Solar 300 watt upgrade DIY

[gmillerok1]

After testing the 300 watt solar upgrade and controller with the existing 7 year old 80amp hour OEM Lifelines over the last couple of weeks, I'm starting part two of my upgrade-the battery bank.

I've ordered the 4/0 cables, lugs, the Blue Sea 7662 battery combiner, and breakers to make the switch. But I'm torn on what battery to use.

It's either two Lifeline GPL-6CT 6vdc 300 amp hours, or either two 100 amp hour Battleborn or two 125amp hour Lifeblue Lithiums.

Pro's for the AGM:

1. We don't boondock that often, if at all. I do a ten day event once each year, but have minimal AC power to keep the batteries charged (but can't use the AC).

2. 1/3 the cost. Even if Lithium lasts for the rest of my life, I figure that even if I had to replace the AGM three times, that's 21 years. I won't live that long and sure won't be RV'ing.

3. Simplicity-pretty much install them and forget them. In the winter, the .6 amp draw of the inverter will not be a problem because they still can be charged when it's less than 32F-unlike Lithiums.

Cons. Heavy. And big. Only can use 150 amps max without damage.

Lithium.

Pro's.

1. Lightweight and smaller size.
2. Can use up to 80%-amps although I've read it will shorten the life of the batteries if you do.
3. Faster charge.

Con's.

1. Price.
2. BMS and winter charging issues (I'd have to figure out how to kill the inveter draw, probably with a disconnect, but chance damaging the inverter if I forget and plug-in if the inverter is not connected to the house batteries.
4. Have to figure out how to charge with the alternator-probably with a dc-dc Sterling battery charger, or something similar.
5. Will these companies even be around in three years?

All in all, I'm think AGM makes more sense to me because we just don't boondock that often and if we do, it likely would never be more than a night. Checking the Victron BM712, with the current 80amp hour, it drops about 3 or 4 amps overnight, but charges back up to 100% within an hour or two of sunlight. With the fridge, I would expect to use about 30 amps overnight, and maybe 30 more for other draws.

We rarely watch TV, or use the inverter, so the only draws would be the fridge, the inverter, and the lights, and pump. So I figure maybe averaging 5 amps per hour, that's still only 60 amps overnight, with plenty to spare. We rarely park and stay put in one place for more than a night, so the alternator will bring them back up quickly as well. So a 300 amp hour battery life should do the trick.

And, there's always the noisy generator.

Anyone disagree?

[gmillerok1]

Has anyone just done away with the Magnum Inverter/charger and replaced it with a charger only? The reason I ask because it would seem to make sense.

What do we use the Magnum MS1012 for when on battery power? All it can do is provide power for the TV. What other devices do we really need for AC? It can't do anything more than 1000 watts.

I can't remember a single time in over 14 years of RV'ing in a Class B I've ever used the inverter for anything other than the TV a couple of times. Seems to make more sense to ditch the Magnum Inverter/charger, get a separate inverter to be used when needed, and a separate smart charger for the batteries. Then, there'd be no draw on the batteries at all when not in use.

Anyone see a downside?

[Pahaska]

I recently had to replace the Magnum. After I did so, I scratched my head and asked myself why I did it. We have never used the Magnum for anything other than a battery charger.

Were I to do it again, I would install a high-quality charger and simply connect the Ac in and the AC out that goes to the Magnum. One thing less to go wrong.

[Air99]

Originally Posted by gmillerok1

Has anyone just done away with the Magnum Inverter/charger and replaced it with a charger only? The reason I ask because it would seem to make sense.



What do we use the Magnum MS1012 for when on battery power? All it can do is provide power for the TV. What other devices do we really need for AC? It can't do anything more than 1000 watts.



I can't remember a single time in over 14 years of RV'ing in a Class B I've ever used the inverter for anything other than the TV a couple of times. Seems to make more sense to ditch the Magnum Inverter/charger, get a separate inverter to be used when needed, and a separate smart charger for the batteries. Then, there'd be no draw on the batteries at all when not in use.



Anyone see a downside?

On my 2014.5, I converted both Samsung TVs to 12v operation and they worked fine, our only use for the magnum 120v anymore is the blender to make juice and the Blu-ray player.

[Mr. B]

Originally Posted by Air99

On my 2014.5, I converted both Samsung TVs to 12v operation and they worked fine, our only use for the magnum 120v anymore is the blender to make juice and the Blu-ray player.

What’s was the actual reason for TVs conversion? There is so simple to activate inverter by pressing the button.

[Alex AVI]

Originally Posted by gmillerok1

Anyone see a downside?

GMILLEROK1 - Read in my manual Converter is used for the 12v led lightning. But dont know for sure. Will test when get back home. Up in mountains of Utah supporting a 500 mile bike race. My AI can not handle this terrain, too big, too heavy, no 4x4

[gmillerok1]

Originally Posted by Alex AVI

GMILLEROK1 - Read in my manual Converter is used for the 12v led lightning. But dont know for sure. Will test when get back home. Up in mountains of Utah supporting a 500 mile bike race. My AI can not handle this terrain, too big, too heavy, no 4x4

I probably couldn't handle it either, LOL!

As for the 12vdc system, I think they are all pretty much run through the house batteries, and the 50amp charger/converter keeps them up and running. The entire 12vdc works that way on mine, and I'm pretty sure on yours as well.

The only thing that is the difference in a separate charger and inverter and a combined charger/inverter is the combined unit both charges and inverts. The combined inverter, even when off, draws .6 amp constantly. In a separate charger and inverter, you could simply disconnect the inverter (or do away with it entirely) without any effect on the charger, and that's something you can't do with a combined unit like the Magnum MS1012.

If you disconnect the MS1012 to kill the draw, then the house batteries won't charge, and you risk destroying the unit if you plug into shore power if you forget to reconnect the house batteries before you do so.

I can see the point of having a high power inverter if you have a massive house battery bank to run the AC, which requires an almost ridiculous amount of amperage for any length of time. I won't be doing that. That leaves the TV and few if anything else. A small inverter can easily handle that.

I will not likely change out the MS1012 unless it fails with this upgrade. But if it does, I doubt I'll replace it and go the separate charger/inverter path next time.

[Air99]

Originally Posted by Mr. B

What’s was the actual reason for TVs conversion? There is so simple to activate inverter by pressing the button.

It was a mis wired SB164 solenoid that cut battery power to the inverter unless shore power used, so I had to find a way to keep wife happy while I’m out golfing [emoji12]

[Air99]

Originally Posted by Alex AVI

GMILLEROK1 - Read in my manual Converter is used for the 12v led lightning. But dont know for sure. Will test when get back home. Up in mountains of Utah supporting a 500 mile bike race. My AI can not handle this terrain, too big, too heavy, no 4x4

I believe all lightings circuitry in our vans are 12vdc

[Mr. B]

Originally Posted by Air99

It was a mis wired SB164 solenoid that cut battery power to the inverter unless shore power used, so I had to find a way to keep wife happy while I’m out golfing [emoji12]

Happy wife - happy life

Btw I arrived in New Jersey, and it was 100.5 degrees today. I took a few hours nap on the parking lot, under the straight sunlights, idling the engine for stock A/C, genset for the roof A/C, and running three 110 volt vents from the inverter. Well, two persons and the dog had survived not bad ).

[Air99]

Originally Posted by Mr. B

Happy wife - happy life



Btw I arrived in New Jersey, and it was 100.5 degrees today. I took a few hours nap on the parking lot, under the straight sunlights, idling the engine for stock A/C, genset for the roof A/C, and running three 110 volt vents from the inverter. Well, two persons and the dog had survived not bad ).

Desperate times call for desperate measures [emoji33] we’ve done that a few times and sleeping with earplugs on!

[Schmitte]

Originally Posted by gmillerok1

Thanks! Yes, they are AMSolar's SP100's. Guess I must have caught them at the right time. For a good substitute, try these, which I almost bought instead. They actually are a bit smaller form factor an similar output. I opted for the SP100's because AMsolar pre-drills the panels and when you add the cost for the tilt-feet, they are about the same. I ended up having the drill holes for the brackets for the middle panel anyway.



I ended up buying the panels, the Victron BMV-712 Battery Monitor Kit, and the combiner box, plus a couple of extra watertight connectors for the combiner box to run the awning and rear camera cable through. I added the MPPT controller later but before I started the installation. But, you could do away with the MPPT controller as the charger can use a smart phone app with bluetooth. But I like to be able to quickly see the state of charge and how the panels are doing on the panel.



I also had to buy a crimper that could crimp 6 or higher gauge wire, and assorted connectors and lugs, plus a half dozen feet of 6 awg wire to hook it all up.



I figured I saved $4500-5000 in labor costs doing it myself. Plus, I didn't take any short cuts in the process, so I know it's done correctly as how long it took was not an issue. But I have to be honest-it was a LOT of work.

Gmillerok1 - I’m planning to add 300 watts to my roof as well. But will wire in series so I can avoid pulling me wire. Is there a reason you preferred the renogy eclipse over their standard 100 w monocrystalline panels? They are nearly twice the price and I am having a hard time justifying the up charge

Thanks and very impressive work on you upgrade!

Eric

[gmillerok1]

Originally Posted by Schmitte

Gmillerok1 - I’m planning to add 300 watts to my roof as well. But will wire in series so I can avoid pulling me wire. Is there a reason you preferred the renogy eclipse over their standard 100 w monocrystalline panels? They are nearly twice the price and I am having a hard time justifying the up charge

Thanks and very impressive work on you upgrade!

Eric

The SP100's (and the Eclipse series) have a higher efficiency rating. In the long run, the difference in price is well worth that difference since the space in my case for panels is limited to three panels. It's the same reason I opted for the Victron 100/30 charge controller as it will draw every watt it can out of the panels.

As for the wire, the wire Airstream used is too small of a gauge and too long of a run and will lose too much voltage so I used 6 awg and just used the AMSolar combiner in parallel, and ran that along with the awning wires down the same hole. I can't remember the gauge, but the original can't be more the 12 awg or maybe 14 awg. I ran in parallel because that way when one panel is shaded it won't be quite as costly energy wise and the wire run was only about 12 feet or so.

Good luck with your upgrade!

[Boxster1971]

I agree with gmiller - the wire Airstream installs for solar is only 12 awg - not adequate for increased solar. I also used 6 awg from AM Solar when I upgraded to four 100 watt panels.

[Schmitte]

Thanks guys
My understanding is that the stock 12 awg wiring is too small for parallel wiring but would still be safe to use when panels are wired in series. Is that correct?

[gmillerok1]

Originally Posted by Schmitte

Thanks guys

My understanding is that the stock 12 awg wiring is too small for parallel wiring but would still be safe to use when panels are wired in series. Is that correct?

It's a bit complicated, and I'm no expert. But, basically, yes, in theory, 12 awg should work with a MPPT controller if it can handle the higher voltage. It's a bit complicated because when you hook them up in series, while you can use a smaller wire, don't forget that you won't always be getting the maximum voltage out of the panels. If one panel is in the shade, it may reduce the voltage of the remainder to the point there is not enough voltage to do much. In parallel, it is my understanding that the amperage may be reduced, but the voltage stays the same, so there's a better chance of more charge getting to the batteries. That may be wrong, but that's my understanding. So, for that reason, and the short wire run, I decided to go with parallel and 6awg wire (actually, 4awg would have been fine with less than a 3% loss, but 6awg has almost no loss at the amperage I'm getting). So it maximizes the charge the panels can provide.

Here's a good video to explaining what happens with series or parallel shade as it relates to energy

Also remember that the sun doesn't shine overhead all day. It moves with the earth's spin, and as the sun rises, voltages/amps will rise and fall with it. At lower voltages, it was my opinion that parallel wiring will do better than series.

So, that's why I went with it.

[Schmitte]

Thanks... I was hoping for a less labor intensive solution but maybe that’s not wise, especially since I still don’t understand the pros and cons of parallel vs series in low light/partial shade situations. There seems to be conflicting opinions when using an mppt controller

[gmillerok1]

Originally Posted by Schmitte

Thanks... I was hoping for a less labor intensive solution but maybe that’s not wise, especially since I still don’t understand the pros and cons of parallel vs series in low light/partial shade situations. There seems to be conflicting opinions when using an mppt controller

If shade wasn't an issue, series is fine. But that's never the case.

This video clearly demonstrates the disadvantage to series with shade-and it's very substantial. I figure that most of the time, any single panel could easily have some shade on it, and with series, it hurts the entire array. Parallel, not so much, as shown in the video.

As she says in the video, "if you have partial shade, parallel is the way to go."

[Boxster1971]

I hooked mine up in parallel since the place I park my van in driveway gets partially shaded. I get good charge in low light situations. My system has been working great for over five years.

[Alex AVI]

Originally Posted by Boxster1971

I agree with gmiller - the wire Airstream installs for solar is only 12 awg - not adequate for increased solar. I also used 6 awg from AM Solar when I upgraded to four 100 watt panels.

MIKE - I have not confirmed physically or in schema since I dont plan on adding my 4th panel until it is much cooler outside - so would you know if the units that came from factory with 300w comes with the 12 awg also? It seems a bit skinny for 300w/25A so maybe my unit came with beefier feed? If I have to fish new wiring, I may forego the 4th panel.