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Lithium Ion Batteries / Thinking Out Loud
We all know a great deal of the happiness of coach ownership is based on our batteries. Good batteries with lots of power are sure to make us happy. Old or failing batteries are going to make us unhappy. We all know why, and until our ailing batteries are replaced we have to make big adjustments to live with them.
We all have coaches set up with space for batteries, and even trays or racks for specific types and numbers. We mostly use AGM, and until now they have been the best choice and have been generally reliable.
But now we have a game changer. Lithium Ion drop in batteries meant to replace our existing batteries are now available. If you compare the space required for our batteries and the capacity of those we have to Lithium Ion of the same size (volume) we find some incredible benefits to making the switch.
On my coach I have a 24 / 12 volt DC system which relies on 4 12 volt 8D AGM batteries rated at 250 amp hours each for a total of 1000 amp hours of which 500 amp hours are available for use. I treat the well. I manually restart my generator while dry camping when they are no less than 12.2 volts to recharge them. They are always maintained in float when the coach is stored, and are always topped off at the specified voltage.
In other words I always expect and get strong performance during the 5 years I keep the batteries. But they have a limited life, and they are heavy at about 165 pounds each, and worse, to get to the I have to pull the entertainment center from a bay just to see the.
They will cost $2600 or more to replace.
If I compare the to the Lithium Ion drop in replacement two significant benefits come about. The closest Li 8D battery has 200 amp hours, of which about 180 are useable which so the entire battery bank of 4 batteries now has 800 amp hours, of which 720 are useable providing and almost 50% gain in available power in exactly the same space.
But while more power is available the Li batteries only weigh 60 pounds apiece for greater than 400 pound weight reduction. But wait, there’s more (they say that on TV) Instead of the number of recharge cycles available on AGM that provide a very comfortable 5 year life, Li batteries used and operated in exactly the same manner are going to get no less than 5 times the number of cycles, and more likely at least 10 times the number meaning once installed I will never buy a set of batteries for the house again.
There is bad news. To buy the Li batteries described above will cost somewhere between 3 to 4 times the cost of AGM.
Decisions, decisions. We are now faced with opportunities to replace batteries with Li ad add more power, or use less batteries and get the same amount of power and use less space and save a lot of weight mostly off the front axle, or use the same space and get a lot of additional power to extend time between generator start cycles.
I am heavily leaning toward the switch to Li so I reduce weight, add more power, and likely will never ever have to worry about or buy house batteries again. It does not make financial sense, but the unknown is if they add enough value to the coach to increase its value compared to any value added with half time AGM.
What do you all say? Can the benefits over shadow the financial disadvantage?
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48 Replies
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Having just bought 5 new Lifeline batteries last week and have the voltage regulator malfunction and totally over charge them on the way home, I would hate to think of another expensive purchase that is 3 to 4 times what I’m looking at now. I do like the idea of more available power and longer life baring no unexpected issues.
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I have been watching this potential switch since I purchased my coach. I am curious what Tom says about this and whether LifeLine has, or will have, the Li batteries.
R
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When I first got my coach, I had some charging issues that made me hesitant to buy anything but the cheapest lead acid batteries. I installed four 6v golf cart batteries, two in series for each of my two 12v house circuits. I replaced the old converters with new Iota smart charge converters, and have new Victron battery equalizers and a battery isolator ready for installation.
I have at least a few good years of service out of the existing batteries, but have been looking at LiFePO4 batteries as a replacement. I could go with a couple of 8D sizes for maybe $5000 to $7000, but that’s all I have room for in the current location. It’s also in the engine compartment, which isn’t ideal.
What are your thoughts on installing these inside the coach? That would eliminate any cold temperature charging issues. I have a wardrobe in the bedroom that is directly above the existing battery bank. It’s awkward to access, given the narrow gap between the bed and the side of the coach, so it would be easy to sacrifice. No chance of a fire blocking my exit from the bedroom, but I’m not really sure of the risks involved. In any event, I love the weight and space savings with the new technology, and it is tempting to plan the upgrade!
Jeff and Lindsay
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Tom, If you had Relion drop in batteries they would have shut down at 15.8 volts and your problem would have never occurred.
What is unknown now regarding your problem is the cause, which is likely to be a defective voltage regulator, but will require verification. From my limited perspective your coach has a gauge out of the normal scan that might have alerted you before the smoke came out, but there could have been a better alert to a problem that might have been mitigated, but until the real cause is learned anything at this point is speculation.
Tom Chilcote of Lifeline fame is selling Relion as an alternate so you could be dealing with someone who knows the advantages and disadvantages of each option.
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While I like to dry camp from time to time, do most of you spend a whole lot of time parked/camping without power for an extended period of time? I would be surprised to find out that this is the case. Now, let’s say that you do. Would you save a crap load of money by running your genset a few a hours each day to top off the batteries compared to spending thousands of dollars on LI batteries?
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If i did a bunch of dry camping i would get one of these with a smaller battery bank. 8 hrs run time on a gallon of diesel
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As an example this week with show pricing, 4 new Lifeline 8D’s would cost 6180 each or 24720. To replace that bank with even more usable amp hours using 2 Relion RB300 8D would cost 63480 and would likely be the last time you ever buy batteries. More run time, less charge time, no heat and with the BMS (battery management system) built in, the batteries are protected from abuse or potential problems. In addition, the weight would go from 652 to 166 lbs.
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Ron – Lifeline is in the development stage of certain Lifepo4 sizes.
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Are LiFePO4 and Lithium Ion the same thing?
It will be interesting to watch the prices of the cutting edge technology batteries as volume kicks in and competition emerges.
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When I use the term Lithium Ion, or Li it is meant to mean the Relion batteries specifically. I spent two days with their representative after spend several hours reading everything I could about them. I asked some difficult questions of the rep and I cannot find any concerns about their use on my coach as i use my coach. So to put my use of lithium ion or Li it is meant as Relion drop in batteries.
I am not going to get into the chemistry of other brands or types because I am not qualified.
Bill, without doing a calculation about dry camping hours, battery bank size battery costs, hours of service between charges, generator maintenance and fuel costs, length of time the coach will be owned it is impossible to speculate if any type battery makes more sense than the other.
I do believe if we did not have to think in terms of cost everybody wouldl be using Li because right now there is nothing out there providing more power per cubic inch of space with less weight so hands down it is the clear winner until the dollars enter the equation.
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What kind of warranty do they have? That’s a lot of money for batteries that could fail in 2 years? for some reason Inverter- Voltage regulator? So a set of 4 8d’s could be 8 to 9 thousand dollars, is that correct?
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I recently published an article in the GMC Motorhomes International magazine about the many benefits of LiFePO4 batteries for use in Motorhomes when properly installed. It is in the Fall2019 edition on pages 24-25. From their web site – GMCMI.ORG – you can also download the slides from an hour and a half presentation on this subject. I titled the article and slide presentation “A heart/lung transplant for your GMC” for a reason (grin).
while size, weight and long life are often cited as benefits, the really important benefit for us is that LiFePO4 batteries operate at a higher voltage than lead acid batteries. Li batteries operate at a higher voltage over 85% of their discharge capacity than a led acid battery has even when fully charged. More volts means more watts to do useful work for us. And While led acid batteries drop voltage and wattage the minute you start to use them, and drop voltage and wattage even faster when you use them hard (think powering inverters) in motorhome use a Li battery bank voltage/wattage will be closer to flat throughout its discharge cycle. That means that in motorhome use you will get nearly three times the wattage out of the Li bank than you can get from a lead acid battery bank. Hence it really takes closer to three time the lead acid battery bank rated capacity to equal the Li battery bank. As a result, the Li battery bank is not nearly as expensive on initial purchase as you might think. And, it is way cheaper over time.
In Prevost conversion applications with residential appliances this difference really adds up. With Li batteries all the appliances will run longer and happier so you will need to recharge less often to stay comfortable. Li batteries also recharge up to six times faster than lead acid, so solar starts to make a lot of sense. This faster recharge will work your alternator a lot harder so be careful there.
If you use the proper size (larger than you would think) and type of wire in your implementation (only use marine grade multi-strand wire) I think you will find the many Li benefits greatly outweighs the small additional investment. You really will think you have given your coach a heart/lung transplant!
Jerry
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A few more things to consider. Lead acid battery amp hour capacity is measured at a fixed, constant rate of draw. In motorhome motorhomeuse, the real world draw is ll over the place so many people experience less life than they think they should get given the manufacturers amp hour rating and what they calculate as the “average” amp draw.
same with life time of the battery. Most literature will tell you lead acid battery lifetime will be around 1000 discharge/recharge cycles IF you never allow the battery to go below 50% discharge. For most Prevost users that is round three to five years. The trouble is, unless you are ultra fastidious about monitoring battery use, you seldom really know when you draw your batteries below 50%. For example, turn on the microwave and the induction cook top at the same time. You can watch the volts (and hence watts) drop like a rock. Now what happens when the refer (the real power hog in a residential appliance coach) also decides to come on at the same time? The voltage really plummets. Same thing happens if the water heater decides to come on at the same time.
The point is, it is really hard to estimate usage without a properly installed, shunt based, battery monitor that you watch like a hawk. Hence it is hard to know how far you really discharged your batteries, or how often, so it is hard to know for sure when you have drawn your lead acid batteries down to 50% on each discharge/recharge cycle.
Li batteries are far more forgiving because voltage does not sag nearly as much. And, many Li battery manufacturers under rate the capacity of their batteries so they can say you can use all the rated capacity (a 100 amp hour battery may actually be able to output closer to 110 to 120 amp hours) so the 85% discharge before the BMS shuts the battery down is already baked in for some Li batteries.
Be sure to read the warrantee language carefully. Some Li batteries are warranted for very short periods, like one year, while others are warranted for ten or more years. A workmanship and materials warrantee won’t do you much good if the battery capacity is woefully short after a short time. You want the warrantee to be stated in terms of capacity compared to beginning capacity. The better manufacturers state their warrantee in terms of how long their battery will output at least 85% percent of what it did when new. That is what you want.
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36 month total replacement warranty, 24 month prorated for a 5 year warranty.
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I just replaced all my house batteries yesterday. This is my first battery buy since I bought my coach. I have a Featherlight 1998 XL with a 8 4D batttery bank.
When I bought my coach two years ago the bank was 1 year old. In it was 8 NAPPA Wet Cell batteries. (NAPA Brand) I knew at the time I needed to replace them with AGMs when they gave out. These lasted three years without any maintenance. Very difficult to add water with out taking them all out.
On my last trip they all just died, so I started the decision process. I found Lifelines AGMs priced at $501 each and went to pick up. When I got the the owner happened to be behind the counter and asked why I needed 8. When I told him it was for a Prevost, he asked if I had Trace inverters. He was great and said I can’t in good conscience sell you these. As they are not all from the same batch. This was the first time I had heard the importance of this. After researching this site, it was stressed many times in different threads.
So to get 8 of the same batch, they would be shipped from the factory and would be now $5770 with shipping.
My tech mentioned another option and that was the Superstart AGM made by Continental. 1 year replacement, 3 year prorated. Exact specs as Lifeline, 3 pound heavier.
$4616 for lifeline vs $31000 for Superstart. I went with the Superstart because of my experience with my NAPA lasting three years (which are inferior batteries and lack of maintaining) I hope to get 5 out of my Superstarts. We will see, and I will keep the forum posted.
Thanks
David Thomas
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