Electric Car Batteries



Okay, let's mention the B-word. Batteries! Electric car batteries!

Lack of good battery technology has held back electric cars for a long time. If electric cars had any drawback, it was due to batteries. Nobody was investing in research to improve on what is a century old science. But this is now finally changing as car manufacturers develop their own types of batteries. Electric car batteries are getting better all the time. As more of us go electric, there will be a bigger market to stimulate better products.

So, even if you buy electric today and need to replace your battery in about four years time, hopefully there should be something better and cheaper for you to buy then. Where there's a market there's a way…..! And for the first time since the early 20th century, there is a growing market for electric car batteries.

Electric car batteries have already been developed that can last up to forty years. Another exciting development is Silicon Nano technology, which improves energy efficiency and density. This type of battery will be installed in a new electric car which is in development.

There is already some wonderful technology in existence but it is not available to the mass market or to people doing their own conversions. However, I am optimistic that this will change in the near future.

The main issue with electric car batteries, is their cost. They cost about $2000 to replace because you are working entirely off battery power. EV batteries wear out faster than a 'regular' car battery because they are the only source of power in the vehicle. Usually, they last about four years. Your battery could last longer if you do less than about 50 miles a day in your car. If so, the cost of replacement may not be a big issue for you.

An EV actually has a group of batteries (between 10 and 25 units, each containing 3-6 cells). Some of the units are weaker, due to their position in the group. Over time, this weakness increases, so that these give out sooner than the rest. This can be expensive, if you have to replace the entire unit when the weakest link goes dead.

Recharging electric car batteries normally takes about four to ten hours from your home electricity supply, depending on the current you use. In the future, it will be different. Recharging grids which are being developed, will shorten the time to possibly as little as ten minutes for an 80% recharge!

electric car battery

This Little Fiat 600 conversion has its battery pack stored in the boot. Photo: Scott Andress

Deep-Cycle Batteries Explained

Batteries are used in gas car engines as well as electric cars. Because they are both called 'batteries', people sometimes think they are interchangeable. However, they are very different products. Gas cars use shallow-cycle batteries. Electric car batteries are deep-cycle ones.

A gas-car battery is made up of light foil electrolyte plates. This small battery is only needed to power the ignition, lights and other accessories. It recharges from the car's alternator as the car drives, constantly topping up its charge. In fact, it needs to top up after only 5% of the charge is depleted. This makes them 'shallow-cycle'.

Shallow-cycle means that if you leave the lights on overnight, 5% of the battery will be depleted and it will go flat. Then you'll have to find some kind person with a jump lead to give you back enough charge to get you going again. Yep. Been there done that!

Electric car batteries work the opposite way. They are made of stronger, metal electrolyte plates. They are 'deep-cycle', because they need to provide a lot of power over a long period before recharging is possible.

Deep cycle batteries can be depleted to 80% of their charge before they need to be topped up.

Deep cycle batteries are used in solar panels, so that when the sun does shine, you can get most of that power over a long period. Other types of deep-cycle batteries are those used in heavy-duty machinery, like forklifts.

(Marine batteries, are sometimes called 'deep-cycle' and sometimes used for electric vehicles, but are not recommended because they are not true deep-cycle, more like 'mid-cycle' and have too short a life.)

Golf cart batteries are also deep-cycle and are the most suitable for use in electric car conversions, where you do not have the access to state-of-the art technology, like electric car manufacturers have.

Lead Acid Batteries

Most people who convert gas cars to electric use humble golf cart, deep-cycle batteries and they are perfectly adequate. These are lead-acid batteries and are usually 6 volt, or 8 volt.

They are a well-developed, tried-and-tested technology. They are widely available and not excessively costly. These electric car batteries are used in most DIY conversions.

The advantage of lead acid batteries is their reliability, availability and affordability.

The main drawback of lead batteries is that they are not as energy efficient as they could be. This means that lead-acid batteries have a lower energy density than other types. They have less range and take longer to recharge than some other types of electric car batteries.

If you are using lead acid batteries, it is especially important to make sure to recycle your battery. Lead is toxic and leeches into water, or into the air, if incinerated. See below for more information on disposing of old batteries.



Nickel Batteries

Nickel Metal Hydride, or NiMH is another type of battery that has been developed for use in electric cars.

With NiMH batteries, you can double the distance you can travel without recharging and they last about twice the length of lead batteries. These are much more efficient than lead in terms of energy density. They are lighter than lead, but not as light as lithium ion.

Alas, they are also more expensive, costing over $20,000 as opposed to $2000 for lead. But this price will come down dramatically over the coming years as the market grows.

Another disadvantage is that they are not very efficient while recharging. They're also not great in cold climates and overall, they are not as reliable as lead.

General Motors developed a high-standard Nickel battery for the electric cars they ended up crushing. But they are sitting on the technology and won't let anyone else use it. Another company, Cobasys, also has battery technology it is witholding. If these companies are not using their knowledge to bring more environmentally-friendly products to the market, they should at least license, or sell the rights to someone who will.

...why don't they?

We only have one planet, one earth. And these corporations are allowed behave like this, doing damage to us all, our planet, our air, our climate….all for a little short-term greed. Whose planet is it anyway? And why are governments complicit in this? Isn't it time the common good of the entire planet's well-being took precedence over the needs of General Motors shareholders?

Okay, rant over. Now back to the technicalities….

Lithium Ion Batteries

electric car battery

This is what a lithium ion battery looks like. Just like the ones in your laptop. Tesla use over 6000 of these in the Roadster. Photo: Qued Quest

Despite the years of wasted research that went into producing a good nickel battery, there is light on the horizon…...the Lithium battery!

(All this science talk is bringing me right back to science class and the periodic table of the elements…...how I hated chemistry.)

So, Lithium batteries are the big hope for electric cars. But lithium sounds familiar, and not just from Mrs Farrell's Chemistry class. Aren't Lithium the exploding things in laptops?

Yes. They are. Laptops do use lithium batteries. And there were safety issues over the years when they overheated. However, when used in electric cars, these problems have been largely eliminated by placing the electric car batteries in a stronger casing unit.

Lithium Ion batteries are very energy-efficient, but do not have a long life cycle, like the Nickel battery. And they are pretty pricey. And if you have one faulty cell, you have to replace the entire unit. Ooch!

(Tesla have solved this particular problem, with replaceable blades in the Roadster batteries, so you can just replace the faulty blade. But these electric car batteries only come with the $100K Tesla car attached and are not available separately! The Roadster has over 6000 lithium ion batteries to power its high speed.)

Lithium Polymer Batteries/LiPo

The Lithium Polymer Battery (LiPo) is a further improvement in battery technology. Instead of storing the Lithium in a liquid solution, the Lithium is stored in dry salt form and packaged in a strong plastic pouches, the 'polymer'. This makes the lithium much more secure, and less susceptible to combustion. These batteries are also very flexible and can be adapted to fit many spaces.

These are less pricey than the Lithium Ion, but are still pretty expensive, compared with other types of batteries. They also have a shorter life than Lithium Ion.

It is now possible to buy Lithium Polymer electric car batteries for your own conversions, but they will probably set you back about $10,000 per car.



Electric Car Batteries Care

To get the full lifespan from your electric car batteries, give them a little tender loving care! Read the care instructions carefully, or ask your dealer what to do. Batteries are expensive to replace, so it is worth taking care of them as the manufacturer suggests.

  • Some batteries like to be kept topped up with water, and to be kept charged.

  • All batteries like to be properly charged with the correct voltages and not to be overcharged. Use a 'smart' battery charger to take care of this for you.

  • Some batteries hate being dropped or struck! Handle them with care.

  • Some batteries prefer to be used up a certain amount before recharging. Others tolerate being topped-up whenever you like.

  • Batteries really like to be recycled. They don't like polluting the environment and hate the thought of death and annihilation!

A Little Battery Etiquette

All batteries should be recycled. They all have useful bits that can be reused. And when they go to a recycling facility the toxic parts can be handled in a way that will not damage the environment by leeching into our water table, or causing air pollution if incinerated. This is why we should never throw a car battery in with our regular garbage. Batteries are too toxic to be treated like household waste.

Most battery shops will now take back your old electric car batteries for recyling when you buy new ones, at no cost. So don't forget to bring the old ones along when you go shopping. Many traders will even take back old batteries for recycling even if you do not buy new ones. In Europe, new legislation has now been introduced to this affect. If you are buying online, you should easily be able to locate a battery-recycling facility by contacting your local authority.

Then we can all enjoy the beautiful forests and mountains and not come upon sights like this one when we go hiking with our children....

used electric car battery

Photo by Archenzo/Creative Commons.

We are destroying what we need to survive. It's air. It's water. When we destroy these things, we destroy ourselves. ---Erin Brokovitch.

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