The Big “Beastly” Solar/Battery Upgrade Part II – Component Details
My last post talked about the WHY. Today we’re going to address the WHAT.
Basic RV Solar Components
Let’s start off with some very (very) “rough” basics. For those of you not familiar with RV solar systems there are basically 3 main components that go into your system:
Solar panels (= the magical panels that take the sun’s rays and convert them into electrical energy). Most RVers put these on their roofs, but some do keep them “mobile” and just put them out on the ground.
- Charge Controllers (= devices that take the “raw” power your panels produce and charge your house batteries). These connect between your panels & your batteries and do all the electrical stuff needed to make sure your batteries properly charge in the correct order/way they need to be charged.
- Batteries (= the storage devices for the energy you’ve produced). These are what your coach “sucks off” to power everything that runs on electricity inside it.
What happens in an RV solar system is that sun shines down onto your pretty solar panels, is converted (very inefficiently mind you) into nice, juicy electrical energy which is used to charge your house batteries. Then you, as the user, suck down those batteries however you’d like. There are other intricate details such as adding an inverter (if you want to power AC stuff in your coach) and how you tie everything together, but from a top-level point of view that’s really it! When you’re out “shopping” for your RV solar system you’ll be shopping for these 3 items.
LOTS of folks have written in waaaay more detail about subject so if you want to learn more, here’s a few nice links:
- AM Solar -> RV Solar Education Series
- Cheap RV Living -> Basics Of Solar Power
- Gone With The Wynns: How Off-Grid RV Solar Works
- Jack & Danielle Mayer: RV Electrical & Solar
- Road Less Traveled: Understanding the Basics of Boat & RV Solar Power
The “Perfect” System Size
When you’re living entirely off your solar system it’s really quite simple. Everyday you generate some power (= with your solar panels) and everyday you use some power (= draw from your batteries by using the electrical stuff in the coach). Ideally you want these two numbers to match (more-or-less) and ideally you want enough of everything that you can do what you want (electrically-speaking) without running out of juice.
But how MUCH that is, is a very individual thing.
Our “starter” solar system in 2010 had 440 amphours of AGM batteries (of which 50% or 220AH is usable) and 600 Watts of solar. For the BBSBU we chose 600AH of lithium batteries (of which 80% or 480AH is usable) and 1500 total Watts of solar. This will aaalmost triple our usable battery capacity (if you subtract phantom draw -> see table below) and more than double our solar generation capability. We have 5+ years of experience with our own use model so we knew this is exactly what we wanted and it was the perfect system size for us.
But YOUR numbers may be totally different!
All-electric coaches suck waaaaay more power (and thus need much more solar/battery) than little trailers. Folks who spend their days working on-line all day have higher power needs than folks who just go to the boonies to hang all day outside. Plus budget and space (how much you can fit into your coach & onto your roof) come into play too. In other words everyone’s energy needs are completely individual and there is NO one “perfect” system size. It’s just whatever size works for YOU.
Before you even think about installing solar on your own rig I highly recommend doing an energy audit to figure out your power needs. I won’t go through these details, but instead recommend checking out some of the following links:
- AM Solar: RV Solar Sizing By Actual Use
- Technomadia: Solar Planning: Conducting An RV Electrical Consumption Audit
- RV Solar Electric: Solar Design Worksheet
- Go Power: Size Your System Calculator
The “Perfect” Component Set
Just like the “perfect” system size, the “perfect” component set doesn’t exist. There are TONS of options for each of the 3 things I listed above (including even more “package” options) and as long as you buy decent quality stuff you’ll probably be fine.
There are specifics you want to look at as far as matching components properly (e.g. you want to be sure the solar charger you’re buying can handle the number of watts & the voltage specs of the solar panels you’re going to load onto it) and there are definitely specifics you want to look at when it comes to installing your components (I’ll go through some of these in my installation posts), but other than this there is really no “one” perfect set-up.
As an example, folks in a small trailer or on a budget might be perfectly fine with a few inexpensive solar panels (say, a few hundred watts?), a single inexpensive PWM solar charger and some inexpensive golf cart batteries. On the other hand folks in big rigs looking to push the limits of newer technology might want lithium batteries, multiple MPPT solar chargers and as many panels (2000 watts???) as they can fit on the roof. It’s all very individual.
If you want to understand more about the technical details of RV Solar components check our some of the following links:
- AltE Store: Solar Panels (Photovoltaic Panels) Overview
- Road Less Traveled: Solar Charge Controllers
- Technomadia: Understanding Solar Panel Specifications
- Handybob: The RV Battery Charging Puzzle
Our Component Choices
Below is the list of our “big 3” component choices and why we chose them. We did a ton of research and also talked through all these components many times with Marvin (our installer). It’s helpful to have a knowledgeable person to bounce ideas off when you’re deciding on stuff like this, and Marvin was awesome at fielding all our questions and guiding us along.
With that said here is our new “perfect” solution 🙂
600AH Elite Power Solution (GBS) Lithium** Batteries
In the Lithium world there are a few, select guys who make the “battery cells” (= the individual “lego block” pieces that go into the battery pack) and a few more guys who put them together to make assembled battery packs. Also since Lithium batteries charge differently than lead-acid and are very sensitive to over-charging & over-draining, you want to add systems that accurately monitor the state and health of your individual cells & your pack. This extra equipment makes Lithium more complicated than regular lead acid batteries both to install & monitor, but it’s important stuff IMHO.
In our case we went with Elite Power Solutions and bought three of the GBS-LFMP200AH battery packs (total 600AH). The cells in our batteries are made by a company called GB Systems (= the blue-colored cells, if you ever see them), while Elite Power Solutions (EPS) are the guys who put them together into an assembled pack. In addition to the packs themselves we bought the EMS 4-cell String Sense Boards, the EMS CPU (basically the computer for the energy management system) and an EMS LCD Screeen so we can monitor and see everything that goes on with our batteries.
We chose the Elite packs rather than other guys for 3 main reasons :
- Experience Of Use -> EPS are the the most-used packs in RV/boat installations and the ones you’ll see most discussed on all the RV & boating forums. Several of our personal friends use them so there’s lots of experience out there and we have many folks we can rely on if we run into questions etc. There’s a certain comfort that comes with using something that other people are using.
- Good Battery Management Systems -> The EPS packs pair very nicely with the EPS cell balancing boards and and management system. It’s just a nice, complete system. We like that we can monitor both the health of the individual cells themselves as well as the overall pack.
- Good Support -> Elite are known for their good customer service & support. Marvin (our installer) has personal experience of this from his multiple years of working with them, plus we have friends who’ve confirmed the same. We place high value on good support.
This trifecta of stuff made them the easy choice for us.
What Else We Considered -> We DID look at Balqon mostly because of price (they typically offer the best lithium prices on the market), but after 4 months of trying to get a hold of them and never getting a single call back we gave up. We didn’t really consider other manufacturers.
**NOTE/ If you want to know WHY we chose Lithium (as opposed to Lead Acid batteries), feel free to click back and read PART I of the BBSBU series.
900 Watts of GS-100 Solar Panels
We decided to keep our original 600 Watts of RV100 (no longer made) solar panels. They’re still great panels, they’re a nice, compact size and they still work perfectly so we wanted to preserve that initial investment.
For our upgrade we decided to ADD 9 of the GS100 solar panels (100 Watts each) sourced from AM Solar. They are NOT the cheapest panels out there, but they’re super efficient (= how efficiently they convert sun to electricity) so they pack that 100 Watts into a really nice, compact space.
Their biggest benefit IMHO is their super-narrow format (they’re only 20.7″ wide) which means we can fit lots of panels on the roof with zero shading from any of our roof objects (vents, air-conditioners etc.). Since shading/shadows are one of the biggest KILLERS of RV solar installations (seriously, a mere 5% shade can crash your output!!) this was the MAIN reason we chose them.
The two sets of panels combined will give us a total of 1500 Watts of solar panels on our roof.
What Else We Considered -> We didn’t consider much else since we were already sold on the narrow GS100 format, but there are tons of other options out there. If you’re using the panels on the ground, you can chose just about any panel you care to carry around. If you’re using panels on your RV roof, it just depends what you can fit on your roof (without shading!!). For the more budget-conscious AM solar offer a slightly bigger SF100 panel (100 Watt), while Renology offers a similarly-sized 100 Watt Panel. For folks who can handle a slightly wider form factor Grape Solar makes the GS-160 (160 Watts) which are a good, medium-format panel for a very reasonable price. AM Solar also offers a medium-sized SF160 (160 Watts). So does Renology with their RNG-150D (150 Watts), but it’s square(ish) in format which makes it harder to place on an RV roof without shading IMHO. The absolute highest efficiency panels on the market are currently the LG NeON LG315N1C-G4, but they are BIG (HUGE) -> the only way to use these on an RV roof is to build a roof-rack so you can raise the panels up above vents/air-con and other shade objects. There are MANY other choices out there.
What About Flexible Panels? Flexible panels are all the rage right now, and for many smaller RV’s or RV’s with weird-shaped roofs they are very compelling since you can just stick ’em on and be done with it. However, we’re honestly not fans. We have friends w/ flexible panels who’ve seen them deteriorate far too quickly for our comfort, and over fairly short periods of time too. We’ve seen cupping issues (the cells deform into “cups”), over-heating issues (since they’re stuck right onto the roof and have no air-flow under them, this is a common problem) and far-too-easy scratching all of which deteriorate their output. Flexible panels are definitely getting better (all the time), but IMHO they’re just not there yet and I’ve yet to see a flexible panel that has “stood up” to long-term RV abuse. On the other hand hard panels have been around forever and are a solid technology. They are waaaaay cheaper, typically come with 10+ year warranties and our experience of 5+ years confirms they can handle serious abuse.
Four Blue Sky 3024iL Charge Controllers
Our charge controller decision was probably one of the most difficult (and most discussed) decisions we made. There are LOTS of great chargers out there and they honestly all do a pretty decent job. In our case we decided to ditch our old Morningstar MPPT-45 and switch to a modular Blue Sky SB3024IL set-up. We also bought the Blue Sky IPN ProRemote and the Blue Sky UCM (so that we can network to our data via our computers).
Each of our Blue Sky controllers is rated to handle up to 40 amps & 540 Watts. So we needed 2 controllers for our 600 Watts of old panels & 2 for our 900 Watts of new panels, for a grand total of 4 controllers.
The main reasons we chose this set-up are partly technical and partly geekish:
- 2 Different Panels/3 Different “Solar Systems”-> We wanted to keep our 6 old 24V panels while adding 9 new slightly lower-voltage panels. Plus we decided (partially for geek reasons) to install our new panels in 3 separate roof configurations (I’ll talk more about this in our installation posts). A modular controller approach was the only way to make this happen.
- Networkability & Central Control -> We wanted all our controllers to “talk” to each other but we also wanted a single, programmable system that controlled them all.
- On The Fly Programmability -> In addition to networkability we wanted to be able to program our controllers “on the fly”. This was (especially) a requirement for our new Lithuim system since we wanted to be able to mess around with parameters, including absorption time, charging voltages and other details.
- Access To Data -> For our “geek” experiments we wanted to have the ability to look at the data log history of both the overall system as well as each controller individually, and we wanted to be able to do this directly from our computers without having to plug into the controllers one-by-one.
Switching to multiple, compact Blue Sky controllers (and adding the Remote & UCM module) allowed us to do ALL of these things -> we will have 3 different “solar systems” running on 4 controllers. The controllers can be individually programmed, but will also seamlessly network together to act as “one”. Plus we can program them as we want, whenever we want and delve into the details of how they’re doing on our computers.
What Else We Considered -> We looked at Morningstar, mostly because we already had one controller and could have expanded our system by adding two more Morningstar MPPT-60 (to handle the additional 900 Watts), but the networking set-up just wasn’t as elegant as Blue Sky. Morningstar requires you to buy separate hubs and you can’t program on-the-fly like you can with Blue Sky. It’s just kind of “clunky”. The other controller solutions out there, although all good solutions, were generally bigger chargers and didn’t give us the modularity and/or integrated networkability we were looking for.
Coming Up Next -> BBSBU Installation Posts!