Turning off Solar Controller when on Shore Power?

[Smitty77_7]

We're in Yuma for our first two months stay. Really enjoying the Foothills and the mega gang of fellow RV'ers. Was shooting the breeze with a few fellow RV neighbors, and one of them said he had turned of his Solar Controller, as he was going to be on Shore Power for the next three months.

 

I don't turn my Solar Controller off on a regular basis, when on Shore Power. Just letting the Magnum MS2812 and MidNite Classic 150 sort things out and determine whom needs to do what when it comes to painting the batteries. (Basically in Float mode most of the time, as we're at 100% SOC most of the time.)

 

Made me want to ask, if others turn off their Solar Controllers when on Shore Power for long periods of times? Sure, if a power failure are to kick in, and you were gone for a few days, it could become an issue. But if at the coach daily, why not turn off the Solar Controller, and let the coaches Inverter/Charger do it's thing?

 

Thoughts, and TIA,

Smitty

[Mark and Dale Bruss]

I leave the solar on and the inverter/charger on all the time. Since I turn the solar on first, the inverter/charger follows what the solar controller is doing. If the solar is charging, the inverter/charger sits in float mode. When dark come, if the batteries need charge, the inverter/changer supplies the needed voltage.

 

When the batteries are charge both the solar and the inverter/charger are in float mode.

 

The question is why would you not want to use free solar energy and use the inverter/charge which uses shore power and if you are paying for metered electricity, pay for it.

[Yarome]

It kind of depends on how your wired and if you're on metered shore power or not. If it's not metered then I don't see any reason not to shut down your solar and let your converter/charger do the heavy lifting. It might save a little wear and tear on your controller, but it would be negligible. On the other hand... I also don't see any specific reason not to keep it on. Depending on the converter/charger and what your settings are, your midnite is likely to be the most 'responsive' to an increased 12v load.

 

If you're a "greeny" I would always opt for free energy over shore power, but that's just a personal choice.

[mptjelgin]

When I am in a sunny spot I turn the battery charger off ("standby mode") on our inverter and let the solar panels take care of the batteries. We are never on metered electricity, but I like the idea of using my solar system and saving that small amount of shore power.

[skp51443]

We'd turn off the charger and live off the panels too, our DC use when plugged in wasn't high enough to be an issue even with only winter sunlight levels. We liked the free part but I also thought it was good for the batteries to see a bit of cycling on a daily basis.

[Jack Mayer]

Yes - what the others said....we handle it the same way. We leave our inverter in standby so we never drop power. We let the solar run as well.

 

Assuming you set the same charge profiles in both the chargers (to the extent you can) then they should not conflict each other in any meaningful way.

 

We often turn off the battery charger in the inverter and just let solar do the job. Right now both are on, but I'll likely turn off the Magnum charger today.

[Smitty77_7]

Thanks for all the input. Interesting the inverter/charger being the popular one to turn off.

 

Is not battery life quite a bit about life cycles? So even though daily discharge and recharge would be small, is that not consuming a portion of those cycles? Where as with the inverter/charger being on, the battery bank is basically maintained at 100% SOC.

 

Is the small amount of discharge/recharge going the Solar Controller route healthier for the longer life of the battery bank?

 

Again, TIA,

Smitty

[skp51443]

The cycles, assuming typical DC power use, will be so small that they aren't really going to make much difference in battery life, check your battery manufacturer's data sheets to see what to expect.

 

I do think the small amount of charge/discharge is good for the batteries, bumping them up to your max charge voltage daily is good for keeping the cells equalized. Also the small amount of discharge is good for keeping the plates happy, too long on float and you can see the battery voltage sag badly when first put under load as the floating has dissolved a lot of the crystals on the plates needed to serve as hosts for the chemical reaction. Not a big deal aside from the minor aggravation from the low voltage and it passes once you have discharged the battery enough that more crystals form.

 

What I'd like to see is an inverter / charger that didn't just charge and float by default with a manual equalize cycle but instead had a multiple level charging profile like the Charge Wizard type devices do that does a regular voltage boost to keep the cells equalized and drops the float voltage enough to not wipe out all the crystals if you aren't drawing the battery down a bit.

 

charge wizard: http://www.progressivedyn.com/prod_details/charge_wizard_9105.html

 

crystals: https://en.wikipedia.org/wiki/Lead(II)_sulfate

 

way to much battery information: https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

[Smitty77_7]

Thanks Stanley - And interestingly I have those Wiki's under my Battery Folder favorites:)!

 

http://www.rvnetwork.com/index.php?showtopic=121596

 

Wet cell vs AGM is a factor here, as I do have AGM's. And, I do have a Maintenance Free 8D Chassis Battery. I posted the above thread, after reading several threads in the boating forums, and also the Monaco user owner group. Many feel they are seeing positive results with AGM's as they are wet cells. And it was the crystals avoidance factor I was concerned about.

 

Here is an IRV2 thread, with more info on this too. (I have an appointment on 3/7 with Larry and Debbie at Starlight. Will be asking for input on whether they see a downside to using the PowerPulse on the chassis wet cell MF 8D, and or the X's 4 Lifeline L16's. Main focus is on crystals avoidance, but I also read threads on the boating community, that said they did see faster recharging times with the PowerPulse in the mix. (Nope, not formal studies, just regular guys and gals like us, sharing what they saw with their usage of equipment in their applications:)!)

 

http://www.magnum-dimensions.com/sites/default/files/MagDocs/64-0013-Rev-A-ME-BMK.pdf

 

I have now turned off the Magnum MS2812 Charger, and am going to go for a week or two like this... No shortage of sun power in Yuma:)!

 

Best to all,

Smitty

[Ronbo]

I have been only using the solar charger for almost a year. It works great.

[Yarome]

I'm saving?? 2 kwh per day, ($0.26 or $8.00) per month. Not much but better than a sharp stick in the eye.

 

Almost 100 bones a year.. that's steak'n'lobsta twice a year while doing your part against greenhouse gases. I'd call that a win-win!

[Jim Seward]

Living in Vegas with a lot of sun, I just turn off the converter and let solar panels keep batteries charged. Seems to work just fine. Check battery water level once a month and add if needed. Coach is connected to 50 amp shore power when stored.

[Smitty77_7]

Well with the Magnum charger off, as well as the inverter off too. While on 50A Shore Power. And shut down for the night, as far as 12V lighting, I'm seeing 62-65AH usage overnight. (Residential fridge in the mix to).

 

I've started a bit of poking around to see if I can determine why I'm now seeming to see 4.4 - 4.6AH draw when no optional 12V systems are on. (I've added some 12V demands that remain hot while the salesman switch is on. But before this, we were down in the mid 3Ah draw range. (I call this 'at idle' or 'parasitic draw'. But on an IRV3 thread about asking for Tips on tracking down these kinds of house battery draws, this choice of words caused some confusion:)!)

 

I've identified:

-Fantastic Fan Rain Sensor

-TST repeater

-LP and CO detector

-WiFi Ranger and Bullet Antenna

-Though set to 'off' some feel our 5 button dual zone thermostat is still consuming poer

-Looks like the radiant floor heats Thermostat is also 12V powered

-Hydro Hot, though in off mode, does have a control board with a 12V power supply idiot light on. So drawing some too.

-Magnum MS2812 remote panel. BMK-Meter and AGS, all seem to consume 12V power too

-MidNite Classic 150 control panels consume power too

-12V Light Switches with the Green Lights

 

Newly added the last year:

-Winegard Travler

-Winegard RAZR Auto OTA antenna

-Winegard Sensar IV antenna

All of these have controllers, and consume 12V power. Note that the Winegard Travler is 'powered off' after satellite raising and locking cycles are over. But still suspect some draw.

 

These are all of the items I think of that draw 12C house battery. Every other item is turned on or off as needed. Suspect the addition of the three Winegard 12V draws, are pulling us up into the mid 4 AH range, from the prior mid 3AH's range.

 

Unknown to me, is if the keyless alarm system and Onstar system, are linked to the House or Chassis battery. Will poke around so on these, just to see where they are powered from.

 

I do regular maintenance to clean grounds, the ones I've found, as part of the yearly cycle.

 

92-93% SOC in the AM, while on Shore Power, and all that I can think of 12V power demands turned off.

 

Still poking around, and trying to learn. Want to have my list of questions for input ready for Larry when I get to Starlight Solar in early March.

 

Best to all,

Smitty

[skp51443]

We ordered and installed some miniature 12 volt toggle switches in several of our accessories so that we could cut out the 12 volt draw when they weren't going to be used. In a few cases we fiddled with the controls and found that on some settings they quit wasting power.

 

The heat / air controller had plenty of room under the cover to drill and mount a switch, don't have the draw numbers any more but it was a fair amount.

 

Our Fantastic Fans could be set to not draw power, again I fail to recall just how.

 

We replaced several incandescent indicators or illuminated switches with LED versions saving a good bit of power, the water pump had two, the steps and TV amp one each.

[Jack Mayer]

That is a LOT of 12 volt draw with everything off. For sure you have a major consumer there. Our coach has a large parasitic draw with all our electrical stuff in it - and it is only about 15 AH. It will be interesting to see what you find....

[Smitty77_7]

Well, I'm feeling a bit better now. 3.8 - 4.0AH at idle. I found the basement lights were on. (These are plunger switched to go off, but the previous owner had for some reason bypassed the plunger. And these are some the few lights remaining not converted to led.)

 

While 3.8-4.0AH is still high, but it was in the mid 3's as long as I've had the BMK-Meter to monitor.

 

Will keep eliminating draws where I can, but at least I found the reason for the larger draw.

 

Best to all,

Smitty

[Yarome]

Well, I'm feeling a bit better now. 3.8 - 4.0AH at idle. I found the basement lights were on.

 

While 3.8-4.0AH is still high, but it was in the mid 3's as long as I've had the BMK-Meter to monitor.

 

That would certainly do it. Like Stan, I have several 12v and 120v switches installed to better control my rigs drinking habits. You just have to find a balance between convenience and conservation. Ie., If you watch the TV off and on throughout the day, you probably don't want to "kill" your receiver and dish and have to wait for a full reboot every time. KWIM?

 

That is still a rather substantial overhead in some estimations. Being aware is critical (seems like you've got a good handle on that), but I wouldn't necessarily sweat the numbers. It is what it is based on your preferences and equipment. You just need to size your battery bank and "budget" accordingly.

[Jack Mayer]

I'd be very happy for 4 AH. Actually, I can get mine down to around 11-12 and am very happy with that. I have enough battery/solar that I don't care to take extra measures to get it lower - and it would be very difficult with several routers and other "stuff" that pretty much has to be up all the time. So it is all relative to what you have and the effort involved in reducing it more.