Lithium batteries

[BeemerJoe]

I sure would like someone to explain why the big excitement about lithium batteries for RV's.
1. I can find 12 vt lithium batteries with about 100ah. but the cost is about 500 to 800 Bucs. I need at least 450 amps for my toy hauler to keep my fridge running all night without generator. Do the math. close to 3000 dollars if go with the supposedly top of the line
2. I now have 4 Trojan 105's that comes out to 450AH. Total cost of these batteries are 400. locally
Now. The Lithiums are much light sure, and supposedly last a lot longer. My Trojan's have always lasted me over 5 years. I've had 3 sets in the last 25 years. It just doesn't make sense to me to spend that kind of money, and probably need a different charger, just to "SAY" you have the latest and greatest.
PLEASE someone explain to me why I should get a much more expensive lower AH battery. Am I Missing something here. Thanks.. just trying to understand

[Javi]

Yep... if you are a dedicated boondocker you are missing a lot.
But I'll let someone else fill you in...

More fun to watch than participate ��

[mikec557]

Originally Posted by BeemerJoe

I sure would like someone to explain why the big excitement about lithium batteries for RV's.
1. I can find 12 vt lithium batteries with about 100ah. but the cost is about 500 to 800 Bucs. I need at least 450 amps for my toy hauler to keep my fridge running all night without generator. Do the math. close to 3000 dollars if go with the supposedly top of the line
2. I now have 4 Trojan 105's that comes out to 450AH. Total cost of these batteries are 400. locally
Now. The Lithiums are much light sure, and supposedly last a lot longer. My Trojan's have always lasted me over 5 years. I've had 3 sets in the last 25 years. It just doesn't make sense to me to spend that kind of money, and probably need a different charger, just to "SAY" you have the latest and greatest.
PLEASE someone explain to me why I should get a much more expensive lower AH battery. Am I Missing something here. Thanks.. just trying to understand

I thought about explaining the errors in your thinking and math. But then I realized. You don't care, you've already made up your mind.

All that matters is that you enjoy your setup and camping experience. Seems you are, so I'm going to move along.

[firestation12]

Beemer, as I read your post, I had the same thoughts as the others that answered…..Why tell the guy whose happy with what his results, to spend money on a replacement battery system? My thought was, why did you spend tens of thousand dollars on your Toyhauler that often gets used for boondocking, then cheap on a battery/solar system that would far outperform your generator/T105 batteries most of the time. I have less than 2k invested in 600AH of lithium and 640 watts of solar. Except for a/c, the generator never gets used. You would need 5 sets of T105 batteries to equal a 600AH lithium system and have to run your generator 4 times as long to recharge the batteries to full status. That can’t be cheap.

[BeemerJoe]

Originally Posted by firestation12

Beemer, as I read your post, I had the same thoughts as the others that answered…..Why tell the guy whose happy with what his results, to spend money on a replacement battery system? My thought was, why did you spend tens of thousand dollars on your Toyhauler that often gets used for boondocking, then cheap on a battery/solar system that would far outperform your generator/T105 batteries most of the time. I have less than 2k invested in 600AH of lithium and 640 watts of solar. Except for a/c, the generator never gets used. You would need 5 sets of T105 batteries to equal a 600AH lithium system and have to run your generator 4 times as long to recharge the batteries to full status. That can’t be cheap.

I think you all misunderstood my question. I'm just trying to understand the benefits is all. I can't figure how you get 600ah out of lithium. I do realy like lithium technology and I don't have solar.. Just trying to figure out how they work. From what I see on 12 vt comparable size lithium is only 100ah, or are the numbers different on lithium

[snoobler]

Originally Posted by BeemerJoe

I sure would like someone to explain why the big excitement about lithium batteries for RV's.
1. I can find 12 vt lithium batteries with about 100ah. but the cost is about 500 to 800 Bucs. I need at least 450 amps for my toy hauler to keep my fridge running all night without generator. Do the math. close to 3000 dollars if go with the supposedly top of the line
2. I now have 4 Trojan 105's that comes out to 450AH. Total cost of these batteries are 400. locally
Now. The Lithiums are much light sure, and supposedly last a lot longer. My Trojan's have always lasted me over 5 years. I've had 3 sets in the last 25 years. It just doesn't make sense to me to spend that kind of money, and probably need a different charger, just to "SAY" you have the latest and greatest.
PLEASE someone explain to me why I should get a much more expensive lower AH battery. Am I Missing something here. Thanks.. just trying to understand

Primary advantages of Lithium Iron Phosphate (LiFePO4, LFP):

1. Weigh about 50% as much as lead acid.
2. Have much longer cycle life, typically 2000 minimum.
3. Have more usable capacity, 80-90% compared to lead acid (50%).
4. Completely maintenance free compared to flooded lead acid (FLA).
5. CHEAPER when you consider the $ for the total energy delivered over the longer cycle life.
6. FASTER charging. FLA/AGM/GEL are typically limited to 0.1-.02C where LFP can be charged at 0.5C - more efficient if charging with gen.

Disadvantages:

1. Can't be charged below freezing or they will be damaged.
2. Tend to be limited to 100A draw due to BMS restrictions.

Responding to your #1:

When you say 450A, I assume you mean 450Ah. 450Ah @ 12V = 5400Wh - that's about 24 hours of typical burn on ~7.6cuft absorption fridge running on AC in moderate weather. If you use lead-acid, you need 900Ah to avoid damaging the batteries.

The solution here is to run it on propane regardless of battery chemistry. The only time an absorption fridge makes sense on AC is on grid.

SOK and other brands make them in 200Ah+ at 12V, and they can be paralleled just like you do on your T-105.

2) I do not believe you when you say $400 total. The cheapest online price I can find is over $150. That puts total price closer to $650. Also important to remember that you only have 225Ah of USABLE capacity.

You can pick up 400Ah 12V for about $1600 with a 7000 cycle life.

400Ah (320 usable) for $1600 = $5/Ah
450Ah (225 usable) for $650 = $2.89/Ah

Lithium is 73% more expensive.

T-105 have a ~2000 cycle life discharged to 50% if you meticulously maintain them, keep them properly filled, check the SG on a schedule, and equalize when necessary.

T-105:
$650 gets 2000 cycles of 225Ah @ 12V, which equals 5,400kWh of energy.

That's $0.12/kWh

Lithium:
$1600 gets 7000 cyles of 320Ah @ 12.8V, which equals 28,672kWh of energy.

That's $0.056/kWh

The lifetime cost of LFP is less than half of your 4X T-105.

LFP comes out even better against AGM/GEL because AGM and GEL tend to have shorter cycle lives.

If you're just a weekend warrior whose batteries may only see a handful of cycles per year, then yeah... Bragging rights.

If you're cycling them daily as part of an off-grid setup, LFP beats the living crap out of lead acid.

[snoobler]

Also, to support my 50% rule, here is Trojan's thoughts:

https://www.trojanbattery.com/tech-support/faq/

2. Does my deep cycle battery develop a memory?
Lead acid batteries do not develop any type of memory. This means that you do not have to deep discharge or completely discharge a battery before recharging it. For optimum life and performance, we generally recommend a discharge of 20 to 50% of the batteries rated capacity even though the battery is capable of being cycled to 80%.

[firestation12]

OK, since Snoobler is an overachiever and has corrected our being curmudgeons, I shall repent and add a few words of encouragement to your quest for knowledge. Snoobler did a great job of providing the science of lithium. I’ll mention that lead acid batteries are SLOW to recharge compared to lithium. Internal resistance that builds during the charging process makes topping the charge to 100% lengthy. Vapors emitted contribute to corrosion and added water Maintenence.
You don’t state whether you have an absorption type refrigerator or a residential style refrigerator. If it IS an absorption type, then as Snoobler suggested, you are better off using propane to operate the refrigerator.
My focus will be to share some thoughts about the buil process and costs.
Cost seems to be an overriding consideration for you, and there is nothing wrong with that. For me as well, but a few other factors are worth looking at. Weight added to my pin box, which may lead to frame failure cracks on the exterior skin, is one of those worries. I removed the Onan 5500 generator and it’s 40# stand that the original owner had ordered. It was 3 months new with 10 hrs on it. It sold the same day posted for sale for $3k. Scratch 350+ lbs from the 5th wheel. Next went the 4 T105 batteries like you have. $200 bucks quick sale and the fiver lost another 300 lbs. Following Will Prose’s YouTube video series, I ordered 14 sets of 280ah Lithium batteries direct from China. I knew I wanted at least 2 sets and that several of my 6 sons would come begging for any I didn’t use. Each 280ah set was $420. 9 weeks later the awaited shipment was delivered and the fun began. Here in the Phoenix area, there is a solar warehouse that is unmatched for pricing of panels. 320 watt panels are $120 each, 400 watt panels are 175. Between myself , family and friends, we have purchase mor than 2 dozen. San Tan solar is first rate! The total of batteries, 2 solar panels, BMS, controller, shunt, Buss bars, cable, etc for a 560ah system came to just under $1,900. I did add a 3500 watt pure sine wave (Edecoa $350).
So, how does it all work, what would I add or do different? 560ah is the minimum to cover our mostly boondocking lifestyle. The microwave and T.V. circuits were wired into the inverter and the inverter has a remote switch to eliminate parasitic drain. Unless air conditioning is needed, this has been a great replacement to what came on the 5er when purchased. The weight savings on the pin box was lowered from in excess of 700 lbs, to less than 110 lbs. The solar panel weight is borne over the axles.
If you want to incorporate using a/c into your boondocking, a Victron Multiplus can be an interesting consideration. The multiplus can combine inputs from a generator, shore power, solar panels, and batteries and integrate them into a coordinated 120 volt 3,000 watt output. That output can be directed to the camper’s circuit breakers, thus energizing all the circuits or supplementing a 30 amp shore power source with solar power or converting battery voltage to 120 volts to meet additional loads the 30 amp shore power lacks. Using a combination of 1200 watts of batteries, 1600 watts of solar panels, a 2200 watt generator in conjunction with the Victron Multiplus, and a/c with soft starts… a no compromise boondocking experience can be had. 2 Victron mulitipluses in parallel are nothing short of amazing!
One last suggestion that can get you started with lithium, you can buy a Chin brand lithium battery from Amazon for just over $300. Not as cheap as the order cells from China, but the Chin battery received a good review from Will Prowse with a caution it doesn’t have a low temperature cut off sensor. To those who don’t operate in freezing climates, this is not a problem. And a work around can be made to fix this deficit given the low price. Best of luck to you.

[snoobler]

firestation, hey neighbor! Didn't see you were in Mesa (assuming it's not a different Mesa).

Not a curmudgen!?

I resent the fact that someone thinks I'm not a curmudgeon!

Nice real-world picture of what to expect.

You over on DIY Solar forum?

[firestation12]

This week the home is Quartzsite for a few days then it’s back to Mesa to get some neglected stuff fixed. Cheers!

[bbells]

You are absolutely right. There is no need for lithium unless you have a weight problem. I have helped hundreds of people put in small solar systems. They have used both lithium and lead acid batteries. Frankly, the users are finding no difference except for the cost. Yes, you can drain lithium down more. But, you don't need to withlead acid because you can afford more batteries. Many of the lead acid setups are 10 years old and going strong. I think litium users are comparing their batteries to marine batteries and not true deep cycle lead acid batteries.

[mikec557]

Originally Posted by bbells

You are absolutely right. There is no need for lithium unless you have a weight problem. I have helped hundreds of people put in small solar systems. They have used both lithium and lead acid batteries. Frankly, the users are finding no difference except for the cost. Yes, you can drain lithium down more. But, you don't need to withlead acid because you can afford more batteries. Many of the lead acid setups are 10 years old and going strong. I think litium users are comparing their batteries to marine batteries and not true deep cycle lead acid batteries.

No, we actually do know the difference between true deep cycle and marine (hybrid) batteries. And you're dreaming if you think lead acid batteries live 10 years and are "going strong".

As for the statement "there is no need for lithium", you're right. But for the exact same reason, there is no need for a lead acid battery. The entire question is "what alternatives will best meet what I want to do." For some campers the answer will be lead acid, for others it will be lithium.

For the sake of newbies trying to decide what to do, do more research.

[bbells]

Originally Posted by mikec557

No, we actually do know the difference between true deep cycle and marine (hybrid) batteries. And you're dreaming if you think lead acid batteries live 10 years and are "going strong".

As for the statement "there is no need for lithium", you're right. But for the exact same reason, there is no need for a lead acid battery. The entire question is "what alternatives will best meet what I want to do." For some campers the answer will be lead acid, for others it will be lithium.

For the sake of newbies trying to decide what to do, do more research.

Please reread my post. Your missing everything I said. With hundreds of solar installations the lead acid batteries have a great lifespan. There is no need to spring the cash for lithium unless you need to save weight. Lead acid leads in every study that shows lifespan vs cost and usefulness.

[mikec557]

Originally Posted by bbells

Please reread my post. Your missing everything I said. With hundreds of solar installations the lead acid batteries have a great lifespan. There is no need to spring the cash for lithium unless you need to save weight. Lead acid leads in every study that shows lifespan vs cost and usefulness.

Please reread my post. Your missing everything I said.

[xrated]

Having had two T105's for the last 5 years as my 12V power source in the camper, I've been pretty pleased with their performance, but I'm not a boondocker per se' and don't intend to be. So half of the 225AH comes down to about 112AH. I am switching over the LFP and the main reason is that I'm also switching my Norcold 2118 absorption/electric fridge over to the JC Refrigeration twin 12V compressor mod. That's right, two 12V compressors...one for the fresh food section and one for the freezer section. When it is running, I'll be looking at 11 amps or so. I know it won't run continuously while traveling, but I'm also not willing to run a battery down as far as it would (along with a few other 12V items) when travelling on long days on the road. So the switch to LFP seems that it will be a great move for me. 302 AH, almost all of which is usable. Between the battery which is around 52/53 lbs, the BMS and wiring, and the insulated/heated battery box I am building, no more than 75 to 80 lbs of "stuff". The two Trojan T 105's weigh in at 62 lbs each, so I will lighten the battery bay by 40 to 45 lbs, have about 2 1/2 times the available AHs and no worries about running out of batteries or adding another 125 lb of batteries to the front to gain another 112 AH's of battery life.........and still have more power than if I did.

[snoobler]

Originally Posted by bbells

Please reread my post. Your missing everything I said. With hundreds of solar installations the lead acid batteries have a great lifespan. There is no need to spring the cash for lithium unless you need to save weight. Lead acid leads in every study that shows lifespan vs cost and usefulness.

Please link one.

As I demonstrated above, when looking at the cycle life of LFP, it's notably cheaper than lead-acid.

[friz]

Originally Posted by BeemerJoe

I sure would like someone to explain why the big excitement about lithium batteries for RV's.
1. I can find 12 vt lithium batteries with about 100ah. but the cost is about 500 to 800 Bucs. I need at least 450 amps for my toy hauler to keep my fridge running all night without generator. Do the math. close to 3000 dollars if go with the supposedly top of the line
2. I now have 4 Trojan 105's that comes out to 450AH. Total cost of these batteries are 400. locally
Now. The Lithiums are much light sure, and supposedly last a lot longer. My Trojan's have always lasted me over 5 years. I've had 3 sets in the last 25 years. It just doesn't make sense to me to spend that kind of money, and probably need a different charger, just to "SAY" you have the latest and greatest.
PLEASE someone explain to me why I should get a much more expensive lower AH battery. Am I Missing something here. Thanks.. just trying to understand

No Joe, no explanation. You are right about everything. Stick with your FLAs. What are you missing? well let's start with everything. Have you been at the movies for the last decade? There are volumes on this subject. Google is your friend.

[friz]

Originally Posted by snoobler

Please link one.

As I demonstrated above, when looking at the cycle life of LFP, it's notably cheaper than lead-acid.

I am afraid you are very correct.

[JRTJH]

Let's see:

I'd guess that nearly half the people towing RV's don't know if they have a GP24 or GP27 battery in that box on the tongue. Most of them couldn't tell you if it was a "marine battery" or a "car battery" and I'd suspect that around 75% of people towing an RV couldn't explain the difference between a true deep cycle battery and a "marine AGM". Most would likely argue that a "maintenance free battery NEVER needs to have the acid level checked" and most would also argue that there are no vent caps on that type battery....

Why do I say this???? Because for most RV'ers, the type of battery is not that important as long as "whatever is in that box keeps working like it does"...

As for me, I bought 2 GC2 batteries in 2013 when we bought this trailer. I replaced them last year, not because they weren't still working well, but because it had been 7 years and Sam's had the same battery on sale for $69 each. I guessed that I'd need to replace them in a year or two, so why not take advantage of the sale? I didn't need them, what I had was serving the purpose and we regularly dry camp for a week at a time throughout the summer.

Whether it's an upgrade to switch to lithium batteries or not is irrelevant for how we camp. I simply don't need more "battery power" than I currently have, we always carry a generator so we can use the microwave and coffee maker, and even with lithium batteries, I'd still need the generator for those "must have appliances"...

My total investment in batteries for 8 years of camping has been $79x2 in 2013 and $69x2 last year. I'd suspect these will last as long as the originals.

So, my total investment in batteries since 2013 has been $296 and I'd suspect there won't be further investments since we'll likely not be camping beyond age 80. To have bought a lithium battery of comparable size in 2013 would have cost me at least 3 times more than what I've invested, for what I figure will be 14 or 15 years of camping with 2 sets of FLA GC2's. For me, the GC2's are a better choice for the way we camp and the way we use battery power.

For some people, the latest and greatest "must have technology" is not only not desireable, it's also not justifiable for the way they use their RV.

I'll say that for some, lithium is "their choice and serves them well". For other's FLA is "their choice and serves them well."

It's not "You're missing everything" in fact, for many, it's not "missing a damn thing"...

Why is it so important that everyone jump on the lithium band wagon or they're somehow "not realizing how great camping can be" ?????

[snoobler]

Originally Posted by snoobler

For Lithium, if you're just a weekend warrior whose batteries may only see a handful of cycles per year, then yeah... Bragging rights.

If you're cycling them daily as part of an off-grid setup, LFP beats the living crap out of lead acid.

Yep, tooting my own horn, but these two sentences pretty much sum it up.