how much the wire would heat up due to line loss.

I agree with your thoughts. Short cycling is the most likely problem. We get this in our dometic penguin that came with the elite II in 2018. Air conditioners are by nature dehumidifiers (they why they have condensate lines). Having to run a dehumidifier seems like poor design when you have AC so it must be a sizing and/or fan speed issue. We’ve lived in the south for many years and never have had issues with humidity in our house even with outside dew points in the upper 70s. And that is even with a whole house ventilation system with some outside air being pulled in. Of course house hvac systems are far better than rv systems in design, etc.

Relative humidity is a pretty worthless measure of moisture in the air as it changes with ambient temperature (rh is the amount of moisture, or vapor pressure to the amount of moisture or vapor pressure at saturation) and warm air can hold more moisture than cold air. I am a big fan of dewpoint (temperature at which moisture condenses in the air) which doesn’t change unless you get a different air mass. I suspect the issue is running the fan constantly versus on auto so unconditioned air is being pulled in. We run our dometic on low (not auto) so the startup of fan/compressor isn’t so alarming. I do notice an immediate change in humidity with our domestic when the compressor turns off (but fan still runs). With a quiet AC it would be better to run it on auto so that the fan is not running when the compressor is off. So I am thinking it is not so much to do with the manufacturer/unit as it is the mode of operation.

We love these gutters as it has solved the perpetual battle to clean (with nominal success in the battle to prevent water ingress) the weep/drainage holes and channels for the windows. I applied in summer so the temps were warm/hot and adhesion was good. Also, as John mentioned, having a decent length of straight run beyond the curved section helps anchor things.

Other thoughts ..... cavitation - is the suction side fully primed? Maybe could tell by water in the filter bowl. Have you tried connecting city water and running it for a short period? Although the pump should be self -priming I think. Could be a bad diaphragm. Although the sound on the video sure sounds like an electrical (switch) issue. When ours primes it sounds a bit like a rumble.

I guess it depends on what you expect and actually do when camping. We have the 4 6v AGMs and over 3 years they have served us well. We can dry camp for 3 nights (we have no solar) and just plug the trailer in when storing. Camping on the East - and mostly mid south to southeast means a lot of trees for us and so the advantages of solar would be minimal. When the AGMs bite the dust I would considers lithium, but honestly I’d rather spend the extra money on a quieter air conditioner.

I can confirm that our Elite 2 has the “new” configuration of pump suction. We have hull no. 372 with a pickup date of August 2018. There is a fitting on the top of the tank about 1 foot from the aft end with apparently a suction tube extending into the tank. This is in addition to the 2 tubes on the side at aft end for fill and drain functions. The line at the top routes to the suction side of the pump so is obviously the suction tube. On a recent dry camping trip, we experienced cavitation at about 10% indicated on the level meter. I think 13% was the last good reading and at at about 8% could not draw anything (from memory and don’t exactly remember resolution increments of level meter). When draining (and raising front end) it seemed like a substantial amount of water drained, but I did not measure. Probably no more than 5 gallons.

Another thing to look at assuming that you have about equal lengths of awning extended is adjusting the pitch of the awning. I just did that with ours and it helped with retracting the awning flush on both ends. I made sure the trailer was level front to back, then checked level on the extended lead rail. I raised the low end by turning the 5 mm Allen screw on the attachment hardware at the top of the arm clockwise until nearly level then finished with lowering the other end a bit by turning that one counter-clockwise (didn’t want to put too much tension on the low arm). That pretty much fixed it. Will check extended length on both ends now that others have mentioned that. See Page 8 of the attached. We have had an arm slide over on the lead rail so make sure those Allen bolts are tight at the lead rail. We’ve also had to replace the manual retractor gear as it would not retract all the way without slipping (like a bad ratchet drive). These things are not carefree over time. Freedom-WM-Service-Manual.pdf