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Panasonic develops 12V NiMH energy recovery system for start-stop vehicles; aims to double fuel economy improvement rate of start-stop systems

8 February 2013

Concept of the 12V Energy Recovery System for start-stop. Click to enlarge.

Panasonic Corporation has developed a NiMH-based 12V Energy Recovery System for start-stop systems in vehicles. This system allows the energy generated during braking to be stored in the batteries and use the stored energy to power the vehicle’s electrical components, thus ensuring power availability even when the engine is not being used. The system is also designed to supply power to the drive assist motor, improving fuel economy.

With this 12V Energy Recovery System, Panasonic aims to approximately double the fuel economy improvement rate of existing start-stop systems over conventional gasoline-engine vehicles.

The 12V Energy Recovery System, which is designed to be connected in parallel with the main lead-acid battery, is based on new D-size nickel metal hydride (NiMH) battery cells. The main lead-acid battery is often placed in the engine compartment. As the new energy recovery system can be installed in the same compartment, it is possible to reduce cable connection resistance and simplify wiring.

To enable such a setup, Panasonic has developed battery cells that can endure the high-temperatures of the engine compartment. Using technology acquired in developing HEV batteries, Panasonic has improved the battery design, such as the polar plates, electrolyte and other battery parts to increase charging efficiency and improve durability in high temperature environments.

As a result, the cell’s maximum charging/discharging temperature is significantly improved from 60 °C to 75 °C compared to existing cells. This ensures that the system can be installed in the engine compartment, and provides a high degree of design flexibility for the system's installation.

Panasonic’s 12V system, comprising 10 1.2V Ni-MH battery cells, eliminates the need for voltage transformation. This helps lower the system’s costs and uses energy more efficiently.

Because conventional start-stop systems depend on a single lead-acid battery to take care of all electrical needs of the vehicle, from restarting the engine to running the air-conditioner and other electrical components with the engine off, the battery is put under too much load, Panasonic says. The new 12V Energy Recovery System addresses this problem and thus extends the service life of the main lead-acid battery.

Tests conducted by Panasonic using a 12V Energy Recovery System together with a lead-acid battery showed that the service-life of the main battery was extended by approximately six times compared to when a lead battery was used alone. (Results of charge/discharge life tests for idle-stop (SBA S0101) conducted at 60°C aging conditions by Panasonic. A Panasonic lead-acid battery (Q-55) and 12V Energy Recovery System were used.)

Panasonic started developing Ni-MH batteries for HEVs in 1997, and has been mass producing them since 2004. Its Ni-MH batteries are durable and able to maintain a high charging/discharging capacity over an extended period of time. This is supported by the company’s proprietary battery manufacturing technologies, including polar plate sintering technology, which involves the firing of metal nickel powder at high temperatures for manufacturing rigid, porous nickel substrate.

February 8, 2013 in Batteries, Fuel Efficiency, Vehicle Systems | Permalink | Comments (16) | TrackBack (0)


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Simply based on the raw materials and their quantities within the cells, Li-ion will easily beat NiMH on cost in the near future. Additionally, theywill be lighter and perfectly capable of accomplishing the same applications. We have this problem where we refuse to move forward because it might disturb some current industry or company. Humans will have progressed to the next level when we no longer seek permission for technological advancement from marketing guy and bean counters.

The majority scares easily?


Are you so sure, Pananasonic is alos a supplier of the most advanced Li-ion batteries cell, so if they propose NiMH for this particular applications they probably have good reasons to do so...

The NiMH batteries are being used as a substitute for a capacitor.
IOW power input/output and cycle life are the important criteria.
These will be small batteries with the total weight relatively low.
Lithium is not a one size fits all solution, and Panasonic's NMiH has proven for many years to have what it takes in power density and durability.

"Panasonic's NMiH has proven for many years to have what it takes in power density and durability."

" based on new D-size nickel metal hydride (NiMH) battery cells" with <10 amp output, just as GM, officially solvent or bankrupt, betrayed NiMH patents - starting decades ago.

Good news from Panasonic. Pretty soon, everyone will have a mini-hybrid in their engine compartment in the form of this technology. Anything that reduces oil consumption TODAY is welcome improvement. No need to wait for fancier technology, do it NOW.

This could become the foundation for lower cost 'minimalist' HEVs with much lower cost 12-Volt NiMH battery and smaller e-motor.

The extra cost over standard ICEVs should not be much over $1,000. However, fuel economy will not be as good as Toyota's HEVs with larger battery.

Interesting specs on the D cell. It's rated at 6 Ah which is very low compared to current non-automotive grade NiMH D cells which are rated around 10 Ah.

Obviously these cells have sacrificed capacity for high power and durability in high temperatures.

Your typical NiMH would not last long at 60-75C.

I look at all this stuff as intermediate solutions while we wait for the "better battery." Of course we have been waiting for 100 years while our Big Oil owned Government and our industrial capitalistic system, strangled by the need to maximize profits for the Greedy Wall Street Gang, keeps slowing down progress.

What we need is a company with a large pot of cash that is willing to risk a large part of the pot to develop that "better battery." I don't see that happening soon. The best bet now seems to be the DOE's JCESR project at Argonne Labs.

What's really sad about all this is the rich oil (energy) companies could have developed this battery long ago had they not been driven by greed to fight instead of to join.

I look at all this stuff as intermediate solutions while we wait for the "better battery." Of course we have been waiting for 12 years while our Big Government wastes our money on hybrids that seem to have accomplished nothing to develop the kind of battery we need, while our industrial capitalistic system, strangled by the need to support the greedy, spendthrift bureaucrats in government, struggles to make progress.

[And how can an industrial capitalistic system slow down progress? It is the government that has such power.]

What we need is scientific advances on all fronts, not a government with large pots of our money, that it spends to support various political eyewash (like 12 years of Prius rebates).
The best bet now seems to be; count on luck.

What's really sad about all this is the richest country in the world could have been producing enough oil to eliminate much of the hundreds of billions per year spent on foreign oil over the years - since about 1973.
It is now (for 2012) down to only (only?) $434 billion/yr.

The United States imports about 6 million barrels of crude oil per day from OPEC nations.

“Hybrid electric vehicles have saved close 5.5 million barrels of fuel in the US since their introduction in 1999.

So hybrids have saved us about one day of imports - (one day TOTAL, since ~1999).

Maybe Obama will increase support for the oil companies :)

Oops, that data was for 2007/2009.

Hybrid electric vehicles have saved almost 35 million barrels of fuel in the US since their introduction in 1999.

So hybrids have saved us about 7 days of OPEC imports - and about 4 days of total imports - since 1999.

Yes TT...5.5 million barrel/day from OPEC and another 6.0 million barrel/day from other countries @ an average price of $100/barrel = about $438 B/year. That is almost 91% of USA's annual trade deficit. It was even worse in 2010, 2011 and 2012.

At that rate, crude imports alone, would create an accumulated trade deficit equivalent to the total USA's real estate value in about 34 years.

Assuming that both crude price and consumption may go up at an average of 5%/year but USA's real estate value may not rise much, 100% of USA's real estates may be required to pay for the related accumulated trade deficit in about 18 short years or by 2027 or so.

This means that 100% of all Americans may be directly and/or indirectly leasing space to live and work from external owners by 2027 unless oil imports are drastically reduced.

This fact, (having to sell out 100% of accumulated properties to pay for Oil) may have more impact on the average American than pollution and climate changes created by burning 20 million/barrel/day.

>>So hybrids have saved us about 7 days of OPEC imports - and about 4 days of total imports - since 1999.

And that is ONLY because we have so few of them. If all cars in the US got 50mpg (like a Prius), we would have cut total oil consumption by close to 50%.

Being *against* highly efficient cars is pure madness, yet many people are.

When you think 95% of the prople are mad, and you are sane, you are either missing the obvious or you are mad, or both.

What is missing for EV is not so much the "better battery", but rather the clean source of electricity in the first place. The current grid-mix contains so much coal and natgas that a Nissan Leaf is WORSE than a Toyota Prius, in terms of CO2/mile.

Better batteries will make EVs more practical in terms of driving distance, but only marginally cleaner in terms of CO2/mile. The elephant in the room is that for the foreseeable future, we do not have ANY surplus of CLEAN (fossile free, CO2 free) generating capacity at all to run electric cars on.

To get that, we need a massive build-out of nuclear power plants. And that will take 20 years, at least, even if the anti-nuclear luddites finally see the light (or the ensuing darkness).

In the meanwhile, we should save oil using the cleanest CO2/mile technology there is: Hybrid diesel cars that can get 70mpg TODAY for a car the size of an accord/camry/passat and using existing technology.

We can get all new cars to 50 mpg average by 2015 by doing this, and reducing purchases of Ford F-150 and Chevy Silverado monster pick-up trucks except for uses where they are actually needed. It is a disgrace that these monster trucks are the two top-selling vehicles in the US.

If, as seems likely, we're going to continue to use a lot of coal for power generation in the future, it would be nice to use it more efficiently. Direct Carbon Fuel Cells could generate power from coal at efficiencies of around 80%:

Rather better (i.e. at least twice as efficient) than the old-fashioned approach of burning the stuff which emits lots of particulate matter into the atmosphere, not to mention plenty of radioactive material.

As seems usual with this sort of advance in technology, the proof of concept has been shown in the labs but nobody has bothered to develop it further.

Now, the DCFC isn't my preferred option - this would be to develop Molten Salt Reactors, another superior technology developed in the US National Labs then abandoned. If we're not going to develop MSRs but instead use lots of coal, surely it should be worthwhile to use it much more efficiently?

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