THE ROLE OF START-STOP BATTERY

Stop start vehicles require enhanced batteries due to the frequent start and stop events at traffic lights. Our Start-stop series has the enhanced durability and battery life needed to withstand such driving environments.

The Start/stop system controls the engine when the vehicle is not in movement and restarts the vehicle when it begins its acceleration. This technology can help avoid unnecessary energy loss caused by engine idling and has been proven to cut fuel consumption by 5-15%. Start-stop systems are expected to grow up to 23 million vehicles by 2017.

Although stop/start idle ­systems have been used on ­hybrid vehicles for many years, a growing number of non-­hybrid late-model import models are also being equipped with this fuel-saving technology. In 2015, almost every major automaker offered one or more models with stop/start idle control. Many experts predict that within the next two years, over half of all vehicles sold in the U.S. will be factory-equipped with stop/start systems.

What does this mean to you? It means a growing service ­opportunity to diagnose and repair these systems as they come out of warranty in the years ahead. The 2015 model year marked the tipping point where stop/start technology really took off. You’ll find it on everything from entry-level cars such as the Kia Rio (with Eco package) to the Acura TLX and various Mazda models, to top-of-the-line luxury and performance cars such as Audi, BMW, Jaguar Mercedes-Benz, Porsche and VW. And as each new model year comes along, stop/start technology will become almost universal.

Stop/start technology has been around for nearly a decade on full hybrid vehicles such as the Toyota Prius and Honda Insight. It’s also used on many “mild hybrids” such as the Honda ­Accord, Civic and CRZ hybrids, Hyundai Sonata hybrid, various Lexus hybrids, Nissan Altima ­hybrid, Toyota Camry and Highlander ­hybrids, and VW Touareg hybrid. On these applications, the high-voltage hybrid battery is used for the stop/start function. It may also provide additional power assist when accelerating, depending on how the system is configured.

What’s different about the next generation stop/start systems is that the idle shut-off feature is being incorporated into non-hybrid cars, trucks and SUVs. In other words, most of these applications will not use a special high-voltage nickel-metal-hydride or lithium ion battery, but instead will get their cranking power from an AGM (absorbent glass mat) 12-volt lead-acid battery.

Some of these new applications (BMW and VW, for example) actually use two separate batteries: a 12-volt AGM battery for cranking the engine, and a second conventional 12-volt wet-cell, lead-acid battery to power the onboard electronics. On the BMW and VW applications, the batteries are mounted in the trunk (one on each side). What’s more, each battery may be charged independently of the other depending on electrical load and demand – which will complicate charging diagnosis if either battery is not being maintained at full charge, or there is a key-off power drain that’s running down one or both batteries.

WHY STOP/START?

There is no federal rule that ­requires stop/start idle control on any new vehicle. It’s just one of the many steps that automakers are having to take to achieve the Corporate Average Fuel Economy goal of 52.5 mpg by 2025 (which is required by law). In Europe, where fuel prices are considerably higher, about 60% of late-model vehicles have stop/start idle control systems. Although we are currently enjoying a temporary drop in gasoline prices, the push for higher fuel economy numbers is more about global climate change and reducing CO2 emissions into the ­environment.

Stop/start systems (also called “idle stop” or “idle stop & go”) use inputs from the steering wheel position sensor, vehicle speed sensor, throttle position sensor and brake pedal position sensor to determine when the vehicle has come to a halt and will likely ­remain stopped for a period of time. The powertrain control module (PCM) will then shut off the engine by killing fuel and ignition. When the driver lifts his/her foot off the brake pedal (or depresses the clutch pedal if the vehicle has a manual transmission), the PCM starts the engine so when the driver pushes down on the accelerator pedal the engine will ­respond and drive the car as if nothing has happened.

Most of these systems will restart the engine in less than half a second, ­allowing a more-or-less seamless stop/start function. On the 2015 Acura TLX, active engine mounts are used to offset and dampen the engine starting vibrations.

So how much fuel does idle stop/start actually save? It depends on how the vehicle is driven. In an urban setting with heavy stop-and-go traffic, a stop/start system can improve overall fuel economy as much as 10 to 12%. Most automakers estimate stop/start idle control saves the average motorist about 6% on his/her fuel bill. For vehicles that are driven mostly on the open road and spend very little time stopped, the fuel savings are ­minimal.

On many applications, the stop/start system can be temporarily disabled by pressing a button. On some vehicles, the stop/start function will remain off until the driver pushes the button to turn it back on.

On all stop/start systems, an indicator light on the instrument panel tells the driver when the ­engine has stopped. Consequently, you may have to educate some customers as to what the indicator light means and how the system operates.

HOW IT WORKS

For a stop/start system to function normally, the ­engine management system has to look at how the vehicle is being driven. It monitors engine speed, temperature and load, as well as vehicle speed, and the positions of the brake and accelerator pedals, steering wheel and transmission gear selector. The PCM may also consider accessory electrical loads on the engine (headlights, wipers, state of battery charge, etc.) and A/C cooling requirements. Using all of these inputs, the control module will then ­decide whether or not to shut the engine off when the vehicle stops.

With most stop/start systems, the engine will shut off after the vehicle has been motionless for a few seconds if the transmission is in drive and the driver is holding his/her foot on the brake pedal. Some systems may even anticipate a stop by shutting off the engine when the driver lifts his/her foot off the accelerator pedal when the vehicle is decelerating. Read more. 

On most systems, the stop/start function may not occur if the cranking battery voltage is low (less than 75%), if there is a high A/C cooling load due to high ambient temperatures, or if there are ­usually high electrical loads on the charging system (lights, ­defrosters, heater, etc., all on at the same time).

On Mazda’s “i-stop” system, the starter motor is used to crank the engine. The PCM also knows the position of the crankshaft and the engine’s firing order, so it also injects some fuel into a cylinder that is past top dead center on its power stroke and fires the spark plug to give the crank an extra kick. This makes the restart much easier and faster, ­reducing the load on the starter and the time it takes to restart the engine to 0.35 seconds.

OTHER CHANGES

The new next generation non-­hybrid stop/start ­systems also require some additional changes to the vehicle itself. In addition to a stronger AGM battery with more reserve ­capacity than a standard battery, a beefed-up starter motor is also required to handle the increased number of startup cycles. Others use a two-way alternator that serves as both a generator and a starter motor to crank the engine.

The main and rod bearings on some engine applications may also have a scuff-resistant, friction-­reducing coating to reduce the risk of metal-to-metal contact from frequent restarts. When the engine shuts off, oil pressure drops to zero. Most late-model cars use relatively thin oil (0W-20, 0W-40, 5W-20, etc.) so the oil may drain out of the bearings fairly quickly depending on oil temperature, bearing clearances and how long the vehicle sits without running. The coating on the bearings provides an extra layer of protection until oil pressure can restore ­normal oil pressure and flow ­following a restart.

On some applications, auxiliary electric pumps may be used to keep coolant circulating to maintain heat during cold weather or to supply hydraulic pressure to the automatic transmission. On a full hybrid vehicle, such as a Toyota Prius, an electric A/C compressor is used to maintain cooling when the engine is not running. We will likely see more of these electric A/C compressors being used on some next generation stop/start non-hybrid applications for the same purpose.

Another change you’ll find on some applications is an auxiliary module that maintains constant voltage to key electronics when the engine is in cranking mode. On a 2013 Kia Rio, for example, there is a DC-to-DC converter behind the glove box. The DC-to-DC converter senses system voltage and maintains steady voltage to the main power relay so system voltage doesn’t drop when the engine is cranking. If this module goes bad, it may cause the radio to stop working when the ­engine restarts due to low system voltage.

WHEN THINGS GO WRONG

Stop/start systems may fail in a number of ways and for a variety of reasons. The system may not shut the engine off when it should. The stop/start system may kill the engine, but fail to restart it when it should. Or, the system voltage may drop noticeably when cranking the engine.

The underlying problem may be electronic (PCM or other control module fault), electrical (low battery voltage, weak battery or poor cable connections), mechanical (bad starter motor or alternator, damaged flywheel teeth, etc.) or sensor related (bad brake pedal, accelerator pedal, throttle position or other sensor). The onboard diagnostic system should detect any major system or sensor faults and set an appropriate code, but as we all know, many faults never set a code.

If a stop/start system is not functioning normally, start with the ­basics. Check the charge and condition of the battery, check the battery cables (clean and tighten as needed to ensure a minimal voltage drop across the connections), check charging output, and use your scan tool to check the function of key sensors that provide input for the stop/start system.

Your scan tool sensor data should tell you if the brake pedal and accelerator pedal sensors are ­responding when the pedals move. Ditto for the steering position sensor. Is the vehicle speed sensor providing an accurate signal? Does the transmission gear selector show the proper gear when it’s moved from one position to another?

If you find one or more fault codes (which could be powertrain, body, suspension or other), follow the vehicle manufacturer’s diagnostic procedures to isolate each fault. This means accessing the service information data on the OEM website or via any of the aftermarket data services. Also, check for any TSBs that may relate to the problem.

At some point down the road, we may also see computer reflashes as a “fix” for certain stop/start issues. This will require a scan tool that is capable of doing reflashes and gaining access to the OEM ­updated calibration.

SERVICE PRECAUTIONS

The next generation stop/start systems on non-­hybrid vehicles are 12 volts, so there are no special precautions to follow other than to make sure the ­engine is off if it has a pushbutton start and/or smart keyfob.

With full and mild hybrid vehicles, however, you do have to watch out for the high-voltage battery. Hybrid voltages may range from 120 up to 330 volts, depending on the application. This kind of voltage can be deadly, so avoid any contact with the orange high-voltage hybrid wiring and battery until the battery has been isolated. Follow the vehicle manufacturer’s procedures for isolating the ­battery. Insulated gloves capable of withstanding up to 1,000 volts are required if working on a live system, and insulated hand tools are recommended.

For non-hybrid 12-volt applications with stop/start, you can use the same hand tools, diagnostic tools, battery and charging system test equipment that you use on other vehicles.

Since most of the next generation stop/start ­applications come factory-equipped with an AGM battery, you should replace same with same if the battery has failed. Substituting a less expensive conventional wet-cell lead-acid battery is not ­recommended.

AGM batteries typically provide greater cranking power thanks to their denser design. They also have a much longer service life than ordinary wet-cell lead-acid batteries because they have no liquid electrolyte in their cells. The electrolyte is held in spongy mats between the lead cell plates. This not only makes such batteries spill-proof, but also less vulnerable to outgassing and loss of electrolyte over time.

Another difference is that AGM batteries have a slightly different charging rate and voltage. AGM batteries recharge about 15% faster than a conventional battery (which is important for maintaining battery charge for reliable starting). A fully charged AGM battery will typically read 12.8 to 13 volts or higher (versus 12.65 volts for a conventional ­battery). A reading of 12.5 to 12.8 volts indicates a 75% charge. A reading of less than 12.5 volts means the battery is low and needs to be recharged and/or load tested.

A low-voltage reading may mean the charging system is not producing enough current to maintain battery charge, or there is a key-off current drain on the battery that’s causing it to run down. This may require testing charging output and/or checking for an unusual key-off power drain.

Battery condition can be determined by load testing or by using a capacitance tester on the battery. For accurate results, a load test requires a battery to be 75% charged. Charge doesn’t matter if you’re using a capacitance tester on an ordinary battery, but with an AGM battery it does. The battery should be 75% charged because an AGM battery has less internal resistance than an ordinary battery.

AGM batteries can be damaged by overcharging. To reduce the risk of this happening, use a smart charger that has a different setting for AGM batteries.

If a starter motor has failed, make sure the replacement is a quality reman or new unit, not a cheap rebuilt that won’t stand up to repeated start cycles. A stop/start system can really work a starter motor to death, so it’s important to use a starter that’s robust enough to handle the job.

Do not hesitate to contact Recor Batteries for more information about the range of Start Stop batteries, as our range of Start Stop batteries are perfect for stop start vehicles with heavily equipped electronic technology. They have many benefits that include:

• Increased stop life cycle
• Increased Charge acceptance
• Increased Starting Power
• Optimal safety for passenger compartment installation

Source: www.tomorrowstechnician.com

She found that by using a gold nanowire in electrolyte gel rather than lithium, a battery could withstand 200,000 charging cycles and only lose 5% of its capacity. Her discovery could lead to rechargeable batteries that last up to 400 years. This means longer-lasting laptops and smartphones, and fewer lithium-ion batteries accumulating in landfills.

Originally, the researchers were experimenting with nanowires for potential use in batteries, but found that over time, the fragile, thin wires would break down and crack after multiple charging cycles. It was on a whim that Thai coated a set of gold nanowires in manganese dioxide and a Plexiglas-like electrolyte gel.

“She started to cycle these gel capacitors, and that’s when we got the surprise,” said chair of the university’s chemistry department, Reginald Penner. “She said, ‘this thing has been cycling 10,000 cycles and it’s still going.’ She came back a few days later and said ‘it’s been cycling for 30,000 cycles.’ That kept going on for a month.”

Thai’s breakthrough is incredible, considering the average laptop battery lasts 300 to 500 charging cycles. The nano-battery developed at UCI survived 200,000 cycles in three months, meaning it could extend the life of the average laptop battery by about 400 years. It’s a pretty impressive set of figures, especially when you consider it was discovered by pure chance.

Of course, the researchers realized the amount of gold nanowire needed to create this battery would drive up prices, so they suggested nickel could be a substitute for mass production.

Sadly, the nanobattery itself is still very much in the developmental stage, meaning it’s probably a long way from intergration into the commercial market, when it finally does see the light of day it could change the landscape of laptop battery use (and much more) forever.

Source: UCI, www.electronicproducts.com

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A battery clean enough to eat may belong in a fictional future world, but the Aquion battery, which is not only clean but also has a long life and is relatively inexpensive, is already on the market. The battery can be used as a stationary storage solution for small operations, like houses equipped with solar or off-grid resorts, but its more exciting application is as a storage solution for large-scale energy farms. It could even be used alongside our existing energy grid, providing a cleaner way for energy utilities to store the excess solar electricity their customers produce during the day.

The technology, a twist on the 200-year-old saltwater battery, is made using abundant, non-toxic materials. Although it is a unique solution, it is not without its competitors. Tesla’s gigafactory is set to churn out hundreds of thousands of batteries per year. Some of these will be car batteries, but their Powerwall battery is also intended to store energy for homes and businesses. Ambri, a Boston-based company, is working on a battery that is based on a low-cost liquid metal technology. But for now, the Aquion factory is working at capacity, manufacturing batteries as quickly as it can, for a host of customers around the world.

Source: inhabitat.com

Originally published on RenewEconomy.

IT guru Simon Hackett must be the number 1 fan of Tesla electric vehicles in Australia. He took delivery of the first Tesla Roadster in Australia in 2009, and now he drives the last Roadster delivered here.

He also took delivery of the first two long range, high performance Tesla Model S electric vehicles in Australia last year, and has two more on the way already as upgrades. One is the latest Tesla model P85D with its “almost frightening” acceleration, and he also has an order for one of the first Model X, the electric SUV with winged doors.

“I love these things,” Hackett says in an interview with RenewEconomy. “The model S has changed the conversation about EVs. ” So much so, he says, that electric motors will soon become a routine consideration when buying a car. Do consumers want petrol, diesel or electric?

And Hackett believes that Tesla’s intervention in the battery storage market will have a similar impact.  Within 10 years, he predicts, battery storage will be as commonplace in homes and businesses as broadband, which barely existed in 2000 but was widespread just a decade later in 2010.

But in this market, Hackett will not be the number 1 consumer of Tesla, but potentially the number 1 competitor, as the newly installed chairman (and largest shareholder) of Australian battery storage company Redflow.

“We are at the start of that 10 year cycle,” says Hackett. “I reckon that within 10 years, energy storage will become a routine design choice. It’s not an experiment. We are at the cusp of that becoming routine and normal and incredibly effective.”

Hackett took over as chairman of Redflow last week, and believes that Redflow has the technology with its “flow batteries” to compete against Tesla, and the myriad other developers of lithium-ion batteries.

“This is the company in Australia that is doing serious innovation in batteries,” Hackett says of Redflow. And he has put his money where his mouth is, and vice-versa.

His first big task is to use his IT skills, and those of his private company Base64, to write the smart software that will allow a plug and play version of Redflow’s zinc bromine “flow” batteries that is simple to use.

As Hackett explains it, the physics and the chemistry of the Redflow flow battery has largely been mastered, although continuing price and performance improvements. The focus is now on IT and software.

“The future of the energy storage and handling sector is increasingly about the deployment of smart and dynamic control mechanisms to manage energy flows,” he says. “Here’s the analogy: Redflow makes hard drives, and what I am designing here is a high availability file server for them to be put into. What you will get early next year is battery system that can be easily configured and also easily scaled up later, and managed with a web browser.”

A year ago, Redflow was barely considering the consumer market for battery storage, at least in Australia. But the rapidly falling feed-in tariffs, rising electricity bills and Tesla’s dramatic intervention, has created a huge amount of interest in the technology.

“Tesla put fire under idea and with the feed-in tariffs going away, batteries are getting cheap enough for consumers to take matters into their own hands,” Hackett says.

“People started ringing Redflow and saying ‘you have got a fabulous looking battery technology – can I plug it into my house’? So I am driving the IT design and architecture to make that happen.”

Redflow announced last week that recent continued successful test results, and progress in the manufacturing process have allowed Redflow to extend its battery warranty and lower the unit price so that the effective lifetime cost per delivered kilowatt-hour has fallen by almost 50 per cent.

Hackett says the cost may come down even more. That’s because the flow battery loves doing what other batteries cannot do – it thrives on full discharge and charge.

So much so, that the latest tests suggest that the battery will live longer than previously though. The battery will have warranty for 3,000 full 10 kilowatt-hour energy delivery cycles. Redflow believes they will be good for at least 4,000, because testing of the latest electrode stack iteration has returned excellent results. “We don’t yet know quite how long our latest electrode stack will last – we will need to do a lot more long term testing – but we’re quite sure that its a lot better than our preceding versions.”

That’s important because the key to the cost of battery storage is in its life cycle, not just the capital cost. It’s just like electrical appliances and solar panels: there are cheaper options but they might not last as long.

At the moment – over a 10 year period – Redflow estimates the cost of production at around US 20c/kWh. Even with the exchange rate taken into account, and given that solar electricity probably costs between 10-13c/Wh, that is putting the technology in the ball-park, where it starts to compete with the grid.

“If we get another halving of that number over time, then everything gets rather fascinating,” Hackett says. That, he notes, is where the price drops between the differential between peak and off peak pricing, and battery storage becomes no brainer in a country with high electricity costs, mostly driven by the high cost of the grid.

In anticipation of this, and in response to more rises in electricity prices, Hackett says the market is “going mad”.

“The interest level is enormous. It feels like exactly what I was doing in internet terms 15 years ago. It is  early days and everything costs more than people would like it to, but volume increases will surely drive prices down.

“It’s like the early days of solar panels, when only true believers could  afford it. But that’s cool, they will tell their friends, and then when their friends get their (feed in) tariffs removed, they will add energy storage as the logical response.”

That’s when the consumers will decide to keep the electricity they generate from their solar panels and use it at night time. Morgan Stanley estimates that around 230,000 solar households in Victoria, South Australia and Victoria will come off premium feed in tariffs by the end of 2016.

Meanwhile, feed in tariffs for new installations continue to be cut, and fixed charges will continue to rise.

Hackett’s own house in Adelaide is “off grid capable. Which is to say that it has 10kW of  solar panels and 20kWh of battery storage (currently lead-acid, and soon to be replaced with Redflow batteries)”.

But as soon as the tariff changes and, say, fixed charges are jacked up high enough, he will reach the point where it becomes sensible to simple go off-grid. And he expects many others to follow.

He will do the same with his office complex in Adelaide. The building will soon take delivery of a 660kWh array of Redflow batteries. Hackett says that is enough energy to run the office building for several days.

In the first instance, he is going to fill the batteries up on off peak and run them during peak demand, to test the economics. The next option is to take the building off-grid, although that will likely need some 70kW of rooftop solar to be installed over the parking area.

“One reaction to electricity companies taking (feed in tariffs) away is to just say ‘I accept’. Taking tariffs away is a core driver for the future.”

Among the new innovations being introduced by Hackett is a decision to have Flextronics manufacture the battery electrode as well as the rest of the product.

He says this will create the cleanest path to high volume manufacture, and will remove any risk that its Brisbane site will become a production-rate bottleneck in the future. And it will allow the Brisbane site to focus on battery R&D.

Hackett describes zinc bromine flow batteries as an “inside out” battery”– because the fluids live outside the battery rather than inside.  It doesn’t mind whether it is totally full or totally empty; it can run in temperatures from 5c to 45C.

“You don’t have to be nice to it. The battery electrode is being constantly refreshed by the electrolyte tanks. For the electrode stack, its like having packet of Tim Tams that never runs out.”

It can be turned off in any charge state, and can spring back to life within a few seconds when needed. At the base level you get a battery that lasts  several times longer than lead acid. And while lithium ion is a “sprinter”, flow batteries are “marathon runners”.

source: cleantechnica.com

I changed my battery recently and after two weeks, battery was dead.

In this case probably the electrical system is not properly charging the vehicle battery and appropriate measurement is nedeed as well as alternator check.

Car batteries are warranted and if so for how long?
Closed type car batteries  that we use have warranty period of one year.

Why change the car battery after the charge indicator (peephole) indicates that the battery is good?
Due to the fact that the charge indicator of the car battery shows only the condition of one of the six elements of the battery.

Source: Opel Service Greece 

As they are inexpensive compared to newer technologies, lead-acid batteries are widely used even when surge current is not important and other designs could provide higher energy densities. Large-format lead-acid designs are widely used for storage in backup power supplies in cell phone towers, high-availability settings like hospitals, and stand-alone power systems. For these roles, modified versions of the standard cell may be used to improve storage times and reduce maintenance requirements. Gel-cells and absorbed glass-mat batteries are common in these roles, collectively known as VRLA (valve-regulated lead-acid) batteries.

Discharge
A lead–acid cell with two lead sulfate plates.
Fully discharged: two identical lead sulfate plates
In the discharged state both the positive and negative plates become lead(II) sulfate (PbSO4), and the electrolyte loses much of its dissolved sulfuric acid and becomes primarily water. The discharge process is driven by the conduction of electrons from the negative plate back into the cell at the positive plate in the external circuit.

Charging
Overcharging with high charging voltages generates oxygen and hydrogen gas by electrolysis of water, which is lost to the cell. Periodic maintenance of lead-acid batteries requires inspection of the electrolyte level and replacement of any water that has been lost.

Due to the freezing-point depression of the electrolyte, as the battery discharges and the concentration of sulfuric acid decreases, the electrolyte is more likely to freeze during winter weather when discharged.

Ion motion
During discharge, H+ produced at the negative plates moves into the electrolyte solution and then is consumed into the positive plates, while HSO−4 is consumed at both plates. The reverse occurs during charge. This motion can be by electrically driven proton flow or Grotthuss mechanism, or by diffusion through the medium, or by flow of a liquid electrolyte medium. Since the density is greater when the sulfuric acid concentration is higher, the liquid will tend to circulate by convection. Therefore a liquid-medium cell tends to rapidly discharge and rapidly charge more efficiently than an otherwise similar gel cell.