DE0061 12VDC Refrigerator Duty Cycle

[al1florida]

Originally Posted by Kayak73

I've got some work to do for certain. Yesterday and today were about as good solar days as we ever get here. Today I harvested 73AH of solar. The fridge plus base draw only thing running for two days. 1st day I do great, start off batteries 100% (which is some number below 150AH to use to stay within 50% SOC). Use 4amp/hr as the load with a 70-75% duty cycle.
24 hour run then is just for the fridge and base about 18x4=52AH used in 24 hours - no other loads applied. That only left 21AH to put back in batteries so best case 150-52 = 98 +21 = 119 AH for next day, continue the math and I have enough to safely run three days which has been proven.
Now what to do?, Add another solar panel is obvious, change all three out maybe to rigid with higher output. That would almost do it but...we still need to live in the rig with other loads. As noted adding a standalone higher capacity charger better suited for the batteries when the generator is run to lessen genny run time will be necessary. There is just not much roof space on the View. It appears I will be taking the EU2000i along to boondock or folks will smell diesel fumes.
As you have noted your solar & charging system is factory installed. Wire sizes are probably designed for just large enough for a 3% to 5% loss (maybe not even that good). I work to make my loss from wire size to be 1% or less. It just doesn't cost that much for the heavier wire size. I always use a wire size calculator such as: Voltage Drop Calculator - for single and 3 phase ac systems and dc systems If you add another panel or larger panels you may not have large enough wire size to get full power from the panels. Same goes for adding a larger charger w/o adding heavier wire or locating the charger nearer the batteries.


BTW, no matter what direction I place the meter clamp on the solar feed there is no polarity indicated, whether on a POS feed on on the NEG to GND feed. Guess it is the nature of solar or the Pulse Width Modulation. So far the Zamp controller is working after the manual reset.


I'm content with the refrigerator, it is working. Overall not a good idea to not use LP 2 or 3-way in this tiny rig. To actually dry camp with little or no generator use I would need over 400watts up there, 500 even better. With a better charger I can pretty much nail BULK charge and perhaps solar can help on good days. It does have output on sunny days, cloudy or rainy days and yes, even in partial shade. I doubt that after three days I can get out of absorption or into FLOAT at all with the duty cycle and 300 watts of solar and a few hours of genny time each day. The solar controller never got out of the defined Zamp bulk charge today. I fail to see how lithium is a solution, especially at price point. You still need a way to pump amps back into the things and you can only pump in what is harvested and not used.
True you still have to get the amps back in the battery, even with lithium. For those who do long term camping w/o electric hookups, the lithium provides deeper discharge w/o reduced life, the ability to keep higher charge rates w/o the amps going in decreasing within an hour or so and to me the very important fact that you don't ever need to get to 100% as you do with lead acid. Not getting to 100% every 5-7 days will greatly reduce your battery capacity. Do it enough even equalize cycles won't recover the lost capacity. Lithium is currently about $1K per 100AH.
Now if a panel is rated for 6.3 amps output you will seldom get that.
Make that "never see 6.3 amps outside a lab test environment. Probably the best you will see in the southern USA in the summer is 4-4.5amps. But then you won't want to be w/o air conditioning in the summer. So it doesn't really matter if they recharge faster, you can only put in what your panels harvest and do not use. Today the two panels were fairly consistent putting out 10-11 amps from 11:30 AM until 3:30 PM, later they were up and down as the sun moved toward the West.



IMHO, the root cause of failure is poor design of the power system for a 12 VDC refrigerator by WGO or purchasers like myself buying the things with the hope of dry camp. It is too big a hurdle to mess with after 3 days. The battery monitor won't help with genny run time, just tell me it has to run. Thinking back about the failures early on they all seemed to be related to the load of that fridge. Converter failed, OEM batteries died (of course), solar panel failed. Just too much stress on the system. I understand you get group 31 batteries now (not as many AH as I have with the Trojans now) with a View and have heard about a lithium power pack coming for mega dollars. How are they gonna charge it? Can't run the add-on alternator because the engine is a new generation diesel - no idle allowed. The View has become a plug-in RV with occasional short dry camps. What you can do is dry camp while touring, drive all day, dry camp at night, drive all day etc.
Even if you charge by idling the engine you may not get as much charge as you hope for. The alternator is designed to "see" the chassis battery, which may be much closer and with much heavier wire than the house batteries. So once the chassis battery is charged your charge current could be very low.
And, yes, dry camping with an elect only fridge is problematic. As you found out, it takes quite a bit of work and planning to support the fridge.

Added reply inside the quote.

[al1florida]

Here are a few links with very good info about RV battery, solar, charging, etc:

This one, Handybobsolar has lots of good advice and examples of what to not do or what to look for in a quality battery/solar install. He is very opinionated, strong worded, the site has not been updated since 2010, and I don't agree with everything he writes. However the narrative related to what not to do is spot on.
https://handybobsolar.wordpress.com/...ging-puzzle-2/
This link to Jack Mayer's website has lots of good info.
RV Electrical

This link to "The 12V side of life: has pretty basic info, but is worth reviewing. 2 parts to the website so be sure to click on "part 2" at the bottom of the link.:
The 12volt Side of Life (Part 1)

[Kayak73]

Al,
The View has 8ga stranded for the solar feed. It shows insignificant voltage loss in the short runs. Yes, if I were doing it I would always use the next larger gauge wire, safer. It will easily support 30amps but I question that it will support the wattage claimed if you put 3 on top and use the portable panel. The problem there is they did add a smaller gauge wire to the plug for a portable - but it is all carried back to batteries on the same one 8 gauge. Yeah, overall a poor design.



Like I said, no argument with the lithium being desirable - as long as you have a way to recharge them, doesn't matter if it is FASTER, only that you have capacity to recharge them. My money is on Trojan FLA right now obviously since I have nowhere to add enough panels to support the application why on earth spend more money on something that will NOT help the situation... IFF the desired result is to camp off grid with no generator use.



Now, even if I were 10 years younger I doubt I would tackle the rewire etc and expense because with today's technology and the density/size of solar panels vs the limited roof space of a View there is simply zero payback - the generator must run. To make it even more clear I will install a switchable, manual circuit breaker to just shut down solar when the generator is running. If I had an oscilloscope to show you the waveforms of PWM interacting with the converter/charger you would see it but current from the solar charger is essentially always positive which lead me to think the refrigerator was drawing double amps with solar ON, it was not. But it also does zero good to have solar on and the charger on together.


Everything is good if there is room on the roof for enough real rigid panels to supply the charge and load refill during the day. That will NEVER happen with the View and the 12VDC refrigerator. Well, until panels are capable of more output per size. If you have roof space and do the install yourself, yes, solar can be a great solution for dry camp. In more ways than I care to enumerate the solar install of the View is really a joke and that is not a bash of Zamp. I can't think of many companies I've ever worked with that had better people on the tech support side to work with, they are great and they won't pull punches - you get the truth and they are very kind, and knowledgeable with their technology. So, if you want to load the roof to the max on the View, 3 panels and use the portable plug in the power bay you better get ready to replace some fuses because the run from the controller carries it all and that wire is NOT large enough. (evidence a quiet recall on that portable plug to add a fuse- funny)


I'm gonna drop this for a few months while we look for a cool place in the mountains if the storms ever let off. The only thing I'm doing right now is adding a 30 amp switchable circuit breaker to the solar, it will be mounted in the small compartment above the pantry in the 18V24D where it is out of the way but I can reach it. Summary again, with my setup I can safely dry camp 4 days, three nights and stay below the 50%SOC and not hurt the Trojans. Despite what some think going below that a few times does not really damage true deep cycles like the Trojans but it will shorten battery life if done a lot. I can extend that significantly by adding an extra dedicated true deep cycle capable charger and connect the POS to the inverter feed, add the switchable breaker for solar and dump a BULK charge back into the Trojans morning and evening.

The refrigerator is the PROBLEM and it is NOT the problem. I suspect a good normal refrigerator like in your home would perform somewhat like this which is why larger rigs can use them with ample roof space for a bunch of panels and a good solar install. The load applied is probably very similar in both a 40ft A class and the View - but the View has a tiny roof space. What works in the A class will never work in the View until technology changes. The panels on the View do one thing good, they will keep the batteries up when not in use, with the Trik-L-Start both chassis and house side will always be ready to go.

[al1florida]

Originally Posted by Kayak73

Al,
The View has 8ga stranded for the solar feed. It shows insignificant voltage loss in the short runs. Yes, if I were doing it I would always use the next larger gauge wire, safer. It will easily support 30amps but I question that it will support the wattage claimed if you put 3 on top and use the portable panel. The problem there is they did add a smaller gauge wire to the plug for a portable - but it is all carried back to batteries on the same one 8 gauge. Yeah, overall a poor design.



Like I said, no argument with the lithium being desirable - as long as you have a way to recharge them, doesn't matter if it is FASTER, only that you have capacity to recharge them. My money is on Trojan FLA right now obviously since I have nowhere to add enough panels to support the application why on earth spend more money on something that will NOT help the situation... IFF the desired result is to camp off grid with no generator use.



Now, even if I were 10 years younger I doubt I would tackle the rewire etc and expense because with today's technology and the density/size of solar panels vs the limited roof space of a View there is simply zero payback - the generator must run. To make it even more clear I will install a switchable, manual circuit breaker to just shut down solar when the generator is running. If I had an oscilloscope to show you the waveforms of PWM interacting with the converter/charger you would see it but current from the solar charger is essentially always positive which lead me to think the refrigerator was drawing double amps with solar ON, it was not. But it also does zero good to have solar on and the charger on together.


Everything is good if there is room on the roof for enough real rigid panels to supply the charge and load refill during the day. That will NEVER happen with the View and the 12VDC refrigerator. Well, until panels are capable of more output per size. If you have roof space and do the install yourself, yes, solar can be a great solution for dry camp. In more ways than I care to enumerate the solar install of the View is really a joke and that is not a bash of Zamp. I can't think of many companies I've ever worked with that had better people on the tech support side to work with, they are great and they won't pull punches - you get the truth and they are very kind, and knowledgeable with their technology. So, if you want to load the roof to the max on the View, 3 panels and use the portable plug in the power bay you better get ready to replace some fuses because the run from the controller carries it all and that wire is NOT large enough.


I'm gonna drop this for a few months while we look for a cool place in the mountains if the storms ever let off. The only thing I'm doing right now is adding a 30 amp switchable circuit breaker to the solar, it will be mounted in the small compartment above the pantry in the 18V24D where it is out of the way but I can reach it.

Really pleased to see tht WGO installed 8ga wire for the solar. I had expected 10ga or even 12ga. BTW depending on the length of the wire is could support 300 watts of solar. However I think you have written that there is pretty long wire run from the controller to the battery which could be a weak point.

[Kayak73]

Originally Posted by al1florida

Really pleased to see tht WGO installed 8ga wire for the solar. I had expected 10ga or even 12ga. BTW depending on the length of the wire is could support 300 watts of solar. However I think you have written that there is pretty long wire run from the controller to the battery which could be a weak point.

Long is relative, since the View is so small that 8ga will easily support 300 watts of panels, probably will loose too much to justify using the 3 on top PLUS one in the portable plug because I think that run is about 25 ft in length from controller to the POS battery feed connect. Three on top is a great benefit if you redo the math with the idea of lengthening the stay without generator run time, another day in good conditions at least.

[creativepart]

Bill, I know I’ve mentioned this before, but a change from your Zamp PWM solar controller to a Victron MPPT controller improves efficiency, charging and monitoring at a ~$230 cost.

No it won’t solve your boondocking issue, but it’s nearly as helpful as adding another panel. I never saw much charging benefit from the Zamp controller. But when dry camping with the Victron I’ve seen 1.19 kwh in one day with mostly bulk charging.

[Kayak73]

Originally Posted by creativepart

Bill, I know I’ve mentioned this before, but a change from your Zamp PWM solar controller to a Victron MPPT controller improves efficiency, charging and monitoring at a ~$230 cost.

No it won’t solve your boondocking issue, but it’s nearly as helpful as adding another panel. I never saw much charging benefit from the Zamp controller. But when dry camping with the Victron I’ve seen 1.19 kwh in one day with mostly bulk charging.

How many panels are in your array, what wattage and voltage? Is this a comparison of the exact panel array with ZAMP PWM vs a Victron MPPT?
The reason to ask is most folks, including the white paper at the Victron site seem to think there is very little benefit in a small array like 2 or 3 parallel panels at around 100 watts each. In fact most demonstrations I've seen show far less than a 10% increase although I'll admit 10-30% on a large array is a no-brainer move to MPPT. The most important thing for me is to have identical electrical characteristic panels and I would go same manufacturer, same exact panel for the three. This is one of those things like which tire is better than another, lithium is superior to wet cells but the bottom line is the folks making and marketing and selling the things advertise well and sometimes might push the real truth. Since we know most of the lithium in the world in not in the US I don't expect any real significant drop in price point any time soon, since the marketing hype has been so good with MPPT it is another good way to trash a perfectly good PWM controller in a small two or three panel array and toss some more cash out the window - until someone can show me the evidence. I'm not being inconsiderate hopefully and I do appreciate all your feedback, I just need more info. Solar is not my thing, I'm learning. All I'm saying is normally more than 3 panels and MPPT starts showing payback fast, when you fill up the roof of a big A class you better have the MPPT, PWM would be silly after all that expense.


From that paper:
3. Conclusion
PWM
The PWM charge controller is a good low cost solution for small systems only, when solar cell temperature is moderate to high (between 45°C and 75°C).
MPPT
To fully exploit the potential of the MPPT controller, the array voltage should be substantially higher than the battery voltage. The MPPT controller is the solution of choice for higher power systems (because of the lowest overall system cost due to smaller cable cross sectional areas). The MPPT controller will also harvest substantially more power when the solar cell temperature is low (below 45°C), or very high (above 75°C), or when irradiance is very low.


My two dinky flexi panels deliverd 12.3 amps today at 14:30 hours for almost 20 minutes, best I've ever seen. Yet my AH harvest will be far less than yesterday probably because all morning was cloudy. As the writer noted in his paper, PWM falls short in colder weather as well but the flexi panels get so hot you can't touch em in the sun. No ventilation, glued totally to the roof by WGO.

[creativepart]

I hav 3-100w rigid panels. My OEM system came with one Zamp panel, the same Zamp controller as yours and the Zamp 3-port connector on the roof.

It was a cheap upgrade to add two more panels, so I did. But Zamp panels cost $400 ea, so I bought 2-Renergy panels from Amazon for about $220 total.

Every time I checked my Zamp controller I saw it putting out 7 or 8 amps max and something like 12.7 volts. (I’m sorry I don’t remember exactly).

I was thinking I’d add another panel but decided to upgrade the controller first.

The Victron shows 20+ Volts from my system pretty much all the time. So it is higher voltage than the batteries. I can’t prove it but the entire system seems to work much better at keeping my batteries topped up. And it automatically stops charging when plugged into shore power or during generator usage.

I will probably add one more panel to my system as we really enjoyed our recent National Forest dry camping trip. Something we’ll do more often.

The way I look at it isn’t all that logical. If it’s better and affordable then I’ll go for it and see for myself.

The Magnum inverter is another such upgrade. My RV came with the ME2012 inverter/charger and a basic remote controller. It was $140 to upgrade to their top of the line controller and it was plug and play easy to install. Once I made that upgrade I had lots more control over the inverter AND the charger. So that was a no brainer. It also let me add a Magnum BMK, which I couldn’t do with the stock controller. The BMK was another $140 or so.

The result of those upgrades wasn’t really expected to be so handy, but for less than $700 all these changes have been a huge improvement in capabilities.

Will this work this way for you? I can’t say. But it’s not that big of a cost to try it and see. It certainly isn’t going to make things worse.

[Kayak73]

I am no solar expert here but I read a lot From what I can tell if your panels are not exactly matched the PWM is a very poor performer and any variation requires MPPT to deliver performance. It could be one panel is 19 volts open and the other is 20 or one has 5.5 amps and the other 6 amps. The two panels on my roof right now are Zamp Flexi, 100 watt each. WGO is now using Sun Power flexi panels I think. I have already decided to go with rigid panels for various reason but I dread removing the flexi panels and repairing all the damage and holes, just life I guess. So if you have a Zamp panel and a Renogy panel you should actually go with the MPPT.
First day of my current run in the driveway I saw over an hour at 14.7VDC and amps were delivered low, harvested high (73AH), that was the charging stage the controller was in. Today I saw mostly 13.2 or more volts and up to 12.3 amps! That's the most amps I have seen at any time. Now it was cloudy in the morning hours, much lower but at 14:30 it was burning bright. Today I harvested only 55 AH.

Seriously I know the MPPT is not snake oil and I believe your experience absolutely confirms that if panels are not an exact match MPPT is the only way to run them, PWM just won't do it without significant loss. Like that white paper says, anything more than three 100 watt panels - go MPPT, non-exact matched panels - MPPT. Another nice thing you can have super high voltage panels and the MPPT will actually use excess voltage to deliver more current. I know the Zamp controller is displaying near battery voltage, depending on charging stage. If the batteries are low the voltage will be low in what I know as bulk but the amps are as high as it can deliver, in absorption it bumps the wet charge up to 14.7 volts and drops the amps delivered. The two Zamp panels are exactly the same open voltage - in bright sun, 20.3.

[Kayak73]

This whole process has taxed my brain. Last evening I turned on the converter when solar shut off, this AM I was out of BULK and the solar came on in absorption at 14.7. Today I will harvest many more AH than I can use, the good news is it might, might, get the batteries FULL. Only way to really know is turn everything off wait overnight and use the hydrometer, a pain. Now I am thinking the T-1275 batteries are TOO large to ever work exactly right in the boondock - strange. There remain a few options like possibly the IOTA DSL 75 amp connected to the inverter POS to battery for trying the bulk charge for an hour or two AM & PM. The math is hard and much more complex than I imagined and trying to find a good real deep cycle wet cell charger is a dove shoot, lots more shells fired than doves in the bag. The great big batteries are great for the 3 night dry camp but charging them is a bear. Based solely on what I've done so far if I can mount three 170 watt panels on the roof and get the right controller and lithium based batteries it will work, then a correct lithium stand-alone charger. Yes, now I understand why lithium drop-in is so attractive. IF I can reach a favorable balance with the Trojans I will hold on and wait for the drop-in technology to advance. I think the reasonable thing now is move to the three panels and see where I am. Even running the CPAP at night and using the rig I only need to harvest just over 100AH. Install shutoff for solar when charging by converter. Oh, I checked that this AM with the FLUKE, with the solar controller running at 14.7 and the PD9245 on I was only reading the exact amperage I had with the converter OFF, so at least that proved intuition. Run the genny all day and there would just be a bigger diesel bill at next fill-up. The shutoff switches will be one on each ground from the solar controller. The shutoff switches will be helpful working with batteries as well. With these monster batteries the last 10-20% charge is grasping at straws, really hard to get there, then again, with 150 AH to use at 50% SOC I might make it but even a good charger will need more than 4 hours probably to get these out of Bulk charge mode, doesn't matter the amp size of the charger it is the battery size and charge rate. DW says we are NOT trading rigs again. At this point I personally am willing to take that hit to get a Wayfarer or any really good C class small rig with a favorable floor plan - as long as they stay with the 2 or 3 way LP fridge. There is just no easy way to make this 18V24D a boondocking machine, perhaps not even a HARD way to make it work. Yes, I can make a ton of improvements, spend a bunch more time and effort and money but I'm ready to say I made the wrong choice for my needs and bite the bullet and hit the check account. At my age I just want to go and use the rig, not play with it or work on it all the time. Sometimes the "old ways" like LP refrigerators just make sense. Of all the possible choices I have looked at the final conclusion would be 1) DW says no trade or buy and sell is gonna happen - forget that - too old to fight 2) Solar is not going to be a real solution with conventional batteries, AGM, FLA etc 3) Only remaining solution is drop-in lithium with an appropriate charger to care for them, just leave the distribution panel for the 9245 in place and turn it off, run the lithium charger with the generator. Done. OK, another 2-$3K and I've still got to listen to the Norcold run at the foot of my bed - nope, CPAP will be on! OR 4)just run the generator and forget about it. NO grammar or punctuation lessons needed here.

[al1florida]

Originally Posted by Kayak73

This whole process has taxed my brain. Last evening I turned on the converter when solar shut off, this AM I was out of BULK and the solar came on in absorption at 14.7. Today I will harvest many more AH than I can use, the good news is it might, might, get the batteries FULL. Only way to really know is turn everything off wait overnight and use the hydrometer, a pain. Now I am thinking the T-1275 batteries are TOO large to ever work exactly right in the boondock - strange. There remain a few options like possibly the IOTA DSL 75 amp connected to the inverter POS to battery for trying the bulk charge for an hour or two AM & PM. .............

I don't understand why you write that the T-1275 batteries are too large.

When you use more AH's than you can replace then you have a problem no matter the size of the battery.
With the T-1275 you have 300AH of capacity. If you had a pair of 6V golf cart batteries you would have about 200AH of capacity. If you used 150 AH out of either of them and only can put 100AH back in you can't get either set to 100%. That is a lack of recharge capacity not battery size.

[al1florida]

Originally Posted by Kayak73

This whole process has taxed my brain. Last evening I turned on the converter when solar shut off, this AM I was out of BULK and the solar came on in absorption at 14.7. Today I will harvest many more AH than I can use, the good news is it might, might, get the batteries FULL. Only way to really know is turn everything off wait overnight and use the hydrometer, a pain. Now I am thinking the T-1275 batteries are TOO large to ever work exactly right in the boondock - strange. There remain a few options like possibly the IOTA DSL 75 amp connected to the inverter POS to battery for trying the bulk charge for an hour or two AM & PM. The math is hard and much more complex than I imagined and trying to find a good real deep cycle wet cell charger is a dove shoot, lots more shells fired than doves in the bag. The great big batteries are great for the 3 night dry camp but charging them is a bear. Based solely on what I've done so far if I can mount three 170 watt panels on the roof and get the right controller and lithium based batteries it will work, then a correct lithium stand-alone charger. Yes, now I understand why lithium drop-in is so attractive. IF I can reach a favorable balance with the Trojans I will hold on and wait for the drop-in technology to advance. I think the reasonable thing now is move to the three panels and see where I am. Even running the CPAP at night and using the rig I only need to harvest just over 100AH. Install shutoff for solar when charging by converter. Oh, I checked that this AM with the FLUKE, with the solar controller running at 14.7 and the PD9245 on I was only reading the exact amperage I had with the converter OFF, so at least that proved intuition. Run the genny all day and there would just be a bigger diesel bill at next fill-up. The shutoff switches will be one on each ground from the solar controller. The shutoff switches will be helpful working with batteries as well. With these monster batteries the last 10-20% charge is grasping at straws, really hard to get there, then again, with 150 AH to use at 50% SOC I might make it but even a good charger will need more than 4 hours probably to get these out of Bulk charge mode, doesn't matter the amp size of the charger it is the battery size and charge rate. DW says we are NOT trading rigs again. At this point I personally am willing to take that hit to get a Wayfarer or any really good C class small rig with a favorable floor plan - as long as they stay with the 2 or 3 way LP fridge. There is just no easy way to make this 18V24D a boondocking machine, perhaps not even a HARD way to make it work. Yes, I can make a ton of improvements, spend a bunch more time and effort and money but I'm ready to say I made the wrong choice for my needs and bite the bullet and hit the check account. At my age I just want to go and use the rig, not play with it or work on it all the time. Sometimes the "old ways" like LP refrigerators just make sense. Of all the possible choices I have looked at the final conclusion would be 1) DW says no trade or buy and sell is gonna happen - forget that - too old to fight 2) Solar is not going to be a real solution with conventional batteries, AGM, FLA etc 3) Only remaining solution is drop-in lithium with an appropriate charger to care for them, just leave the distribution panel for the 9245 in place and turn it off, run the lithium charger with the generator. Done. OK, another 2-$3K and I've still got to listen to the Norcold run at the foot of my bed - nope, CPAP will be on! OR 4)just run the generator and forget about it. NO grammar or punctuation lessons needed here.

I really believe there is a fairly simple fix. It will cost some $$ but not anything like a new RV or the frustration of an unhappy owner.
1) A new converter which will put out a reliable 75amps. (75amps is 1/4C charge rate for your 300AH of battery. 1/4C may be more charge amps than the proper charge rate, but for an 30min to an hour at 75amps I don't think that will cause a problem.
2) Add a 3rd matching solar panel.
3) I believe you estimate 25' from the controller to the battery. With that much distance from the controller to the battery, at 13amps at 12V you have about a 4% loss. That is about 0.5 volt loss. That is enough to slow the actually charging into the battery.
4) pull the old controller, splice the wires at the old controller location, put the panels in series, which gives you around 50volts greatly reducing your wire loss, and finally install a MPPT controller within 2-3 feet of the battery.

Now when your run your generator for an hour in the morning you will get 60-70AH in your batteries. Now the solar panels will finish off the job of getting your batteries fully charged.

One down side to panels in series is shade one small part of one panel you loose 80-95% of the output from all the panels.

AND install a battery monitor to show 24/7 the amps/volts and the total AH used or put back in. Now you know exactly the status of your system and the SOC of your batteries.

[Kayak73]

Al,
Even if you could put a 100 amp charger on the batteries I have it would take about 7-8 hours to get BULK charge complete. The size of the charger in amps really matters nothing at all past 15% of c20. The present charger is 45 amps, well exceeding that 15%. It relates to the charge rate due to physical bulk of the plates etc. Well, it will cause some gassing and boiling but I get that at manual Equalize. Normally once a month is required to keep FLA deep cycle happy, especially connected in parallel. The controller in place does have an equalize, it works only if you turn off the fridge, otherwise it never holds FULL long enough to bump into the 15 day interval equalize mode programmed for WET.



I indeed plan to put three rigid panels on the roof, the flexi panels will not last much longer, one already failed and was replaced warranty. The distance from the panels 3 port plug to controller is about two feet. Output of the controller is about 25ft of 8 ga. At this time the panels connects to port are very short, about a foot or less. The loss measure with the FLUKE at the connection of the solar POS to the battery is .1 VDC less than at the controller end. Not significant to me.


Well, the battery MONITOR is a rough estimate of SOC, the hydrometer is a tad better but yes, the monitor is a helpful tool. It is far more important to me to know exactly what I'm using, what is being put back in. Solar is just not the solution but can be a part of it. Considering I don't worry about shade effect now at all. I will never choose to camp in full sun unless it is a nice cool day - today we hit 93*F, tomorrow going up. You don't look for full sun spots where I live, you look for the shade trees. Now on a cool day at Two Medicine in Glacier I would be looking for the full sun site. Of all the things mentioned the battery monitor has the least value to me personally but I'm a different kind of tech freak. I know exactly how many AH I am harvesting each day, it's recorded. I know the charge state the controller or converter is in simply by checking voltage at a glance - the monitor tells me very little past that because that's really all it can do as well, it just makes it much easier to see. What I don't know is the calculation unless I've done it and kept up with it that the monitor will show at a glance - SOC while in BULK mode, that's the only time that really matters. So shutting down solar for the genny run I pretty much know I'm gonna wast some diesel. It is a depreciating asset. If I start the day with a FULL charge on the batteries at rest, 12.7+ vdc the solar I have will run everything, fridge and all on a good sun day and the battery will be FULL end of solar collection for the night run, the next day it goes down as I have shown before.


I do appreciate the suggestions, the solar panel work is about three months away. I will check BULK charge rate with my massive charger on a 50% SOC one day, that charger dumps out a smart 250amps. Farmers have all kinds of stuff

[al1florida]

Originally Posted by Kayak73

Al,
Even if you could put a 100 amp charger on the batteries I have it would take about 7-8 hours to get BULK charge complete. The size of the charger in amps really matters nothing at all past 15% of c20. The present charger is 45 amps, well exceeding that 15%. It relates to the charge rate due to physical bulk of the plates etc. Well, it will cause some gassing and boiling but I get that at manual Equalize. Normally once a month is required to keep FLA deep cycle happy, especially connected in parallel. The controller in place does have an equalize, it works only if you turn off the fridge, otherwise it never holds FULL long enough to bump into the 15 day interval equalize mode programmed for WET.



I indeed plan to put three rigid panels on the roof, the flexi panels will not last much longer, one already failed and was replaced warranty. The distance from the panels 3 port plug to controller is about two feet. Output of the controller is about 25ft of 8 ga. At this time the panels connects to port are very short, about a foot or less. The loss measure with the FLUKE at the connection of the solar POS to the battery is .1 VDC less than at the controller end. Not significant to me.


Well, the battery MONITOR is a rough estimate of SOC, the hydrometer is a tad better but yes, the monitor is a helpful tool. It is far more important to me to know exactly what I'm using, what is being put back in. Solar is just not the solution but can be a part of it. Considering I don't worry about shade effect now at all. I will never choose to camp in full sun unless it is a nice cool day - today we hit 93*F, tomorrow going up. You don't look for full sun spots where I live, you look for the shade trees. Now on a cool day at Two Medicine in Glacier I would be looking for the full sun site. Of all the things mentioned the battery monitor has the least value to me personally but I'm a different kind of tech freak. I know exactly how many AH I am harvesting each day, it's recorded. I know the charge state the controller or converter is in simply by checking voltage at a glance - the monitor tells me very little past that because that's really all it can do as well, it just makes it much easier to see. What I don't know is the calculation unless I've done it and kept up with it that the monitor will show at a glance - SOC while in BULK mode, that's the only time that really matters. So shutting down solar for the genny run I pretty much know I'm gonna wast some diesel. It is a depreciating asset. If I start the day with a FULL charge on the batteries at rest, 12.7+ vdc the solar I have will run everything, fridge and all on a good sun day and the battery will be FULL end of solar collection for the night run, the next day it goes down as I have shown before.


I do appreciate the suggestions, the solar panel work is about three months away. I will check BULK charge rate with my massive charger on a 50% SOC one day, that charger dumps out a smart 250amps. Farmers have all kinds of stuff

The loss measure with the FLUKE at the connection of the solar POS to the battery is .1 VDC less than at the controller end. Not significant to me.

I believe you wrote that on one day you saw something like 13 amps flowing from the controller. When you saw the 0.1VDC loss was that when the 13amps were flowing???? If not your 0.1V reading is meaningless. The loss is only there when there is high current flow. Take a look at a wire size calculator and put in a 3 amp current for 25 feet of wire and then put in 15-20amps for that same wire size. Quite a difference in percentage of loss.

Back to my suggestions about a process to get your batteries charged on a daily basis.

I think basically you are writing that you don't believe you can get your batteries back to 100% in less than 7-8 hours even with a larger charger followed by quite a bit more usable solar power than you have now. I disagree. That is if keep your usage down to around 100-120AH from late afternoon/early evening to the next morning when you can run your generator again. If you are using 150AH or more over night (i.e. 50% of your battery capacity or more) then recharging takes longer. THAT is why you want your larger battery, instead of going smaller like you wrote a couple of posts ago!

Here is a link to an extensively detailed article about battery charging. They charge a battery from 50% SOC to about full in about 5 hours. That may not match exactly what we see in our RV's but we should be able to come close. https://marinehowto.com/how-fast-can...ry-be-charged/

More than once you have brought up not wanting to park in the sun where you go camping.

I agree trying to dry camp in 93* weather doesn't work very well. To me it doesn't work very well even parked in the shade. That brings up the question, "Why are you going though all this frustration and work when you are not going to be able to dry camp anyways." Just go where you have elect or run your generator and air conditioner. Just park where your generator doesn't bother other people or park where everyone is running generators.

[Kayak73]

Many times I have read of folks complaining about loosing a cell in parallel battery connects. The thing is with two in parallel you must put the POS charge on one battery and the chassis ground on the other battery. You do the same with series and there is no other way for current flow to go in series but parallel connects it can start favoring the stronger (less resistance) path. Failure to do that simple thing will almost guarantee a dead cell in the battery further from charge source. In parallel all loads are distributed equally but not CHARGES. Battery life of a massive backup of 2 volt deep cycle monsters for a PBX (phone system of old days) would last forever, 15-25 years easily because they are not used, cycled. The reason we have normal 5 years or less life in our RV batteries is we use them, with solar or just a converter they are worked very hard with a residential or with my 12vdc compressor marine fridge. Add in possible inverter time and they really take a beating. So far I have never seen an RV with a really correct OEM converter or inverter/charger but the new ones in the past 10 years or so are much better than the old ones were. Check out some of the residential solar experiments guys are blogging about. Small systems, running a few things like a fridge, the complaint is not about going green but keeping batteries alive to store the charge. I don't have enough "right" equipment to prove it but solar charge from either MPPT or PWM appears to be very different in behavior than from a battery charger. From all those blogs I'm guessing most of them know how to connect parallel batteries for storage but almost ALL of them are reporting HALF life in the PV application on ONE battery, usually a "sudden" dead cell in that one. It may be that PV solutions only work or work far better in a SERIES installation of batteries. A few of those guys are reporting with amazing graphing monitors but they never state that they ever check true SOC with a hydrometer etc. They are trusting a monitor and one even posted photos of the install clearly showing that he applied all charge and all load to the same battery! That was a series/parallel of 4 T-1275 batteries. At 2 years a dead cell in the weak series side of the parallel - does it matter with solar which shows no directional flow (polarity) in the charge current applied? Is there no "correct" way to connect batteries in parallel with solar because of that? Does the non-polarized charge current have a predilection for the strong side even more? No one was working in our physics lab with solar when I was at UA, a long time ago and I never have messed with it before.

[Kayak73]

Al, that is a very good link and presentation. At least someone else in the world really understands BULK vs Absorption vs Float. In his test the flaw is NO LOAD is being applied. He is also using AGM (they will charge slightly faster than FLA). In our case we have the refrigerator on 100% of the time, load is being applied which greatly extends BULK charge time. Again he is correct in stating "current that the battery will ACCEPT" which is exactly what I said, his presentation is simply better at saying that with pictures and test equipment. The other real issue is that I'm just being realistic.
BTW, it was another poster who stated before that he was "not looking for a spot in the full sun", maybe I did as well, not rereading it all.
So, regardless of charger size past 15% c20 it will take 7-8 hours to get my batteries out of BULK - what I said.
The discussion is truly about the refrigerator and what has happened to all of us who got the 18V24D with the DE0061. The point I think I finally intended to make is the failure is with the power supplied, not the refrigerator. Even if you park in full hooks all the time the thing will fail or you will loose food until you replace the OEM batteries, my converter even failed - probably when those OEM batteries died. I did not even check them to see if they had a short or a dead cell, in either case it killed the converter as well. Now during the first months of early ownership we had many, many failures of the refrigerator. While waiting for the new refrigerator I installed the T-1275s. Refrigerator has worked fine since that time, not one single burp. All the discussion around the issue related to dry camp etc., battery charging, solar is all to point out the flaws in the design of the setup from the factory. Just a little time off grid destroyed the OEM batteries the converter and one solar cell and resulted in refrigerator replacement because no one ever wanted to look at the power supply side or consider that it was inadequate. This fridge simply works on 12VDC, if that supply is compromised it appears the fridge is not working right, every single thing that happened to owners can be attributed to the poorly designed OEM 12vdc power supply, not the refrigerator.
I'm well aware that I can camp with hooks or not and not many folks in their right mind disagree since the RV is a heat box in 93*F weather. I really had rather be in Maine right now on an unnamed lake paddling my SOT with highs in the 50's and lows in the 40's.
It is a discussion for owners with the DE0061, not someone with a larger A class roof and touching some issues we face that you might not, although any such discussion you always want folks to chime in who have experience to share - that's why these RV forums work. Frequently we get advice, suggestions etc. that help lead to a solution and that's why I engage with you, clearly you have a well working solar setup with which you are happy and it is functioning for you - good experience and advice is always welcomed. ...and Thanks!

[Kayak73]

Of course Al is correct about the voltage drop across 25ft of 8 ga stranded copper. At a normal charge voltage around 13.2 the drop is .31vdc with 10 amps current load, 2.8% voltage drop. The current flow is still there, the voltage drop does hinder the charge somewhat. In other words, the same volume of water is flowing out the hose, just under less pressure. Similar loss applies to the converter charge line as well. That's the real advantage of mounting a charger next to the inverter to use the inverter POS cable - shorter run, bigger water hose, more pressure. I mentioned before that WGO should have mounted that controller and 3 port combiner forward of the passenger door - that would save about 15 ft of copper run and would have made an improvement, from what I can tell they just threw this 12 volt compressor fridge thing together with little planning on how it was going to actually RUN or perform for the end user and with very little change in the "old" technology requirements and little thought about supporting the new fridge - just put it in and they will buy it. I did. There is no accountability for RV manufacturers regardless of brand or company because we still BUY them as fast as they make them. In any case the little Norcold works great, the electrical system for 12vdc not so good.

[RJ2]

Well thanks for the INFO..... we were about to upgrade to the24 D from the View 24J. Have beenre thinking , how nice the J really is . Now with all this refrigerator crap going on , definitely on hold till Winney starts to acknowledge the refrigerator issues . We were talking , and I think we would have test drove and bought one without ever even turning the fridge on, as in the past ...

[SocioSam]

The refrigerator in our 2014 Profile G was our most costly problem. Just after warranty, the refrigerator motherboard burned up. With the new costly motherboard the refrigerator has been working great, far better than it was new. We now realize that it was probably defective from the day we purchased the RV (new) but did not run tests like this or have a comparison experience as to how well it should be working.

[creativepart]

Correct me if I’m wrong but the issue is the elimination of propane on the RV, correct? Removing propane saved space in the design and necessitated the switch to 12v compressor fridge.

If that’s so then there is not much an owner can do if they want to use the RV for extended off grid camping - other than making modifications to their electrical charging and storage system.

An owner may not like this reality but is it really Winnebago’s “fault”? I don’t recall that RV been promoted as a boondocking specific RV. Many RVs are created that can’t boondock for extended periods without modification. It’s not really a design flaw on the manufacturer’s part.

Perhaps a buyer isn’t aware of that fact when they purchase the model, or the selling dealership is glossing over this fact (likely) when selling the model.