81 replies to this topic

[Vic Harder]

Statements like this just make me cringe and want to run away "#2  According to Zamp; MPPT controllers only effectively optimizes power input to the batteries if you have 1,000w or more."  The BS is just oozing out of that statement.

 

Phil, I could complicate things by quoting the amps and volts (nuts and bolts?) of the panels you have and are considering, but won't unless you ask me to.  Just be aware that those panels are not going to give you the 250W on the roof that you hope for.  I was just looking at the ZAMP website, and details on their panels are hard to find.  That said, their 170 "Legacy" panel will only produce 135W under ideal conditions.  Under ideal conditions, a MPPT controller can get all 170W out of the panel.  Ideal never happens though.

[Vic Harder]

And if it were me, I'd go with a bigger single panel up on top, with a MPPT controller.

 

And yes, the Victron or Chinese knock off Battery monitors are independent units.  Well worth having.

[Wallowa]

Vic,

 

All you say rings true and the "1,000w" statement from Zamp had me tilting my head and frowning but since I have no technical knowledge, yet, in this arena I just let it slide.  It does seem that there is a break point where the MPPT becomes superior to a PWM; see #36 comments.  

 

Single large panel and MPPT does indeed make sense if feasible.

 

Question for you or anybody 'listening':  Who makes the most efficient and dependable solar panels?  I want a rigid panel so the mounting on my rails will be straight forward.  Are the Zamp panels high quality?  Why did FWC go to Overland panels?

 

So thanks for being patient with my endless questions.  I will get this.

 

Phil

 

Ps...Just found this statement in a 2018 article:  May be a course correction in my thinking.

 

Stan: We were using Zamp solar panels and controllers, but the Overland Solar 160-watt panel and MPPT controller is a much higher quality.  Overland Solar’s technology is better and offers improved output with a lighter weight.  We have tested the system for months both in the sun, in the shade, and inside the building.  The output is better in every aspect; especially when part of the panel is shaded.  We also dropped 12 to 15 pounds of weight off the roof.  With a pop-up camper that has a manual roof lift, roof weight is important.

 

 

https://www.truckcam...-announcements/

Edited by Wallowa, 24 November 2020 - 05:01 PM.

[wicked1]

Statements like this just make me cringe and want to run away "#2  According to Zamp; MPPT controllers only effectively optimizes power input to the batteries if you have 1,000w or more."  The BS is just oozing out of that statement.

 

Yeah, I was holding my tongue a bit yesterday when I replied.. But I want to say it..  I've dealt w/ three solar companies in my short 6 months or so in this hobby, and all of them either have no engineers and are simply reselling Chinese products they don't know much about.. Or they're the kind of engineer who thinks they're super hot stuff, and no one else understands anything, so they go way out of their way to talk down to their customers.   I even told one of the guys, you don't need to keep it simple, my degree is in EE.  But still..  spoke to me like an uneducated child. 

 

Question for you or anybody 'listening':  Who makes the most efficient and dependable solar panels?  I want a rigid panel so the mounting on my rails will be straight forward.  Are the Zamp panels high quality?  Why did FWC go to Overland panels?

 

Any panel using the 'Sun Power' cells will be the most efficient at the moment, I think.. Though, this stuff changes fast so I may be wrong.   But, they are likely not the most durable, as most using those cells are flexible panels, which seem to die faster than the rigid ones. 

Those overland solar panels are good, using the sunpower cells.  But, they're super expensive for what they are.  You can get panels for 1/4 of the price with the same cells and efficiency.  (And they're one of the companies who spoke way down to me, while the people at Sol-Go were actually helpful.. and they have panels w/ the same cells for 1/4 the price.. But I have not tried them, and there's not a lot of info about them out there). 

Anyway, like I said, I've only been researching solar for the past 1/2 year or less, so someone more experienced will likely have better advice.   And, I only researched 12v panels built for RV/camping stuff.   But, I figured I'd share what I know.  As Vic always says, maybe consider the bigger house panels.

[Wallowa]

Wicked 1,

 

Hey, an EE, not an easy course of study!  I was a biological oceanographer and Diving Safety Officer...so anything electrical scares me!  Normally I can smell out the tripe and like you sense when someone is talking down to me.

 

Rigid vs Semi-flexible [Overland] and durability / longevity is a new realm for me to investigate.  The MPPT approach makes sense, but as you so succinctly state the solar technology is anything but static.  Need to also match my existing Hawk wiring capacities to any changes I make.

 

Vic mentioned a single large panel to come on the market that is reasonably priced.  Hope to find out more; who and when.

 

Hate to discard fairly new ['16] Zamp 160w and 80w [portable]; plus install new controller and a monitor.  If the utility of such a jump and the cost vs benefit then I am all in. 

 

When AGMs croak I may also jump to LiPo4 batteries to get past that "50%" limit on the AGMs. 

 

I am approaching getting more usable amps when off grid by increasing input and the availability within the battery bank.

 

Anyway...yet again, thanks for the insights.

 

Phil

 

Ps...Just checked Sol-Go; flexible panels and owned by SunPower....

Edited by Wallowa, 24 November 2020 - 06:18 PM.

[wicked1]

FYI, the Sol-Go panels specs closely match the Zamp panels.  I think they'd be safe to mix. 
 

But they are flexible, and you'd need to build a frame for them. 
Not too tough, and there are plenty of posts about doing it here on this forum with the Overland panels.  Basically just build an aluminum rectangle w/ a couple cross members for supporting the panel.  A few pieces of Z channel to mount the aluminum frame to the top of the camper. 

[Wallowa]

Checking into rigid home panels...rigid vs flexible, again for longevity and mounting ease...penalty in weight for sure.

 

This is 60"x40" [@46 lbs] so too large for my Hawk with two vents...BUT I like the output..

 

https://stellarsolar...2618-revb-0.pdf

 

Phil

[Vic Harder]

THE most efficient?  I'm not sure.  I like using products from Canadian Solar, since I am in Canada (pretty sure they are made in China though) because they are pushing the envelope in high power, low maintenance gear.  I believe most panels are hail proof, so that should say something about toughness.  I'd be inclined to go with the highest power available, but that is often super expensive.  Staying out of the top 5% of "the best" often results in big savings, and not just when talking about solar!

 

665W panels are here! - http://pardot.canadi...ar.com/series-7

 

(no affiliation ... )

[wicked1]

THE most efficient?

If their specs are accurate, the sunpower cells are almost 24% efficient.  While most on the market are 18-20%.  The ones you just linked specify 21.4.    That's all I based my "most efficient" comment on.  Otherwise, I have no real world experience. 
Plus the sunpower cells have that lower voltage drop when they're shaded which makes them 2x more shade tolerant.  (meaning two leaves falling on the panel will kill it, instead of one.. Which either way is not great, heh)

[Jack]

I vacillated between rigid and flexible and finally went with 3 HQST 100 W flexible panels mounted with velcro. The velcro provides about a 3/16" gap and has held up just fine on several trips. I'm still concerned about heat so come summer, I'll have a small USB temperature logger (it normally monitors the fridge) slipped under a panel and I'll be checking the top with an IR thermometer. If heat is a problem, I will add a layer of 1/2" polycarbonate under the panels, again with velcro.

 

As to reliability issues, HQST has a 5 year warranty - if they are still around in 5 years. Renogy has a similar warranty and is probably a better bet to be around in 5 years. Renogy had problems with their first line of flexible panels but they replaced them. If one of the 3 panels fails, I can bypass it - I made sure my MC4 cables are long enough - and I still have 200 W left.

 

Yeah, I was holding my tongue a bit yesterday when I replied.. But I want to say it..  I've dealt w/ three solar companies in my short 6 months or so in this hobby, and all of them either have no engineers and are simply reselling Chinese products they don't know much about.. Or they're the kind of engineer who thinks they're super hot stuff, and no one else understands anything, so they go way out of their way to talk down to their customers.   I even told one of the guys, you don't need to keep it simple, my degree is in EE.  But still..  spoke to me like an uneducated child. 

This just happens way too often.