Lithiums in winter

[Mfturner]

I have always had at least 15a service available where I store, so as long as that's enough to run some heating pads while in storage, and as long as it is automated, then I don't see a problem with my next RV having lithium batteries. In my next unit, I'd like to be able to run AC a couple of hours a day, eliminate propane, and use greater than 700w appliances, so lithium is in my future. Having said that, 200 ah of FLA (with some solar and propane) works surprisingly well so long as I don't use the AC or microwave and stick with 700w appliances like the 3qt instant pot (I drive a little pretty much each day). I gave up totally on AC in our unit due to noise until I went to ARV fest ... Wow that's quiet, and would let me visit family in the SE year round.

This is a great conversation, thanks.

[Davydd]

In my previous home I installed a 30a service outlet for my vans. So when I moved I negotiated to install a 30a service in my condo garage. As it turns out I don't use it as I didn't think it through that I would not be running the air conditioner in the garage. Oh well, it was tossed in with no extra cost to me. The 15a outlet is satisfactory for inside storage. Same with a garage ceiling fan. I got that installed but it turns out I don't think I would have to use it when the garage temperature seems to stay at least 20 degrees colder than the outside temperature.

[avanti]

Originally Posted by Mfturner

In my next unit, I'd like to be able to run AC a couple of hours a day, eliminate propane, and use greater than 700w appliances, so lithium is in my future.

I can routinely run my run-of-the mill rooftop A/C from my 440Ah AGM for two hours without going below 50% SOC (and I am not afraid of going a bit lower if I have to). So, measured in usable Ah, the rough threshold for "really need Li" is "about 250". Measured in hours of A/C, the number is "about 2".

Of course, 2 hours leaves me pretty empty, so this is more a "middle of the day after a sweaty hike" thing than a "evening in camp" thing.

[Phoebe3]

Originally Posted by avanti

I can routinely run my run-of-the mill rooftop A/C from my 440Ah AGM for two hours without going below 50% SOC...

Very helpful. Thank you.

[GeorgeRa]

Not inline with OP first post but I found it interesting. The World’s hunger for good battery results with worldwide efforts to develop a killer battery. Recent discovery of graphene material (2004/Nobel 2010) is well recognized as potentially best material for electrodes.

This is good summary for current efforts. Graphenano company developed a battery claiming 1kWh/kg hopefully it is not snake oil salesmanship.

There is even a possibility for double functionalities of cassette toilets with Bill Gates’ help, but it could impose beer consumption limits (see half way down the article).
https://www.pocket-lint.com/gadgets/...r-over-the-air

All technologies go through their S-curves, certainly AGM is heading towards the end if its lifecycle, but I will wait for the one after Lithium. Technologies change fast, Kodak with its film factories is gone, consumer cameras killed by smart phones with Instagram and Snapchat apps.

[Frankshay]

I have lithium batteries in several vehicles (EV's) one of which is used exclusively for racing. I've never worried about storage temperature, in fact, Dr. Jeff Dahn at Dalhousie Univ. says to store 'em in a freezer as it will extend their life.

There are of course different flavors of lithium: I'm assuming most commercial available for this type of application are Lithium Iron Phosphate. My race cells are LiPo (lithium cobalt oxide) which have excellent power density. I'm going on my 5th race season and they're still going strong. I'm pretty anal about charge/discharge parameters and can afford to be in this application as it's not everyday usage.

For all the advantages of lithium, if you can make AGM's work I would probably recommend sticking with them. It's not like saving 100# is going to make a huge difference on a RV.

[Reed]

The weight savings on our Roadtrek is about 100 to 150# and perhaps 300# on our fifth wheel. This is consequential

Avanti - we can run air in Roadtrek for about an hour as combination of solar and LFP and keep above 60% SOC. We can do four hours in fifth wheel but generally only run 15 minutes several times a day and one final at nightfall

Reef and Elaine