Thinking of solar

[mocarski]

Originally Posted by hoggem

I don't understand how a solar panel will help? If you run the gen set before bed are do you not have a full charge on your batteries?
Im thinking I need to replace my two house batteries, and there is actually room for a third one so I think I will see if that helps.
Thanks for the reply.

lead acid batteries charge quickly to 80% then take hours more to get to 100%. Lithium ions charge to 100% quickly. If you are relying on the converter in your unit most are simple trickle chargers and do not have multiple charging patterns that are desired to fully charge batteries. On my last RV no matter how long I was plugged in or ran a generator the converter never would charge the batteries fully. After 2 1/2 weeks of being plugged in it only got the batteries to 51%. My new RV came with an upgraded converter with 3 set charging patterns. I replaced that one with a Magnum inverter that I could customize the charging pattern to my battery specs.

The first thing I install on all RVs now is a Trimetric controller so I know exactly how charged my batteries are all the time.

[pasdad1]

Originally Posted by hoggem

Hope im posting in the proper place? I'm looking for a solar battery charger/maintainer to use during outdoor winter storage, and instructions on how to install. Also looking for a way to run my wife's CPAP off batteries when we occasionally boondock. I bought the inverter (resmed) but she only get 4/5 hours off the house batteries

The inverter is not as efficient on battery power as getting the DC converter.

Which resmed machine do you have? I have the S9 auto set and it can run directly from the 12 volt batteries with this converter.....much more efficiently than using the inverter.

[hoggem]

mocarski, which inverter did you buy and how do you program to battery specs?

pasdad1, it is my wifes machine and I believe it is an S9, and that is the converter I bought for her, and with that she only gets about 4 hours till the batteries die????

[lonfu]

Here is my ten cents worth. First you need more batts, 4 batts, 6 volt or 12 volt doesn't make any difference, you need more amp storage. 2nd, you need at least 200 watts of solar panels to recharge those batts during the day. Most after market installers run the charge wire down through the fridge compartment to the batts, but there are always exceptions. Get a charge controller that is rated at higher than the total output of your solar panels. you can check the one you have now, but more than likely it will have to be replaced. good luck

[mocarski]

Originally Posted by hoggem

mocarski, which inverter did you buy and how do you program to battery specs?

hoggem, I have the MS2812 - 2800W Pure Sine Inverter Charger MS Series | Magnum Dimensions

When you buy the remote panel you get access to the programming end of the unit. You select the type of batteries you have. They have preset charging patterns for wet cell and agm and there is also a custom option. When you select custom you can program the voltages you want going to the batteries for bulk, absorb, and float charges. You can also set the length of the charging patterns based on time or voltage levels in the batteries.

There are a lot of inverters on the market and Magnum is not on the less expensive side but it is the best and worth the money in my opinion.

For battery monitoring Trimetric is phenomenal. I have both a Trimetric and Magnum's BMK and the Trimetric is more accurate, measures a much lower draw, and is able to read the battery levels when the Magnum cannot.

If you go solar consider a Morningstar charge controller. There are many others on the market but Morningstar makes the best. MPPT controllers are not the same. Morningstar is one of the very few who have really figured it out. Many of the other companies exaggerate their products. Morningstar just works as advertised. So does Magnum. Worth the money by a crap ton in my opinion.

[pasdad1]

Originally Posted by hoggem

pasdad1, it is my wifes machine and I believe it is an S9, and that is the converter I bought for her, and with that she only gets about 4 hours till the batteries die????

Your original post said you bought an "inverter".....which is also sold to power a CPAP from a battery.....if you bought the DC-DC converter then that is good.

You should turn OFF the heater on the humidification chamber.....you can still fill the humidifier with water....the unit just won't try to heat it. The heater takes a great deal of power compared to just the CPAP function.

This is taken from Resmed documentation ....if your batteries only power the S9 for four hours, either you have other items stealing power from your batteries, or your batteries are ruined and need to be replaced.

The chart specifies a 13 ah battery should power it at least 8 hours.....just one group 31 battery is at least 100 ah........

[rarebear.nm]

If you do install a solar system, should read the following, it could save a lots of issues with a poor system. It's kinda long, but it covers a great deal of information. Many things others have said above is good information, but this article brings it all together in one place.

Good luck and safe travels.

[hoggem]

rarebear,

Where is the article you are referring to?

[rarebear.nm]

Oh- my bad sorry about that, here it is:

RV Electrical

[jackfish]

Originally Posted by mocarski

Morningstar just works as advertised. So does Magnum.

But apparently not the BMK according to you.

[rarebear.nm]

What's a BMK?

[twinboat]

Battery monitor.

[mocarski]

Originally Posted by jackfish

But apparently not the BMK according to you.

Most people would be thrilled at the Magnum BMK and wouldn't notice the differences unless both were installed side by side. The Magnum works but the Trimetric is better. If I was doing it again I'd skip the Magnum BMK since the Trimetric isn't very expensive.

[mocarski]

Originally Posted by rarebear.nm

Oh- my bad sorry about that, here it is:

RV Electrical

That is an excellent source of info but it is a little outdated. You can now run A/C on batteries if you have enough lithium ion batteries. I disagree with his order of upgrades. I'd do the BMK first. Without a BMK you don't know how much power your RV systems really draw so sizing the battery bank becomes more about guesswork and other's experiences.