Low end gen starting inverter

[Eric]

Anyone have any suggestions? Only need 1000 watts everything else is 12 volt. I would like to have it start the bus instead of a genny is that safe? Hoping combined batteries and 180 watt solar won't necessitate it but would still like to have it ..

Have fun !

Eric

[Geoff]

No comprende.

--Geoff

[Eric]

I just small pure sign unit(1000 watts) that can remote start a gen.. I've turned up nothing on google and was wondering if someone has used or heard of such a thing.




Eric

[PCC]

My concern would be if it started the main engine and ran the fuel level low, and left you stranded.

It is possible to start any engine with that system. If your tank has double pick-ups, install a close valve (operated by the key and not the auto start) on the main (full tank) pick-up to prevent that from happening.

Just my thoughts (2 cents)

[Sean]

Anyone have any suggestions? Only need 1000 watts everything else is 12 volt

I have not done a comprehensive survey of this market recently, but I have never heard of an inverter with a generator interface below about 2,000 watts capacity.

. I would like to have it start the bus instead of a genny is that safe? ...

I can't imagine how you would make this work, unless the bus engine had something like an Auragen on it (very expensive).  The way all (AC) generator auto-start systems, including those built into inverters, ultimately know that the generator is running is by the presence of 120VAC (or 240VAC as the case may be) at the generator output or inverter input.  Since the bus alternator does not produce this, there is no way for the autostart to know the engine is running, and it will continue to attempt to start it until the pre-set timeout is reached.   So, no, it is not safe, or even possible, really.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[Eric]

Well thanks all... The bus is 100% 12 volt dc except I have a perfectly good 16 cubic ft refrigerator that I wanted to use it only pulls 7 amps peak on defrost .. And yes I would remove the defrost.and it is in a well insulated panel...but I guess I should spend the $$$$ on a 12 volt model.


Thanks again

Eric

[desi arnaz]

I thinks what he is asking for is an inverter that would start the bus when the juice gets low so it would charge the batteries???

[Jeremy]

I would think that one of these could be the basis of a 'home built' auto engine starter:



Having said that, there do seem to be various extra complications if you're trying to start the main bus engine, rather than simply a generator - for example, as an absolute minimum, I'd want interlocks on the gear lever and engine access doors, to prevent the engine starting when the bus was either in-gear, or when people or pets were in close proximity with the engine.

Then you'd have to rig-up some sort of circuit to activate the glow-plugs, and either a timer to control how long the starter motor runs, or (as Sean was saying) a way of sensing when the engine starts. It's easy enough to buy a remote start kit for petrol and diesel engines, but they usually work off a key fob-type remote control, so it wouldn't necessarily be easy to activate one of those kits from the voltage-sensing relay.


Jeremy

[Eric]

S why couldn't I use a vsr to trigger a cheapo remote start kits start button? Not only would that start the bus though the key switch . That would also use the safety's and I could set the starters run time, most do 10 minutes to as much as an hour..... Would this not cover all the afore mentioned concerns?

Oh the possibilities !

Eric

[luvrbus]

Check Murphy Gauges they have a unit that will start your engine not cheap 500 bucks get a idea and maybe you could find a used one.

My wife had a 1990 Chevy Van with a Clifford (not me) alarm system that would start the van when the battery went below a certain voltage,we left it parked for about 6 months while on a trip and the van used up a tank of gas was empty when we returned

[Sean]

There are lots of ways to make the engine start (and stop) based on battery voltage or even SOC, but that's not the question that was originally asked.

If you plan to run a fridge, you should know that you will need a true sine wave inverter, and its surge capability will need to be at least as high as the compressor start current.  That's a tall order, and I suspect that most inexpensive 1,000-watt inverters will not be able to handle it. 1kw is good for about 8 running amps, which should handle most 16' refrigerators, but starting current can easily surge to 30 amps or more for a split second, overwhelming the absolute rating of the inverter which would be in the neighborhood of 16-18 amps.

As far as starting the engine, I recommend a true SOC meter such as the Xantrex Link-10 with auxiliary contacts, rather than a voltage-based system.  Voltage is an unreliable measure of SOC under most circumstances.  Connect the contacts to a simple SPST relay to engage the ignition switch and a 10-second delay timer to engage the starter.  Make sure you have a working fuel-pressure cut-out on the starter circuit.  Bear in mind that all of this will cost you around $300 or so.

Buying a DC fridge will not mitigate the issue of battery depletion and automatic charging, if that's what you think you need.  A more efficient fridge, of course, will allow you to go much longer between charges.  Also, DC models usually have an LBCO feature, which should at least leave you enough juice to start the engine manually should it come to that.

Lastly, I will point out that using the main engine as a battery charger (while not under way) is both fuel-inefficient and bad for the engine.  I think you would be money ahead by picking up a small used generator set for this purpose.  It will not take a lot of hours of running like this to pay for it, at roughly $4-$5 per hour delta.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[Oonrahnjay]

(snip) If you plan to run a fridge, you should know that you will need a true sine wave inverter, and its surge capability will need to be at least as high as the compressor start current.  That's a tall order, and I suspect that most inexpensive 1,000-watt inverters will not be able to handle it. 1kw is good for about 8 running amps, which should handle most 16' refrigerators, but starting current can easily surge to 30 amps or more for a split second, overwhelming the absolute rating of the inverter which would be in the neighborhood of 16-18 amps.   (snip)   

       Yes, I was thinking this but I was also thinking about a comment made about "solar".  Since a fridge will be running part-time versus the part time loads, and you'll never know the inefficiencies of your solar set up (angle of the sun striking the panels, software control inefficiencies, battery charging inefficiencies, inverter inefficiencies, sun-hours per day, sun obstructions at your parking place, etc.), you could do no better than a very rough guesstimate of your solar provision for these "small" loads -- but Im going to guess that "every square foot of the top of the bus in solar panels" would hardly be able to keep up all the time.  (OK, it probably would most of the time but you understand my point here -- and all that solar equipment is going to be big $$$pendy!)

       It would be pretty annoying to have to jump in the toad night after night to run to the convenience store to stock up on ice for the cooler to keep your food from spoiling because you didn't have battery capacity to keep the fridge running.

[Uglydog56]

I personally am drinking the solar kool-aid, plus I went camping once with a contractor grade generator, so I'm biased. BUT:

My fridger averages 231 watt-hours per day.  Figuring 2.5 sun-hours per day (which is pretty conservative), 30% loss for flat panels (cuz I'm lazy), 20% for inverter losses, that's around 180 watts of solar panel required as a WAG.  With the prices of solar panels today, I think you could build a 200 watt solar system for a grand, especially if you already have house batteries.  That's about the cost of a good new Honda generator, and it wouldn't cover the entire roof of the bus.  I have 1150 watts of panels for the roof of my bus, and yes, when I get the brackets done, the top is going to be pretty well covered.  2 100 watt panels on the roof are not that intrusive, and way cheaper than a 12 volt fridge.  231 w-h is also 19.25 a-h at 12v.  2 89 dollar golf cart batteries could power it for 5 days with zero sun.  A 16 cuft house fridge with a 200 watt solar system AND a 2000 watt honda generator is STILL cheaper than a sunfrost rf-16.

[Eric]

Well now we are talking ! I was planning on a pure sign unit and I have no space for a genny I do however have 180 watts of solar . 30 amp pull on startup for this little fridge is insane I just wanted the smallest inverter possible to save space unfortunately I have all my batteries tied together due to space constraints, i intend getting an isolator for the startup batteries but again real estate is really lacking I'm approaching the point of having a new battery bay fabricated to give me the needed space. I'm really just try to keep anything from hanging down farther them the body which is tough with the tanks and such..Perhaps I should just invest in more serious solar panels. My current ones are Kyocera 60 watts(x3) I purchases them for $1.00 a watt from CL.


Thanks again

Eric

[Oonrahnjay]

I personally am drinking the solar kool-aid, plus I went camping once with a contractor grade generator, so I'm biased. BUT:

My fridger averages 231 watt-hours per day.  Figuring 2.5 sun-hours per day (which is pretty conservative), 30% loss for flat panels (cuz I'm lazy), 20% for inverter losses, that's around 180 watts of solar panel required as a WAG.  With the prices of solar panels today, I think you could build a 200 watt solar system for a grand, especially if you already have house batteries.  That's about the cost of a good new Honda generator, and it wouldn't cover the entire roof of the bus.  I have 1150 watts of panels for the roof of my bus, and yes, when I get the brackets done, the top is going to be pretty well covered.  2 100 watt panels on the roof are not that intrusive, and way cheaper than a 12 volt fridge.  231 w-h is also 19.25 a-h at 12v.  2 89 dollar golf cart batteries could power it for 5 days with zero sun.  A 16 cuft house fridge with a 200 watt solar system AND a 2000 watt honda generator is STILL cheaper than a sunfrost rf-16.

     Yes, that's a pretty good analysis.  And I agree that a good dose of contractor grade generator is a fine way to make somebody go another way.  I like the control of being able to fire up most anytime if I need it, but your system should be good to go.  I think that you've built in a lot of extra capacity and that's a good thing.  Let us know how it works.