Partial re-wire of my trailer - need help please

[Chorky]

What I really want is one of those small quiet Honda generators and with a bi- or tri-fuel and be able to connect it to the trailer propane so I could throw a bulk charge on the trailer batts if necessary.

I have a champion dual fuel 3400w gen/inv. It's pretty darn quiet.... Although, it is not an open fram design which I now realize really sucks. I geuss it's a tradeoff. Open frame design is louder, but has benifits... The closed frame ones are quieter, but you basically have to tear down the entire freaking thing to get any sort of access. I think the Honda's are a little quieter, but not sure of their output... Mine can run 8 hours on a tank of gas, about 2 gal I think, or I think 12-14 hours on a 20# LP bottle.

 

[dreadlocks]

yeah I'm not getting why the hell anyone would have a trailer hooked up to both power mains and a generator at the same time... either you have mains power and dont need a generator, or you dont have mains power and need a generator.. plugging em both in at same time w/an ATS just seems beyond all reason, your generator wont even automatically start up if mains power is lost so what exactly do you think this unnecessary complexity is going to accomplish? Now if your trailer had a fancy built in Onan genset with a starting circuit then it might be logical, but nobody puts an onboard genset on a TRAILER.. only vehicles like an RV that already has a large fuel supply onboard.. I never liked any onboard generators, they are even more loud and obnoxious when they are mounted to the same chassis as your bed and you cant hide it behind a rock off an extension cord.

Some high end inverters like Victron can use very minimal power when idle, but the feature only works with analouge appliances.. it actually kicks on every few seconds and see's if there is any load, a microwave oven with a turn knob will work, but a digital microwave wont because you cant flip it on when its not powered.

 

[Chorky]

It seems you want mains or generator as primary power. Inverter supplied UPS for the fridge 100% of the time with ability to add/remove other loads to UPS as desired ?

Said that, as a legitimate ‘ExPo guy, I suggest building your system on DINrail inside a suitable enclosure.
You can get just about any circuitbreaker, relay, terminal, etc. you want. Fit it to rails and assemble as desired.

I actually want to use shore as my primary power source. But the power is not 100% reliable where I currently am. It has gone out for up to 3 days while I was gone for work... thus loosing food from the fridge.

Unfortunately building my own entire power system is not an option at the moment..just trying to do best with what I have. Some day....

yeah I'm not getting why the hell anyone would have a trailer hooked up to both power mains and a generator at the same time... either you have mains power and dont need a generator, or you dont have mains power and need a generator.. plugging em both in at same time w/an ATS just seems beyond all reason, your generator wont even automatically start up if mains power is lost so what exactly do you think this unnecessary complexity is going to accomplish? Now if your trailer had a fancy built in Onan genset with a starting circuit then it might be logical, but nobody puts an onboard genset on a TRAILER.. only vehicles like an RV that already has a large fuel supply onboard.. I never liked any onboard generators, they are even more loud and obnoxious when they are mounted to the same chassis as your bed and you cant hide it behind a rock off an extension cord.

Some high end inverters like Victron can use very minimal power when idle, but the feature only works with analouge appliances.. it actually kicks on every few seconds and see's if there is any load, a microwave oven with a turn knob will work, but a digital microwave wont because you cant flip it on when its not powered.

So here is my situation - was trying not to share too much info. I travel 100% for work. 8 days on, 6 off is the 'typical'. It can be as little as no travel for a few months, to up to 3 months straight of being 'gone'. But the schedule can change daily....so I have no way of being able to plan. I am currently at a place with shore power. But this place is 'unstable'. Even being here, the power is not 100% reliable. So yes, I have a generator, and have used it a few times over the last year alone. However, there have been times I have been away when power died thus loosing food, or risking pipes freezing. With a combination of genset, solar, and inverter, the idea being at the least the fridge might be stable for up to 3 days of no power. Past that my neighbor can come turn on the genset to recharge things while I am gone. So reducing risk of loosing food, or freezing pipes (winter). To further complicate things, I may be attempting to purchase property which may or may not have power at the ready depending on varying factors. So I want the capability to be 'off grid' until (if I got said property) I can put power in place. My life/work situation is complex and has, well, relatively zero abiliyt to plan. It's just how it is. So trying to do the best I can with what I have currently, and avoid wasting hundreds of bucks on renting a place if I'm hardly there. To even further complicate, the current owner of the place I am is acting strange. So this in itself is not 'fully' stable, so having abilities to be off grid if i had to be nomadic for a period of time is desired. Necessary, I suppose not - one can always use a cooler, tent, and ice after all. But I have the trailer, so mine as well do what I can without doing more than what it's worth. Hope this maybe clarifies my situation and why I'm pursuing these ideas.

 

[dreadlocks]

I see, well then you need to look at Victron Venus and figure out how to wire it up to your GenSet (assuming its got electric start), I believe it has the capability of monitoring the house bank and if it gets discharged below an alarm threshold it will fire up the genset, recharge the batteries and shut the genset back off... its got a bunch of advanced features for that, including black out schedules if you dont want it firing up the generator in the middle of "quiet time" at a park.. It will be a little different than AC -> Genset -> Battery, but more like AC -> Battery -> Genset to recharge but would consume far less fuel unattended.

and yeah, you'll want a 30A or larger ATS on both external sources so everything is safe and automatic.

 

[Chorky]

One thing to consider too is the genset currently does not have automatic starting function - although I think this is something that could be easily added.... It's about to become more or less a permanent fixture on the trailer.

That being said, it would be great if I could have the generator battery hooked up into the trailer's system, but also separate so the generator isn't using power from the trailer to start. So would I be correct in that a simple diode connecting the positive battery terminal of the trailer one way to the positive battery terminal to the generator would be the way to go? - to allow for the trailer to continually keep the generator battery charged, but not backfeed if say shore power went out? Basically to make sure the generator battery stays at max capacity to ensure good starting?

 

[dreadlocks]

generator battery should be charged by generator, no need to tie it into your DC system at all.. best your starting batteries just stay isolated if possible... Can you just push a button and it start up now? or do you have to pull the choke and push the button then put the choke back? If it requires manual choke to fire up you have to add a servo to pull the choke, it'll be on a timer and after like 20's it'll unchoke.. also if it had a heavy load when it transferred to the genset I could see it bogging down and dying if it didnt wait for genset to ramp up and get off choke.. most switchovers to a generator might need the auto transfer switch controlled by the monitoring circuitry.. so when power is lost it instantly switches to battery, fires up the generator, waits til generator is ready to transfer the load over to it then switch off battery.

yeah auto start is something you have to wire up externally, needs a computer of some sort to do it right as it needs to monitor the house bank and shut off the generator once its full.. if the Victron's control panels are too rich for your blood the VenusOS is open source and you can setup your own controller on a RaspberyPi, but that requires certain skills and is far from plug-n-play like their off the shelf components.

I dont have a starter on mine but I'm going to wire up auto shut off when I put my own home brew controller in.. I want to be able to fire up the genset then go on a hike, when the bank is full it'll short the kill switch on the genset instead of just idling all day long til I get back to camp or it runs out of fuel.. I'll just have a small lead that plugs into the generator when its mounted to my trailer's rear hitch.. could just be a headphone jack really.

 

[Chorky]

Hmm..... Sounds liket this is gonna be more work than expected, which is fine. I'll have to rely on my neighbor until I can get it done though.. So the generator has a few things. It does have a manual choke for one. So I see the issue there. It starts fine without it, but not so easy on the components... It also has a battery disconnect though. So I usually have to turn it 'on', set the choke, and then start it... So I would probably need like you said a servo, and a relay that is powered by a computer control. I'm starting to see $$$$$'s

The other issue I forsee though is space. It's a small trailer. So I'm a little concerned I would even have the space for all this equipment.... I did reach out to victron to see what options they have available. But as for programming all of this, thats more than what I have time for, with work and other life stuff.

 

[dreadlocks]

Another option would be see if you can find a RV in a scrapper and snag its nice Onan genset.. that has all the push button start equipment and most of the work is done, my parents old RV has one onboard and it fires up and shuts down with a simple 12v switch, that would wire right up to something like Victron w/no extra stuff needed.. they also support external fuel tanks and a fuel pump so that could let you hookup to some 55 gallon drums of fuel or something.

 

[Buddha.]

You could even have an onboard gas tank like the toy hauler trailers.

 

[rayra]

Diode isolation will work. But as often repeated in other threads, voltage drop thru the diode is detriment to many shared charging schemes. Much like other dual battery schemes, simple isolation relay or ACR is better.
But better yet for cost and simplicity, I suggest using separate mains powered charger whats optimised to keep the generator battery ready.
Dedicated house battery charger a separate thing.

As mentioned, automatic generator starting adds alot of complexity/expense.
Automatic starting an inverter on a dedicated circuit is easy.

so does anything that has you fiddling with a smartphone interface.

OP needs to go back to the basic minimal design elements for what he NEEDS, with a design eye for later WANTS (added costs). Make the design function at a basic level with the different power sources. While leaving the design open in a way for future upgrades that won't require any cost'y re-work.