Lithium batteries for caravans

Over the past decade, from almost zero commercial profile, lithium batteries (lithium iron phosphate – LiFePO4) have risen to become the highest profile portable electrical storage system in the RV industry, and really only their price point has prevented them from becoming the standard go-to for everyone in the field. It’s a rare brand of caravan, camper or boat which does not offer at least optional lithium battery set-ups in their product range, and for many it’s the only choice. So what is so attractive about lithium batteries for caravans and why are they set to fulfill their destiny as the prime source of electrical storage over the coming decade?

Lithium batteries present a number of advantages over conventional lead acid formats:

  1. For a given output they are much lighter (less than half the weight) and often smaller in size, reducing overall payload and increasing storage space within the RV.

  2. A longer life through a capacity for as many as over 2000 cycles, as much as eight or nine times greater than that of a lead acid storage battery, spreading the initial cost over a much longer period of time.

  3. They can be safely discharged down to as little as 10 per cent state of charge without any harm to the output or life of the battery itself, and will sustain their voltage right down to that point, enhancing appliance performance.
    Conventional lead acid batteries should not be discharged below 50 per cent state of charge (for example, because of this a 200Ah AGM battery only has 100Ah of safe useable capacity, whereas a 200Ah lithium battery has 180Ah of useable capacity; a 80 per cent increase) and their voltage will drop as they lose charge. This latter causes the battery to work harder to meet the demands of the appliance and increase the rate of discharge.

  4. Lithium batteries will sustain a much higher rate of discharge (suited to higher draw appliances, such as microwave ovens) and will fully recharge in as little as one-sixth of the time of an equivalent AGM battery.

  5. Lithium batteries are ideally suited to use with solar charging systems, and operate at their optimum efficiency when only partially recharged. This suits RVs used off-grid, where weather, shade or other factors can limit the recharge capacity on any given day.

  6. Lithium batteries have an extremely low self-discharge rate, so they can sit unused for longer periods of time without harm. Also, battery temperature is less critical to performance. With a lead acid battery temperatures above 25 degrees Celsius reduce efficiency of the battery and also shorten its life.

  7. Without the use of toxic lead in their make up lithium batteries are safer for the environment.

Lithium batteries for caravans – are there any minuses?

Attempts to push lead acid storage batteries outside their safe limited “envelope” not only reduce their immediate capacity but also lead to reductions in the life of the batteries. While there are limits applicable to lithium batteries they are much broader and generally outside those normally experienced by sensible RV use. At present, lithium batteries, like any new technology, are relatively expensive when compared to lead acid storage batteries (around three times the price). This is a situation which the market will correct as the rate of lithium battery production increases and consumer take-up rises with it. The use of lithium batteries for caravans is not simply a matter of buying and bolting in the batteries. Lithium batteries require precise management of the individual cells within the battery and the charging system must be specifically attuned to the requirements of the batteries.

BMPRO Invicta Lithium batteries

Leading Australian battery management innovator BMPRO searched the world before settling on the proven Invicta brand of lithium batteries to match to its increasing range of quality RV battery charging and monitoring equipment. BMPRO Invicta batteries are less than 50 per cent the weight of equivalent capacity lead acid batteries, along with up to eight times the cycle life, greater utilisation of available capacity through increased Depth of Discharge (DoD) and fast charging. Currently, the 100Ah and 125Ah Invicta options are available for the Australian market. All BMPRO Invicta batteries are fitted with their own internal battery management system to protect them from short circuit, impact, thermal abuse, over-charge, over-discharge and internal short circuit problems. Each battery is certified as a complete battery, not just at cell level like some others. This means that each complete pack of cells and its battery management system are tested and certified as a complete unit.

Future of lithium batteries for caravans

“In our view within the next 10 years the majority of new battery set-ups will be lithium based,” said BMPRO brand ambassador David Bayliss. “This is starting to happen already. Many car manufacturers are already stating that they will no longer be supplying lead acid batteries in their motor vehicles. This market is largely driven by the automotive industry and when vehicle makers such as VW, Porsche, Volvo and BMW have confirmed they will be phasing out lead acid batteries as they move to electric only vehicles, and when we have reached that stage the price will be driven down, making them more affordable all round for the RV sector.” “On a price per kilowatt basis lithium batteries already smash lead acid batteries,” Bayliss continued. “The problem has largely been one of convincing the marketplace that an investment in lithium batteries is a saving in the long run. And this just isn’t a win-win for the consumer in terms of the efficiency of battery storage, getting rid of lead is also a win-win for the environment all round.” Watch a series of videos dedicated to lithium batteries for caravans to learn more.

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32 thoughts on “Lithium batteries for caravans”

  1. I would be interested in your assessment of the Lead Crystal (LC) battery, as it seems to have a few advantages over some of the other battery types around. Also, I consider that the article has ignored LC, based on the “advantages over conventional lead acid formats:” heading and article contents. I am not anti-Lithium at all, but at their current price point, and need for specialised management, I am not sure that they will meet the needs of all RV users. One of the main current issues with LC is the fact that the use of the technology appears to be restricted to one company, with its associated cost, development and support issues.

    1. Olga kustova

      Thanks Rob, at BMPRO Head Quarters we have tested Lead Crystal batteries through full charging and discharging profiles as per the manufacturers recommendations and to date we don’t see them as a via alternative. The claimed performance did not meet our strict test regime and as such believe that whilst LiFEPO4 is more expensive it is also far superior in short and long term capability to deliver to RVers energy powering your adventures.

  2. Keith Nicolson

    I would like to know how many lithium ion baterys do I need to take the place of 160ah AGM baterys as every one talks about the technology of lithium but a person only wants to the replacement and performance of them.

    1. David Bayliss

      You could replace a 160Ah with a 100Amp Lithium battery. A 160Ah deep cycle battery should really only be discharged down to a remaining 80Ah (50%) where as a Lithium can be discharged comfortaly down to 20Ah remained which give you 80Ah capacity same as the lead acid solution. for more info on the Lithiums go to the GoRV website and checkout their Lithium series.

    2. David Bayliss

      A 160ahr lead acide system can be discharged down by 50% giving a 80ahr capacity for use. A 100ahr lithium can be discharged down to 20% remaining – giving the same ahr(80). so answer is 100ahr Lithium if all other things are constant

    1. Olga kustova

      Hi Michael,

      To swap for lithium, you would require lithium compatible power management system J35D. Most likely your Silverline model has a J35C model. Please contact your local Jayco dealership for pricing of the upgrade.

  3. Hi, if a BMPRO Sentry has a built-in BMS, why does the battery charger have to have a lithium setting? Won’t the BMS take care of the requirements of the lithium battery? My RV has 3x 120 AH AGM batteries which are charged by a 240v battery charger (which has a lithium setting), a solar controller (with no lithium setting) and a DC-DC Redarc charger (with no lithium setting). Will I be able to just drop in 3 x 120AH Sentry lithium batteries and continue to use the 3 sources of charge?

    1. Olga kustova

      Thank you for your question, Geoff.

      The BMS in the battery is for the battery protection of low voltage cut out, excess current turn off, over charging protection. It is mainly for preservation, not charge management.
      It will also limit the battery output to 100 amps (Max) and will shut down with a short of up to 350A for 3 seconds. Below 10V the BMS will turn off and no voltage will be seen at the battery until a wake-up source is put onto the battery.

      Here are the recommended charger requirements for BMPRO Invicta lithium battery:
      Charging A standard Constant Voltage (Automatic) SLA Battery charger can be used to charge BMPRO Invicta Lithium batteries, however the following requirements must be met:
      • Charger must not contain Sulphation/Equalisation setting. If so then this step needs to be turned off.
      • Maximum charge voltage of 14.6V
      • Recommended float charge voltage 13.9 +/- 0.1V.

      The solar and DC-DC may be suitable if they can achieve the specified voltages as long as they don’t have the sulphation and equalization.
      If they only charge to a lower voltage, they may work but not fully charge the battery.

  4. Hi
    We are about to take possession of our new van in which we have made several changes from standard. It has the 35HA , BC300 shunt, trek and mini boost pro. This was done to facilitate a seamless transition to Lithium from the standard AGM when the price of Lithium rationalises a little more. In the interim period the Lead Crystal option looks far more equitable with many of the benefits of Lithium. Whilst the clear winner on weight is still Lithium, the winner on usage life would appear to be Lead Crystal at roughly twice that of Lithium. This is not to be confused with cycle life in which the Lithium still wins, albeit on a far reduced scale than to the AGM. They also have an increased charging capacity over the AGM but still not as good as Lithium. Again this will totally depend on your battery management and charging system. The DoD of both Lithium and Lead Crystal again appear to be similar but research would suggest that the draw down rate on Lithium is higher. So for a battery with a cycle life roughly 4 times that of an AGM with a better usage life, twice that of Lithium and a quarter of the price and at the same dimensions and weight as an AGM surely it would be a better and more equitable option for those who aren’t living full time in their vans with a large draw down via inverters. So if I changed over from my 2 x 120 AH AGM batteries with a usable AH rating of around 60 AH x 2 to the equivilant Lead Crystal, I would increase to approx 90AH per battery. This would be the equivilant of running 3 x AGM. So, 2 questions.
    1/ Would there be any issues at all running Lead Crystal on my setup. I cannot see any but need to confirm.
    2/ Can you present any viable argument against the Lead Crystal setup. My largest draw load is a compressor fridge.

  5. I have a 2012 Jayco Sterling with a jayco setec battery management system, My AGM batteries 2 x100ah (with 170w solar panel) are dying,can it just fit a 200ah lithium battery,or do i need install a new battery management system ?

  6. Hi what is the difference between your lithium Battery the invicta and the sentry.

    And can the Sentry battery be laid on there side?

  7. Hi are the differences between your lithium Battery the INVICTA and the ZEAL. There is an obvious price difference, so what gives?

    1. Olga kustova

      Hi Chris,
      Invicta comes with 7 years warranty while Zeal with three. Invicta was tested and certified both on the cell and on the battery level, while Zeal only on the cell level. They are both excellent quality batteries built to last and perform.

  8. Hi guys
    We have a van with the HiTech 1230L battery charger. Van has 2 agm batteries and where hoping to swap these for lithium batteries. Can this charger handle lithium. I can’t find any info online about them.

  9. Hi
    Thanks for all of the interesting questions and feedback.
    I recently had a BMPRO lithium 120ah system installed in my van and very happy with it.
    It’s kept under a carport, so no solar input. I have it connected to a 7 stage 240v charger.

    My van has a panel of switches with 3 small LED’s. I monitor my battery and have found it goes from 99% to 62% over 2 or 3 days. I cannot see any other discharge apart from the LED’s. My question is how often should I turn the charger on and for how long?
    Apologies if you have already covered this, I just received my first newsletter

  10. Hi, I have a Bailey OZ van with a BMPro 35HA controller. I have AGM batteries that after 4 year are getting a little weak.. I am changing to Lithium soon. Will I need the controller updated? If so could you let me know how this is done please?

  11. Hi Olga,

    We have a 6 year old van with a BMPRO Genius II power supply currently attached to 2 x 100AH Deep cycle Lead Acid’s. I am looking to upgrade to Lithium for both better capacity and weight (which I suspect means going something bigger than 100AH in lithium). I gather from the earlier comments that this power supply is not compatible with Lithium batteries.

    Which BMPRO power supply is recommended as a replacement when upgrading to lithium? Will there be any need to change the current TOPRAY SOLAR TPS 1230 charge regulator? (Will be looking to add and beef up our panels as well).

    1. Olga kustova

      Hi Will,
      Correct – Genius is not compatible with lithium batteries.

      Please note any lithium battery needs to be charged with a charger with lithium profile to get the most out of your investment.
      Using incorrect charger may lead to the following issues:

      – Battery monitor or display you are using displays incorrect information as the charging algorithms are AGM
      – The low voltage disconnect voltages are wrong for lithium.
      – Incorrect charging profile which has desulphation and equalization which the Lithium does not like and it may damage the battery’s internal BMS
      – If the battery turns off, your battery management system will not wake it up.

      You would need our new power management system BatteryPlus35-II-HA. It has an inbuilt MPPT solar regulator, 30A smart charger capable of charging both AGM and lithium batteries, a distribution board for all your loads, and much more.

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