Why so few LIFEPo4 batteries in RV?

[gemini5362]

Lets see. Extremely sensitive to overcharging and full discharging, Needs to be kept in a temp sensitive environment, Very Very expensive. I wonder why I have not rushed out and bought these batteries yet. Especially when i could spend the additional cost in solar cells and get more usage out of my conventional batteries.

[Tony Lee]

RV applications, especially class A and other large units, have plenty of storage volume and plenty of load capacity, so straight away most of the stated advantages of LiFePo4 aren't relevant.

Then there is the problem inherent in adding more battery capacity and that is very simply, how do you recharge a discharged large battery the next day.

Obviously an on-board generator and large charger will take care of that problem, but then the question becomes - why would you need huge battery capacity when you have a generator.

Obviously the equation changes if you are the sort of boondocker who wants to do it quietly, but now that solar panels are so cheap, it is more cost effective to just load every square inch of roof up with panels so even in adverse weather you will be able to get enough charge each day to maintain a reasonable lifestyle.

Actually some LiFePo4 aficionados are their own worst enemies when it comes to spreading the word. Right from the start they made two big mistakes - exaggerating just about everything positive - meaning stupidly high life-cycles, unobtainable depth of discharges, cost effectiveness values obtained by using impractical values AND to cap it off, they made it seem that you had to add a ton of sophisticated electronics plus expensive chargers to keep them from self destructing under normal use. Most of us want a battery to do its thing without having to arrange our life around the needs of a new-fangled battery and who could be bothered doing that for such a small gain and potentially a lot of extra expense.

[wa8yxm]

The answer to your question is multi-fold but the primary on i$ not

One pair GC-2, Purchased in bulk can be less than 200 dollars a pair.

The same amount if LIFEPo4 storag, easily 2,000 dollars or more

[Timon]

Originally Posted by gemini5362

Lets see. Extremely sensitive to overcharging and full discharging, Needs to be kept in a temp sensitive environment, Very Very expensive. I wonder why I have not rushed out and bought these batteries yet. Especially when i could spend the additional cost in solar cells and get more usage out of my conventional batteries.

Overcharging and over discharge can easily be handled with battery montering which most manufactures can supply. Tempeture range could be an issue in very hot or cold climates. As far as costs, well it's the way it is.

One thing you should remember, with lithium batteries you can get an 80% depth of discharge where on AGM is basically 50% so for 400 useable amp hours you only need a 500 AH vrs 800 AH. charge cycles is much higher on lithium so the cost over life span is still less.

I suspect in a few years Lithium will be more common in RVs.

[gemini5362]

Originally Posted by Timon

Overcharging and over discharge can easily be handled with battery montering which most manufactures can supply. Tempeture range could be an issue in very hot or cold climates. As far as costs, well it's the way it is.

One thing you should remember, with lithium batteries you can get an 80% depth of discharge where on AGM is basically 50% so for 400 useable amp hours you only need a 500 AH vrs 800 AH. charge cycles is much higher on lithium so the cost over life span is still less.

I suspect in a few years Lithium will be more common in RVs.

One of the things i was reading talked about having to have them in a compartment that had seperate heating and cooling. Depending on what you call hot or cold climate. If I drive to California again this summer will be really hot crossing the desert. Do I need to have a seperate air conditioning system for that. If I can get a higher discharge rate can i ever recoup the expense. I can get a autostart for my generator. When my batteries get to a certain point it starts and recharges them. At what point do I spend enough with the auto start option to offset the difference in cost of the Lithium. And How much can i spend on solar cells to offset the difference in the lithium.

I do not think they are cost efficient and too many other issues to make it worth while other than to just be able to say I have lithium batteries in my coach.

[ahicks]

Originally Posted by Timon

Overcharging and over discharge can easily be handled with battery montering which most manufactures can supply. Tempeture range could be an issue in very hot or cold climates. As far as costs, well it's the way it is.

One thing you should remember, with lithium batteries you can get an 80% depth of discharge where on AGM is basically 50% so for 400 useable amp hours you only need a 500 AH vrs 800 AH. charge cycles is much higher on lithium so the cost over life span is still less.

I suspect in a few years Lithium will be more common in RVs.

I'm interested in the equipment you say most manf's can supply. Links?

The lower "cost over lifespan", does it include the cost of the charging/monitoring equipment?

[Smitty77]

I keep up on the Technomadia Lithium experience, and a few others including boaters. For sure the technology will work well, and yes, is still on the pricey side.

For now, I find the balance of cost vs output vs ease of use gave AGM the nod for us. (X's 4 L16 Lifelines, for 800AH. 1200W of 48V Solar Panel via MidNite Classic 150.) I figure this will give me 7-10 years to let things sort out in the evolving Lithium usage for RV's/Boat's!

For anyone on the fence, unless you have one of the mentioned reasons, for example limited space or weight concerns, I would hold off a few more years on going with Lithium. Even going as far as buying a bit less expensive battery to bridge for a few years. My thinking is when the Tesla Giga Factory kicks into production, we may see some trickle down of battery products to RV usage. Already Musk's Tesla gangs are doing some impressive improvements on recharging of lithium banks. When you toss in the Solar City connection, and my understanding that they too should benefit for house related lithium products from the Tesla Giga Lithium factory. You can see lots of moving pieces and systems changes/improvement in regards to lithium usage.

Two-three years from now, I really do expect to see some lower costs opportunities to repurpose house or auto batteries to RV usage.

If you can't wait, and go with a lower costs bridge battery today. Do be sure to try and future proof supporting infrastructure as much as possible. Right size cabling. Right size solar controllers, and be sure they have custom programing options. This should hopefully allow repurposing of some of these supporting items if a future shift to lithium banks.

Exciting times not just for RV/Boating Solar Power/Battery applications, but for housing, industrial, and auto applications too.

Best to all,
Smitty

[CountryFit]

Originally Posted by Technomadia

There actually are some companies in the US offering LFP battery installations and pre-built kits.

We recently published a 3.5 year in review of our LFP setup (you linked to our cost analysis done when we first installed the system):

Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update | Technomadia

The article gives an update to the industry and companies we know of who are providing products and services. We also speculated on why our system isn't living completely up to the theoretical advantages.

With the higher cost of acquisition, and the battery technology not being fully proven in an RV house system application over the long term - it's no wonder it's not yet mainstream.

- Cherie

thank you cherie for sharing your experience. i first time read your writing 2 years ago just now finished reading your updated version. a lot of great info in your post, really enlightening . have been digging on this for a while, i might jump on the wagon this year or next (bought a bms already - balancing board for each cell up to 20; overcharge and overdischarge cutoffs. the only thing missing is the cells).

[CountryFit]

has anyone used this chinese calb 400ah?

12V Pack Made of 4 Each 400AH 3 2V Lithium LiFePO4 Calb Batteries USA Stock | eBay

[Shangri-La]

I wonder how Tesla's recent announcement of their new Powerwall battery for homes might be impact Lithium in RVs in the next year or so? This might bring the price down enough to jump start it in RVs, depending upon the eventual technical configuration. Still, it would probably take a toy hauler to store the battery appropriately. I think we're getting close though....

[Imurphy907]

The tesla battery is 7.5kwh at 350-450 Volts. It could be used as a stand alone inverter system. With solar panels and dedicated charger, feeding an inverter. Unless this 400 volts was reduced to 12v you could not use it as a standard house battery. There is currently a lack of "off grid" high voltage input inverters. It would be easier to disect the pack into lower voltage segments then go thru all that work.

[Tony Lee]

Originally Posted by Imurphy907

The tesla battery is 7.5kwh at 350-450 Volts. It could be used as a stand alone inverter system. With solar panels and dedicated charger, feeding an inverter. Unless this 400 volts was reduced to 12v you could not use it as a standard house battery. There is currently a lack of "off grid" high voltage input inverters. It would be easier to disect the pack into lower voltage segments then go thru all that work.

The battery pack feeds the inverter and that feeds a normal 13.5V converter that feeds the coach 12v system.

Or just use all mains lighting and other items in the coach.

5 years off yet - or 10.

[marcham]

$3000, 7kWh and 220 lbs, it would be a great addition to any RV, if money was no object. As a comparison a pair of Golf cart batteries are normally used for about 1.2kWh (50% discharge) and weight 120lbs.


The weight and energy density are impressive. However the cost per kWh is still quite high, compared to even running a generator with a normal flooded battery. However if you had a lot of solar capacity, once could make a case for it. It would be nice if they came out with an RV version with say 3-4 kWh and a built in inverter, charger, solar controller and external power source switch.

8 100w solar panels would be able replenish about 3-5 kWh depending on conditions.

[Imurphy907]

I'd buy that pack in a heartbeat once more tech specs come out. As with most tesla products the information is very lacking.