Where does your charging come from survey
Buried in another, very contentious, thread on this forum is a question that I think would be interesting for many of us to better understand and for those contemplating charging system changes and upgrades to see from actual users.
The question is: What percent of your power comes from the various power sources available in our class b vans? The question is simple, but the answers are certainly not be precise because conditions camped in change all the time, for all of us. Just try to hit a median approximation of normal conditions and primarily based on when shore power is not commonly available. Be sure to give an estimate of your daily power use also, as that is a critical factor for people to know when they try to decide on a charging system.
For us in our 07 C190P Roadtrek, 440ah of AGM, engine generator, 300w solar, no generator, no air conditioning on batteries:
Our power use in normally in the 30-70ah per day
5-30% engine generator
0% for generator as we don't have or need one
Shore power only needed of solar conditions so bad (very, very, rare) for a week that we need to do a full top off AGM batteries for life preservation. Shore power never needed for daily use power replacement. We have been known to get shore power to run air conditioning if it is 100*+, though.
I can easily use over 160-200ah per day but it is a drop in the bucket when I have an 800ah lithium battery bank. I don't worry about electrical use with an all electric system coupled with diesel-fired heat and hot water. So cooking in a convection oven and induction cooktop and making several cups of coffee in a Keurig is routine. Having the inverter on all the time is standard for us since I'm constantly fidgeting using my 120V electrically powered articulating beds when stopped to adjust them for sitting up, lazy-boy fashion or zero-gravity positions or making a quick two mugs of coffee while stopping at a service station. Having the inverter always on takes about 3 amps per hour power. It's transparent with electrical use whether I am on shore power (seldom) or boondocking.
Driving up to about 45 minutes a day maximum replenishes my daily electrical use with a Delco second alternator rated at 330a but consistently gives me over 270-280a running for an hour. So I don't know if it drops in performance as I reach 100% charged by that time. There is some solar contribution with 420w panels but I have pretty much dismissed that and will not get solar again. And, no, I don't need to idle my engine with the second alternator. That's a false assumption by many of those who don't have second alternators. The capability is there and offered by Mercedes Benz to install it with idle adjustment capability and brackets but it is just a bells and whistle emergency situation which we never encounter. I have idled when staying more than 3 days in a non-electric campground without driving anywhere but that was just more of peace of mind as I have never come near depleting our batteries.
Air conditioning use? Almost never with our traveling habits. If I really needed it, I would seek a shore power campground. You can only get probably up to 10 hours with just about anyone's system and you typically stay about 16 hours minimum in an overnight stay. It doesn't compute. I can count the fingers on one hand where I desperately felt I needed air conditioning in a boondocking situation in 12 years and over 200,000 miles of travel.
100% charge from shore power at home before trip.
Partial recharge (~25%) from engine alternator during day trip away from camp.
Full recharge from engine alternator on drive home.
No solar or generator .
Lights, bed, awning, and recharging electronics only. Cooking and refrigeration on LP. No heat or A/C needed. 2@6V GC2 wet cell
Never went below 2/3 on the battery monitor.
This was our first trip (6 days) and we’ve got a lot to learn yet! Couldn’t figure out how to work the TV via the inverter so we played scrabble instead. Win-win.
2000 RT on a Chevy chassis.
Normal daily usage 15-20 AH/24 hours, significantly less on a one nighter when traveling. Cold weather will increase the AH. LP fridge.
Virtually all extended boondocking recharge is from 150 watts of portable solar. On two nighters I use the chassis alternator for recharge, not bothering with the solar
Battery is a Wally World Everstart Maxx. group 27 deep cycle maintenance free non AGM.
Plugged in at home to maintain 13.2 volts with a cigarette lighter jumper to the chassis battery.
This is a summary of our usage in 2013 Sprinter Camper Van.
Power sources: 300W PV panels, Engine alternator up to 25-30A, Shore charger 40A
Batteries: 230 Ah AGM
Main loads: Isotherm 85 fridge, Espar Airtronics D2 diesel space heater, Espar Hydronic D5/electric 750W Isotemp water heater, Origo 1100W electric/alcohol stove, 650W Microwave, LG Projector ~ 100W, NO AC.
3 scenarios based on different camping conditions:
1. Solar harvesting campsite – about 45 Ah/24 hours, batteries usually replenished by midday, no time limit.
2. Cloudy or shady campsite – up to 3 – 4 days pending ambient temperature and TV/computer use.
3. Cloudy or shady campsite with shore power – no time limit.
1997 PW on Dodge 3500 chassis.
Batteries: 100AH Lifeline AGM
Solar: 100W Renogy suitcase
Needs: water pump, furnace fan, LED interior lights, vent fan.
So I'm pretty basic. We don't watch TV rather use an iPad pro loaded with movies, TV series etc. Cooking, water heater, furnace heat = LP
Generally we're on the move each day but when we're in Cibola, AZ we're on BLM land and don't move or idle. Typical is that we're down 20% in the morning and regain that power by noon or so. Remember AZ is usually full sun without a cloud in the sky.
Bottom line: When we're traveling the chassis alternator always charges us up to full. Solar is a benefit when we're stationary but that's rare. We are rarely in campgrounds that have shore power. However, our power demands are minimal.
A little over 2 weeks into our first trip with the 200ah lithium upgrade and here's how I'd roughly describe our experience.
- Solar 0%.
- Engine charging while driving 25%.
- 30A plug in 75%.
We've boondocked 5 nights (in 1 night intervals) and plugged in 11 nights (oddly this is the reverse of our usual experiences but full service parks have been plentiful this trip).
When plugged in we leave with batteries in the 92-89% range in the morning since the batteries don't seem to want to automatically charge until down closer to 80%. But somewhere in the mid to upper 80% range, I can add a brief load (microwave) to trigger the charging to 100%. This morning at 91% the charger did not come one when the microwave (load) was used.
However when driving, if I have the switch on to activate the DC-DC charger, it will always charge (no matter what the battery level) until they are 100%. But I don't always allow the engine alternator to charge the coach lithium batteries since it sometimes won't charge enough at idle. Have to look into that when I get home.
For the most part, 200Ah of lithium's has erased my battery anxiety and could probabaly allow us to boondock for 3-4 nights if we were to conserve use by limiting the microwave.
Our system: Promaster campervan. I just added e-bikes and upgraded the power so I have 2 systems shown below, old and new (which I haven't had much time on yet). 12V fridge and espar heater are the biggest loads.
Old: 210W solar, 150 ah, 12V aging/failing Lifeline AGM. no generator, 60 amp xantrex charger for shore power or while driving.
Typical about 25 ah DOD in the morning. That sulphated battery takes many hours in absorb to get to 100%. I typically stay in one place for several days and rarely have AC power, and never idle the engine to charge, so the power is mostly from the solar. Sometimes a short drive to a trailhead & charge from the van alternator while driving will get me halfway to 100%
New system +180W solar, so now 390W solar. Kept the old battery until its dead. Added a 200 ah AGM. Added 2 e-bikes, with 505 wh batteries each. A typical ride will take them down to 20-40% SOC.
Promaster with optional 220A alternator. Home built 180Ah LifePo4 battery in parallel with a fresh 105Ah AGM. Lithium Charge algorithm controlled by a Thornwave Powermon Bluetooth controller that connects and disconnects the Lithium battery via a simple automotive relay to keep it in the 20% to 85% charge range. AGM camper battery is always connected to the alternator and is separated from the coach battery with a Shure Power battery separator.
Alternator: 100% (usually disconnects Lithium battery after around 30 to 45 minutes of driving)
Shore power: 0%
I've travelled the month of Oct on a typical trip from Oregon to Texas. I'm usually going somewhere every day, but there were a couple of times when the van sat idle for 2-3 days. I never needed to idle the engine to charge the battery. Normal driving worked fine for re-charge. Biggest load is the microwave oven, but it's only used up to 10 minutes max on a typical evening and morning meal time. Heater on 24/7 in cold climates and Norcold electric fridge on non-stop.
I've got a 200W solar system that I can't decide if it's even worth putting back on. Note, I travel with lots of toys and use roof rack space to haul them while camping in the van.
200 AH lithium 225AH FLA 200 watts solar
150AH per day. 2/3 from generator 1/3 solar
100AH lithium 100AH FLA 100 watts solar
Designed to use the generator but with a DC to DC 40 amp charger the alternator takes care of all of it.
80 AH per day with a compressor cooler .
DIY Promaster campervan
200Ah Trojan AGM
15A Shore power charger (anemic—bought when I only had one battery)
180A Alternator with SurePower Separator
700W Microwave that draws 1100W
750W Sous Vide for hot shower water
800W Water boiler
We consider all three charging methods essential:
Shore power is necessary when parked in our shaded driveway. It also allows us to camp for days in the rain, which I enjoy. When the sun shines, solar is almost always sufficient, but if we’re moving, we let the alternator do the heavy lifting.
Our loads increased considerably after we bought our batteries. We really would be better with 3-400Ah. I’m also monitoring lithium prices.
2007 Roadtrek SS Agile as it was built plus a 200w solar setup. 220ah of wet cells, Onan propane genny.
I rarely plug in unless I am staying in a friend's drive or topping off before a trip. I run the genny in small spurts to run the ac/microwave/coffee maker. The solar keeps the batteries topped more or less while sitting and helps with minor usage on trips...
Just a reminder that how much each charge source is used, and how much power you typically use in a day would be very useful to know. :D
I never calculated how much power I use.
My Airstream Interstate has the noisy Onan generator that I rarely use. It has more hours on it from routine exercising than for actual use.
I have four 100W solar panels, 400 watts total, charging my 440AH AGM battery pack. Same pack as booster with four 6V Lifeline AGMs.
Most of my charging is from solar on a total hours basis as the sun keeps all batteries fully charged when parked in my driveway. The van is my second vehicle so it sits in the driveway when I'm not on a road trip. I travel in the van about 12 weeks per year for about 20,000 each year. When I'm home I drive it at least once a week.
When traveling the sun and engine alternator keep batteries charged as I tend to boondock when just driving from point to point.
When arriving at a designation like a friends house solar keeps the Nova Kool refrigerator running and batteries charged.
When at a campground I will plug into 120VAC external power as it is available. If I need air conditioning overnight I'll seek 120VAC external power. Generator is too noisy to run while trying to sleep. Heck the A/C is noisy enogh that I need ear plugs to sleep when it is running.
TL;DR - for cross-continent trips in which I remain off-grid for up to 5 weeks at a stretch:
- 4-way charging (shore, propane generator, solar, and alternator)
- 90% solar recharge
- 5% alternator recharge
- 5% propane generator recharge (largely because of it being exercised periodically)
Elaboration - DIY system with:
- 300 watts solar (the original high-efficiency panels that had been sold by Grape Solar but are perhaps no longer available)
- 2,000 watt inverter
- 300 AH lithium battery
- Vitrifrigo marine fridge (Danfoss compressor)
- A heavy load of electronics because I run my professional office part time out of the van, so I might be running cell booster and inverter, two 12 V cell receivers (AT&T and Verizon) a large workstation (larger than a laptop) plus multiple display screens and an iPad 12.9-inch Gen 3 up to 12 hours a day at times. Just as a point of reference, Cherie Ve Ard once declared that I was "eating the sun" (in other words, using a lot of power).
No doubt some readers will look at that assemblage ^^ and think “What the freak!” on my non-intuitive charging distribution. Let me explain.
- The propane generator was already on the van when we bought it second hand. We thought about taking it off, but “if it ain’t broke, don’t fix it.”
- We started out with just one AGM battery, and originally added solar for that, because the OEM alternator charger was useless.
- But then about a year later, we got bit by the lithium bug and installed all of that stuff.
- As part of the lithium job, we upgraded the alternator but quickly learned the hard way not to rely exclusively on it as a charging source after burning out the alternator clutch pulley 17 months into its life (Bosch 200 A). Even with precautions such as the Sterling which is specifically designed to prevent alternator damage, we still use the alternator charging option sparingly and electively. A properly-sized and managed alternator is NOT going to be trouble-free because of this weakness that has been engineered into it (the clutch pulley).
Theory meets real life when you learn just how valuable it is to have charging OPTIONS on the road. I love having redundant solar because I’m almost always in a “set it and forget it” frame of mind. But there have been specific circumstances when I’ve had to switch to all of the other three charging methods in turn.
Did you happen to check to see if other brands, duty rating, clutch pulleys were available for your alternator. There appear to be a lot of different brands and costs out there, up to a very expensive one the I think davydd had a video of some time ago from ARV. I assume yours was the kind of one way mechanical clutch style that are used to take out belt flutter and not a true on/off clutch? A lot of folks think that we are referring to a air conditioner type clutch from the confusing terminology the industry uses. Adam at Nations may also have some input on the issue as they are big supporters of using clutches on all of the high output alternators.
Perhaps it would be of benefit to be truly redundant and add the second standalone alternator so if it does have a failure you can still run the van off the original, and if the original fails you can run the van off the add on.
The local shop to which we took it told us that it used to be possible to defeat the weak clutch pulleys and install a workaround to make them more robust. But Bosch got wise to that practice, and proceeded to re-engineer their alternators so that this could no longer be done.
I don't know the full story here, but it seems bat-poop crazy to me that Bosch would not only PRODUCE a fragile alternator to start with, but then they'd intentionally prevent the end user from hardening it.
We have not run down the true backstory and causes of this situation, because of competing priorities. One day, maybe I'll find the time to give it the analysis that it deserves. The problem is reportedly not specific to Bosch, nor is it specific to alternator charging such as we are doing. Here's a useful 3-minute YouTube made by an independent alternator specialist that talks about it further (except this is a 2013 video and reportedly, the workaround he shows can no longer be accomplished).
My old travel trailer had a propane fridge, LED lights, two 6V golf cart lead acids and a 65W solar panel. My load was low enough that the 65w panel could keep the fridge and lights going indefinitely even in part shade. I didn't have a battery monitor, but suspect my load was 10-20AH per day, all of which was replenished by the solar.
I have a compressor fridge, two 100W panels, alternator that as configured can charge up to about 40A, a 55A WFCO converter, Onan generator, two 100AH lead acid and a 100AH battleborn behind a 40A B2B.
Load is 50-70AH per day, almost all from the fridge.
The solar keeps the fridge going during the day, but doesn't add much net charge to the batteries. If I'm not driving I have to run either the engine or generator for at least an hour.
Estimate that less than 50% of my load is replenished by the 200W solar.
After running the Onan for an hour, I decided that the engine is a vastly better at power generation than the Onan. From what I can figure, the existing heavy duty alternator on the Transit can charge at least 80A without issues, so that'll be what I focus on next.
If our circumstances change such that we come to need a beast of an alternator and we need it to be absolutely foolproof, I will look into whether ARV will sell it to 3rd parties. But we have a T1N Sprinter and I'm not 100% sure that one would fit.
Meanwhile, we make do with our other 3 charging mechanisms, and our ordinary Bosch 200 A is used sparingly.
One thing to consider is that the "normal" Nations (DC Power Engineering) alternator is rated at 280 amps. In reality, if you pull that many amps it will go into thermal cycling from the Balmar regulator temp sensor, though. The better setup, especially for you as you are OK with the lower output from your current setup, is to use the Balmar to turn the output down to around 140 amps. The alternator can run continuously at that load without overheating and it will put less load on the belt and clutch pulley, so a win, win, win benefit. It is fails just have a manual switchover to the stock alternator, but at 140 amps those alternators should last a very long time as they are very well built.
On the issue of "belt flutter", folks may want to check out the video I made of my Nations/Balmar setup vs the ARV results:
This thread was a good idea. Anyone care to summarize? Or, message me your numbers so that I don't have to comb through the thread and deduce, and I will fill in the table.
hbn7hj 200AH lithium 225AH FLA 30% solar 70% generator
hbn7hj 100AH lithium 100AH FLA 10% solar 2,0% generator 70% alternator
Excellent idea, Interblog.
For us use 80% solar, 15% alternator, 0 generator, 5% shore
Great topic! I won't participate because although I've spent 400 nights or so in an RV over the last 3 years it hasn't been in a Class B RV. I'd guess the rigs were plugged into the grid 99% of the time.
Excellent idea from Interblog to summarize the data in table form. :thumbup:
I'm looking forward to reading more replies, keep them coming! :clap:
Shore percentage is about 75 percent while driveway camping.
100 AH LA.
While in use:
Second Alternator 50%
Oops. Forgot capacity:
For me with 440AH AGMs:
70% solar, 10% alternator, 0 generator, 20% shore
This my shot at average use:
230 Ah AGM
800ah Lithium Ion
330a second alternator
No Onan generator
10% shore power (based on 90% boondocking)
The more battery amp hours means solar is more insignificant especially when a second alternator can produce a charge rate that can replenish your batteries in under an hour and the rest of the time during the day when you drive solar contribution is wasted.
Just a thought, in addition to the Engine Alternator a second alternator such as RV alternator could be added to the table to eliminate possible confusion.
100 AH AGM
While in use. Depends on trip. In 4 years I can count the times we've camped where there is shore power on one hand. Usually we're on the move and don't use solar (suitcase). No need. When we're stationary for a few days, solar provides our total power. We obviously don't use much as I've stated earlier. We also use lithium packs to charge phone and ipad.
200 AH lithium
As GallenH said, it depends on trip. This particular "maiden voyage" on the lithium batteries has been far less boon docking that in the past due to plentiful 30A availability in the Southeast. Reverse the alternator and shore power charging figures above and they'd be more representative of our prior two years.
It does depend upon travel objectives, yes. My numbers are for my defined tech-limiting travel scenario - the exact boondocking scenario that our van was DIY-built to handle.
However, for instance - we also have a camp shack on Lake Sam Rayburn in east Texas. The camp shack has a full panelized metal canopy over it, so obviously I'm not using solar when I'm there. In that case, I plug in, because the 30 amp outlet is 5 feet from our van. But that's not "travel" the way I define it - that's just incidental driveway camping. I also plug in at my home when we are running the roof a/c because it's 98 degrees outside and we are trying to do work inside the van. That's not travel either - that's just driveway camping (or working).
I'll roll up my table at the point when it appears we are no longer continuing to receive posted numbers.
Where does your charging come from survey
Nations second alternator
80% second alternator
While not traveling (garaged with occasional drive):
50% second alternator
50% shore (30amp overnight every few weeks)
200 AH Lithium
1% shore power - every month or two a 10 Amp charger to reset SOC meter
Roadtrek CS with 800 AH lithium system (4 batteries). Since we drive most days, at least some, I rarely think about charging or bother to plug plug in. We usually only have 2 batteries on at a time. If I cook dinner on induction and microwave, bake cookies in oven, watch tv and run fans all night I might have to switch on another battery in morning for the coffee maker.
We have a Promaster custom conversion with an Elite Power Systems 600 amp hour lithium battery and two Nations high output alternators. Each is rated for (roughly, working from memory) 280 amps per hour at idle speed which translates to 100-120 continuous amps per hour each in the real world (running hot). Other than shore power, that is our only power source. We have a combiner switch which allows us to take the primary OEM replacement alternator off line and charge only with the secondary alternator, or we can charge with both together to deliver 200 to 240 amps per hour to the battery. We also have an engine auto-start system based on a Viper remote start module and a Victron battery monitor.
Starting with 100% state of charge in the morning, our normal daily use is about 90 amps total. That's without even thinking about power conservation. Cooking with a microwave, making coffee, watching television for 2 or 3 hours in the evening, etc.
We live in Texas, so sometimes when boondocking in the summer we sleep with the air conditioner powered by the battery. Sleep would be impossible otherwise. On those nights, about an hour before bedtime we idle the engine to get the battery up to 100%. Then we fire up the air conditioner.
Our van is designed with a door to close off the sleeping area where the AC unit and the thermostat are, so we're actually only cooling half of the van when we sleep. Because of that arrangement, the AC only draws about 70 amps per hour since the compressor cycles off more than usual. (It's 90 amps per hour with the compressor on.) The inverter and phantom loads are another 5 or so, which leaves about 120-140 amps per hour for charging when the AC is running and the alternators are combined.
With a full battery at bedtime, our auto-start system is set to start the engine when the state of charge drops to 20%. That usually takes about 5.5 to 6 hours. Then while we're still asleep the engine runs for one hour (maximum auto-start system time) which delivers another 120 amps total to the battery (the AC is still cooling). Then we get another 1.5 hours or so on battery alone, which gets us our 8 hours of sleep. We wake up with enough power for breakfast and coffee, then we have to either drive or idle to recharge. Takes about 2.5 hours to get back up to 100% SOC from 20% at idle with no loads.
So our worst case power usage is about 730 amps per day while boondocking in the Texas summer, idling the engine about 4.5 hours per day (burns about 2 gallons of gas). The rest of the year it's about 90 amps per day of use and less than an hour of idle time. In practice, when it's cool enough to sleep without the AC we could boondock for 5 days without running the engine. But we rarely stay anywhere more than two nights.
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