Solar / Lithium

[ElCampo]

Greetings all,

Well, we did it. Pulled the trigger and joined the group as proud owners of a '16 View 24J. We intend to upgrade the electrical system and I will need some help. I'm very capable with wiring and installation but I still have lots of questions.

Proposed system:

300 watts solar (poly panels to help prevent shading issues)

MPPT controller

300 ah lithium battery - most interested in prismatic (non-cylindrical) construction with a built in battery management system,

Upgraded inverter - 2000 watts

Upgraded converter/charger - one that plays nice with lithium batteries

Battery monitoring system


General thoughts so far:

The electrical draw for evaporative cooling Norcold is quite high - too high to sustain with only solar charging so this will remain unchanged (12v while driving, 120v plugged in, propane off grid) unless I could find a suitable danfoss or swing compressor style replacement - anyone wanna trade?

I'm not convinced the voltage regulation from the alternator is adequate for lithium battery charging, and beyond that I'd prefer to keep the lithium system entirely isolated from the lead acid starting battery system. That being said, I'd be open to suggestions on this point.

I'm going to try to complete the installation with as little rewiring and reconfiguration as possible so that most systems function "like normal"


Questions so far:

Is there any point in having both an inverter/charger and a converter/charger? I believe right now the converter/charger handles coach battery charging while plugged into A/C power or while the generator is running - correct?

Does anyone have recommendations on a replacement refrigerator that uses a danfoss or swing compressor?

Has anyone tried the "drop in replacement" lithium batteries with an integrated battery management system?

Recommendations on a solar controller, converter/charger, inverter, monitoring system that would play nice with big lithium?

Suggestions on installation locations? I'd like to keep any low voltage wiring runs as short as possible to keep internal resistance and voltage drop to a bare minimum. I'm considering building an insulated battery box with a very small electric heating element to keep the enclosure above freezing (can't charge lithium below freezing) or coming up with a low temperature cutoff for charging

What am I missing?

Thanks in advance!

I don't mind being the test bed for this stuff - just want to be free of the generator and extension cords!

[creativepart]

I sure can’t answer most of your questions.. but in general a inverter/charger completely replaces any converter/charger.

I have 300 watts of solar but with a PWM controller and 400 amps of AGM batteries. I have a Magnum 2000 w inverter/charger and magnum ME-ARC50 remote with BMS.

It’s a pretty modest system that sees use mainly running our residential fridge for short overnight stops. And it keeps our batteries charged when the rig is in storage. 300 watts is pretty minimal.

There is a ton of info on solar RV installs on YouTube. Look at, Gone with the Wynns, Less junk more journey, the fit RV, RV with Tito, and probably dozens of others.

Most use the drop in Lithium batteries. Some move the batteries inside the RV so that they are sort of climate controlled.

Hope this helps a little, sorry I don’t have more info.

[luvlabs]

Your Norcold is an absorption style refrigerator, not an evaporative cooler. It works best on 120V or Propane. A compressor style refrigerator is available from Norcold but power usage is a bit higher.

300 watts of solar is good but it really doesn't matter which style panel you use. Conventional 100 watt panels are available on Amazon for around $120.

If you are serious about going with lithium the you will most likely need to change out the charger and carefully select your solar controller. The battery maker can tell you what you need. The cost might take your breath away, however.

Keep us posted on your progress and expenditures. With the addition of a couple of hundred watts of solar, a couple of 6 V golf cart batteries, you have a pretty capable boondocking rig. You still need the generator to run the A/C, microwave, and charge the batteries on cloudy days but your only real expenses are the solar stuff and a couple of 6V batteries.

[ElCampo]

Originally Posted by luvlabs

Your Norcold is an absorption style refrigerator, not an evaporative cooler. It works best on 120V or Propane. A compressor style refrigerator is available from Norcold but power usage is a bit higher.

300 watts of solar is good but it really doesn't matter which style panel you use. Conventional 100 watt panels are available on Amazon for around $120.

If you are serious about going with lithium the you will most likely need to change out the charger and carefully select your solar controller. The battery maker can tell you what you need. The cost might take your breath away, however.

Keep us posted on your progress and expenditures. With the addition of a couple of hundred watts of solar, a couple of 6 V golf cart batteries, you have a pretty capable boondocking rig. You still need the generator to run the A/C, microwave, and charge the batteries on cloudy days but your only real expenses are the solar stuff and a couple of 6V batteries.

Yes, absorption is what I meant - thanks for catching that! I believe at least in the short term I will stick with primarily propane off grid, or 120v on grid for refrigeration.

I was able to negotiate a great deal on the rig and that left about 5k for upgrades which will be put into the electrical. I can either recapture that money at resale, or take the battery with me for the next rig and replace with 6volt GC batteries.

We are primarily off grid so the electricity really matters. I designed my own solar setup for our sailboat and didn't own a generator, never had to start the engine for charging BUT the voltage drop and current draw from high load appliances (hair dryer etc) would take its toll on battery health (AGM). Refrigerator swing compressor at full load was only 2.3 amps DC...incredible technology - frozen icecream under Bahamas sun!

The big draw to lithium in a solar install I think is avoiding the float charge which can take a long time and be very detrimental to battery health if not done on a lead acid install.

[NYBobbo]

I find 200 solar w/factory installed Zamp controller and AGM to be more than sufficient. Golf cart batteries are similar but the AGM are care free so I went that way. Using the gen as Luvlabs says is not a problem for me. A little of solar and better batteries will do for most.

[NYBobbo]

BTW - Congratulations!

[Mike Owens]

I would use the ZS-30AD CONTROLLER because it sounds like you will be going to lithium in the future. It has the dual bank setup so you can throw a couple of 6 vdc cart batteries to start with then expand to a inverter dedicated setup as your second system. Your issue will be weight IMO. I get to vessel stuff as I have spent my adult life with stinkpots. Weigh your rig after you load up what you think you need or after a few local trips and see what you have left. Lithium will require a charger upgrade from the converter and we just keep adding weight.

[ElCampo]

Originally Posted by creativepart

I sure can’t answer most of your questions.. but in general a inverter/charger completely replaces any converter/charger.

I have 300 watts of solar but with a PWM controller and 400 amps of AGM batteries. I have a Magnum 2000 w inverter/charger and magnum ME-ARC50 remote with BMS.

It’s a pretty modest system that sees use mainly running our residential fridge for short overnight stops. And it keeps our batteries charged when the rig is in storage. 300 watts is pretty minimal.

There is a ton of info on solar RV installs on YouTube. Look at, Gone with the Wynns, Less junk more journey, the fit RV, RV with Tito, and probably dozens of others.

Most use the drop in Lithium batteries. Some move the batteries inside the RV so that they are sort of climate controlled.

Hope this helps a little, sorry I don’t have more info.

In regards to inverter/charger vs converter/charger would one be more appropriate for this install? The way I understand the factory system, there is an inverter that will power several 120v outlets in the coach and receives 12v power from the coach batteries. There is also a converter/charger which will convert shore power 120v to 12v for the native 12v equipment as well as to charge the coach batteries.

I will need to upgrade the inverter regardless.

Inverter/charger would allow either shore power or generator to charge the batteries, 12v coach needs would be supplied by the batteries (which may be charging at the time) and then I assume any 120v needs would be supplied by the inverter itself either through (external A/C source sensed?) the generator or shore power mains, or by batteries (no external A/C source sensed?)

Converter/charger would allow either shore power or generator to charge the batteries, 12v coach needs would be supplied by the converter portion while connected to either generator or A/C mains, 120v needs are supplied by the 120v distribution panel.

Correct?


If this is all true, then maybe the easiest solution might be to replace the current converter/charger with a quality inverter/charger, install the batteries under the bed (corner bed model where the converter/charger is installed at the foot of the bed) so the wire runs are short and battery is in a temp controlled environment. 12v would always be supplied by the batteries (regardless of whether or not they are charging), and 120v would be supplied by the inverter when no external source is present, and by mains (generator or shore) when an external source is present. Thoughts?

[creativepart]

Originally Posted by ElCampo

If this is all true, then maybe the easiest solution might be to replace the current converter/charger with a quality inverter/charger, install the batteries under the bed (corner bed model where the converter/charger is installed at the foot of the bed) so the wire runs are short and battery is in a temp controlled environment. 12v would always be supplied by the batteries (regardless of whether or not they are charging), and 120v would be supplied by the inverter when no external source is present, and by mains (generator or shore) when an external source is present. Thoughts?

Sounds about right to me.

Here’s a suggestion. Get the new RV and use it as is for a season. See how it works for you. If you add anything I’d suggest adding a standalone Battery
Monitor Kit. Such as a Victron 712 with Bluetooth. It’s easy to install, you’d need it later if you go the route you’ve planned and most importantly it will detail you actual usage while camping. It will show you exactly how many amps you need daily on a typical camping trip.

THEN you can adequately size the rest of the system from a place of actual knowledge of what power you need.

[Kayak73]

Congratulations on the RV purchase! Enjoy it. Now here is what I did when I was faced with battery upgrade in our new 18V24D. Answers on lithium install were difficult to obtain, drop-in lithium batteries are not drop-in, the expense is far more in a retrofit than battery purchase. I finally asked the engineers at one of the great solar/lithium RV shops to assist in my decision. I got a response, detailed, on what was necessary. My results from that engineer show the lithium battery purchase is about 1/3 the total expense of "going lithium" retrofit. For me the decision was to take a Sawzall to the ridiculous battery tray made to fit only group 24 batteries, rebuild it and install two Trojan T-1275 golf cart batteries for 300AH. Cost of the Trojans was $300 (yes, that included tax, $1.00/AH) from a nearby golf cart shop and the pallet of batteries were just unloaded from the factory truck when I got there. Done. Your expectations of solar are OK but my experience for the past few months on the road show that solar is really a pretty fixture but not very useful in hot weather. If you are indeed planning on dry camp only in cool weather - yeah, great expectations. Personally I will not and can not sit inside an RV when it is over 80*F outside with no air conditioner. These things are like sardine cans, sun hitting the thing means instant heat. Your tolerance for heat may be far greater than mine but the expectation of dry camping without a generator involves a massive lithium battery pack, better insulated rig, much better air conditioning systems than available now and on and on. If your idea of fun is sitting inside a rig that is approaching 90*F, perspiration flowing down your chin - all to prove that you don't have generator noise or need one - great. My reality is I bought the diesel genny, I use it all the time unless we are in a shore power camp like right now at Chatfield St Pk. There have been a precious few days for boondock where A/C was not needed and the solar delivered enough amps to keep everything up and running three consecutive days but those are big honker batteries. Rumors have been floating about a factory lithium pack from WGO in the future Views. That would help but it would need to be a monster to run the A/C and dump the generator altogether. Now in a gasoline powered rig it is simple to install an additional alternator (power plant) and set it up to autostart the engine when the battery pack gets below preset levels. Impossible to do that in a diesel View with new emissions systems, can't idle the engine. This approach is in production now and it works just fine but you do produce bad stuff from the tailpipe of a gasoline engine so not really great solution if you want to wake up next AM. One last thought is the View is not natively a great winter rig. You can make some improvements but IMHO it is not four season. Last Spring we sat out a two foot dump of snow on our class A DP. The View would have frozen solid.



I'm a retired electrical engineer myself and I was not at all dazed and confused about the lithium install - just amazed that the things are being advertised as "drop-in". Sure you can but you will chop the life cycles down or kill them defeating the advantage at great cost. Stay conventional unless you have lots of spare cash and don't mind spending it.

[ElCampo]

Thanks,

The heat is definitely a concern. I never had A/C growing up, we never had it on the boat either, and just relied on high quality marine fans, but even those don't make it "cool", just tolerable until the sun goes down. Then again, that was in the Caribbean sun with limited ventilation. When we lived in Southern Spain for a summer, our apartment had no A/C, just a single box fan and man, those summers are hot! We've definitely found that shade plus a breeze is usually adequate for being comfortable. It'll be interesting to see just how much that will apply to the RV.

On drop in lithium, I'm somewhat skeptical about integrated battery management systems, but I am well aware of the charging criteria for lithium batteries. That being said, my intention is to completely isolate the coach 12v power from the 12v chassis power to eliminate some of the issues that would otherwise exist.

Point taken on the Trojan install - it's a consideration. I'm going to try and work with a few battery manufacturers and source compatible components and get a more accurate costing for a complete install.

Hopefully my research will help future lithium hopefulls

I'll try to keep everyone posted on what happens.

[al1florida]

Originally Posted by ElCampo

In regards to inverter/charger vs converter/charger would one be more appropriate for this install? The way I understand the factory system, there is an inverter that will power several 120v outlets in the coach and receives 12v power from the coach batteries. There is also a converter/charger which will convert shore power 120v to 12v for the native 12v equipment as well as to charge the coach batteries.

I will need to upgrade the inverter regardless.

Inverter/charger would allow either shore power or generator to charge the batteries, 12v coach needs would be supplied by the batteries (which may be charging at the time) and then I assume any 120v needs would be supplied by the inverter itself either through (external A/C source sensed?) the generator or shore power mains, or by batteries (no external A/C source sensed?)

Converter/charger would allow either shore power or generator to charge the batteries, 12v coach needs would be supplied by the converter portion while connected to either generator or A/C mains, 120v needs are supplied by the 120v distribution panel.

Correct?


If this is all true, then maybe the easiest solution might be to replace the current converter/charger with a quality inverter/charger, install the batteries under the bed (corner bed model where the converter/charger is installed at the foot of the bed) so the wire runs are short and battery is in a temp controlled environment. 12v would always be supplied by the batteries (regardless of whether or not they are charging), and 120v would be supplied by the inverter when no external source is present, and by mains (generator or shore) when an external source is present. Thoughts?

Without knowing precisely what inverter or converter came with your RV it is difficult give you really good advice.
I'll try to provide some info which hopefully will answer or confirm some of your questions & statements.

It would be highly unusual for WGO to install a converter(which is always a charger, although it may be very inefficient) AND an inverter with a charger.

Some RV's come with a small inverter which powers the entertainment system, but little else.

The mid price and higher Class A's usually have a 2000 watt inverter (almost always with a charger in the inverter, but no converter installed in the RV) that powers most all outlets and the microwave. These do sense 120V AC power either from gen or shore power. In this setup the inverter always provides 12V when 120V power is present, it also charges the battery. The one 120V power outlet usually not wired to the inverter is the 120V to the absorption fridge. If it has an ice maker that is usually wired to the inverter.

So you need to determine if you have an inverter which is wired to the AC power outlets. If not you will have to wire a new inverter to the AC power panel or provide a sub panel.

Here are some links to lots of great info about RV power, inverters, solar, etc. You probably know some, or lots, of the info, but it never hurts to read the info.
The 12volt Side of Life (Part 1)
The 12volt Side of Life Part 2
RV Electrical
This guy is very blunt, but has very good advice about solar and wiring for solar:
http://handybobsolar.wordpress.com/t...ging-puzzle-2/

[al1florida]

About Lithium Batteries.
In Jan 2016 I installed 400AH of lithium using four 100AH batteries bought from Starlight Solar: Elite Power Solutions li-ion battery packages
I also installed 650watts of solar.

I love the lithium batteries. However I don't consider them plug and play or drop in. I monitor the charge and discharge values fairly closely to be sure I don't over charger or over discharge. Yes I have an excellent BMS (Battery Monitor System) but that is just for extreme over charge, over discharge and temp extremes.

We use the system extensively, 10 months in 2016, 6 months in 2017, and so far 2 months in 2018.

Recommendations:
If you only occasionally dry camp for a few days then lead acid (including AGM) will serve you well.

If you dry camp/boondock for many days (weeks) w/o elect hookups, the lithium is wonderful.
About the drop in lithium batteries. Standard 3 stage chargers (inverter or converter) well exceed the recommended 14.2V max charge voltage. For me the jury is still out on these drop in batteries.

Whatever you do you want to install a battery monitor such as Trimetric: TriMetric Model Descriptions - Bogart Engineering Others make excellent monitors as well.

[ElCampo]

Originally Posted by al1florida

About Lithium Batteries.
In Jan 2016 I installed 400AH of lithium using four 100AH batteries bought from Starlight Solar: Elite Power Solutions li-ion battery packages
I also installed 650watts of solar.

I love the lithium batteries. However I don't consider them plug and play or drop in. I monitor the charge and discharge values fairly closely to be sure I don't over charger or over discharge. Yes I have an excellent BMS (Battery Monitor System) but that is just for extreme over charge, over discharge and temp extremes.

We use the system extensively, 10 months in 2016, 6 months in 2017, and so far 2 months in 2018.

Recommendations:
If you only occasionally dry camp for a few days then lead acid (including AGM) will serve you well.

If you dry camp/boondock for many days (weeks) w/o elect hookups, the lithium is wonderful.
About the drop in lithium batteries. Standard 3 stage chargers (inverter or converter) well exceed the recommended 14.2V max charge voltage. For me the jury is still out on these drop in batteries.

Whatever you do you want to install a battery monitor such as Trimetric: TriMetric Model Descriptions - Bogart Engineering Others make excellent monitors as well.

While I still have a few unanswered questions I think I can get the answers from the manufactures directly. Here is a rough outline of the system and install design:

300w (100x3) solar panels $300
Victron Bluesolar 30amp charge controller $200
Xantrex 2000w/55amp pure sine inverter/charger (customizable charge profile) $1,000
Victron BMS 712 battery monitor w/Bluetooth $200 (shunted system)
300aH lithium battery $3,000
Wiring, mounting hardware, fusing, misc $300

Mount solar panels for maximum heat dissipation / minimum shadowing
Oversize wiring to reduce internal resistance and voltage drop
Location of components TBD but likely build an enclosure under the bed
No charging input from alternator, however I may revisit that in the future
Remove (disconnect) installed converter/charger and inverter
Connect generator/shore power to inverter charger (it has an automatic transfer switch)

Price estimate $5,000

I'm going to chat with a few manufacturers and make sure all components will play nicely with one another. We've got a pretty good handle from prior experience on what our normal power requirements are. Obviously if AC is required we can always plug in. I believe the xantrex has a 30amp bypass built in which is the max rating on the shore power / genset anyhow.

[al1florida]

Originally Posted by ElCampo

While I still have a few unanswered questions I think I can get the answers from the manufactures directly. Here is a rough outline of the system and install design:

300w (100x3) solar panels $300
Victron Bluesolar 30amp charge controller $200
Xantrex 2000w/55amp pure sine inverter/charger (customizable charge profile) $1,000
Victron BMS 712 battery monitor w/Bluetooth $200 (shunted system)
300aH lithium battery $3,000
Wiring, mounting hardware, fusing, misc $300

Mount solar panels for maximum heat dissipation / minimum shadowing
Oversize wiring to reduce internal resistance and voltage drop
Location of components TBD but likely build an enclosure under the bed
No charging input from alternator, however I may revisit that in the future
Remove (disconnect) installed converter/charger and inverter
Connect generator/shore power to inverter charger (it has an automatic transfer switch)

Price estimate $5,000

I'm going to chat with a few manufacturers and make sure all components will play nicely with one another. We've got a pretty good handle from prior experience on what our normal power requirements are. Obviously if AC is required we can always plug in. I believe the xantrex has a 30amp bypass built in which is the max rating on the shore power / genset anyhow.

Excellent plan.

One suggestion, I would go with the Victron Multi Plus inverter instead of the Xantrex. For one thing it would keep all your devices in the same family. Yes the Victron is probably more expensive. However you are already going with premium products, so why not stay with it. I believe you will find the Victron to be more programmable than the Xantrex. Also the Victron can share power, that is if you are on a 15 amp 120V circuit, the Victron can take 15amps from shore power, the amps from the solar and the rest from battery if need be.

Here are a link to a great solar/lithium setup using Victron inverter: Running an RV AC off Solar, Batteries, and a Hybrid Boosting Inverter | Technomadia
Also here is a link to more solar & battery info from the same couple: Solar Electrical Systems for RVs | Technomadia
One thing about putting inverter and stuff under the bed, the cooling fan in the inverter may make more noise than you want when sleeping. Also be sure to provide a couple of 12V computer muffin fans for air circulation to keep the components cool. They generate quite a bit of heat when under significant loads.

[ElCampo]

Thanks for the tip, I'll check it out!

The reading material reminded me of a question I had...floating....around in my head about the float charge parameters.

If lithium longevity is increased by not routinely hitting 100% of charge capacity, why not set the charger to not float at all, or a set a float voltage lower than the nominal unloaded voltage of the cell? The cell would still bulk change to 99% or so but it wouldn't be forced to a constant 100%.

One thing that stuck out when reading that article was that without extensive testing, they would have never known their capacity had decreased over the years which tells me their battery bank might have been over sized to start with. I had read several articles about marine installations that talked about the pitfalls, with respect to lithium banks, of over sizing the bank and overall loss of longevity because of this. For this reason, it's recommended to build an expandable system (oversize wiring, controllers, etc). Also, a few general rules of thumb - 1aH capacity per watt solar, 10amp charge controller capacity for every 100w solar etc, can be observed to create a well balanced system.

The hybrid inverters look interesting, but that Victron is physically huge!! I'd definitely consider that on a larger rig, but I'm not sure I'll have the physical space! That being said, I'll take another hard look at the Victron inverters. Their battery monitor is very capable, but not overly user friendly.

One other question that someone may know the answer to -- is it possible to run a victron monitor system without the monitor? In other words, just use the shunt and Bluetooth dongle, not the round monitor portion? This is more curiosity than anything.

[al1florida]

Originally Posted by ElCampo

Thanks for the tip, I'll check it out!

The reading material reminded me of a question I had...floating....around in my head about the float charge parameters.

If lithium longevity is increased by not routinely hitting 100% of charge capacity, why not set the charger to not float at all, or a set a float voltage lower than the nominal unloaded voltage of the cell? The cell would still bulk change to 99% or so but it wouldn't be forced to a constant 100%.

One thing that stuck out when reading that article was that without extensive testing, they would have never known their capacity had decreased over the years which tells me their battery bank might have been over sized to start with. I had read several articles about marine installations that talked about the pitfalls, with respect to lithium banks, of over sizing the bank and overall loss of longevity because of this. For this reason, it's recommended to build an expandable system (oversize wiring, controllers, etc). Also, a few general rules of thumb - 1aH capacity per watt solar, 10amp charge controller capacity for every 100w solar etc, can be observed to create a well balanced system.

The hybrid inverters look interesting, but that Victron is physically huge!! I'd definitely consider that on a larger rig, but I'm not sure I'll have the physical space! That being said, I'll take another hard look at the Victron inverters. Their battery monitor is very capable, but not overly user friendly.

One other question that someone may know the answer to -- is it possible to run a victron monitor system without the monitor? In other words, just use the shunt and Bluetooth dongle, not the round monitor portion? This is more curiosity than anything.

You have done some very good research. Much more than most people do.



I agree with the numbers you have posted.

[moonie]

At one time I was very interested in going with Lithium batteries and a solar charging system. However, after boondocking for several months my mind has changed. My experienced advice is:

1. Stay with the two 12V batteries(Parallel wired)you have and just perform occasional maintenance on them. Very adequate and reliable power over the long haul.
2. 300 watts Mono Cris Solar panels will be very adequate. ~6amps each panel. Each 100 watt panel is warranted 25 years.
3. Wander 30Amp charge controller is simple and reliable. Expansion avail. if needed later.
4. Call :"Renogy" in Ontario Calif. Free tech advise and lower cost with all the completed kits free shipping. Great warranties and engineering advise.
5. 10 awg gauge wiring. Good up to 40 amps. So you can expand if needed.
6. Use propane for your refrigerator needs. Generator for Microwave, air conditioner, and or heatpump/furnace.
This list is about 1/3rd the cost of what you were looking for and just as reliable and very useable for long term boondocking. I'll be out for two months with this set up that worked flawlessly in the winter.
Moonie

[ElCampo]

Thanks Moonie (and everyone else),

I decided to pull the trigger and ordered all of my parts and equipment today for the lithium solar project.

Why lithium? I like solar, freedom, and have a lot of experience with lead acid battery banks and their problems. This will represent a new challenge and is something I've been interested in for a while.

Yes, it is expensive - I've given myself a $5,000 budget and it looks as though I should hit my mark. I'll do a full write up of parts and equipment used with prices should anyone be interested.

I took the time to speak with the representatives of all the various (major) component manufactures to make sure everything will be compatible and I'm excited to install everything!

I'll update when it's up and running.

[al1florida]

Looking forward to your update when the system is complete.