Lithium Ion Batteries

[garyde]

I recieved a News letter from Liberty today.
Their new H3's 3 slides will have new technology Lithium Ion batteries.
About 1150 lbs less in weight, 10 year life expectancy, 2000 cycles.
Additionally the batteries communicate on a proprietary network which continuously monitors each cell.
This technology is truly a game changer for the industry.
The down side is they are much more expensive, but they last at least twice as long and the pricing probably will come down within 10 years.

[jack14r]

I had heard this a few months ago,will they get rid of the watchdog,and will they start the generator before the batteries are depleted?With the Chevy volt coming and the money that has been granted by our government for lithium ion technology we should see real benefits in product and price soon.

[Jon Wehrenberg]

About 1150 less in weight???????

This information obviously comes from the guy that also said bus air was eliminated on four slide Liberty coaches to save weight.

My 8D batteries (four) weigh 165# each for a total of 660 pounds. I assume from the previous thread about eliminating OTR and going to 8 batteries that 8 batteries will be used and the new batteries weigh almost nothing. I don't think so.

Batteries are perhaps the simgle most important elements of living comfortably in our coaches. Having ample battery power allows us to live comfortably without being connected to shore power or having the generator run continuously. But being the cynic that I am I would want to see the data which suggests putting in a pricey set of batteries is the smartest approach.

I doubt the 10 year life, but lets explore that premise. Lets guess a coach equipped with them has 8 batteries on board, and those batteries do have a 10 year life and they cost twice what an AGM costs so their cost is proportional. (I seriously doubt that) That means replacing a set using my bogus numbers is $1000 per battery or $8000 every 10 years, or $800 per year.

Let's look at this in another way entirely. Let's assume as the average coach owner we take a trip per month, and for each trip we spend two nights parked in camp WalMart, the balance of the time we are either driving or connected to shore power. That means we will depend on batteries 10 hours per night, times 2 (once getting to our destination, once returning home), times 12 trips or 240 hours per year.

If my generator fuel consumption is typical at about 1/2 gallon per hour that means I should eliminate all but one or two house batteries and just riun the generator any time the engine is not running or I am not connected to shore power. The house batteries would only be used to provide lights to find the generator switch. My cost to run the generator would be about 120 gallons annually or at todays prices $360. Not only cheaper than replacing a full set, but a considerable weight savings.

I think we are going the wrong direction adding more and more batteries, more and more weight when we already have the means to live comfortably using the generator which also weighs a lot and which we drag around and rarely use.

Instead of adding batteries, instead of switching to more expensive batteries, instead of having coaches that weigh more and more, maybe autostart needs to function anytime the bus engine is turned off and the bus is not connected to shore power.

[jack14r]

Liberty's news letter states a 397% increase in cost,the batteries are 24 volt,so there could be a savings in cable weight,I think that a H might have 6-8D's which would be 900 Lbs.I doubt 1150 lbs. savings on a H would be reality.I have read that lithium ion have twice the storage capacity and 1/3 less weight compared to lead acid.

[JIM CHALOUPKA]

I would appreciate Solar technology applied to the bus more than LI batteries.

I think the LI application is a marketing tool to stimulate sales by making their real customers (those that buy new) think they will need to trade up to keep up with the times.


JIM

[Jon Wehrenberg]

I am on intimate terms with the cables in my 24 volt coach. Having just gone through the process of checking and tightening every one I can say with confidence that I have big cables despite them carrying 24 volts.

They are about the diameter of my thumb. Four run about 15 feet from the batteries to the inverter terminal block. There are some smaller diameter cables such as those going to the equalizer but in addition to the 60 feet of cables listed above there may be a total of another 20 or 30 feet connecting the batteries and going to the chassis ground. Then there is a long run going from the batteries to the electrical compartment, but my point is mine are carrying 24V and I don't see any smaller cable size. Even if it were possible to reduce their size the weight savings wouldn't come close to compensating for the weight of the third slide.

If the new batteries are 4 times the cost, and 66% of the weight my tongue in cheek suggestion to run the generator any time the coach is not running or hooked to shore power is no longer so much of a joke. My 4 batteries were just under $2000 so 8 lithium batteries would cost $16,000 at replacement time. At today's cost of fuel and even .75 gallons per hour an owner could dry camp with the generator running 700 hours per year and still be money ahead by eliminating all house batteries and running the generator.

How many owners even spend 700 hours per year in the coach, much less 700 hours dry camping?

[garyde]

Before everyone starts making assumptions, it would be best to get the info from Liberty directly why they have made the change and the long term reasoning and benefits.
Not knowing Liberty very well at all, I do know Frank does not move into new technology easily. It is with much planning, testing, and considerations.

[Jon Wehrenberg]

Agreed. Consider my comments generalizations. Also consider me anti progress unless the new and improved design or device is in fact a benefit and not a trade-off.

[FrankK]

I would like to jump in here to give you all a run down on what we have done related to battery technology. On our Triple Slide coaches we have been installing 8 of the traditional gel type batteries and 4 of the Outback Inverter systems, I did this since the Triples Slides do not have Over the Road Air and I wanted enough starting capacity to run multiple Cruise Air systems simultaneously. The Triple Slides do not have Over the Road Air for two reasons, one being the inability to duct the air and the other is the 750-800 lbs of weight that it eliminates which a majority of that is on the front axle. Our Triple Slide units had the 8 batteries divided 4 on the driver side and 4 on the passenger side of the 4 bay (Over the Road Air bay) which basically was a trade off weight wise to the Over The Road Air.

I have been studying the Lithium Ion batteries for a while and did some testing last fall, it is important to note that we are using Lithium Iron Phosphate batteries which utilizes phosphates as the cathode material, this makes the battery very stable since phosphates are not prone to thermal runaway and will not burn. I bring this up because I'm sure there will be a number of you that will Google "Lithium Ion" to the end of the internet and find information completely unrelated to the technology we are using.

I have been able to install 3 of the 24 volt Lithium Ion batteries instead of the 8 gel units we were using in the past, this proved to be virtually equal in capacity and in fact with the elimination of cables, racking, and various other parts the weight of the coach dropped by 1,150 lbs compared to an identical coach with the 8 gel batteries, close to 700 lbs from the front axle alone.

Since these batteries communicate on their own network we are triggering the generator auto start by amp hour usage instead of voltage which means we are utilizing the battery capacity more efficiently.

There is no way to rationalize the additional cost of these batteries by determining if the generator will run less or by how many times you will have to replace batteries over a certain length of time. I can tell you that there is a monitoring system on board that will give you the complete history of the batteries and they do have a cycle life of 2000 cycles. A cycle is the battery running completely dead and charged back up, which should actually be more than 10 years. As a manufacturer and dealer this will allow us to show future purchasers of these coaches that the batteries have "X" amount of cycles left which will ultimately save the purchaser money and eliminate the monumental waste we have related to battery replacement.

This technology is very cutting edge and the information that is available on the control network is amazingly complete in fact we are currently developing software which will allow us to stream that information on our Crestron system so customers can view how may hours of capacity are left at a certain amp draw until the generator will start; this is just a start.

I know that I'm not on here very often, but I will try to look through here occasionally. If there are any questions you have about this or anything else please do not hesitate to contact me directly. Also I would like to thank all of you for your continued support of our industry, with out you we would definitely not be able to continue looking for improvements in technology and quality to move this industry forward.

[Jon Wehrenberg]

Thanks for the clarification. Apparently pushing the need to embrace new technology is the need to offset the extra weight and design issues brought about by the increase in the number of slides.

Your explaination raises more questions however.

Those of us with the AGM or gel cell batteries seem likely to benefit from the new technology if it can be used. For example, my vintage coach has 4 8D batteries and they have a 5 year life.

Trying to pull some data from that which has been included on this thread it appears we who have the older batteries can reduce the number of batteries we carry around (2 instead of four, or one instead of three for example, get the benefit of less weight, and twice the life. If the cost is in fact four times greater per battery, but a ratio of 3=8 is correct, then the cost considering fewer batteries, but twice the life suggest it is a dollar for dollar trade. The benefit if they can be retrofitted is a weight savings. I would go for the new batteries on that basis alone.

My batteries are easily accessed so I don't gain much there, but those whose coaches have batteries located behind the entertainment center not only get a weight savings, but they only have to go through the issue of accessing and replacing those batteries every ten years. I see that as a huge benefit.