Advancing Alvar

[Davydd]

Here is a relevant thread by an owner of a new Roadtrek CS Adventurous with 240 watts of solar, 400 amps of factory installed batteries and 400 amps of after market batteries. He shares Booster's solar skepticism and messed up his batteries somehow to where he might remove the after market batteries. It is a detailed review of his first 4,500 miles. Worth a read.

http://www.sprinter-source.com/forum/sh ... hp?t=35212

[gerrym51]

Originally Posted by Davydd

Here is a relevant thread by an owner of a new Roadtrek CS Adventurous with 240 watts of solar, 400 amps of factory installed batteries and 400 amps of after market batteries. He shares Booster's solar skepticism and messed up his batteries somehow to where he might remove the after market batteries. It is a detailed review of his first 4,500 miles. Worth a read.

http://www.sprinter-source.com/forum/sh ... hp?t=35212

i agree with one thing-he messed up his battery charging himself. He should have gotten the full E-trek in the adventurous in the first place.

Roadtrek is selling a system. whether you agree with their systems or not-they do build it to work to their specs. If you disturb the balance by adding your own additions you mess it up.

[Davydd]

Gerry, It wasn't clear to me if he did it himself or the dealer sold him a bill of goods. I can't remember now where it was posted but someone else was talking about a Roadtrek dealer after market battery upgrade that read kind of weird.

[gerrym51]

Originally Posted by Davydd

Gerry, It wasn't clear to me if he did it himself or the dealer sold him a bill of goods. I can't remember now where it was posted but someone else was talking about a Roadtrek dealer after market battery upgrade that read kind of weird.

as Jim hammill stresses. the total e-trek package can only be done at Roadtrek factory'the e-trek package uses a different wiring system than Roadtreks partial enhanced battery system. just adding batteries to a system that was not built to handle it is a mistake.

[markopolo]

The battery monitor he's using might only have a shunt rated at 80 amps. 80 x 12v = 960 watts (I took a quick look at the specs). That could explain why he reports A/C runtime on battery problems.

[gerrym51]

Originally Posted by markopolo

The battery monitor he's using might only have a shunt rated at 80 amps. 80 x 12v = 960 watts (I took a quick look at the specs). That could explain why he reports A/C runtime on battery problems.

Marko- i do not know if your correct-but if so why don't you leave him a message on the sprinter forum site. it might help him out.

[Caped Crusader]

I deleted my post, it was off topic.

[markopolo]

I know Davydd brought up the post on Sprinter Source but I think the intent was to highlight that you might not get what you expect out of solar panels because of many factors. (angle of panels, shade or overcast days, time of year, etc) Let's try to get the discussion back to that and other things to do with Alvar.

[markopolo]

Caped Crusader - It was interesting to see the history of that unit between the posts on the two different forums and nice of you to want to see this thread back on topic.

Topics are like conversations - they drift - and that's fine by most of us. Some really interesting stuff can come up when things get a little off topic I can move posts and split posts etc. all within the forum software with little effort whenever needed. I don't want anyone to feel that they have to stay rigidly on topic as we might lose some of the spontaneity that makes it fun. I'll occasionally try to nudge the conversation back on topic.

I'll go ahead start two new topics based on the "interesting stuff" that came up in recent posts in this topic.

[booster]

Davydd, My point was not that you would have solar that would always run you 3 days. My point was that I would increase the battery bank size to cover the three days, and then increase the solar size to help recover the batteries better and give longer time if things go right. The bigger solar is icing and the bigger bank is the cake

WE use 40 to 70AH per day I would guess, and our goal was also 3 days off grid. We have 375AH of batteries, which at 50% would be only 180AH, so some days we would make it and some not. Put in 10 to 70AH per day of solar, and a willingness to go under 50%, and we are fine pretty much all the time.

[Davydd]

Booster,

We will have at least 400 ah of lithium batteries that would give us 320 ah to play with. My estimates as I mentioned were liberal on the high side. Historically we could manage dry camping on 210 ah of lead-acid batteries and no solar. I kind of surmised that 300 watts of solar would compensate for the compressor refrigerator that doesn't run on propane that our current absorption refrigerator would use. I am just trying to determine going in if that would be enough. It is I believe more than what you have right now. You did mention the over selling of solar as did that Roadtrek CS owner I cited. It kind of gives one pause if 500 watts is the limit you could load on a B. My wife's cousin had a lake home off grid and 300 watts was adequate but he also had it adjustable to track the sun at an optimal angle. The B lacks that ability.

We are in Cleveland, Oh tonight and tomorrow we will see our raw cargo van and sit down and finalize the details. I know some of the advances in lithium ion batteries Advanced RV has made. I'm curious to see if they have anything new in solar as they have hinted at it.

[Davydd]

BTW, we drove 11 hours today. Imagine the battery bank size we could have charged if we weren't driving a Subaru Outback.

[markopolo]

Asked Advanced RV about optimal storage voltage / state of charge for lithium batteries if you get a chance. I'd like to know what they recommend and how they handle it.

Does resale appeal matter in your decision making? More amp hrs - more wow factor ........., maybe. Would 1500ah be crazy expensive or way too large (physically)? It's clear you don't need that much capacity but is 400ah going to seem very small in a few years? An impressive rig might need an equally impressive battery bank. Maybe not 1500ah but you get the idea. What would you have advised a client to do in your professional life?

Just something to consider (as if you don't have enough decisions to make already).

[pattonsr]

I believe the cost of assembling cells together along with all of the necessary controls is around 1/3 the cost of drop in Lithium like a Smart Battery. I would go larger if the space was available and the cost is reasonable. This is a custom setup and trying to increase capacity later on may not be feasible. One day of driving to get to a destination would fill up any size battery bank given that the charging is over 300 amps which is what Advanced RV is saying at this time.

[Davydd]

Resale value is not a concern. We spent a day and a half at Advanced RV and pretty much got everything squared away. I mentioned before they are developing 400, 600 and 800 ah lithium battery assemblies. They will install one size box under the floor that will be big enough for all three. So you could increase in the future. We are going with 600. Also we will be installing about 450 watts of solar based on a new flex panel design that will be stealth. Speaking of stealth we eliminated the awning that sticks up in the air. The solar made that determination. The side skirts will be all new and not fiber glass. Think steel tube nerf bars to imagine them.

I'm typing in a car on an iPad heading for Indianapolis. More later. Here is our raw cargo van as delivered.

[pattonsr]

Davydd,

I wasn't sure when you said you eliminated the awning that it was due to being more stealthy or that you could have more solar without the awning.

[Davydd]

Any time the passenger side faces south there would be potential partial shadowing of the panels and diminished performance since the panels will be low profile flex panels on the roof. You won't see them from standing height and there also won't be the tell tale awning either. There will be three separate panels each with its own controller. However an awning would shade all three panels at the same time.

[stanw909]

What kind of awning are you getting?

[Davydd]

We eliminated the awning in our build. We never put our awning out once this year. In fact it was nearly impossible to do so on the windy Texas Gulf coast where we spent a month last spring. We have always carried a large screen tent which is more practical in bug infested areas like the woods of Minnesota. It was going to be an electric operated Fiamma.

Advanced RV had sold around 20 Bs in its first two years and very few had awnings. Also learned only two were built with Onan generators. Most are opting for 400ah battery banks and solar.

[markopolo]

600ah battery bank
480 ah useable battery bank and 450w solar combo