[Bill]

Li is going to become the new norm. It cannot be beat for battery life or substantial weight savings.

The fact new Li batteries are now drop in replacements for AGM is a game changer.

If you are scheduled to replace coach batteries now is the time to gather information about what is available and based on factors such as economics, how you use your coach, how long you intend to keep your coach and your need for weight savings, long life or reliability you need to think about Li.

[Bill]

Jon’s words are so prophetic … as I sit at ETLC and RV Resort having brand new LifeLine AGMs installed in the coach as I type!

I suppose mine will be the very last set of LifeLine AGMs that ETLC ever installs.

[Bill]

Dollar for dollar there is no way that the new Lithium batteries make any sense. The upfront costs are still WAY too high. Some will argue that you only need have as many batteries at 4 times the price and somehow that makes sense. There are charging issues and temperature issues that must be carefully dealt with to make Lithium’s usable and viable. I will stick with the cheap Universal AGM Batteries until some major changes in the battery technology happen.

[George]

You’re behind the curve Bill, the latest Lifepo4 batteries will be the norm as Jon pointed out. I’ve spent lots of time trying to get up to speed on these batteries and I’m impressed with the performance and ease of operation.

Nothing wrong with staying with AGM’s if it works for you, but those that want the latest and greatest will be very happy with Lithium. Especially if you’re a dry camper, it starts to make lots of sense.

[Archived]

Bill, the economics of Li will not work for everyone and it sounds like you will not benefit enough from them. But don’t trash the technology because Li is here to stay and some coach owners who dry camp as an example are going to receive benefits far greater than the costs because of the capacity and weight.

AGM are great and some of us can never justify the cost of Li, but a whole lot of owners are going to benefit highly from Li.

[Archived]

Wow, we have entered the twilight zone…….

[Jeff]

So can we see some pricing and capacity comparisons? I know the Li batteries can be used well below the 50% SOC than lead batteries so fewer batteries might be required.

[Harry]

Tom,

We are not ready for new Li’s yet but I have been You Tubing this for a while and would like to know more and maybe the group about the RELiON and how it interfaces with existing systems. I have a couple questions though which would help me understand. They say the RELiON is plug and play solution.

I have six GPL 4D Lifeline Batteries (JQ) codes. Three set up for 24 volt and three set up for 12.

2000 Marathon XL Chassis – 270 AMP Alternator and 175 AMP Marathon installed alternator. 20K Generator original to bus. No changes to bus electrical systems since new.

1st – I have two 4000 watt Trace Inverters. They are set for factory Marathon charge settings bulk and float. So, would I need to change any settings on master panels for Trace Inverters? And if changes are required, how would I make them permanent so they are not erased during a reboot to default settings.

2nd – Would any new monitoring equipment need to be added. Right now house and chassis battery are monitored by Techlink and several current LEM Fluxgates Marathon added (Current transducers). Three monitoring 24VDC and three monitoring 12VDC in battery compartment. Will a new monitoring system using shunts be needed such as Victron or RELiON’s own system.

3rd – Alternator and generator charging – will any new equipment be needed to existing Prevost/Marathon setup to prevent alternators generators from just wanting to keep charging battery since I have heard Li’s will take whatever you throw at them.

4th – To get same AMP Hours I have now…. I understand with Li’s ….I can use less batteries. How many less?

To price Li’s I ask myself:

1. How long am I going to keep coach?

2. Do we live off grid for long periods and run off of batteries?

3. Etc….

Since most of the Marathons I my year have similar setup I would be interest to know in private email or to group what you think upgrade cost for battery bank would be and what it would entail.

There is just nothing out in You Tube space that address’s Prevost Conversion’s.

Thanks in advance

[Jerry]

Less batteries, less weight, less gen charging time and more cycles.

They’re not for everyone and it will be up to the owner to decide. You can view the specs here to make an educated decision: Relion

[Jeff]

I just completed a 34 slide presentation and a magazine article on changing out Lead acid batteries in GMC Mororhomes (those 73-78 front wheel drive units) for lithium iron phosphate batteries along with devices needed to properly charge them from all three charging sources – alternator, generator and shore power. The information is equally appropriate for the 12vdc house battery bank on Prevost coaches.

Contrary to what many still think, LiFePO4 batteries are not that much more expensive than quality AGMs and will outlast them by several times. They will likely be the last batteries you will ever buy in your time of coach ownership.

In addition to the well known weight and capacity advantages, less well known is that LiFePO4 batteries operate at higher voltage for 85%of their capacity than AGMs do when fully charged. That means more watts to do more useful work for you. The least well recognized advantage is that the LiFePO4 batteries recharge 4 to 5 times faster so make solar not only feasible, but also cost effective for many Prevost owners.

as soon as my AGMs age out there is no question what I will do.

[Archived]

To the question on price vs capacity, most Prevost conversions using 12vdc house battery banks will do well with a 600Ah LiFePO4 battery bank (generally six 100AH units) to replace the six 8D or 4D AGM batteries in the common Prevost house battery bank. Most have already changed out the interior lighting from high draw, high heat halogen bulbs to low draw, low heat LEDs which reduces power draw significantly. Running your residential refer and cooking are the greatest remaining draws. The refer is by far the greatest for most coach owners.

The fact that voltage in your existing AGM lead acid batteries drops the minute you begin to use them, plus the fact that they loose voltage even more quickly the heavier the draw, means the real world watts available drop very quickly. Not so for LiFePO4 where voltage drops far less quickly all the way down to full exhaustion. As a result, the watt hour capacity (a much better way to express capacity than amp hours) is two to three times greater for LiFePO4.

Modern LiFePO4 batteries have all the required battery management already built in and generally cost $800 to $1000 for 1500 or more usable watt hours of capacity. Two to three 8D or 4D AGMs which offer about the same usable watt hours of capacity can cost nearly that much so real world initial acquisition cost is not that much greater and the Lithium batteries will outlast the AGMs by a wide margin.

[Doug]

Bill,

Tom sells both. From my perspective either Lifeline or Relion are the best choices based on overwhelming feedback.

Neither are cheap. If you are looking for cheap go to lead acid and carry a supply of distilled water to keep them topped off. If you want AGM there are cheap alternatives to Lifeline, but feedback has almost been universally poor.

I have done a lot of research and based on how I use my coach AGM makes the most sense, but if I did a lot more dry camping than I do now it would be no contest. I would go with Li because they would do a lot better than AGM. But right now I could get along just fine with only half of my AGM batteries so the economics become the deciding factor.

You have to look very hard at how you use your batteries, if you can reduce the number while still retaining the same performance, if getting weight off your front axle is important, and if you will still own your coach in 10 years.

For some the decision is a no brainer. For the vast majority of us it is a toss up with how long we intend to own the coach as a serious factor, and for some there is no way to justify Li. This is a discussion in which the correct answer is personal.

[Joe]

If you do not dry camp, you will see little to no value in the Lion battery….

However Lion number you is set to discharge at constant voltage, vs all other from AGM, deep cycle etc…voltage is a constant change…So with Lion you will get much more true power…

With this you must also look at if you use gen auto start, then you will need to make a change here as well…we need gen to auto start at a different voltage or state of charge…

Inverters need to be something that the charge rate and settings for voltage can be adjusted…Not your old freedom 25 inverters

Lion batteries do not like freezing temps…therefore they need to have a way to be heated if in this environment…many ways to accomplish this…

With Lion you do have the potential to reduce number of batteries in the system and maintain the same or still larger capacity.

Standard engine alternators do not need to be changed with this type of battery…

[Jerry]

Will the Freedom 458 charge these?

[Dick]

It is important to keep in mind that there are six different battery chemistries all called “lithium” or “lithium ion” and they vary greatly in all aspects of safety and performance, and they all require different management strategies to be safely deployed. They come in two basic configurations – prismatic cells and cylindrical cells.

Prismatic cells are usually flat and designed with all the ampacity built into each cell, and 3.4 to 3.7 volts per cell. So, a nominal 12vdc battery will be made up of four cells. Loose one and you are left with a nominal 9vdc battery. they are used where the ability to mold the flat cells into intricate shapes to fit the geometry of the application is key. Think cell phones.

cylindical cells are generally 16 to 25mm in diameter and 65 to 85mm in length. The voltage is 3.4 to 3.7vdc and amps depend on physical size and specific chemistry. The designer assembles them to create the ampacity and voltage required for the application. Any one of the six different Li battery chemistries can be packaged in either prismatic or cylindrical shapes.

The original Tesla model S for example used over 7000 cylindrical cells of a chemical type where cobalt was mixed with lithium and other ingredients to result in very high capacity (about six times the energy density of lead acid) but which required very sophisticated heating, cooling and microprocessor management to make them safe for that application. The cells used now are still cylindrical but now are a bit larger, use less cobalt, and are now the same across all Tesla models.

For replacing lead acid batteries, the best and safest bet is lithium iron phosphate chemistry which has no cobalt content. These are called “drop in replacement” batteries meaning they do not require extreme measures to keep them within the required temperatures, they already have the electronic management built in and can be recharged from most alternators.

Older converter/charges generally will offer too low a voltage profile to fully recharge LiFePO4 batteries. They generally bulk charge at around 13.8 volts and float at a bit less. LiFePO4 batteries need 14.2 to 14.6 volts for bulk charge and 13.8 or so for float. Modern converter/chargers or inverter/chargers allow the user to set the charge profile so do work properly to fully charge Li batteries.

Unless you really know what you are doing and like to tinker, avoid trying to repurpose lithium batteries designed for a different application into batteries suitable for use as replacement house batteries for your prevost conversion. At best those will have questionable life and at worst can be very hazardous for your health. Ignore all the internet blog posts you see about repurposing Tesla or Leaf batteries, especially. That is not for the inexperienced or the faint of heart!