LiFePo4 (Lithium Ion) Battery Project Photos

[Vic Harder]

Mark,

The MPPT controllers pull out way more power from the panels than a PWM controller can. And to do that, you need to wire the panels in series, to pump the voltage up and give the controller room to play in.

The advertizing/review on the 100/50 is flashy... and the same applies to all the Victron controllers. They are all very quick. So don't let that disuade you from getting any other Victron controller!

The series/parallel connection thing is even more important for those remote/portable panels, because instead of a 10' of wire, you now have 5 to 10x that. I have 100' of cable for mine, so I can get them into the sun easily if I am in the shade. That's why I have TWO Victron controllers. One for the roof array and another for my portables.

LiFePo4 batteries discharge about 3-4x slower than regular chemistry batteries. If you are not parking for months, it won't be an issue. Otherwise, I second Craig's recommendation of a NOCO Genius 7200. I use one too.

I have bluetooth on my battery monitor, and at the time I didn't include bluetooth for my controllers. I don't miss that feature much, as I ALSO have the remote displays and can change settings from those. That said, there is little need to adjust the controllers. I love having BT for my batteries, as I can monitor them from the house or cab of the truck.

Sorry about the upside down gauges!

 

[Stokeme]

Ok, looking at a wire sizing calculator, I can see the relationship between volts, amperage, wire gauge & distance. So questions are:

Does a portable, if plugged into the rear wall outlet, combine with the amperage total of the panels, run in parallel, on the roof? Also, would you have to combine the roof to battery wire length with the portable to battery wire length in calculating power loss? Would the power loss at least be separated between by the two different plug in points, roof vs portable?

Say I do run the roof in series, 2 panels x 12v=24v. If I had originally planned on buying only one portable, at 12v, would I then be forced to buy 2 portables, to be able to match the 24v on the roof, if I wanted to use the same controller? Or be resigned to using two, one for each site?

Bottom line summary? If all the truck panels are run in parallel, you have to limit the # of panels & the wire length, or suffer measurable power loss ... or use real heavy gauge wire. The wiring from the roof to the house battery would be unpleasant to modify.
Running all the truck panels in series, roof & portable, almost requires two separate controllers. But, the increased voltage affords enhanced power efficiency & travel length, using much lighter gauge wire.

Could someone use a red pen & make corrections to my summary? Mid term exam, I’ll study a bit more for the final. I never wanted to deal with electricity.
FWC is using 10 gauge wire. I checked today.

Thanks again Vic & Craig

 

[rando]

As an armchair theoretician it pains me to say this - but we are all over thinking this. The loss to thinner wires is a very minor effect, that you don't really need to worry about. The difference between two parallel or 2 series 120W panels is ~3% under the absolute worst case scenario and usually much less than this.

If you want to use a single controller with roof and portable panels, but them all in parallel and use the same type on panels for all your panels. Your thought process should be:

1. Decide how many panels you want (2 x 120W on the roof and 1 x 120W portable seems to work well for most folks).
2. Add up the short circuit current of all the panels (with the solar Cynergy 120W panels this would be 6.6A * 3 = 20A.
3. Pick the next biggest size charge controller (the 100V/30A either with or without built in blue tooth, probably worth the extra $30 to get bluetooth).
4. Wire it all up and be happy!

 

[Vic Harder]

As usual, rando is being very real, and helpful.

To answer your question "Does a portable, if plugged into the rear wall outlet, combine with the amperage total of the panels, run in parallel, on the roof?" Yes, to keep it simple, that external plug would usually be in parallel.

And to your question "Say I do run the roof in series, 2 panels x 12v=24v. If I had originally planned on buying only one portable, at 12v, would I then be forced to buy 2 portables, to be able to match the 24v on the roof, if I wanted to use the same controller?" Yes, you need to feed more voltage than what you would get from one panel to really see the advantage of an MPPT controller.

And no, you never really need to upgrade the wiring already in the camper from the roof to battery box. That run is too short to care about at the current levels and losses we are talking about.

Now to rando... are you suggesting that Mark run all the panels in parallel and use a Victron MPPT controller? I'm not sure I see the advantage of MPPT in this case.

 

[Stokeme]

Rando, thank you, that is what I was hoping to hear. Vic, thank you for the replies & answering my questions. Craig, thank you for your patient PM & posting replies.
This Forum & it’s members are awesome ! I now have basic understanding, not to make harmful decisions about $ spent on a Solar System. Electricity was the one thing I never wanted to be involved with around the house or the yard.
I need & want to stay light with my build. Wish I could share a cold one with everyone ...

 

[rando]

Yup, I am saying run them all in parallel and use an MPPT controller. This makes using a portable panel dead easy.

You get the same advantages from an MPPT controller whether the panels are in parallel or series. The only difference is that you get slightly less resistive loss in the wiring with the panels in series, but as pointed out before, this difference is small.

Using the 120W solar cynergy panels as an example - they produce maximum power at 20V and 6A (thus the 120W rating). An MPPT controller will run the panel at this point and under ideal conditions could provide the full 120W. A PWM controller may pull slightly more current from the panel (but not more than the short circuit current of 6.65A) but only at the battery charging voltage of ~13.7V . Therefore the PWM charge will provide a maximum of 13.7*6.65 = 91W under ideal conditions, so 25% less power from a PWM charger. Realistically you will be in less than ideal conditions and get less power from either charge controller, but the MPPT will always provide more power.

To be truly pedantic (which we all excel at) you also get a slight advantage from series panels in the voltage is higher and so the charger will switch on slightly earlier in the morning - but this has to be a third order affect.

For someone who is not an electron enthusiast - go the simplest route possible: all the panels in parallel and all the same type of panels.

As usual, rando is being very real, and helpful.

To answer your question "Does a portable, if plugged into the rear wall outlet, combine with the amperage total of the panels, run in parallel, on the roof?" Yes, to keep it simple, that external plug would usually be in parallel.

And to your question "Say I do run the roof in series, 2 panels x 12v=24v. If I had originally planned on buying only one portable, at 12v, would I then be forced to buy 2 portables, to be able to match the 24v on the roof, if I wanted to use the same controller?" Yes, you need to feed more voltage than what you would get from one panel to really see the advantage of an MPPT controller.

And no, you never really need to upgrade the wiring already in the camper from the roof to battery box. That run is too short to care about at the current levels and losses we are talking about.

Now to rando... are you suggesting that Mark run all the panels in parallel and use a Victron MPPT controller? I'm not sure I see the advantage of MPPT in this case.

 

[Vic Harder]

Thanks for adding to my understanding rando and Craig, and for asking all these great questions Mark!

I am now wondering about how to wire/switch my external panel connection to wire that in series with the roof panels when I plug it in.... hmmm.

 

[Stokeme]

I initially gleamed parallel which I was happy to read. Thanks for a further & more detailed addition. I am highly into “dead easy”.
I purchased two flex 120w solar cynergy panels last night. I would like three but not sure how that might work yet with a kayak, & hopefully a canoe, on the roof too. Looking at a 80 or 100w (weighing best value) folding flex portable, from Lensun, very light weight. Going to buy a Victron SmartSolar 100/30 & Noco G7200 charger. I will initially rely on the inherent Bluetooth monitoring function in my battery instead of buying a battery monitor. - Any further thoughts are welcome - Putting my stamp on this Camper is fun.
I am initially abandoning my engine to house battery connection. If I need to initiate that later, I hope not, I would probably purchase this, as it was recommended by StarkPower, but yikes on the price ... It seems almost necessary to keep my LiFePo4 Battery healthy ...
http://www.sterling-power-usa.com/SterlingPower12volt-12volt-30ampbatterytobatterycharger.aspx

 

[rando]

To reiterate, if you are going to combine panels into one controller, they really should be the same. So putting an 80W lensun portable panel in parallel with the 120W solar cynergy panels on the roof may not be optimal depending on what their I-V curves look like. When you put them in parallel, you are forcing them all to be at the same voltage which may mean the some of the panels are operating pretty far from their maximum power point.

 

[Stokeme]

So, I need a 120v portable panel? By the same, do you mean overall voltage, not manufacturer, correct? Or can you suggest I try to match (which particular?) provided numerical criteria, V or A, documented on the panel?

 

[rando]

I mean same specifications - primarily close to the same voltage at maximum power point (Vm or Vmp on a spec sheet). If you use the same panel from the same manufacturer they will of course be the same. If you use a different panel from a different manufacturer you want to read their spec sheet to see how close they are.

This is not a huge deal, but could make a 5-20% difference in overall efficiency depending on how far off they are.

 

[Stokeme]

Edited previous post completed below maybe after/during your reply. I am glad now I listed my proposed solar components. Your reply above answered my question. Thanks for the fumble recovery.

“So, I need a 120v portable panel? By the same, do you mean overall voltage, not manufacturer, correct? Or can you suggest I try to match (which particular?) provided numerical criteria, V or A, documented on the panel?”

 

[Vic Harder]

Mark, why not get exactly the same panels for the portable setup? Remember you don't need/want a built in controller for the externals, which often come packaged as a kit. The panels are so thin you can store them under your bed matress when not it use, or do I what I do, which is shove them between the truck and camper at the front wall of the truck bed.

 

[Timothy McGowen]

I just tested these out and so far am very happy. Does not include include a controller so it helps bring the price down. My friend likes the build on these better than the ones he purchased from Camping World at almost twice the price.

Note: You will need to add the proper plug to bare wires for your appropriate use, SAE, MC4, etc. unless you use a 50 amp grey Anderson connector which comes reattached.

https://www.bioennopower.com/collections/solar-controllers/products/120-watt-foldable-solar-panel-for-charging-power-packs-bsp-120

 

[Stokeme]

Thanks for these suggestions ... Vic you are probably correct, but ideally I wanted something smaller. So, after Rando explained Vmp, as a determining factor, there was no Solar cynergy foldable Vmp over 17v. My roof flex panel happens to be 20v. The Lensun was 18v. Then, I ran across this dude at 18.9v, link below, at half the price of the Lensun & not much more than my roof panels. Obviously, the accompanying controller is a piece of poo, so I will chuck it. I may go back to getting another cynergy 120W later, but I will check this one out. It has a ok looking travel case. Almost done getting stuff.
Vic, what kind/brand of 100 ft. cable/wire did you get to extend your Portable panel?

https://www.amazon.com/gp/product/B0748FYFSK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

[Vic Harder]

mc4 cable i think 10 or 12g

 

[Stokeme]

I have the Victron Smart 100/30 on order. I assumed I could use it for both FWC solar plug in points. A little late to be asking but can the controller handle both, the fixed roof & rear portable, at once, from different plug in points?

 

[Vic Harder]

I have the Victron Smart 100/30 on order. I assumed I could use it for both FWC solar plug in points. A little late to be asking but can the controller handle both, the fixed roof & rear portable, at once, from different plug in points?

Yes. Wired in parallel, your max voltage (first number = 100) will not be higher than any one panel... instead, it is the current that is additive. And each panel is max 6 amps, so even with 4 panels you would only be at 24A. Safely within the 30A rating (but recall my math above, because the controller will still try to maximize power output, and could put out more than the incoming 24A). Still, sounds like the right part for your application.

 

[paddlesurf.net]

I noticed that the original poster has 2 100aH Lithium batteries in his system. Awesome.

I have a 2017 Hawk Flatbed that I'm getting installed in 8 days (YES) the camper has the IOTA DLS30 with the IQ4 charging module.

My question, for the OP, or for anybody else who might know is this: Can those StarkPower 100aH Lithium batteries be safely charged with the IOTA charger in my new Hawk?

I read on the StarkPower site that the batteries can be charged with any charger that does not have a de-sulfate mode. Here's what it says on the StarkPower site: "Can be charged with most traditional lead-acid chargers that do not have “Desulfate” mode, provided the current levels do not exceed lithium battery charge specification."

I did a little reading on the IQ4 module and it does not state that it has a desulfate mode.

I don't know what the "lithium battery charge specification." is and how it compares to what the IOTA provides.

I'd like to use the IOTA that comes in the camper (if I go with lithium batteries) is this a bad idea?

 

[fwctaco]

I noticed that the original poster has 2 100aH Lithium batteries in his system. Awesome.

I have a 2017 Hawk Flatbed that I'm getting installed in 8 days (YES) the camper has the IOTA DLS30 with the IQ4 charging module.

My question, for the OP, or for anybody else who might know is this: Can those StarkPower 100aH Lithium batteries be safely charged with the IOTA charger in my new Hawk?

I read on the StarkPower site that the batteries can be charged with any charger that does not have a de-sulfate mode. Here's what it says on the StarkPower site: "Can be charged with most traditional lead-acid chargers that do not have “Desulfate” mode, provided the current levels do not exceed lithium battery charge specification."

I did a little reading on the IQ4 module and it does not state that it has a desulfate mode.

I don't know what the "lithium battery charge specification." is and how it compares to what the IOTA provides.

I'd like to use the IOTA that comes in the camper (if I go with lithium batteries) is this a bad idea?

I would not recommend using the existing IOTA with IQ4 to charge a LiFEPO4 battery. The bulk stage on the stock IQ4 goes up to 14.8V, which is too high. It also has an equalize or "de-sulfate" mode which you cannot turn off. Iota does have a new IQ4-LiFEPO4 module that you might be able to swap onto the DLS-30.. that could work.