Solar and Lithium battery Questions

[WhereItsAt]

This is perfect! 24V is definitely more efficient. Thank you for taking the time to respond. Be safe and well.

[cookinwitdiesel]

This is perfect! 24V is definitely more efficient. Thank you for taking the time to respond. Be safe and well.

There are some great FB groups with good active discussions about these sort so systems and components. I learned a ton there myself.

[BeerBrewer]

This is perfect! 24V is definitely more efficient. Thank you for taking the time to respond. Be safe and well.

I concur with WhereItsAt! Those diagrams are excellent, they explain so much. Thanks for taking the time to put that together!

Thanks!

Bob

[cookinwitdiesel]

I concur with WhereItsAt! Those diagrams are excellent, they explain so much. Thanks for taking the time to put that together!

Thanks!

Bob

Well, I selfishly did it for my own system, but glad to share with anyone who can benefit!

[Flyhighone]

We have a 2019 2400BH. Phase I of our solar install has been working so well that I have been slow on ordering the second lithium battery and 4th solar panel.

Current setup:
• 3 100-watt Renogy flexible solar panels
• Renogy 100 Watt Lithium Iron Phosphate Battery
• Renogy Rover 40 Amp MPPT Charge Controller
• Renogy 2000W Pure Sine Inverter (Wired through all of the coaches AC outlets)
• Renogy Bluetooth Module
• Progressive Dynamics re: PD4655LIV Charger (Needed this to provide the correct voltages for the Lithium battery)

The only thing that we have to remember to do when running AC via the inverter, is to flip the breaker switch on the charger/converter!! Aside from that, we have been thrilled with how it's all been working. We can even run the central A/C in fan mode for about 30-min, although I don't recommend this, it was just for testing purposes.

Good luck!

[KenBeccard]

I'm in planning stages to do some power and electrical upgrades to our trailer. I'd like to add more battery capacity, most likely with Lithium batteries and I'd like to add solar panels. Our power needs are not that great and I'm fairly certain that 200 amp-hours of battery power would more than cover our needs.

If we go with Lithium batteries is it true that it would be best to replace the factory Power Converter that is in my trailer with one suitable for Lithium batteries?

Since I'm also thinking about adding solar power I know that I'll need to install a Solar charge controller as well. I was wondering if someone makes a solar charger controller that also acts a Power Converter?

Would 400 watts of solar panels be enough to charge back the batteries?

Where can I find a logical schematic diagram for my trailer, does Grand Design provide them? I've seen other general Travel Trailer schematics, but it would be nice to one that is specific to my trailer, with part numbers and the actual wire colors use. It would be ever nicer to know how and where the wires are run in the trailer, but I already know that I can't have that.

Thanks

Bob

I installed a 400W solar system on the roof of my Reflection 320MKS 2 months ago. I use 2 Battleborn batteries for a total of 200AH of storage. We installed a 2000W inverter for AC power and hooked it up to a transfer switch along with the shore power cord. I bought a starter kit for my RV from Renogy for the solar side and I also bought the inverter from Renogy. The batteries, transfer switch, etc. came from Amazon.

So far, we're basically happy and we're getting plenty of power to run our TV and other miscellaneous appliances. We can even use our microwave sparingly. We did find that the system isn't adequate to run our refrigeration, however. The panels would keep up in the daylight hours but our batteries ran out of power in the night. If you want to run your refrigeration, you'll need more of both batteries and panels for that. We're in Arizona during the summertime when I make these comments. I have no experience with wintertime or lower sunlight locations so you can take this with a grain of salt if you live/travel elsewhere.

As to the converter, I've considered replacing it but haven't done that yet. The converter is really only important for recharging the batteries on shore power. Since we've been living on solar for more than a month now, the converter isn't part of the equation so I don't view that as an important upgrade. I'm sure a lithium specific converter is better but like I said, I'm not even using a converter on a day to day basis at the moment. It hasn't been powered up for some time now as the only way to do that is to hook up to shore power (you need to wire it that way, BTW).

One other lesson learned it that the cabling provided by Renogy to go from the roof to the basement is adequate but doesn't leave me room to expand the solar panels. If I were to do it over, I'd buy bigger cables to save a later rewire if you want to add panels and batteries. The same is true of the charge controller. The 30A controller leaves no room for expansion and would need to be replaced to upgrade. It might be better to buy bigger in these two items at the start than to have to buy new ones and rerun wiring later.

[SolarPoweredRV]

If you can't tell I have zero experience with solar, but I do have a lot experience engineering AC and DC power systems (I was in Telecommunications). I took a quick look a the AM Solar web page, your correct its got a ton of info in there. I also found this web page https://www.mobile-solarpower.com/ which also seem like a interesting source of info.

I am doing as you suggested, first I'm going to start with lithium batteries, battery monitor and new converter. If all goes well I'll introduce solar into the mix.

Everyone thanks for the info!!

This is a really good plan. Live with your new batteries a while before you add Solar, you may find out that you don't need Solar, you may find that adding an extra battery is all you need.

If you do add Solar, I would recommend you look at having more than 400 Watts of Solar on your roof because 400 Watts is not going to give you much energy in Northern Latitudes or Winter.

Look at house sized Solar panels, they are higher wattage, higher quality and they cost less per watt than the 100 Watt panels. I have 4 Canadian Solar 305 Watt panels on my roof as an example, they only cost $0.69 cents per Watt.

You should be able to fit at least two panels on your roof at 300+ watts each for the same price of your four 100 watt panels.

[skier8674]

If you can't tell I have zero experience with solar, but I do have a lot experience engineering AC and DC power systems (I was in Telecommunications). I took a quick look a the AM Solar web page, your correct its got a ton of info in there. I also found this web page https://www.mobile-solarpower.com/ which also seem like a interesting source of info.

I am doing as you suggested, first I'm going to start with lithium batteries, battery monitor and new converter. If all goes well I'll introduce solar into the mix.

Everyone thanks for the info!!

I agree with the other experienced off-grid setup folks who responded. I have 1625W of solar, 600Ah battery bank and tons of equipment (sorry, being brief on system). Great feedback and I concur that you should start with your 200Ah of BB's along with your basic inverter and upgrade your converter for lithium. Use it for a while and learn what works and doesn't for you before taking next steps (more batteries, adding solar, inverter/charges, and so on). It will save you money in the long run doing things in phases... better to know what you are doing before just throwing the wallet at it.

I specifically wanted to follow-up on the comments related to voltage of LiFePO4 batteries while in storage and DOD (depth of discharge).

Relion also states the LiFePO4 batteries like to be at 50% SOC (state of charge) while in storage for extended periods of time. Since I have ample solar and only use my fiver every. 10-14 days for 3-5 days at a time I run an AC appliance for an hour or two before closing down to bring my battery down to roughly 50% since I know I will charge it right back up when prepping for our next trip or I flip on our solar (2-3hrs of charging).

DOD (depth of discharge) - It is true you can safely run a LiFePO4 battery down to 80, 90 and even close to 100% of DOD without damage to the battery. However, if you routinely do deep DOD's you do cut the lifespan of the battery fairly drastically. I believe BB and most brands advertise around 3000-5000 cycles. This is using an average DOD rate of around 70-80%. However, if you are kind and gentle to your batteries (ie: 50% DOD) they will reward you with much longer life as seen in the charge below. Now... there is of course a point of when you have to ask yourself will you ever be able to cycle your battery 7000+ times before some other life event happens and you no longer want or need the batteries. Which means a DOD of 70-80% is probably more realistic and at the same time gives you more performance NOW when we all want it!



Giving credit to Relion Batteries who created this information. https://relionbattery.com/products/lithium/rb200. (scroll to bottom of this page to see graphs - you can visit the RB100 page which is a very close setup to the BB 100Ah batteries).

The other thing I will mention is the charge rate you choose for your battery bank. LiFePO4 batteries can take much higher charge rates than other chemistries. If I am correct one BB can charge continuously at a 100A rate safely. However, as noted in the chart above they are using a 0.5C rate which means charging the battery at only 50A. For this purpose I actually have my convertor set to charge at 50A instead of the 100A to help extend the life of the battery/bank. Though, when I know I am going to be off-grid and need a fast charge I will change my settings to 100A charge rate if for some reason I need to run the generator for a quicker charge and shorter run time of the generator (hopefully with solar now I only see a few days pulling out the generators going forward).

[Indy Tim]

I installed a 400W solar system on the roof of my Reflection 320MKS 2 months ago. I use 2 Battleborn batteries for a total of 200AH of storage. We installed a 2000W inverter for AC power and hooked it up to a transfer switch along with the shore power cord. I bought a starter kit for my RV from Renogy for the solar side and I also bought the inverter from Renogy. The batteries, transfer switch, etc. came from Amazon.

So far, we're basically happy and we're getting plenty of power to run our TV and other miscellaneous appliances. We can even use our microwave sparingly. We did find that the system isn't adequate to run our refrigeration, however. The panels would keep up in the daylight hours but our batteries ran out of power in the night. If you want to run your refrigeration, you'll need more of both batteries and panels for that. We're in Arizona during the summertime when I make these comments. I have no experience with wintertime or lower sunlight locations so you can take this with a grain of salt if you live/travel elsewhere.

As to the converter, I've considered replacing it but haven't done that yet. The converter is really only important for recharging the batteries on shore power. Since we've been living on solar for more than a month now, the converter isn't part of the equation so I don't view that as an important upgrade. I'm sure a lithium specific converter is better but like I said, I'm not even using a converter on a day to day basis at the moment. It hasn't been powered up for some time now as the only way to do that is to hook up to shore power (you need to wire it that way, BTW).

One other lesson learned it that the cabling provided by Renogy to go from the roof to the basement is adequate but doesn't leave me room to expand the solar panels. If I were to do it over, I'd buy bigger cables to save a later rewire if you want to add panels and batteries. The same is true of the charge controller. The 30A controller leaves no room for expansion and would need to be replaced to upgrade. It might be better to buy bigger in these two items at the start than to have to buy new ones and rerun wiring later.

I also have a 320MKS and am looking at adding solar and some Battleborn batteries. How well did the manufacturers roof access port work for you and where does it come out in your basement? Where did you locate your batteries and inverter? Thanks.

Tim

[DaveMatthewsBand]

...
The other thing I will mention is the charge rate you choose for your battery bank. LiFePO4 batteries can take much higher charge rates than other chemistries. If I am correct one BB can charge continuously at a 100A rate safely. However, as noted in the chart above they are using a 0.5C rate which means charging the battery at only 50A. For this purpose I actually have my convertor set to charge at 50A instead of the 100A to help extend the life of the battery/bank. Though, when I know I am going to be off-grid and need a fast charge I will change my settings to 100A charge rate if for some reason I need to run the generator for...

Battle Born 100ah lithium recommended charge rate is 50a.

I doubt you could put 100a into your batteries unless you only have a single battery.

Because a battery charger’s output is divided equally across each battery so let’s say your charger puts out 100a and you have 4 batteries you’ll only be putting 25a into each one.

The charger in my Magnum Hybrid inverter puts out a measured 127a but I have 4 Battle Born lithiums so each battery gets a maximum of 31.75 amps.


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