Solar watts: how much do I need?

[bdreinv]

If you have solar and the MPPT conroler will do that and much more!

[PlayersZ28]

Originally Posted by Bandit12

Question for you. I'm not a spark chaser, just an old retired jet engine mechanic. Where do you install this monitor and exactly how easy is it?

Thanks!

I think that the one that Don linked has a shunt that goes in the main feed loop to measure power usage and charge flow. I have a custom setup that is a high side shunt. I also have a cheap monitor that I haven't installed and it's a low side shunt install.

[PlayersZ28]

Originally Posted by bdreinv

If you have solar and the MPPT conroler will do that and much more!

A charge controller doesn't know anything about AH drawn from the battery, only what's put in by the panels.

[bdreinv]

I believe mine does!Its showing battery input from panel and and whats being pulled out of batteries!

[JesseS]

Most solar controllers only show the voltage and amperage going INTO the battery from the solar array, and it estimates the charge status using battery voltage levels, it will not show the amp draw from your batteries or true DOC. For those measurements you need a shunt on either the high or low side of the battery, with the shunt being between the negative side of the battery and ground the best, that way ANY power draw anywhere in the coach is registered, even parasitic draws. My tri-metric even shows charging amps when the engine is running (nice test for your alternator) or the Genny is on using the converter to charge.

[PlayersZ28]

Originally Posted by bdreinv

I believe mine does!Its showing battery input from panel and and whats being pulled out of batteries!

Then you must have a shunt in either the main positive or negative lead from the battery.

[Mustang65]

Originally Posted by Bandit12

Question for you. I'm not a spark chaser, just an old retired jet engine mechanic. Where do you install this monitor and exactly how easy is it?

Thanks!

Here is a link where other members went with the inexpensive battery monitors. If you buy 2, you can connect one to monitor for charging amps and one monitor for charging Amps. It is cheap enough to start with even before you decide to go SOLAR. It will give you a good idea as to how much SOLAR and battery power you will need.

There are plenty of pictures to guide you through the installation. Any questions just yell.

Don

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[spark of insanity]

I was told if you use solar power forget using the ac and the microwave. The best you can get is television, hot water tank and lights. I read an article where they mentioned one thru Amazon. I also saw some at Home Depot. So if I dry camp? It will be if I really am desperate. I prefer my full hook ups. Good luck.

[PlayersZ28]

Originally Posted by spark of insanity

I was told if you use solar power forget using the ac and the microwave. The best you can get is television, hot water tank and lights. I read an article where they mentioned one thru Amazon. I also saw some at Home Depot. So if I dry camp? It will be if I really am desperate. I prefer my full hook ups. Good luck.

I run my m/wave, hair dryer, etc (1 at a time) off the 2000w inverter. With a bigger inverter and more battery capacity I could run A/C. If you choose you can build a system that makes your RV completely electric (no propane) and runs on solar (Technomadia did)

[JesseS]

Originally Posted by spark of insanity

I was told if you use solar power forget using the ac and the microwave. The best you can get is television, hot water tank and lights. I read an article where they mentioned one thru Amazon. I also saw some at Home Depot. So if I dry camp? It will be if I really am desperate. I prefer my full hook ups. Good luck.

If you stick to full hookups you will miss some of the very best camping there is, My solar system will power everything in the coach except the AC, that includes the coffee pot, hair dryer, TV, Microwave, and whatever else we need. I can run my batteries DOD as low as I need to (down to 10%) and have them fully charged by 2PM in most cases. It all depends on how you size your system and battery storage. I opted for 700+ watts of panels, 40 amp controller and lithium batteries as we boondock a lot

[bdreinv]

How many batteries we only have 2 deep cycle and one 275 watt industrial panel? Thanks

[PlayersZ28]

Originally Posted by bdreinv

How many batteries we only have 2 deep cycle and one 275 watt industrial panel? Thanks

If you're referring to JesseS then he said he has 2x 12v @ 100AH Li. With the Li's being able to draw down to 10% that's a total of 180AH available. Works out to a bit less than what I get from 4x 6v 224AH (448AH total * 50% = 224AH) but less weight to carry and longer life (and more $'s)

[JesseS]

Originally Posted by PlayersZ28

If you're referring to JesseS then he said he has 2x 12v @ 100AH Li. With the Li's being able to draw down to 10% that's a total of 180AH available. Works out to a bit less than what I get from 4x 6v 224AH (448AH total * 50% = 224AH) but less weight to carry and longer life (and more $'s)

The main reason I went with LiFePo4 is I only have room for 2 batteries, might get a 3rd with a trey add on. Also I don’t get the voltage drop flooded get when the inverter gets a big draw so no dimming lights or slow pump. I have a business account with alibaba so got the batteries a 50%, only a $100 or so more than Gel batteries. So far am very happy with them, at only 39# each half the weight of my GC batteries, and no maintenance at all.

[Fleetman]

Why 2x 6 volt vs.2 x 12 volts?

[JesseS]

6 VDC golf cart batteries have taller and heavier plates, and thicker buss bars allowing more amperage to flow for longer times without heating up. These are very heavy duty batteries designed for large amperage draw and long life.
12 volt batteries on the other have are not so robust, designed for short heavy start amperage, have thinner and smaller components.

[Mustang65]

Originally Posted by JesseS

6 VDC golf cart batteries have taller and heavier plates, and thicker buss bars allowing more amperage to flow for longer times without heating up. These are very heavy duty batteries designed for large amperage draw and long life.
12 volt batteries on the other have are not so robust, designed for short heavy start amperage, have thinner and smaller components.

The 12Volt deep cycle batteries have come a long way over the last few years. When I have to replace my 2 Trojan T-145 (260Ah) 6 volt batteries, I am thinking of going with a couple of the USBattery 12Volt deep cycle batteries. Cost more, but I want to see how they perform. Below is the Life Cycle graph for the USBattery 12Volt deep cycle batteries. You will notice that the 50% rule numbers are about the same for the 12Volt batteries as they are for the 6 volt batteries, about 1200 cycles. A bit bigger in size/weight.



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