Solar flex 200

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

Bearcatrp

Well-known member
Joined
Jul 11, 2019
Posts
118
Location
Central Minnesota
Just purchased a 2022 Keystone Cougar that has the solar flex 200 system. Has 2 panels on the roof and a 30A controller. Have talked to the dealership guru on this but always looking for more information. According to their guru, it’s an automated system that needs no tweaking or adjusting. Got the app to monitor the system. Anyone have one with more information on this? Thanks.
 

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
5,858
Location
SW Louisiana
Are you sure about that, according to their web site overview, this system has 200 watts of solar panels and a 15A controller, where it gets confusing is that it mentions having a 30A MC4 connector port.
 

Bearcatrp

Well-known member
Joined
Jul 11, 2019
Posts
118
Location
Central Minnesota
Reason why I’m asking more questions. Now get this. Been reading on this forum about folks upgrading to lithium batteries for there solar system. When I asked the so called guru, which was head of the maintenance department, he said not to get them. Not ready for prime time yet. Said airstream came out with lithium batteries for there rvs for a year, then went back to lead batteries and lithium upgrades are a dealer option now. He did say to go with AGM batteries for now for a good investment and better battery life. For me, I’ll be researching for a little while before I make any decision.
 

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
5,858
Location
SW Louisiana
LiFePo4 Lithium batteries and there support hardware (DC-DC chargers and solar controllers with LiFePo4 charge profiles, etc.) are a quickly evolving technology. Having said that I have been watching it somewhat closely for the last 5 years or so, and decided that it was mature enough to make the jump to about 6 months ago. It is hard to know for sure, but I get the feeling that things are beginning to stabilize and mature in the market, particularly in the form of so called drop in batteries.

Think of it the way flat panel TV's have evolved over the last 20 years or so, I remember seeing my first flat panel plasma screen TV at a trade show in 2001, it was 36 inch screen and cost $30,000 with I think a 640x480 resolution, a year later they were down to under $10,000 and had 720P resolution, by 2007 I bought my first LCD flat panel TV, a 35 inch model, which was not really flat, but about 7 inches thick, and the picture was not all that great, 7 years later in 2013 we bought our next flat panel TV, this one was 42 inch and 1080P and we still have it today, our latest flat panel TV is a 50 inch model bought 7 years after that in 2020, and other than weighing about half as much as the 2013 42 inch TV the picture is not all that different, sure it is better (slightly sharper, brighter colors, etc), but not that dramatic difference I saw between the 2007 TV and the 2013 model, a difference so great that the 2007 unit was relegated to the storage closet, and not even the guest bedroom.

To relate this to LiFePo4 batteries, right now I feel LiFePo4 lithium batteries are closer to that 2013 flat panel tv than they are to that 2007 model, and they are certainly way beyond that $30,000 36 inch panel I saw at a trade show in 2001. Sure they will continue to improve, but like that 2013 flat panel TV, even now 7 years later it is good enough for daily use. Now I don't know what sort of experience this guru had with LiFePo4, but if it was based on the products that were shipping as little as 2-3 years ago, and how they were being installed, I can see why he might be soured on the technology.

It is not that the batteries from 2-3 years ago from the better manufacturers were all that bad, instead of lot of it was installations being designed by people with no experience in Lithium batteries, as well support hardware such as companies that should know better putting out so called "Lithium" converter/chargers that were little more than brain dead versions of their lead acid chargers with a premium price tag. (this is one area that still needs improvement, but it is starting to get there). On the installation side of things LiFePo4 Lithium batteries prefer the same temperature range that humans do, so when RV designers install them in locations that see temperature extremes like the tongue of a trailer in a metal box in direct sunlight, no one should be surprised when they experience a premature death, but so often instead of admitting this was a design mistake caused by people that thought "drop in" meant direct replacement, these people and companies blame the batteries for their own mistakes.

Ike

p.s. the advice that LiFePo4 is not ready for prime time and to go with AGM is the exact same advice I was giving to most people on this subject in about 2019, a couple of years makes a lot of difference.
 

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
5,858
Location
SW Louisiana
They are, and they have went up like a lot of other things in the last 6 months. Though even considering that once you calculate in their improved performance, and longer projected life they are on price parity with good AGM batteries now.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
Thanks Ike. Since my current batteries are new, I have time to do my research. Current prices for lithium are a bit pricey.
The prices have come down enough to finally make sense. Think about it like this - Current lithium batteries have a 6000 - 8000 cycle life. That means a full discharge and charge every day for over 2 decades!
When you consider that AGM batteries only have 50% useable capacity, I think you'll find that $800 in lithium gets you more benefits than $800 in AGM. When I started selling LifeBlue and Battleborn 5 years ago, they were about $1200 per 1250Wh. Now that is down 33% to $800 per 1250Wh. And they last for generations.
The leaders in the industry, such as Victron Energy, are already getting ready for the higher voltage of calcium batteries. These are expected to be the next generation of battery chemistry, at a voltage of about 14.8. Bottom line is lithium has reached it's full potential, and the next technology is on the near horizon. Prices won't come down that much further.
That being said, the Grid Point Power Box we designed this year has over 8000Wh of lithium for a lot cheaper than you might think.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
Reason why I’m asking more questions. Now get this. Been reading on this forum about folks upgrading to lithium batteries for there solar system. When I asked the so called guru, which was head of the maintenance department, he said not to get them. Not ready for prime time yet. Said airstream came out with lithium batteries for there rvs for a year, then went back to lead batteries and lithium upgrades are a dealer option now. He did say to go with AGM batteries for now for a good investment and better battery life. For me, I’ll be researching for a little while before I make any decision.
That's interesting because my bread and butter was putting Victron Energy systems into Airstreams for the past 5 years at AM Solar (www.amsolar.com). I would say 95% of the installations were lithium, partially because you can use them indoors and gassing isn't an issue for the larger systems. It is probably the fact Airstream couldn't produce one in-house. Lithium is complicated, it took LifeBlue (a great lithium company) 2400 full charge and discharge cycles to test their battery's lifespan. That's years of testing!

Did the guru use the advertised capacity of the AGM batteries rather than usable capacity into account when making the comparison to lithium, and did he take the fact lithium lasts 10 times longer for reaching his cost figures?
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
They are, and they have went up like a lot of other things in the last 6 months. Though even considering that once you calculate in their improved performance, and longer projected life they are on price parity with good AGM batteries now.
We get our batteries from Victron Energy, Battleborn, Lifeblue and other name brand vendors in the off-grid industry. Prices have basically flatlined over the last couple years, and indeed have had very small fluctuations back up in price but it's not significant enough to pass on to customers.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
LiFePo4 Lithium batteries and there support hardware (DC-DC chargers and solar controllers with LiFePo4 charge profiles, etc.) are a quickly evolving technology. Having said that I have been watching it somewhat closely for the last 5 years or so, and decided that it was mature enough to make the jump to about 6 months ago. It is hard to know for sure, but I get the feeling that things are beginning to stabilize and mature in the market, particularly in the form of so called drop in batteries.

Think of it the way flat panel TV's have evolved over the last 20 years or so, I remember seeing my first flat panel plasma screen TV at a trade show in 2001, it was 36 inch screen and cost $30,000 with I think a 640x480 resolution, a year later they were down to under $10,000 and had 720P resolution, by 2007 I bought my first LCD flat panel TV, a 35 inch model, which was not really flat, but about 7 inches thick, and the picture was not all that great, 7 years later in 2013 we bought our next flat panel TV, this one was 42 inch and 1080P and we still have it today, our latest flat panel TV is a 50 inch model bought 7 years after that in 2020, and other than weighing about half as much as the 2013 42 inch TV the picture is not all that different, sure it is better (slightly sharper, brighter colors, etc), but not that dramatic difference I saw between the 2007 TV and the 2013 model, a difference so great that the 2007 unit was relegated to the storage closet, and not even the guest bedroom.

To relate this to LiFePo4 batteries, right now I feel LiFePo4 lithium batteries are closer to that 2013 flat panel tv than they are to that 2007 model, and they are certainly way beyond that $30,000 36 inch panel I saw at a trade show in 2001. Sure they will continue to improve, but like that 2013 flat panel TV, even now 7 years later it is good enough for daily use. Now I don't know what sort of experience this guru had with LiFePo4, but if it was based on the products that were shipping as little as 2-3 years ago, and how they were being installed, I can see why he might be soured on the technology.

It is not that the batteries from 2-3 years ago from the better manufacturers were all that bad, instead of lot of it was installations being designed by people with no experience in Lithium batteries, as well support hardware such as companies that should know better putting out so called "Lithium" converter/chargers that were little more than brain dead versions of their lead acid chargers with a premium price tag. (this is one area that still needs improvement, but it is starting to get there). On the installation side of things LiFePo4 Lithium batteries prefer the same temperature range that humans do, so when RV designers install them in locations that see temperature extremes like the tongue of a trailer in a metal box in direct sunlight, no one should be surprised when they experience a premature death, but so often instead of admitting this was a design mistake caused by people that thought "drop in" meant direct replacement, these people and companies blame the batteries for their own mistakes.

Ike

p.s. the advice that LiFePo4 is not ready for prime time and to go with AGM is the exact same advice I was giving to most people on this subject in about 2019, a couple of years makes a lot of difference.
Very good entry Ike!
I can tell you from a pricing perspective on cost from vendors like Battleborn and LifeBlue lithium, prices have come down about 33% in the last 5 years. But in the last year it's only been about 5% less, and prices are flatlining this year. This means the technology has reached it's peak in both performance but also price. Of course things like cold weather charging or adjustable BMS parameters are getting added, but those aren't chemistry development just bells and whistles.

Yes the beginning of lithium was a mess! The higher voltages caused a lot of systems to fail early since people used old controllers and cooked the lithium. Existing converters wouldn't be replaced (ack!). Even some "reputable" lithium chargers still forced them into 2 hours of absorption (I'm talking to you Progressive Dynamics)! But they got better. I had the benefit of working with Victron Energy for many years, who is very much on the ball with Lithium and what is needed for a properly designed system.

I think you are spot on with your timing estimates for the industry.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
Have watched there videos and it does mention for this system 2 panels for 30A and a converter. I have a converter in mine as well.
I created extensive material on Victron Controllers and would be glad to help you out.

Here is a link to their manual for reference: https://www.victronenergy.com/uploa...charge-controller-MPPT-100-30-&-100-50-EN.pdf

In short the bluetooth app is extremely robust and has many parameters. It will automatically adjust to the panels voltage (up to 100v of series panels), but you'll want to enter the charge parameters.
Victron has several battery profiles with fixed voltages for bulk, absorption, float etc. They also have user defined to enter custom settings.

What battery type do you have? I have a guide that can help.MPPT Victron Lithium.jpg
 
Last edited:

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
5,858
Location
SW Louisiana
Grid Point, I think the thing we have seen the most in the last 24 months or so is more robust, feature rich support hardware, sure you can call some of it bells and whistles, but by the most part they are meaningful ones. More, smarter, and cheaper DC-DC chargers, internal bluetooth enabled BMS which partly eliminates the need for a shunt style power monitor, higher amp ratings from the onboard BMS in typical 100AH drop in batteries, low temperature sensors and internal heaters becoming more common,... A lot of that stuff simply was not there just 24-36 months ago.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
Grid Point, I think the thing we have seen the most in the last 24 months or so is more robust, feature rich support hardware, sure you can call some of it bells and whistles, but by the most part they are meaningful ones. More, smarter, and cheaper DC-DC chargers, internal bluetooth enabled BMS which partly eliminates the need for a shunt style power monitor, higher amp ratings from the onboard BMS in typical 100AH drop in batteries, low temperature sensors and internal heaters becoming more common,... A lot of that stuff simply was not there just 24-36 months ago.
Oh yes I certainly agree, I was referring to the technology within LifePo4 batteries specifically. The ability to charge below freezing, have a shunt off the negative post, and a programmable BMS to adjust things like the low/high voltage disconnect have been great developments. LifeBlue is what I consider one of the best lithium providers in the market, and these low temp models have come a long way!IMG_2180.JPG
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
What makes the other 50% "unusable" - ?

Mark B.
Albuquerque, NM
The thing with deep cycle AGM batteries is their life is severely decremented if you use the battery past the 50% State of Charge on a consistent basis. That's why we always discussed "usable capacity" when comparing AGM to lithium.

You can of course drain an AGM battery past the 50% SOC mark, which is usually about 11.95v, but it hurts the chemistry and greatly shortens the life of the battery. We always told people the power is there "if you need it in an emergency", but don't depend on it. Each time you drain it past 50% it's very important you immediately get it fully charged within 12 to 24 hours or the damage will continue.

Here is an estimate of AGM battery life based on how far you drain the batteries:
50% average discharge = 800 cycles
70% average discharge = 550 cycles
95% average discharge = 250 cycles

So when comparing AGM to lithium, to be accurate you need to halve the capacity of the AGM battery to get an apples to apples comparison of usable capacity. And of course lithium lasts for 6000+ full cycles.
 

Isaac-1

Well-known member
Joined
Dec 3, 2016
Posts
5,858
Location
SW Louisiana
Grid Point, that often commonly sited advice on lead acid batteries, and perhaps best when designing an off grid cabin, but it is often not a practical choice in typical RV applications where other factors like available space and weight carrying capacity comes in to play along with use patterns of the typical RV owner.
 

Grid Point Designs

Active member
Joined
Jun 7, 2022
Posts
27
Location
Eugene OR
Grid Point, that often commonly sited advice on lead acid batteries, and perhaps best when designing an off grid cabin, but it is often not a practical choice in typical RV applications where other factors like available space and weight carrying capacity comes in to play along with use patterns of the typical RV owner.
Yes lithium batteries are much more energy dense than lead-acid, so going with AGM batteries takes up both more space and is heavier. I've designed hundreds of power systems for "homes on wheels", and lithium has become the clear choice as the price has stabilized. It's rarely justified to use AGM batteries but there are special cases (usually with extreme weather).
IMG_2184.JPG
For example this system shown here has 5000Wh of lithium capacity for a total battery weight of about 110 pounds. If you went with 5000Wh of Renogy AGM batteries instead it would be weigh 250 pounds, more than twice the weight of lithium. But remember that AGM batteries don't like being drained past 50% capacity! So you would actually require 10000Wh of AGM batteries to equal the usable capacity you would get from 5000Wh of lithium.

So with useable capacity to ensure we are comparing apples to apples - The lithium system would be 110 pounds and the AGM system would be 500 pounds.
 
Top Bottom