Lithium Ion Batteries for Boat
Lithium ion batteries for boats are a battery technology that is revolutionizing the mobile power market as a result of the rapid advances in the electric vehicle space. They are a viable alternative to lead acid, AGM and Gel batteries. What about Lithium-ion batteries for boat questions that I receive are frequent and almost any conversation I have with other sailboat owners about batteries very quickly centers on Lithium-ion battery technology.
If Lithium-ion batteries are on your upgrade agenda then you really need to understand not only the advantages but also the disadvantages. There is no free lunch on these batteries as many try and spout how good they are without either considering the issues or properly installing them.
Lithium
Ion Batteries for Boat
A word of clarification on these batteries. Lithium-ion batteries use Lithium Cobalt Dioxide (LiCoO2) or Lithium Manganese Oxide (LiMn204) as a cathode. A Lithium-Iron battery uses Lithium (Li) Iron (Fe) Phosphate (PO4) or LiFePO4 as the cathode and are also referred to as LFP (Lithium Ferro phosphate) batteries. This chemistry provides much longer cycle life than other lithium-ion chemistries with some quoting 3,000 to 10,000 cycles depending on conditions. The big advantages of LFP batteries are significantly greater chemical and thermal stability due to the absence of cobalt, so they have much increased safety. For the purposes of this article, we will refer only to LFP type batteries which are the majority of installed units on boats.
Lithium
Ion Batteries for Boat Advantages
There are many advantages in installing Lithium-ion batteries on your boat. These advantages include minimal power loss when discharging to near 10% of capacity. I do not recommend this. Nearly the entire battery capacity is available unlike lead acid chemistry batteries which is approximately double the useable capacity of lead acid types. Lithium batteries possess a very high energy and power density. They can be charged much quicker due to the low internal resistance. Other advantages include much lighter weights than a lead acid battery, in the range of up to 60%. Thet also have approximately 500 to 1000% or greater cycling capability than a standard AGM battery.
Lithium
Ion Batteries for Boat Disadvantages
There are also quite a few disadvantages when choosing and installing Lithium-ion batteries on your boat. The drawbacks are that they are not generally suitable for engine starting although that is starting to change. Like all batteries, they do not tolerate rough mistreatment very well. Added to that is they are significantly more expensive than traditional batteries. In most cases electrical wiring in the charging system will require upgrading. The battery charging systems will also require upgrading in many cases. Engine mounted alternators will usually be under rated and require upgrading to handle the higher charge currents. They will also require regulators with the required charging algorithms. The same applies to mains powered chargers when on a marina or charging from a generator. Solar and wind generators also require the correct charging algorithms as over-charging is a major issue for Lithium-batteries. The existing charging sources need to be Lithium-ion compatible. Insurance companies may not accept an installation, even LiFePo batteries so check before you start.
Lithium
Ion Battery Installation Standards
In practice very few installations I have inspected and reviewed are properly installed to relevant codes, and battery installations in general should comply with relevant codes or regulations. Lithium battery installations are also now coming under separate and enhanced codes.
In the United States these are ABYC E-10 Storage Batteries; ABYC E-13 Lithium-Ion Batteries and ABYC E-11 AC & DC Electrical Systems.
In Australia these are AS-NZS 3004.2: 2014 Part 2 Recreational Boats Installation, more specifically Battery Installation (AS-NZS 3004.2: 2014 Reference 2.9.1) and Lithium-Ion Battery Installation (Reference AS-NZS 3004.2: 2014 2.9.3). It should be noted that for some inexplicable reason these standards are not mandatory except in the state of Queensland.
UK/Europe
Lithium Ion Battery Installation Standards
In Europe and the UK standards are covered under the Essential Requirements of the Recreational Craft Directive 2013/53/EU and ISO standards which are under revision. The ISO 13297 AC & DC installations of electrical systems will contain four different sections that support each other and this includes ISO 23625, Lithium-ion batteries. But be aware here. Recently Recreational Craft Sectoral Group (RSG) issued recommendation no. 199. They have done intense consideration and review of lithium-ion batteries installed in boats. In the resultant RECOMMENDATION FOR USE No. 199, it concludes that the replacement of conventional batteries with lithium-ion batteries will constitute a “major craft conversion” within the meaning of RCD Article 3 (7). This will lose the CE certification and therefore is non-compliant with applicable safety and environmental requirements. This means that a boat without valid CE certification can end up leading lead to substantial liability risks in the event of boat damage. Insurance companies may refuse to pay out claims and the boat owner may have major legal consequences in the event of any accident. To regain CE conformity after retrofitting Lithium-ion batteries an authorized body would have to reassess the boat for compliance which is challenging and costly. The general advice here is before you start avoid any DIY fitting. Only use reputable companies for planning and installation, in other words don’t play at amateur electrics, and don’t experiment. Only select and purchase marine-certified battery systems and components. In the case of newer boats, you should reach out and consult with the boat manufacturer and clarify how any retrofitting would jeopardizes the existing CE certification.
Lithium
Ion Batteries for Boat Installation
There are several good practices to observe when installing Lithium-ion batteries and these also cover any battery type.
1. Never install these batteries with other battery chemistry types.
2. Do not parallel a Lithium-ion battery with an AGM or other flooded cell battery type, as this can create an explosion and fire risk.
3. Lithium-ion batteries are no different to any other battery chemistry type in that they do not tolerate rough mistreatment. Do not crush or fracture the casing. It is a no brainer I know but people throw batteries around like they are indestructible.
4. Do not attempt to disassemble a Lithium-ion battery cell as you may experience chemical burns as well initiate a fire and explosion. (Yes! people actually attempt this.)
5. Absolutely never ever short-circuit a battery either accidently or deliberately (I Know! Who would even contemplate that but you would be amazed at what I come across professionally.)
6. Do not overcharge them, read further descriptions on this
7. Do not subject the battery to reverse polarity.
8. Lithium-ion battery age and life expectancy is subject to the temperature and the state-of-charge (SOC). The higher the temperature, the faster these batteries will age; ideally, the cooler they are kept, the better they will age. Read further descriptions on this.
Lithium-ion batteries are transformative for many however make sure you follow the rules when selecting and installing them. Understand they are not the holy grail of onboard electrical power, but improve things in both capacity and reliability. Understand they also have disadvantages as well that need consideration.