Adding inverter, faster charge, solar, LiFePO4 battery

[K6NCX]

I have a 2016 Thor ACE 30.1. (As I've been typing this I realize that I'm dealing with pretty much the same set of issues with a communications vehicle I oversee for my county's Office of Emergency Services.)

For a whole lot of reasons I want AC power (clean sine wave) available boondocking without running generator, much greater stored power in batteries, and the ability to charge those batteries more rapidly (with generator or shore power.

I do not intend to run air conditioner on inverter, but I do want to be able to run microwave or hair dryer as well as TVs and etc.

I know there are charger/inverter units which also handle the transfer of AC load to generator or shore power to inverter and back, and charge batteries at a higher rate. But I don't know if any of them will properly charge LiFePO4 batteries. Nor do I know if any of them will also manage charging from solar panels. Recommendations? Ideally I'd like to manage everything in one place, but two units would be better than three or four, or more!

And I'm not sure what to do about the chassis battery, which I would probably not replace with LiFePO4 battery. Since the updated house system would not optimally charge the chassis battery (and vice versa, the F53 chassis electrical system would not optimally charge the house battery,) I've thinking maybe I should just make them independent.

[twinboat]

Check out Victron Energy. I've heard that they have moved toward lithium charging solutions.

Some of their isolation relays can also control the different voltages between the chassis and house battery charging.

[ajohansson]

Your concerns are exactly why I am staying with lead acid. Unfortunately the industry has not got lipo dialed in yet. A major killer of lipo technology is heat and in the RV your chasing your tail if your having to cool your batteries to extend their life cycle. I use lipo in my kids RC cars and man I do believe in the technology but not yet in the RV application. It will come but until I can have a balancing charger for it I just dont see the advantage yet.

[CountryFit]

i have been using lfp for 2 years and solar even longer.

there are a few inverters allowing full configurations for lithium. magnum is one, victron is another, there might be more. it charges lithium from shore power and/or generator. the only thing it does not do, is charging from alternator. you can look up sterling power products for that.

from solar panels to lithium is a different story. it does not go through inverter, but a charge controller. a few good ones can be configured for lithium, such as midnite solar, outback, etc.

google some nice writeups by technomadia, wheelingit, gone with wynns. they all had some coverage on lithium and solar in their blogs. for rv solar basic, search handybob's.

as for chassis battery, you can leave it on lead acid if you prefer. it gets charged by two sources - alternator and house battery (dc to dc charger). if you want to use lithium for chassis battery you can do it but you'd better have a sterling power charger.

good luck and have fun.

[ajohansson]

Originally Posted by CountryFit

google some nice writeups by technomadia, wheelingit, gone with wynns. they all had some coverage on lithium and solar in their blogs.

For me it was technomadia long term write up that sort of steered me away for now believe me I wanted to do it bad with a new trailer coming.

VICTRON has bitchen stuff I wish they would get stuff a little more compact on their easy solar config which is their built in MPPT CC/Inverter and Charge in one package. The 12 volt one is 29" tall. I know that one day this will be here in the near future with an all in one and done package. Would love to see the surge protector built in it too. one device that does it all. Hopefully the price on batteries falls as well

[jim93546]

Originally Posted by CountryFit

i have been using lfp for 2 years and solar even longer.

there are a few inverters allowing full configurations for lithium. magnum is one, victron is another, there might be more. it charges lithium from shore power and/or generator. the only thing it does not do, is charging from alternator. you can look up sterling power products for that.

from solar panels to lithium is a different story. it does not go through inverter, but a charge controller. a few good ones can be configured for lithium, such as midnite solar, outback, etc.

CountryFit, looks like you have a setup similar to what I've been thinking of. If you were starting from scratch, what would you go with today for batteries, inverter/charger, solar controller?

My 99 CC Magna has the original Freedom 25 and some lead acid batteries. Would like to step it up to lithium and 1000 watts of solar. Been looking at the Calb batteries.

Thanks!

Jim

[CountryFit]

Originally Posted by jim93546

CountryFit, looks like you have a setup similar to what I've been thinking of. If you were starting from scratch, what would you go with today for batteries, inverter/charger, solar controller?

My 99 CC Magna has the original Freedom 25 and some lead acid batteries. Would like to step it up to lithium and 1000 watts of solar. Been looking at the Calb batteries.

Thanks!

Jim

welcome onboard!
if i were doing it today, as you asked, i would probably be doing the same thing or with a very minor adjustment. my system was set up to cater more than rv applications, so read this with a grain of salt.

1) batteries: i have two groups of lithium batteries for coach - calb 700ah and winston 600ah. both are good. i slightly like calb better, as it is the largest li manufacturer in china. it caught my attention when i noticed they sold a lot cells to ev users. after two years, my batt capacity has not decreased yet. other brands are good too, just cost more.

for pure rv application, 500-600ah li would be enough.

2) inverter/charger: i used to have an interface freedom 20d inverter. i replaced it with a magnum ms2812 inverter. it has been working flawlessly. i have never used victron, so no comparisons between the two. ms2812 and msh3012 both are good, but latter allows 2x50a ac to pass throuh while the former only allows 2x30a pass through.

at the time i did the swap, i picked up a used ms2812 for about 60% of the would be cost of a new unit. it was a bargain, otherwise i would go with a msh3012.

for most people on rv, ms2012 is probably a good choice (notice NOT me2012, a model with modified wave sine). it has a built-in output breaker/load protection on each leg. 2812 and 3012 do not have the load breakers, i had to install a sub-panel for that.

3) solar charger: i am using midnite classic 150. it can output up to 96a.

4) solar panels: since I targeted for ev charging (14 c-max energi toad), i maxed out the roof space with 2160w panels. from april to october, at 10am i plug my car to an outlet in a storage bin; at 3pm, the car is ready for 28 miles.

for pure rv usage, i normally consume less than 200ah a day, that includes a residential fridge.

these are just for your reference. good luck with your project and happy trails!

[Jammin H]

We will start an RV build soon. I thought I had the batteries, inverters, solar. I thought LifePO4 was the way to go but I received an email from Volta explaining their lithium ion (tesla) battery set up was the safest and best. We do want to boondocks, run air if needed and keep fridge running. So is lithium ion or lithium ion phosphate the way to go?

[CountryFit]

Originally Posted by Jammin H

We will start an RV build soon. I thought I had the batteries, inverters, solar. I thought LifePO4 was the way to go but I received an email from Volta explaining their lithium ion (tesla) battery set up was the safest and best. We do want to boondocks, run air if needed and keep fridge running. So is lithium ion or lithium ion phosphate the way to go?

I think you are asking "so is lithium ion or lithium iron phosphate..." (you mis-spelled iron?).

According to some tech papers on websites, lifepo4 is the safest. here one wrote:

Lithium Iron Phosphate (LiFePO4)

Phosphate based technology possesses superior thermal and chemical stability which provides better safety characteristics than those of Lithium-ion technology made with other cathode materials. Lithium phosphate cells are incombustible in the event of mishandling during charge or discharge, they are more stable under overcharge or short circuit conditions and they can withstand high temperatures without decomposing. When abuse does occur, the phosphate based cathode material will not burn and is not prone to thermal runaway. Phosphate chemistry also offers a longer cycle life. source.

recommend a writeup: Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update | Technomadia.