Community Forums

NealC · 09-16-2017, 09:10 AM

I get it. It's all a game of free energy. I just don't know the batteries in my VTDP are the right match as mentioned I do believe the batteries are as important as the panels.

4x4 · 09-16-2017, 09:34 AM

Quote:

Originally Posted by NealC

I get it. It's all a game of free energy. I just don't know the batteries in my VTDP are the right match as mentioned I do believe the batteries are as important as the panels.

LOL, yea "free" energy... If there ever was an oxymoron, this is it!

Yes, you are 100% correct in your last 2 points. The lead batteries are not really made for solar, but in reality they really aren't so good at any boondocking, with or without solar.

Here's another thing to think about when going solar.
When you decide to go solar you should do it at the same time as changing the batteries to lithium so you can also get the 30% tax credit on the batteries in addition to the panels. If you do the panels first and install the batteries at a later date you can't get the deduction, at least that is my understanding of it.

NealC · 09-16-2017, 09:57 AM

Quote:

Originally Posted by 4x4

LOL, yea "free" energy... If there ever was an oxymoron, this is it!

Yes, you are 100% correct in your last 2 points. The lead batteries are not really made for solar, but in reality they really aren't so good at any boondocking, with or without solar.

Here's another thing to think about when going solar.
When you decide to go solar you should do it at the same time as changing the batteries to lithium so you can also get the 30% tax credit on the batteries in addition to the panels. If you do the panels first and install the batteries at a later date you can't get the deduction, at least that is my understanding of it.

Thanks, good info to know. I'm all of 3 months into my RV'ing experience. I'll certainly see how boondocking is without solar then see if the value is there for me if it's what I truly enjoy and do it frequent enough to justify it. It's all the question of is the RV to get you to your destination or is it your destination.

NealC · 09-18-2017, 05:15 PM

I've been thinking this through and I guess there are different "tiers" or categories of solar:

1) Used to recharge house batteries
2) Used to recharge house batteries and provide limited functionality which will likely further drain house batteries
3) Used to recharge house batteries and have significant function without taxing house batteries

Since lead acid batteries have such a small window of use between charged and discharged, almost reminds me of the might A-10 engine where idle is around 65% and then you have 100% for max power. Lead acid batteries give you a small operating range, lithium, the other end of the extreme, gives you a much larger range of use. I'm not sure where AGM's fall other than maintenance free, do they still parallel usage limitations of lead acid?

I think I may fall inline with where Charlie is with the same config. Panel up to provide dry camping recharge capability. If I can get my refer to run off of solar then that would be a benny so I could leave it on in storage. If solar is lacking due to weather then the gen would kick in as needed. Still finding my way around the solar equation without giving up my dream for a 2027 Essex by over doing solar on my 2017 Ventana

C.Martin · 09-19-2017, 08:58 AM

Conservation!

Remember when all you had was a flashlight, signal mirror, and pack of strike anywhere matches in a waterproof container? I don't think I even knew what a WATT was.

Well...we sure have evolved in our "camping" experience. I have been in a site the past few days with a metered post. I'm averaging about 42kW per day. If I wanted to use my coach on solar without conserving...I'd need a solar array of around 8,800 watts...and enough storage to get me thru the night. Obviously, an exercise in impracticality. I do think, however, as technology evolves...it may be a possibility in the future.

In the meantime...my minimum goal was to satisfy the 260aH drain I have (per day) with the fridge running. I think 960 watts of solar would be the right amount of solar for this goal. So...why go to 1440 watts, you might ask? Well...because it seemed to be the most efficient use of the components I was working with. The main factors driving this were...

Roof space, while leaving a bit of room to work up there.
Wire size...I was working within the capability of the 6AWG "solar prep" wire.
Charge Controller... 100 amp controller. 1440W/14.4V=100A
Battery limitation of C/10 charge rate...or 92.8 amps max charge rate.

Although the limits of my system will demand thier respect...esp. on cloudy days. This combination will maximize our ability to use other appliances, etc...on sunny days.

If I changed to AGM batteries...I would have the advantage of not adding water and having clean terminals. My rate of charge would go from a cap of C/10 to C*5...in other words...no longer a limitation.

Lithium would add the advantage of full rate of Charge right up to 100%...so I could pack more in within the hours of sunlight available, or charge more on less generator run time. They would be much more efficient when powering high load items, such as air conditioners...as they are much more efficient at allowing power to flow in or out at high rates. If I had a nice climate controlled location near my inverter to place them in...I would consider it. Especially if allowed to bundle it into my 30% tax credit incentive...but I don't have that figured out.

That's where I'm at. And if it allows me to get an Essex in 2027...that would be an added bonus...LOL.

NealC · 09-19-2017, 10:27 AM

I'm getting my solar mojo back again now that I understand some goals. Out of curiosity, what is the cost of an AGM battery for our VTDP's? Or 8 of them for that matter?

I'm hoping for a megawatt on my 2027 Essex

I'll see if it's not too late to put in a special haha.

C.Martin · 09-19-2017, 12:15 PM

https://www.baltimorebattery.com/ind...MaAnKvEALw_wcB

About $300 per

I hope you'll let me copy your specials list in 2027...

oh...here's another link...

https://www.wholesalesolar.com/99601...0ah-6v-battery

NealC · 09-19-2017, 12:42 PM

Hmm, I think I'd put in AGM with solar at the same time. Someday I'd love to get a list of everything I would need to install what you did. Either here or via email. I'm also waiting to hear back from Marvin but if it's not as hard as that dang BMK to install I may do it myself too. I know your number!!!

C.Martin · 09-19-2017, 01:05 PM

Quote:

Originally Posted by NealC

Hmm, I think I'd put in AGM with solar at the same time. Someday I'd love to get a list of everything I would need to install what you did. Either here or via email. I'm also waiting to hear back from Marvin but if it's not as hard as that dang BMK to install I may do it myself too. I know your number!!!

I'll scan my receipts for you...

If you drop by...I've got hydraulic crimpers, cable cutters, etc for fashioning the lug ends on 6AWG, and 2AWG cables...that way you can borrow them instead of buying them.

I'm away from home now...but I can give you a few leads to look into...

Rooftop Mounting Hardware:

AMSolar.com
- (8) rocker foot mounts
- (1) combiner box
- (?) 10-2 awg cable, up resistant
- (8) tilt kits

Invertersupply.com
- Victron SmartSolar MPPT 150/100-tr Charge Controller w/Bluetooth built-in

HomeDepot.com
- (8) Grape Solar 180watt US moncrystaline Solar Panels (buy them when on sale)

Amazon.com

https://www.amazon.com/gp/registry/w..._wl_your_lists

C.Martin · 09-19-2017, 02:11 PM

I also purchased heavy duty cable cutters from Harbor Freight.

I picked up plywood, paint, misc. mounting hardware, maroon scotchbrite pads, alcohol, cleanup rags, uv resistant zip ties, adhesive zip tie anchors, etc...from the local Home Depot.

I ordered a 5' section of 4/0 welding cable, black...from Temco. That may have been thru thier eBay store... This was to make sure the negative cable from the battery bank to the BMK shunt was capable of ALL the loads.

Tools I had on hand...

Hammer, screwdriver, drill, wire strippers, crimping tool, heat gun, AC/DC clampmeter, assorted bits, and hole saws, circular saw, scissors, utility knife, caulk gun for Dicor.

A smartphone, or tablet capable of running Victron Bluetooth app.

Neal, as you can see from the list...you've done the hard part... Installing the ME-BMK and ME-ARC. The rest of the solar install is gravy.

I found it easier to get panels up on the roof with my Little Giant ladder instead of trying to pull them up with me on the coaches rear ladder.

An interesting note...I ordered extra roof "feet" for my two leading panels that are directly in the slipstream. This was done to double the adhesive strength of those feet. They're really and honestly taped to the roof ..,

NealC · 09-19-2017, 02:35 PM

Charlie, it sounds like a great winter project for us don't ya think?

C.Martin · 09-19-2017, 02:42 PM

Quote:

Originally Posted by NealC

Charlie, it sounds like a great winter project for us don't ya think?

It certainly is!!! Summertime was a challenge. It is way too hot up in the roof with the sun beating down. Impossible to stay hydrated up there.

You just need to be aware of the temperature range for the VHB tape. It won't like cold temps. Winter, in a heated indoor space...or a sunny fall day is fine....

C.Martin · 09-19-2017, 02:56 PM

Here's a double rocker foot attachment.

NealC · 09-20-2017, 07:46 PM

Any concerns of solar panels growing legs? i.e. disappearing? I have to store mine in a self-storage/rv lot as the HOA won't let me keep it at home, nor do I have a pad for it.