Lithium Batteries Buyer's Guide—BMS Requirements

So we have carefully thought about the tradeoffs after reading this chapter (where I cut through all the fanboy crap to what really matters), and decided that lithium batteries are the way to go for our offshore voyaging boat.

Lithium Storage are exported all over the world and different industries with quality first. Our belief is to provide our customers with more and better high value-added products. Let's create a better future together.

And we have figured out how much usable battery capacity we need and which charging sources and output power are required to keep up with our usage, as well as whether our system will be 12 or 24 volt, all covered in earlier chapters in this Online Book.

Now what? What gear should we actually buy?

Sure, we can dive into a hundred YouTube videos, but most are by someone who has never, or rarely, been offshore voyaging, and, worse still, many of the presenters could not explain ohms law if their lives depended on it&#;being a great presenter can mask truly stunning ignorance.

Or we can read who knows how many manufacturer web sites, reviews, and/or videos claiming that one particular lithium battery and BMS is best, or best for the money. But how do you decide who is making sense and who is full of shit and/or just trying to make a sale?

And even if we can figure that out, there is no best, there is only best for each of us.

To solve these problems I&#;m going to explore how each of us can develop our own set of buying criteria so we can cut through the noise to find and buy the best system for us.

The key points that are vital to understand are in the blue (tip) and pink (alert) boxes; that said, it will make more sense if you read the whole article carefully.

Also, I have used photos of various equipment to illustrate the article, but that does not mean I&#;m specifically endorsing that piece of gear.

What Matters To Us

The absolute number-one thing we need to fix in our minds before we go any further down this lithium-battery system selection road is that the needs of offshore voyaging boats are different and more stringent than pretty much any other usage case except aircraft.

Don&#;t Look To RVs (Campers)

For example, a system designed for a recreational vehicle (RV) is useless on an offshore voyaging boat because:

• Lithium-battery system load dumps on an RV don&#;t result in the power steering shutting down (think autopilot), the headlights going dark (think nav lights), and the dials blinking out (think plotter and instruments) in the middle of the highway.
• RVs generally spend a lot more of their time under power and have more room for solar panels in relation to their needs&#;an RV is more like a motorboat than sailboat.
• Most RV campers spend a lot more time on shore power.

RV lithium-battery systems do not supply mission-critical safety systems (driving), offshore voyaging boat systems do.

It&#;s also important to understand that RVs are a far bigger market for lithium-battery systems&#;for example, less than 10% of Wakespeed WS 500 alternator regulators are sold to boat owners&#;so most of the documentation and suggested configurations we find on the internet do not apply to us.

Compare Against a Benchmark

Next we need to compare against the long-proven solution, a well designed and installed lead-acid based system, and be realistic about what we are taking on when we leave that behind:

1. Installing a lithium system that increases the chances of an electrical blackout is bad seamanship.
   • If you doubt that, please read this before going further.
2. Lithium systems are way, way more complex and intrinsically less reliable and fault tolerant.

If we install a lithium-battery system that&#;s anything less than done right, we will have taken a huge step backward. The ocean doesn&#;t give a shit how cool our electrical system is, it only cares about how functional and reliable it is.

Good News, Bad News

The good news is that today we can build a lithium battery-based electrical system that&#;s makes the offshore voyaging boat grade, and even do that at a relatively reasonable cost.

The bad news is that it&#;s on us to figure out how to do that in a seamanlike way, since there are no turnkey systems specially designed for our needs.

Actually, there are from Ocean Planet Energy, but even if we decide to buy the whole system from Bruce and his good folks (highly recommended), we still need enough understanding to know what he&#;s talking about, and to install and maintain the system right; yes, even if we pay someone else to do the actual work.

Why I&#;m Writing This

But, before I dig into the technology, this article and how it will unfold was, as happens so often, inspired by a member comment:

Right now my hang-up is why LFP communication with the Alternator Regulator is necessary, and I have heard no reasonable technical explanation from anyone yet.

Member, Rick

I have to say that when I first read that I was a little put out. After all, I have written a complete Online Book, much of it explaining just that in detail. If you are too lazy to read it&#;yada, yada, yada&#;

But then I realized Rick has a point:

1. I need to explain this more simply and in one place, rather than scattered throughout the Book.
2. I also need to come up with a solution for those who don&#;t want to go that far or already have lithium batteries that don&#;t communicate; often, but not always, called &#;drop in&#;.

And then, once we have covered that off, we need a simple, or as simple as it&#;s possible for me to make it, list of criteria we can use as we buy stuff.

By the way, if you were wondering why there was no article or tips last week it was because I spent a ton of time researching for this article&#;this stuff is still complicated!

Let&#;s do that.

LiFePO4 battery is the best you can buy among any deep cycle batteries. However, there are countless options, even among LiFePO4 batteries. These batteries come in different voltages, ampere-hour ratings, features, and many other parameters. Therefore, you need to know how to choose a lifepo4 battery to buy the right one.

This article will provide all the information you need on the subject. You will know about all the factors that play a role in buying decisions. You will also learn about the best places to get these batteries.

What is a LiFePO4 Battery?

LiFePO4 battery stands for Lithium Iron Phosphate batteries. They are named so because the cathode material is LiFePO4. The anode is made of graphite. LiFePO4 batteries are a considerable improvement over conventional lithium-ion batteries. Additionally, their performance is leaps and bounds ahead of lead-acid batteries. These reasons have made LiFePO4 the most popular battery choice in recent years.

Factors to Consider When Buying LiFePO4 Battery

Different users will have different preferences when buying a LiFePO4 battery. Your decision should be based on factors like:

Capacity

The capacity of a battery represents how many appliances it can power and for how long. It is measured in Watt hours (Wh). The capacity is the primary factor to consider and the main factor that drives up the LiFePO4 battery cost.

Users often get confused when they cannot see a Wh rating mentioned on the battery. Instead, they find voltage and Amp hours (Ah) ratings.

That is alright. You can find the Wh rating by multiplying voltage and amp hours.

Wh = V x Ah

For a 12V battery with a 320 Ah rating, the Wh will be:

Wh = 12 x 320 = Wh

To find out how much capacity you need, you can add the wattage of all the appliances you use. Then you can multiply it by the hours you want to run them without charging the battery. This will give you the minimum watt hours of the lithium-ion batteries you should buy.

For instance, if you want to run a total of 300W load for 10 hours, you require a minimum of:

Minimum Wh = 300 x 10 = Wh

For more lithium iron phosphate battery manufacturerinformation, please contact us. We will provide professional answers.

Since the load or running time can increase or decrease, the required battery should have more capacity than the minimum Watt hours you require. Therefore, the Wh battery will be a good fit for the Wh minimum capacity.

Value For Money

Many users focus on &#;price&#; as the deciding factor. However, a better factor to consider should be the value for money of the battery.

Lead acid batteries are the cheaper option in the market today. However, their lifespan is only one-tenth that of a LiFePO4 battery. While LiFePO4 batteries can last over 10 years, a lead acid battery will run out after a year or so. Additionally, there is always the risk of cheaper batteries running out while on the job.

Therefore, opt for value for money instead of the price as the deciding factor. It can save you countless trouble in the long run. This brings us to our next important criterion.

Battery Life

It is essential to consider how many years a battery will last. You can save money and buy lead-acid batteries if you want a short fix for a few months. However, most users do not want that. Instead, they require a long-term solution.

A LiFePO4 battery is the best option in terms of battery life. A good quality LiFePO4 battery will easily last upward of 10 years. AGM and conventional lithium-ion batteries can work well for three to four years.

Cycle Life

Cycle life means the number of charge and discharge cycle that your battery can undergo. A longer cycle life means a battery will last longer. Batteries do not come with a suggestive lifespan on the box. However, they do mention a cycle life. Choose an option with a longer cycle life for a better return on investment.

Warranty

Warranty is a good indicator of the build quality of the battery and its lifespan. Lead acid batteries come with a 6-month warranty. Therefore, they are workable for up to a year until they demand replacement. LiFePO4 battery is a whole different game.

You will find different kinds of warranty periods with different LiFePO4 manufacturers. Eco Tree Lithium is the leader in the game as it provides a warranty of an astonishing 6-year. You can expect the Eco Tree Lithium batteries to easily work for over 10 years with a warranty like that.

Depth of Discharge (DoD)

Depth of Discharge (DoD) is a significant factor that makes people switch from existing lead acid batteries to lithium iron phosphate batteries. Depth of discharge denotes the usable capacity of the battery.

For instance, the depth of discharge for lead acid batteries is 50%. Therefore, you can use these batteries to 50% of their capacity. After that, they will require charging. However, for Eco Tree Lithium&#;s LiFePO4 battery, the DoD is a whopping 100%. You can use LiFePO4 through the full rated capacity.

Here is an example for putting things in perspective. Suppose your capacity requirement is 200 Ah. You can meet this requirement with a 200 Ah LiFePO4 battery. However, you will need a 400 Ah battery capacity if opting for a lead acid battery due to its half depth of discharge.

Maintenance Requirements

Every battery has a distinct maintenance requirement. Lead acid batteries have many requirements like electrolyte top-ups and venting the buildup gases. Fortunately, maintenance of LiFePO4 battery is much simpler and easy.

Dimensions

Battery dimensions are important for applications like motorhomes. The battery compartments can accommodate a particular size battery bank. LiFePO4 battery has prefixed size groups to denote the standard size of the battery. Match the lithium battery group with your requirement.

Weight

Weight is not always on the priority list of important parameters. However, some users find having a lighter battery preferable. If that is the case, any lithium battery is a better buy over a lead acid battery. For instance, a lead acid battery pack of 500 Ah can weigh around 850 kg. The same job can be done by a 250 Ah lithium-ion battery weighing 210 kg. This means a considerable difference in weight.

The main differences come from the eliminated weight of lead plates and electrolytes. Additionally, lithium iron phosphate batteries have lighter electrodes.

Safety

Safety becomes essential when you operate your battery near life and property. There have been instances where lead acid battery leak fluids that cause corrosion of the battery and nearby appliances. Conventional lithium batteries have fire and explosion hazards with them. However, lithium iron phosphate batteries are made using very stable compounds of iron and phosphate. These will never explode or cause fire injury.

Voltage Rating

The voltage of the battery pack is important because it determines its usability. For instance, you cannot replace a 24V battery with a 48V battery and vice versa. Every type of voltage rating has a distinct application, advantage, and disadvantage. If you are replacing your old batteries, you will need to find old voltage rating and match new batteries with the same rating for a constant voltage.

Common voltage ratings are:

• 12V: Ideal for powering lights, science projects, and small-scale energy storage.
• 24V: Used for trolling motor, solar panels in motorhome, and electric scooters.
• 48V: Used for home solar batteries, data backups, motorhomes, etc.

Cold Weather Usage

All batteries are known for performance stuttering in extreme temperatures. Freezing conditions can lead to battering running flat. These batteries often do not recover once the temperature toll takes place. Therefore, find the optimal temperature range of the battery. Better yet, choose Eco Tree Lithium batteries with an inbuilt heater for cold weather.

Features

Modern batteries come with many features that add to the convenient user experience. Take the case of this battery. It has a Bluetooth feature to check your battery stats remotely. You do not have to open the battery compartment. You don&#;t have to use a multimeter to check the voltage and current parameters. You can manage the battery remotely from a Bluetooth device.

Other secondary features can include LED indicators for the charging system. Having a handle to transport the battery is also a handy feature to have.

Battery Management System (BMS)

Always choose a LiFePO4 battery that comes with a BMS. A battery management system has a lot of safety protocols against potential hazards. All batteries are prone to irreversible overcharge and over-discharge damage. BMS protection measures cut off the circuit to eliminate any possibility of damage.

Environmental Impact

Modern energy technologies are pushing towards greener initiatives. It is recommended to choose an environmentally friendly battery option. For instance, cobalt-based batteries (like lithium cobalt oxide) are not environmentally friendly. This is because cobalt is rare and toxic in nature. LiFePO4 battery is one of the greenest battery out there.

Toxic

Cobalt and lead come in toxic heavy metals category. These materials can cause health hazards if they come into human contact. Therefore, batteries that include these metals are considered unsafe. This includes all lead batteries. However, a lithium iron phosphate battery does not have any toxic substances in them.

Additionally, lead acid chemistry leads to the emission of toxic gases. You might be familiar with the pungent smell that often comes from lead batteries. Therefore, choose a battery that does not have any such risk. You will never need to vent lithium iron batteries because it releases no toxic gases.

Do You Need BMS in a LiFePO4 Battery?

Yes, you should always buy a LiFePO4 battery with a BMS. Lithium iron phosphate battery is a hefty investment. A BMS protects that investment from any harm. BMS will prolong the life of your battery significantly by monitoring every parameter.

Battery management systems come with surge protectors to avoid the harm of excessive currents. Additionally, many other circuits shield the battery from adverse situations. Many BMS also come with displays and relays that monitor data.

Where to Buy a LiFePO4 Battery?

Eco Tree Lithium is the best place to buy a lithium iron phosphate battery. These batteries outperform most batteries on the market. They have features like BMS, Bluetooth, an in-built heater, and a 6-year warranty. Additionally, you get the brand name of the leading LiFePO4 battery supplier globally.

Conclusion

You can easily choose the best battery with the above information. You can also differentiate between LiFePO4 and other lithium-ion batteries. A good battery can be the driving point for a decade of worry-free operation. A lousy option can lead to hazards, breakdowns, and chasing the manufacturer for a replacement. Therefore, spend extra time choosing the battery to avoid wasting your time later.

Frequently Asked Questions (FAQs)

Here are the answers to some common questions regarding LiFePO4 batteries:

Are all LiFePO4 batteries the same?

No, all LiFePO4 batteries are not the same. The build quality of the batteries differs between manufacturers. These batteries also come in many different types, dimensions, capacity, voltage rating, and features.

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