Community Forums

yourpcgeek49 · 08-15-2014, 10:51 AM

We are planning to go full-time an about a year, and anticipate spending about 60% of our time boondocking with the balance in campgrounds.

Our 2011 5th wheel came equipped with a single 12v Marine Battery and a Progressive Dynamics PD9260C "smart" converter/charger and 50 amp service.

From what I have read, many chargers do not provide the Absorption charge voltage recommended by Trojan (14.8v) - including the PD unit.

We are planning to purchase a new battery bank (probably four Trojan T-105) and Solar Panels. We will need to buy a Solar controller/charger and a power inverter.

I have read various posts here and elsewhere about proper battery charging, recommended equipment, etc., but everything I read seems to be oriented to charging from shore power/generator OR from solar. There are many good recommendations for the Magnum MS Inverter/Chargers and the Morningstar Tristar TS-MPPT series Solar Charger/Controllers. But is there a single device that can be used as a solar controller/charger when on solar AND a converter/charger when on shore power. I could stand to buy a separate Inverter only, but buying two chargers with two separate charging systems is driving me crazy.

Am I missing something in the specs of these devices? How do others who use both Solar & Shore Power manage this?

Walt Bennett · 08-15-2014, 11:45 AM

I piecemeal installed my system in our Monty, shopping for best prices and best value for each item. Whole 400 watt solar system came in under $2,700, but I installed it all myself. I started with a Trimetric battery monitor. The panels are 12v 100w mono from eBay, because the size let me put them where I wanted and also allowed me to NOT have to buy MPPT. Got a Morningstar TriStar 45 for about 60% of the cost of the same thing in MPPT. (I really don't think there's all that much to be gained with MPPT other than using bigger panels at higher voltages.) Although I was about ready to sink big bucks into a Magnum inverter, I found an AIMS 3kw inverter/charger for 1/3 the price on eBay. Turns out it also has a built in MPPT solar charge controller! Figure out that since it's way over sized for what I need, I'll try it out in spite of the up and down brand reputation. I didn't scrimp on the batteries and went with four Trojan T-105s. They're the most expensive part of the whole system.

The deal though is this; you need an inverter to make AC out of DC. That inverter will be wired in such that it will pass through shore power when it's present, and almost all of them also have a charger built in. On our rig, the TriStar is charging at the same time as the AIMS during the day, but they both sense how charged the battery bank is and it's only at 1 - 2 amps combined (as read on my Trimetric). At night, the AIMS will charge by itself. I've turned off the old Xantrex converter and am thinking about pulling it out, but will probably leave it as a backup.

If you wanted to only have one box taking care of everything, an AIMS inverter/charger/solar charger would do it. Mine would run the AC if I had enough battery bank, but it was what I could get for the best price. According to the manual for it, they make 1.5k, 3k (what I have) and a 60k watt versions.

vsheetz · 08-15-2014, 02:58 PM

You will already have a charger included with the RV for shore power usage, so why buy another inside a combo unit? Additionally, even when on shore power I most often leave the converter/charger off and let the solar provide for all the charging. My Morningstar solar controller is a much better charger and charges to the appropriate voltages as you mention. added benefit of being a bit more 'green'.

My solar setup described.

Walt Bennett · 08-15-2014, 05:28 PM

Quote:

Originally Posted by vsheetz

You will already have a charger included with the RV for shore power usage, so why buy another inside a combo unit? Additionally, even when on shore power I most often leave the converter/charger off and let the solar provide for all the charging. My Morningstar solar controller is a much better charger and charges to the appropriate voltages as you mention. added benefit of being a bit more 'green'.

The included converter/charger is almost guaranteed to not be a good one for charging almost any kind of battery. The bulk rate of any Xanatex is only 13.8 to 14.2 and that is not enough. They are made for people with one or two cheap 12v batteries that stay connected to shore power for months at a time.

As I said before, you've got to have an inverter to make AC out of DC, and the better ones come with an included charger. The lower quality ones don't charge at a higher voltage than the cheap converters trailers come with so you've the same problem. Only having a solar charger that puts out the higher volts isn't a good idea if you've sunk close to $800 for four just lead acid quality batteries - at least not unless you've stock in a company that makes them.

vsheetz · 08-15-2014, 06:10 PM

Quote:

Originally Posted by Walt Bennett

The included converter/charger is almost guaranteed to not be a good one for charging almost any kind of battery. The bulk rate of any Xanatex is only 13.8 to 14.2 and that is not enough. They are made for people with one or two cheap 12v batteries that stay connected to shore power for months at a time.

As I said before, you've got to have an inverter to make AC out of DC, and the better ones come with an included charger. The lower quality ones don't charge at a higher voltage than the cheap converters trailers come with so you've the same problem. Only having a solar charger that puts out the higher volts isn't a good idea if you've sunk close to $800 for four just lead acid quality batteries - at least not unless you've stock in a company that makes them.

Not sure of your comments. Agree that many of the standard converters are not good charge red. That is why I commented I use the solar controller to charge my batteries most all the time. Because it's a quality multistage charger (Morningstar).

Quality standalone inverters are available.

Walt Bennett · 08-15-2014, 06:22 PM

Vince - I've also a Morningstar (TriStar-45) that's powered by four 100 watt mono panels. What I think you're confusing is that a converter (what comes with an RV) converts AC to DC. An inverter (that seldom comes with an RV unless it's got a residential refer) converts DC to AC. A quality inverter will also have a built in transfer switch (to recognize when shore power is there and when it isn't) and a battery charger (to charge batteries when there is shore power whether or not there's a solar charger).

vsheetz · 08-15-2014, 07:32 PM

I am not confusing anything. I well understand converter vs inverter functions and usage.

My point is you do not need to have a multifunction unit to get quality function as you seem to be saying, or the inverse that it must be multifunction to be quality.

Another point I am making is regarding the OP's original question about buying two quality chargers. My converter is low quality. But I seldom use it. Instead the solar charger, a quality Morningstar charge controller like yours, provides for nearly all the charging regardless of whether I am connected to shore power or not. The converter remains turned off nearly all the time. So I have no desire or need to spend money on another quality charger to replace the standard converter.

Walt Bennett · 08-16-2014, 04:49 AM

Quote:

Originally Posted by vsheetz

I am not confusing anything. I well understand converter vs inverter functions and usage.

My point is you do not need to have a multifunction unit to get quality function as you seem to be saying, or the inverse that it must be multifunction to be quality.

Another point I am making is regarding the OP's original question about buying two quality chargers. My converter is low quality. But I seldom use it. Instead the solar charger, a quality Morningstar charge controller like yours, provides for nearly all the charging regardless of whether I am connected to shore power or not. The converter remains turned off nearly all the time. So I have no desire or need to spend money on another quality charger to replace the standard converter.

And the point I'm making is that you cannot have AC without having an inverter. The OP stated he was getting one, but one without a transfer switch. And I'm further stating that if you get one with a transfer switch the quality ones come with a built in charger for pretty much the same price.

yourpcgeek49 · 08-16-2014, 10:10 AM

Yes, I will need an inverter. If I buy the Magnum MS2812 for about $2,000 it will have a charger & converter included. Then, for my solar I would buy a Morningstar Tristar TS-MMPT-60 with a charger included for another $500 or so. In this case, I would just disable the current PD Charger/converter, leaving it in place in case I ever wanted to move to a different RV.

Yes I "can" use my existing Progressive Dynamics converter/charger when I have shore power (sub-optimal charging but only when in a campground), and buy a stand alone Inverter & a separate transfer switch.

OR I can (probably, but haven't investigated the details) disable the charging portion of the PD 9260, and use it's converter when on shore power, let the Solar system do the battery charging, and purchase a stand alone Inverter & Transfer Switch.

Of course, in any of these scenarios, I would still need to buy batteries & solar panels.

It just "seems" like there ought to be a way to have just one good charger that covered either input. But maybe not???

If I went with the Stand-Alone Inverter, does anyone have any experience or recommendations for a reliable 2,000 - 3,000 W. Inverter? Also transfer switch for this setup?

vsheetz · 08-16-2014, 11:10 AM

Quote:

Originally Posted by Walt Bennett

And the point I'm making is that you cannot have AC without having an inverter. The OP stated he was getting one, but one without a transfer switch. And I'm further stating that if you get one with a transfer switch the quality ones come with a built in charger for pretty much the same price.

Ok, thanks. This clarification helps. And the OP appears to have a good grasp of his options.

Myself I prefer separate units for each function. Easier to troubleshoot. Easier and cheaper to upgrade just a portion if needed. Combined units have their advantages as well of course.

Walt Bennett · 08-16-2014, 12:44 PM

One last comment and I'm going away. My Morningstar TriStar-45 with remote sensor cost me under $200. I went that way because I wanted smaller panels that would be easier to place here and there on my roof and MPPT gained me nothing for the more than twice the cost. I can still add more 12v panels if I want as I've only got about 25 amps max coming from the ones I have. IF you want to use larger panels or higher voltage ones, MPPT may make sense. All I'm saying is don't just get it because it's the hot thing today; do a for real cost analysis first.

yourpcgeek49 · 08-16-2014, 03:27 PM

Thanks to both of you for your thoughts & insights. If you think of anything else along these lines, I'd love to hear from you.

Mark

vsheetz · 08-16-2014, 05:14 PM

Quote:

Originally Posted by Walt Bennett

One last comment and I'm going away. My Morningstar TriStar-45 with remote sensor cost me under $200. I went that way because I wanted smaller panels that would be easier to place here and there on my roof and MPPT gained me nothing for the more than twice the cost. I can still add more 12v panels if I want as I've only got about 25 amps max coming from the ones I have. IF you want to use larger panels or higher voltage ones, MPPT may make sense. All I'm saying is don't just get it because it's the hot thing today; do a for real cost analysis first.

Walt and I are in complete alignment here. In my solar system write up you will see same/similar comments and that my system is designed this way.