Battery chargers, inverters, engine generators-parameters

[Davydd]

I don't like cooking inside on our propane two-burner. That almost implies frying most of the time which is the worse thing you can do in a small B, IMO. This last trip we did use our convection/microwave more for baking. We cook outdoors with every opportunity with a Coleman propane stove which is basically the same as our B cooktop. So, I wonder how well those electric induction cooktops do. We also carry an electric frying pan and an electric crockpot.

For hot water I can't say propane has been trouble free. I had a controller go bad on my previous B and a regulator go bad on my present B. Besides that, the tank itself is a pain to maintain and winterize. Until diesel heat became an option most all Bs used the propane Suburban noisy blasters even in the diesel Sprinters. That's what we have now.

In all our travels we rarely used the generator to run the air conditioner. If the situation ever got that dire we just searched out an electrical hookup campground. I simply could not stand running an air conditioner overhead and a generator underneath at the same time and it just seemed out of place in a pristine quiet boondocking situation. With our current B we have 13 hours on the generator in over 60,000 miles of driving. I'm sure most of that was to brew coffee in the morning.

[booster]

We got the van out to wash it today, finally. Pretty cold and windy, but it is going to be worse the next few days.

As long as it was out, and had full batteries from the testing, I decided to see what the solar would do if turned on under those circumstances. It had been off while sitting in the garage.

Good news with that, as the solar controller went into a regular charge cycle and went up to the programmed 14.8 volts. The Trimetric showed a about .15 volt less, so I need to check the ground on the solar controller, I think, as it is grounded through the mounting screws, not with a dedicated wire.

This makes life very easy for us, as we can leave the solar off when not needed and know it will go to "top off" voltage when we turn it on. Should be best of all worlds that way. I was afraid it would go right to float, but it didn't.

[booster]

Raining like crazy here today, and will be for almost all next week, but I took the multimeter to the solar connections to see why it mismatched the Trimetric by so much. They both connect to the batteries within a couple of inches of each other. The Trimetric goes though the added Blue Sea fuse block with a 5 amp fuse, and the solar goes through the same fuse block on a 25 amp fuse and though a 30 amp toggle switch. Only resistance I found was across the 25 amp fuse, through the fuse block. It was about .2 ohms but that probably in use less than that in use, as that is really large for this stuff. Pulled the fuse in and out a few times and the meter went back to reading baseline, so hopefully we are good. I will know more when we can get out in the sun again. Temperature comp on the solar was reading the right battery temp, but it hadn't kicked up the voltage when charging, so I will need to retest that, also.

[Davydd]

Do your solar panels work at all, albeit I assume at a reduced capacity, on an overcast or rainy day?

[booster]

Originally Posted by Davydd

Do your solar panels work at all, albeit I assume at a reduced capacity, on an overcast or rainy day?

What I was told by AMsolar, and from what we have seen they are probably right, is that with these monocrystalline panels we will get about 1/2 ouput in cloudy weather. Of course there are various amounts of "cloudy", so I would expect some variations. 1/2 output from out 200 watts of panel should be in the 40 AH range per day from what I was told, but we haven't been out enough off grid without other inputs, like driving, yet to know for sure.

[booster]

We moved on to the next step in testing to start to see what will actually happen while we are camped. As with most stuff like this, the instructions don't come close to telling you what is going to happen under various circumstances.

The charger completes charge and goes into float based on minimum absorption time and ending amps to each battery, so the big question for me was what would happen if the amps went back up above the ending amps once we were in float. This is guaranteed to happen when you are camping with your stuff running, and if it kept going back into absorption, the full batteries would be seeing high voltage much longer than they should.

I charged up everything and then let is sit a couple of days, and used a little of the power. Put it back on charge with some things on, so it would not get to ending amps on one of the banks. This is what would happen when you stop and plug into shore power, and are using some power. As expected, it did not go into float, because it didn't reach ending amps. I shut off the extra loads, and it went under ending amps. It then went into float very quickly, probably under 30 seconds. That's good, as we will be able to get it into float easily, just by shutting things off for a bit once the batteries are full. If we don't want to do that, it would go into float when it hit maximum absorption time, but that could be several hours later.

I let it run in float for a few hours and then started turning on loads in the van, running off of the biggest bank, which has the lowest % ending amps. Ran it up to over 3 times the ending amps and it stayed in float, like we hoped it would. I think it would stay in float until you were using enough power to drop the voltage off of the float, or battery full, voltage, and we would not ever use that much in any way I can think of. Looks like it works just as we would want it to.

Now I just have to decide if I want to include any load in the ending amps. I may just put in the "resting" amps for the van, which would include the meters, detectors, etc, but no discretionery things like lites, tv, frig, etc. They are always the same, and it would probably make life a bit easier. Even with the frig turned on, it cycles, so the first time it went off, the ending amps would be met and the charger would go into float and stay there. The rest of the stuff is off most of the time, so it would not be much of an issue.

I like the way it handles this scenario. They did it just about as well as you could when you have the ending amps to deal with during charging. Of course, it is the ending amps that make it so this charger does such a good job of getting batteries full, so you need it.

[booster]

Finally got some sunshine, so I could get a better look at the solar and how the ACRs work with it. The ACR part is a bit confusing, but always to the good side. It appears they will not connect unless there is voltage on both sides of them, with charge voltage on one side. That makes it so they will not close if I have the engine battery separator turned off, which is just fine with me. That way I can charge either one or both banks off the solar right off the main selector switch. Very easy.

The solar was another matter. It started off good at about 65 watts with low sun in the morning and kept climbing until it was at nearly 170 watts, with the voltage at that point about 14.2/14.3. At that point the watts started dropping, which made no sense, as it was not near the 14.8 programmed absorption voltage, and it was noon. I turned on the second bank of battery, and the watts maxed out at 175 watts at 14.1 volts. Turned off the second bank and it went to 100 watts at 14.3 volts. It was acting just like it was set at 14.4 volt absorption. Hooked up the Morningstar programmer and computer and checked the custom settings, and all looked good with 14.8 absorption. It then went into float 2 hours faster than programmed. I read, read, reread, reread, the instructions and finally came to the conclusion that I must have misinterpreted what they said about dip switch positions. The settings are in a couple of places in the manual, and in the software, and basically say that when you are running wet cells, all 4 of the dip switches are down. It says the switch 4 is turned to up to switch the phone plug connection to read the programmer instead of the remote when you swap that in where the remote plugged. It also said that switch 1 needed to be in the up position to use the custom settings. Switch one changes the controller from wet cells to gel in running mode. I read that to be needed to get the custom settings to take while programming. I think that is where I went wrong, as there was also a tiny number 1 on the table for the gel switch position that referred to a footnote that said something about "custom settings apply to this program". It did not have that note for the wet cell position. I think it was running with the default wet cell settings, even though I didn't have any way to tell that. I turned switch 1 to the gel position and will test it again when it is sunny. I think it will then go to full voltage and not limit the wattage like it did today.

It was in the sun, with a little haze and a few clouds, and it did 62 AH from 9am until 4pm. It had over 40AH by noon, so it definitely was reducing in the afternoon. Max whats was at 175 watts from the 200 watt panels, which are horizontal, so that doesn't look too bad.

[booster]

Got a chance to check out the different switch position on the solar controller, and that was why the voltage was not increasing, and the wattage tapered off so far. Moved it into the sun, with nearly full batteries today and by after about 1/2 hour it was at 14.8 volts and putting out 125 watts (9:45am) with only a few hazy clouds.

Only oddness that showed up is that the ACRs have a low voltage cutout on both battery connections. Both our ACRs are connected on one side to the coach battery through the separator, so if the engine isn't running and closing the separator, the ACRs won't close to charge the starter battery, which we would do sometimes but not all the time. A momentary jumping of the separator kicks in the ACRs and then they hold fine off the solar. Since the separator is really redundant with the ACRs (I only left it in because I can control it from the driver's seat. I think I will probably just take it out and put in an on/off battery switch so I can isolate the van electronics when we equalize.

[booster]

We had a chance to get away for a few days and see how the new electrical parts worked in the real world, before we leave for Custer in 10 days. We started with batteries that were a little low as I had turned on the frig a day earlier to cool down, but not plugged in shore power. Cloudy and very foggy start, and the solar would barely do anything but the frig only takes a few amps, so batteries fine. After an hour of driving, it cleared and solar started recovering the batteries. Stopped at Scamp to look at their trailers, and solar was putting out well. Drove on to Itaska state park, still with the alternator charging off. Shut off the solar. Plugged in when we got parked and were not quite full based on the amps to the batteries. The charger ran minimum absorption time and and the amps were within .1 amp of ending amps, so I shut off 12v power for 30 seconds and it went into float because the amps dropped below ending amps. Stayed in float the rest of the trip, no matter what we ran on 12 or 120 volt. Everything was just as expected.

One thing I did notice that was pretty different from the way it used to work, was the Trimetric meter readings. Float ran at 13.4 volts most of the time (13.2 setting plus temp comp) and the amps to the batteries was barely readable, usually .1 amp or zero. If the frig turned on, it would actually go discharge for an instance until the charger reacted, then back to .1 or zero. The Trimetric didn't know what to think of all that. The charging lite would come on, go off, start flashing fully charged, repeatedly. Kind of a cool light show. Batteries showed 100% on the Trimetric, and that didn't change. In the past, when we plugged in, the charger would run it's cycle and go to float at 13.5 volts, no temp comp. The amps would always be significant, being above 2-3 amps for many hours or days. The difference has to be that the batteries are now really full, and in the past they weren't, even though we thought they were.

Hopefully it will all perform this well for our 3 week run.

[Davydd]

Anxiously awaiting your real life test results that seems only you understand what needs to be reported. Wouldn't it be nice if some E-Trekkers would do the same beyond dwelling on running an AC? We are getting a B built without propane or generator but solar, large inverter and multiple batteries yet to be determined. My gut and experience tells me you'll have success. If I can brew my morning coffee, use the microwave/convection oven and induction cooktop routinely every day and never have to debate or worry whether I need an electrical hookup I'll be a happy camper.

Overkill or not, diesel idle controversy or not I will have the second alternator high idle option. If I use it no more than I have used my propane generator the last 4 years (13.9 hours) I doubt I'll ever have warranty issues many seem to be concerned about.

[booster]

Originally Posted by Davydd

Anxiously awaiting your real life test results that seems only you understand what needs to be reported. Wouldn't it be nice if some E-Trekkers would do the same beyond dwelling on running an AC? We are getting a B built without propane or generator but solar, large inverter and multiple batteries yet to be determined. My gut and experience tells me you'll have success. If I can brew my morning coffee, use the microwave/convection oven and induction cooktop routinely every day and never have to debate or worry whether I need an electrical hookup I'll be a happy camper.

Overkill or not, diesel idle controversy or not I will have the second alternator high idle option. If I use it no more than I have used my propane generator the last 4 years (13.9 hours) I doubt I'll ever have warranty issues many seem to be concerned about.

As we are slowly progressing through finding out how this stuff works, or doesn't work so well, together, it has bee pretty obvious to us that many of the old standards that we all have heard and accepted may not be all that accurate. I wouldn't go to the extremes that Handybob does in criticizing the entire world of rv electrical systems, but I do think there are some major issues.

Most of the issues have been discussed at various places around here and elsewhere, and I think I am getting closer to having some final opinions, which are just opinions, and need to be either get final testing, or be proved or disproved by the industry over time. Just a quick runup of things as we see them with our system and use, and from what others say and do.

* Throw out any and all discussions of running air conditioning on batteries. Even if you can run for "X" number of hours, you pull the batteries down so far that recovery is a very long process. If you need air conditioning when shore power is not available, you need a generator. If you are OK having that be an engine generator, you obviously need to run the van engine, so at that point you may as well use the van engine air conditioner and skip the coach air conditioning except when on shore power. I think Roadtrek really muddied up this whole issue with the initial claims for the e-trek, and way too many folks are still seeing the old claims on the internet, or getting them from less than stellar salesman. There are way too many way overly optimistic ideas of what to expect from the various systems.

* I like the idea of having some sort of a very large engine generator, although I think that the best system for most would turn out to simply be a very large single, or dual normal sized, alternator. Roadtrek appears to have their engine generator on the e-trek running at 24 volts, to a dedicated 24 volt battery bank, which runs the inverter at 24 volts also, I think. While more efficient in transporting high wattages, the 24 volts requires all kinds of other ballancers, etc. Without the continuos high draw of the air condtioning through the inverter, the 24 volts probably is more trouble than it is worth. The one thing in the engine generator area that I have not really seen much of anything about is the use of 12 volt to 12 volt multistep chargers with them. I find it very interesting that folks will carefully be sure they have a multistep converter/charger in their RV, that is putting out maybe 40-60 amps to the batteries, but then will not hesitate to hit the same batteries with a constant, and often poorly regulated voltage, from a big alternator, that could be well over 100 or even 200 amps. My guess is that the 12 volt to 12 volt chargers will become more standard as engine generation takes off. We address this with a manual separator cutoff switch, but that would not be the solution for many folks, I think, and it is not best solution either. I think the engine generators are very useful for recovering big battery banks, if you drive enough. For us, the biggest benefit should be to be able run the microwave or hairdryer without draining the batteries too much. Using the engine generator for the short shots should be able to stay within even the most restrictive MB rules, if there are drives every couple of days. It is the running of air conditioning that really bumps off the MB rules as it is many hours beyond the recommended.

* The, probably overly, discussed topic of the ability of the currently available chargers to get you batteries full. IMO, pretty much all of them have some issues. I think in the future you will see most of the higher end ones with more progammability, with charge completions based on ending amps, not just timers. They will be programmed to your battery style, size, age, etc, and not one size fits all like they are now. Temperature compensation is absolutely essential if you are trying to charge accurately.

* Automatic switching beween charging systems will be needed, I think. A system with a shore charge, solar charger, engine charger could seemlessly only use the one that is the most desierable at the time. From what we have seen so far, it would be very difficult to have the individual chargers not interfere with each other, unless shut off when they are not the one you want to be charging with.

* Power use calculations and past history, I think, are going to get a few folks in trouble when the transition to a more sophisticated rig. Many will be coming out of an older unit with no solar, 75-200 AH of batteries, no engine generator, maybe a rv generator, propane frig, propane stove, propane heat. Those older rigs also don't have lots of multiple control and monitor panels that use some energy, or continuously running inverters. In an older style rig, you can run on 20 AH per day if you are careful, but if you base your new rig on that you may be very disappointed. A compressor frig, especially if you go bigger like most are now, will use something like 40-80 AH per day by itself. Throw in a couple of microwave runs off the batteries, maybe an electric cooktop run, entertainment system off the inverter, etc, and you could easily be looking at 200 AH per day. 200 watts of solar sounds like a lot to someone who uses 25 AH per day, but it won't cut it at 200 AH per day, as you could only get about 80 AH on a good day. Same thing with battery bank size. Folks will need to determine, relatively realistically, how long they would like to be off grid, and size appropriately, based on what their new, not past, usage is going to be. Davyyd's moving almost every day (if the drive is long enough) is going to be very different from our desire to be in a spot 3-5 days, with only short trips to trailheads, etc. I think on many of the newer rigs, their 200/250 watts of solar will barely cover the refrigerator for many folks. With solar, you also have to be willing to park in the sun, which will be kind of tough for us, as we like shady.

* Solar and battery sizing. IMO if you want to be able to be off grid for extended times, with some cushion for poor solar conditions, you would probably want to have 4-500 watts of solar and 4-500 AH of battery. That would give a reasonable amount of reserve power to get you through cloudy days, and enough charging to catch you back up, and give a reasonable amount of charge when cloudy. It also allows you to have enough solar to get your batteries full, and not short cycled, which is important. Currently, I think the manufacturers are concentrating too much on big battery banks, and putting in too little solar, and they need to match better. IMO, this is one thing that Handybob has exactly correct, and which he proved by reducing his battery bank size to better match his solar and getting much better results.

* I don't know how the propane will turn out. For gas rigs, I can't see it going away because of the heat and hot water, but diesels can use their fuel for that. Even with diesel, we would want it built in, maybe with a smaller tank, because we use a gas grill and stove multiple times a day, many days. The little bottles are horrible and wasteful, in our opinion, and wouldn't want to have a loose 20# bottle.

* Having most everthing as 12 volts is very desirable. If the inverter runs 24 hours a day to keep something running, it will cost you as much as 30+ AH per day, depending on the inverter.

In Davyyd's specific case as he describes, his electrical use would be the frig, micro, induction cooktop, lights fans for the furnace and water heater, and maybe 30-40 Apple chargers Say 60 AH on the frig, 140 AH per hour on the micro and induction cooktop, lights/chargers/fans/tv/ another 40 AH. With 1/2 hour of cooking, he would be at 170AH a day. That would take about 400+ watts of solar to keep up with in less than stellar conditions. If he is willing, and the rules allow it, running the engine generator while the microwave or cooktop, will put him down to 100 AH a day. I would guess that it would take something in the 1.5+ hour range of driving to get a good refill of 170 AH of battery, with a big engine charger, as the batteries don't take as quickly as they near full, but I have no basis for that guess from real experience. From that I would say if he drives a couple hours a day, small solar will be OK. If he wants to sit longer off grid, and especially if he can't run the van for short spurts for the cooking, I think 400-500 watts of solar would be better. 400-500 AH of battery in either case. If he is counting on doing much/most of the charging while driving, a 12v to 12v multistep charger would be a very good idea, I think. Of course, there still would be the question of needing to hook up to shore power if he got into an area that air condtioning would be desired, if he gets the air conditioning at all. It is very possible that Advanced has all this covered and available already, as they seem to be more on the leading edge than most.

All and all, I think it is going to be very difficult for the manufacturers to build a one size fits all, mostly electric, mostly off grid, rig, and I don't know if RV sales types are really capable or interested enough to evaluate what a custome needs to make them more customer specific. It will be very interesting how that end of it shakes out.

[Davydd]

Our preliminary assessment is 400 amp hours of lithium ion batteries (320 amps usable) and 265 watts solar. We will have the second engine alternator, high idle option, and engine auto start with low batteries controlled by Silverleaf. I'm awaiting more details. That's why I appreciate your comments and user experience. Advanced RV has taken two extended trips to Florida and Arizona with a similar setup in their "Mzungo" B. I hope they learned something. They were doing a lot of sophisticated simulation testing at Advanced Fest.

[booster]

Originally Posted by Davydd

Our preliminary assessment is 400 amp hours of lithium ion batteries (320 amps usable) and 265 watts solar. We will have the second engine alternator, high idle option, and engine auto start with low batteries controlled by Silverleaf. I'm awaiting more details. That's why I appreciate your comments and user experience. Advanced RV has taken two extended trips to Florida and Arizona with a similar setup in their "Mzungo" B. I hope they learned something. They were doing a lot of sophisticated simulation testing at Advanced Fest.

Did Advanced give you an estimated daily amp hour usage based on your predicted use patterns. If they have simulation software, they would have the actual power requirements for all of their components programmed in, and should be able to come very close to what you will really use.

[Davydd]

Yes, based on my supposed usage. Nothing is finalized yet. Of course, if you increase your capabilities you might push your personal envelope but I don't expect to be spending time in the summer in Texas, Arizona and Florida anytime soon.

[accrete]

Originally Posted by booster

...It is no question that we "technoloonies" spend a lot more time and effort on these things the we probably should, but it is a better hobby than drinking in the bar, I would think.

One technoloony to another...my wife would totally agree.
And i found the trick is to get her hooked on said technology. Onee Apple comes out with a bigger screen (like the once rumored "Pro" w/12" screen) i will bequeath the iPad Air to her since it is currently the first thing she looks for when arriving home.

Thom

[accrete]

Originally Posted by booster

Those getting the diesels do have an advantage in getting rid of the propane with the diesel heat. Those of us with gas are stuck with the noisy Suburban furnace for heat.

I've shared this elsewhere, and after a re-read of this thread did not see any mention of this so i'll chime in here on what i've seen used by gas rigs...

If you follow this link to the Espar Airtronic 5 heater page, you will see there is a gas version of the popular air/water heater used in many expedition rigs over in Europe. I have a couple of netquaintences living in the UK that have these in their gas rigs and really like them. They say their gas version does much better than the diesel as far as maintenance on the unit, and it sips gas. So single fuel source for hot air/water. Sure they still have to figure out how to power a cook top, though there are many that cook with gasoline also. Utilizing the MSR Dragonfly multifuel stove and the other is coleman 2 burner 424 (they also have a single burner 533)...all running on regular grade unleaded fuel.

Not something that anyone here will necessarily do, but fun to read what others are doing with small rigs...

There is a nice write up of one expedition rig (an old Landcruiser) that has toured much of south america and europe/asia utilizing the gas stoves. Most of my netquaintences are really die hard expedition types. Living in their rigs for months on end. Many also prefer gas rigs as there is not the issue of the new diesel fuel type in USA rigs not being readily available around the world. They will load up their rigs in a 20ft container and ship to the next destination.

I'm open to the idea that a rig such as a Ford Transit or Dodge Promaster gaser could include such a air/water heating system. I do know that the install of said device will be several thousand dollars (~$4K last time i checked)...so the decision is not for the faint of heart! BUT a diesel is at least +$5K and i'd still have to purchase the diesel maintenance-plagued version of the Webasto or Espar...

Thom

[Davydd]

You can still buy Coleman camp stoves that use Coleman Fuel or white gas sold in one gallon cans mostly. I think for the most part they are not as popular as propane because they are more trouble in handling liquid gasoline, storing the gasoline, etc. be it white gas or your vehicle's gasoline. I just don't see it happening. The market has already spoken on this. We had the white gas Colemans for our stove and lanterns back in our tent camping days.

We still cook mostly outside at every opportunity and use the small propane canister with a Coleman stove. We have the BBQ connection with 12 ft. hose to our built in propane tank but often it too is a pain to deal with logistically if say you want to cook at a picnic table that is locked down more than 12 feet away. That seems more often than not. So, if you are going to have a multi-battery setup with a large inverter, solar, etc. to run AC appliances we figure if forced inside we will have the time efficient cooking of a microwave and induction cooktop, ...or the local diner.

There hasn't been much opportunity to adopt the Espar gasoline version that I can see. The development in using the fuel of the vehicle so far in the B world has been mostly with the diesel Sprinters. Winnebago is not going to be the company pushing the envelope on this with a Travato when they are mostly interested in offering the most inexpensive B. I suspect it won't until the Ford Transit goes into B conversion with companies that it will be attempted since it hasn't happened with the old Ford and Chevy vans.

The compressor refrigerator seems to be driving that interest as well with one more item weaned off propane need. If the old standard of a 3.8 - 4.0 cf absorption refrigerator nearly broke the battery amp bank on DC I imagine the newer 6.8 - 7.0 cf standard for Bs would be nearly impractical with an absorption frig on DC in a parked situation.

[eric1514]

I still use my Coleman gas stove and gas lantern. It's a nostalgia thing. I like the noise and the smell. For me, nothing says camping quite like burning off all your arm hairs lighting the stove.

[accrete]

Originally Posted by eric1514

...nothing says camping quite like...

If you are doodling on YouTube sometime, do a search for the MSR Dragonfly stove (dual fuel)... the sound of that thing would scare even a grizzly bear out of the neighborhood! Fortunately there are a couple of 3rd party nozzle replacements that tame the beast.

David...Yup i hear you on all you posted and ditto your general thoughts on the matter. I only mentioned the concept (gasoline variants/offerings) as there might be some die-hard expeditionists amounts us that would enjoy upfitting with such items if available.

[accrete]

additional random brain-synapse-firings...

I might go ahead and pick up one of the coleman single burner 533 dual fuel stoves, or maybe and MSR Dragonfly (i'll do some more research). One thing i enjoy doing once in camp is doodle. Not that one wants to necessarily _doodle_ with gasoline! But, i think having an additional stove to play with would be enjoyable (i'll skip the singeing of hair on arms though). I will often take down any tarps (usually a couple of Noah's Tarps are set up for sun shades) and preposition or mess around tying them off different ways just to pass the time between chapters in a good book down by the river, keeping the bear spray ready while watching my wife gold pan.
Ah, maybe the stock afterburner MSR stove might be the ticket.

I'm five years out from actual purchase of van2, a goal set by my wife and i. So it will be fun dreaming here and elsewhere reading and pondering what others have chosen for their "B" conversion (...Battery chargers, inverters, engine generators-parameters, etc...) Cari and i have pretty much concluded that once we break the ties to the 9 to 5 we will most likely sell both trailers (the 38ft fifth wheel and our 15ft fiberglass TT) so we can be more mobile. Our adventurous spirit (if in Van alone) will often take us ~20+ miles up some forestry road to a beautiful spot to spend a day wishing we didn't have a _base camp_ back at some BLM/USFS camp that we should probably return to cuz there is a cute little trailer that wants some luv'in.

Happy trails,
Thom