Lithium batteries, are they really that expensive?

[TitanMike]

After reading numerous posts where people have said "Lithiums are too darn expensive" I got to thinking, are they really? Especially when ALL factors are taken into consideration.

Yes, the initial price is more but are people comparing "apples for apples"?

First let's look at a single 100 Ah installation.

One 100 Ah LiFePo battery can be purchased for ~$800. It can provide almost the full 100 ah and recharged without loosing significant capacity. Rated for 3,000-5,000 cycles.

In order to provide the same usable power (following the 50% rule, one needs to purchase two lead acid batteries, either two 100 amp deep cycle batteries wired in parallel or two 6V golf cart batteries wired in series. 12 volt lead acid deep cycle batteries can run from $120-to $200 +. Golf Cart batteries are from under $100 each to over $200, depending on quality and capacity. An equivalent battery bank in lead acid type batteries (100 ah "usable" power) will run from $200 to over $400, depending on choices.

Next is the number of cycles available from Lead Acid batteries. Regardless of anecdotal "evidence", lead acid batteries are hard pressed to provide much more than 500-550 cycles unless only operated with shallow DOD's of 10-20%.

How long can one expect a Lead Acid battery to last?

Here's what one source says:

These are some typical (minimum-maximum) expectations for batteries if used in deep cycle service. There are so many variables, such as depth of discharge, maintenance, temperature, how often and how deep cycled, etc. that it is almost impossible to give a fixed number.

Starting: 3-12 months
Marine: 1-6 years
Golf cart: 2-7 years
AGM deep cycle: 4-8 years
Gelled deep cycle: 2-5 years
Deep cycle (L-16 type etc): 4-8 years

(not shown are larger fork lift, industrial sizes)

So assuming one follows the 50% rule religiously, over a ten year period of time they COULD be facing battery replacement from 1.25 times to as often as 5 times, depending on use.

Considering that a single 100 ah LiFePo battery has only used up 1/6th of it's estimated (minimum) life by that time (assuming 500+ cycles), on this basis alone the LiFePo is really less expensive.

Another misconception is that one HAS to purchase a special Lithium compatible converter/charger. In reality a battery like the Battleborn can just be "dropped in". Yes, it will only charge to around 95% capacity but in most installations that last 5% won't even be missed. For those that want to make sure it's topped off a less expensive charger like a CTEK or NOCO lithium compatible "maintainer" can be purchased for $50-$75. Connect to battery when attached to shore power and battery will not only be topped off but internal BMS will see to it that cells are balanced.

If your RV is equipped with a newer converter that has an adjustable voltage output, merely adjust for proper voltage to charge LiFePo batteries (usually 14.4-14.6V. If you have a Progressive Dynamic's 9100 series Converter you can merely purchase a module that fixes the output voltage at whatever the module is set for (you pick the voltage you want) and it costs less than a $20 bill.

If you have a Progressive Dynamic's Converter with "Charge Wizard" merely push the button on the pendant to force the converter into Bulk Mode and voltage will rise to more than enough to top off the LiFePo battery.

In summary, one LiFePo battery will do the duty of two lead acid batteries weighing twice as much. Twice the available power at half the weight.

One LiFePo battery will outlast as many as 5 (or more) Lead Acid "Deep Cycle" batteries in just a 10 year period. I don't know how long most keep their RV's but I kept my last TT for 22 years before selling and buying a new unit that fit my needs better.

LiFePo batteries can be installed ANYWHERE in an RV, even the most remote, inaccessible space, with no need for water, terminal cleaning, etc. ("indoor installation" overcomes the issue of charging in freezing temps. As babcock said once in a post "If I'm not freezing, they aren't freezing")

Regardless of the battery type one chooses they will always have to have a charging system. Solar and perhaps generator for boondocking/dry camping. For this reason I left out the costs of those systems as they really don't fit in an analysis of LiFePo vs Lead/Acid. I will say that a LiFePo battery will charge completely in a fraction of the time of a lead acid battery with recommended absorbtion charge times recommended being 30 minutes per 100 Ah in capacity. Now compare that with the hours and hours required for Lead Acid. Able to take advantage of limited solar power time or far less generator run time.

In the end just looking at the immediate cost of LiFePo batteries is short sighted. As the saying goes "it's not how much you pay, it's how often you pay it".

Here's link to an article answering the "How long will a battery last" questions.

https://www.solar-electric.com/learn...es%20vs%20Life

I don't sell LiFePo batteries and don't particularly care what choice others make when selecting batteries. I just thought I'd try and put out some information regarding how one should look at the cost to benefit the newcomers that may be convinced that LiFePo's "are too darned expensive" without looking beyond the initial cost.

[The Evil Twin]

For those that want to make sure it's topped off a less expensive charger like a CTEK or NOCO lithium compatible "maintainer" can be purchased for $50-$75. Connect to battery when attached to shore power and battery will not only be topped off but internal BMS will see to it that cells are balanced.

If you are plugged into shore power, isn't the converter charging the batteries?

[hobienick]

Originally Posted by The Evil Twin

If you are plugged into shore power, isn't the converter charging the batteries?

Yes, but I think TitanMike was talking about getting the last 5% of charge into the battery. In most cases the factory converter will not output a high enough voltage to do this without some sort of modification or the maintainers he mentioned.

[TitanMike]

Originally Posted by The Evil Twin

If you are plugged into shore power, isn't the converter charging the batteries?

Yes, the converter is charging. The reason for using the lithium compatible maintainer is that unless the onboard converter has been changed to one capable of a 14.6 volt output (considered optimum charge voltage for fully charging a LiFePo battery) that last topping charge won't occur.

The use of a maintainer like those I mentioned is merely a less expensive way to top off LiFePo batteries without the expense of a new converter with the exceptions I mentioned for Progressive Dynamics or other adjustable output converters.

FWIW, I predict that it won't be long before we see adjustable converters as OEM. This will give customers the option of LiFePo batteries or Lead Acid Batteries, either as an option from the factory or as down the road replacements. Over the years I've seen converters evolve from those with changeover relays in them, to float voltage converters, to "smart" converters, to "even smarter" converters. Once the converter mfr gets past the basic current supply internal devices the rest is merely a few $$ for for a different control module.

[wharfrat48]

Interesting topic. I had considered the upgrade to lithium, but ultimately decided to stick with flooded 6V. I recently purchased 2 6V for $162 (115a/h), and I have always been able to get 6-7 yrs per set before they needed replacing (not real heavy use). At $800, lithium is 5X more expensive, so even if I replaced my 6V's every 5 yrs, I would be able to power my RV for 25yrs (for $800). Are the lithiums expected to last that long? I have heard that "real world' experience with lithium batteries do not align with the 3000-5000 cycles, but I have no experience nor do I know anything about lithium life expectancy in regards to time.

Until lithium becomes considerably cheaper, I will stick with flooded 6V for my application. I think everyone needs to evaluate the switch for their particular situation and needs (capacity, storage, weight, etc.), but even with the extended lifetime I'm not sure the cost of switching to lithium is at a break even point yet.

[babock]

There are more advantages than just the overall cost savings(over time) and faster charging.

1) They can be left discharged. Unlike FLA and AGM that will sulfate when left discharged.
2) One 100A lithium battery weighs 30#. 2 GC batteries weigh 120#.
3) Peukerts constant is 1. If you have a high draw on a FLA battery which has a Peukerts constant of 1.3 or so, a 100A draw on a 200AH battery will pull the equivalent of 50%of your capacity in just 30 minutes.
4) Since the impedance of the battery is so low, you will never have low voltage cut offs with your inverter under high loads.
5) Can mount anywhere...not just the tongue. I have mine under my bed. Saved my large tongue weight issue.

[NJKris]

Sounding more and more appealing. I hopefully have years to go on the pair of golf cart batts that are just over a year old before making decision. Hoping price will have fallen a bi by then too. Mike and babock, you really should consider working for Battle Born, lol.

[babock]

Originally Posted by NJKris

Sounding more and more appealing. I hopefully have years to go on the pair of golf cart batts that are just over a year old before making decision. Hoping price will have fallen a bi by then too. Mike and babock, you really should consider working for Battle Born, lol.

Or Lifeblue. I actually like their batteries a lot too.

If I was doing it again today, I might consider doing a DIY battery bank with cells. Problem is, it's not in a nice case, you have to supply your own BMS and no guarantees.

[rk06382]

Originally Posted by babock

There are more advantages than just the overall cost savings(over time) and faster charging.

1) They can be left discharged. Unlike FLA and AGM that will sulfate when left discharged.
2) One 100A lithium battery weighs 30#. 2 GC batteries weigh 120#.
3) Peukerts constant is 1. If you have a high draw on a FLA battery which has a Peukerts constant of 1.3 or so, a 100A draw on a 200AH battery will pull the equivalent of 50%of your capacity in just 30 minutes.
4) Since the impedance of the battery is so low, you will never have low voltage cut offs with your inverter under high loads.
5) Can mount anywhere...not just the tongue. I have mine under my bed. Saved my large tongue weight issue.

You forgot to add NO Acid Corrosion. I am glad I do not need to worry about corrosion on my Battle Born batteries.

[Flybob]

One thing that has not been mentioned here is that battery life and cycles are two different things. The actual life of the battery is more like the lesser of the battery life and cycles. For normal RV use it will be difficult to reach 5000 cycles before the life expires.

[dbledan]

Great write up thanks for sharing...

I did find a guy on youtube that buys the liFePO4 batteries used out of medical equipment (they require you swap early in the life) on Ebay. A bit of a shot in the dark on life expectancy bit most of the ones he had were better than 90% because most hospitals dont lose power often. Makes it much cheaper.

The down side is you have to wire them together yourself and add a charge controller. This is what I have seen that battleborn has done well. They put a solid control system in place to protect the battery and as a result it lasts longer and is safer. The cheap controllers were admitted to be poor quality and would reduce life expectancy. You get what you pay for.

[wharfrat48]

Originally Posted by Flybob

One thing that has not been mentioned here is that battery life and cycles are two different things. The actual life of the battery is more like the lesser of the battery life and cycles. For normal RV use it will be difficult to reach 5000 cycles before the life expires.

I think that is the big unknown right now (at least unknown by me). As I said in my post above, I'd get a minimum of 25 yrs of battery life with $800 of 6V GC batteries (2 batteries every 5 yrs). For that same $800, I'd get 1 Li, would I expect that single battery to last 25 years? I don't know, but I doubt it. So if I assume the Li would need to be replaced after 12.5 years (just a guess), the Li costs 2x the amount of the GC. Is the weight reduction, faster charging, Peukerts constant, etc, worth the extra $$.... not to me, but maybe for others. I'd really like to know how long the Li batteries will last under real RV usage conditions.

[SeaDog]

expensive sort of depends on how deep your pockets are.

[TitanMike]

Originally Posted by wharfrat48

I think that is the big unknown right now (at least unknown by me). As I said in my post above, I'd get a minimum of 25 yrs of battery life with $800 of 6V GC batteries (2 batteries every 5 yrs). For that same $800, I'd get 1 Li, would I expect that single battery to last 25 years? I don't know, but I doubt it. So if I assume the Li would need to be replaced after 12.5 years (just a guess), the Li costs 2x the amount of the GC. Is the weight reduction, faster charging, Peukerts constant, etc, worth the extra $$.... not to me, but maybe for others. I'd really like to know how long the Li batteries will last under real RV usage conditions.

Your cost assumption for 25 years of golf cart batteries doesn't take into consideration any price increases. 5 years ago I could have purchased two 12 v true deep cycle batteries for just over $200. Happened to look at price recently for same batteries and if I'd played down 3 one hundred dollar bills my change wouldnt be enough to buy lunch at Burger King.

Lead is a hazardous material and regulation has driven up the cost of everything that uses it.

I think you'll find that over 25 years you'll pay a lot more than $800 for replacements.

[iconnekt]

Everything is clear about the advantage, but I found another one that for me was very significant...
I’m now 67, I have a nice brand new Lance and chances are that this will be my last trailer. So it makes no sense to install a “temporary” solution when actually I can have the Lithiums for the foreseeable rest of my camping career. I bought a couple of BB and I am really happy, once for all...

[sytsmasj]

Thanks Titan Mike. Excellent article. I went out 2.5 years ago and bought 2 x 6V golf cart batteries from Sam's Club for about $200 total. I was careful to be sure to not drop voltage under 12.4 Volts, so I should not have abused them. My batteries are unfortunately now bad, so looking at replacement. I wish I would have made the Lithium decision back then. I have seen Lithium cells on EBay which are from Hybrid car battery packs. Any merit in looking there, or is the Battle Born the way to go?

[llr]

One other benefit I have not seen mentioned is there should be much lower thefts if you move them inside the camper. This would especially apply to units stores away from home.

[babock]

Originally Posted by llr

One other benefit I have not seen mentioned is there should be much lower thefts if you move them inside the camper. This would especially apply to units stores away from home.

Yep...forgot to add that one. Mine are under my bed. I keep the old size 24 battery box on my tongue as a decoy. Makes people think the battery has been removed.

[babock]

Originally Posted by sytsmasj

Thanks Titan Mike. Excellent article. I went out 2.5 years ago and bought 2 x 6V golf cart batteries from Sam's Club for about $200 total. I was careful to be sure to not drop voltage under 12.4 Volts, so I should not have abused them. My batteries are unfortunately now bad, so looking at replacement. I wish I would have made the Lithium decision back then. I have seen Lithium cells on EBay which are from Hybrid car battery packs. Any merit in looking there, or is the Battle Born the way to go?

Some of those on eBay, in particular the Valence batteries, have cell balancers inside them but no BMS so keep that in mind.

[hobienick]

I have mentioned this guy before in another thread about solar.

Here

is his video about using a Telsa car battery in his 5er. There are some drawbacks but he describes what he has done. If it is not in this video I think it is the the 3rd video on his solar installation.

He is an electrical engineer and seems to know his stuff.