PowerGenix enters micro-hybrid market with Nickel-Zinc batteries
17 May 2011
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| PowerGenix NiZn micro-hybrid prototype. Click to enlarge. |
PowerGenix, a manufacturer of high-performance, rechargeable Nickel-Zinc (NiZn) batteries (earlier post), has entered the burgeoning micro-hybrid electric vehicle market with its first production prototype product. PowerGenix has begun engineering qualification activities for the new battery with several automotive OEMs and will be fielding demonstration vehicles later this year.
PowerGenix’s NiZn batteries can offer several advantages over the lead-acid batteries found in current micro-hybrids (start-stop systems). NiZn batteries are half the size and weight of lead-acid batteries, provide better charge acceptance and have a much longer lifespan. These performance advantages mean that NiZn batteries reduce vehicle weight and handle more start-stop events over a longer sustained life, significantly raising micro-hybrid fuel efficiency.
NiZn batteries also offer a single solution, powering all starting and micro-hybrid functions.
| Comparison of lead-acid and NiZn batteries for micro-hybrid applications | ||||||
|---|---|---|---|---|---|---|
| Parameter | Lead-acid | PowerGenix NiZn | ||||
| Form Factor | Prismatic | Prismatic | ||||
| Nominal voltage | 12V | 12.8V | ||||
| Nominal capacity | 60 Ah | 40 Ah | ||||
| Pack energy | 720 Wh | 512 Wh | ||||
| Gravimetric Energy Density | 35 Wh/kg | 69 Wh/kg | ||||
| Bare pack weight | 20.6 kg | 7.4 kg | ||||
The micro-hybrid pack is in a 8S1P configuration, and offers a discharge current of 400A continuous, 800A pulse. Operating temperature range is -30°C to 75°C, and internal impedance is <1mΩ per cell.
Early NiZn batteries (first developed in the 1920s) suffered from short cycle life due to dendrite growth leading to short circuiting, caused by the high solubility of zinc oxide—a discharge product of the zinc anode in the alkaline electrolyte. In addition to dendrite formation, zinc oxide solubility can result in shape change and densification of the anode on repeated charge/discharge cycles.
The basis of PowerGenix’s approach to making its NiZn battery commercially viable is a patented electrolyte formulation that reduces zinc solubility and prevents the dendrite shorting and shape changing problems. Further enhancement of cell capability is due to cathode and anode materials that are free of any heavy metal elements.
Micro-hybrids are about to become a fact of life in the auto industry. Within four years, almost two out of five new cars sold globally will be micro-hybrids—we’re talking about over fifteen million micro-hybrid cars per year. Since Nickel-Zinc uniquely hits the sweet spot of cost and performance for micro-hybrids, we see this as a phenomenal growth area for PowerGenix.
—Dan Squiller, CEO of PowerGenix
In China and other markets, vehicle makers will depend on micro-hybrid offerings to meet the new fleet fuel efficiency standards, so they’re scouring the globe for a battery solution that can meet the demanding performance and cost requirements of start-stop systems. Nickel-Zinc meets these requirements and can drive help drive the sales of millions of vehicles in Asia and elsewhere.
—Dr. Xu Gang, PowerGenix’s managing director for Asia
This looks like a good battery, but one of the original concerns was cycle life. If it can not do 1000 deep discharge/recharge cycles with little degradation, then it may not be considered for anything BUT micro hybrids.
Posted by: SJC | 17 May 2011 at 12:18 PM
Potentially good battery, but introduced at least 5 years late.
Posted by: yarross | 17 May 2011 at 01:40 PM
It may become another alternative in a growing world market.
Posted by: HarveyD | 17 May 2011 at 02:30 PM
'"Higher Energy Density":
Despite what the confusing rating on the package ("2500 milli-WATT-hour") may suggest, the PowerGenix AA cell does NOT contain more energy than a SANYO eneloop AA cell. This is because its current capacity is much lower at just 1500 milli-Ampere-hour (based on data sheet of PowerGenix AA cell, and verified by my own testing).
- Energy in eneloop AA cell: 1.25V * 2000mAh = 2500mWh
- Energy in PowerGenix AA cell: 1.65V * 1500mAh = 2475mWh
As an example: Suppose a set of 4 eneloop AA cells can power your external flash unit for 1500 shots, then a set of 4 PowerGenix AA cells will provide roughly the same number of shots. The difference is that your flash unit will recycle about 30% faster with the NiZn cells due to 30% higher battery voltage. On the other hand, this high rate of fire could cause the flash to over-heat and burn out.
"Long Cycle Life":
PowerGenix claims that NiZn has a service life that 'meets or beats' that of NiMH cells. But according to technical data found on PowerGenix web site, the NiZn cell is only rated for 200 cycles at 100% deep discharge. Most NiMH cells are rated for 500-1000 deep discharge cycles.
"Long Shelf Life":
PowerGenix claims the NiZn cells have longer shelf life than Lead-Acid batteries (which are notorious for high self-discharge rate), but did not compare against NiMH cells. In the "Charging Procedure" section, it says to recharge the NiZn battery every 30 days!
In summary: While the higher voltage offered by PowerGenix NiZn cells sounds attractive, it could damage or shorten the life span of your battery-operated appliances. In addition, NiZn cell does not pack more energy than eneloop NiMH cell, yet it suffers from lower cycle life and higher self-discharge rate. '
http://www.amazon.com/PowerGenix-ZR-PGX1HRAA-4B-Charger-Rechargeable-Batteries/dp/B0029NZVZ0
Posted by: Davemart | 17 May 2011 at 04:26 PM
Thanks for the analysis Dave, always appreciated.
Posted by: SJC | 17 May 2011 at 05:25 PM
Well the point here is you can replace the normal strarter battery with one of these saving alot of weight and gain the ability to power a micro hybrid design. And it should still be more durable the a normal car battery even with the extra use.
That should spark alot of microhybrid designs in various places.
Posted by: wintermane2000 | 17 May 2011 at 11:03 PM
Hi wintermane.
If the engineer I quoted who analysed the data is right, nickel zinc batteries would not survive long in a starter motor function, as their claims of long life simply do not pan out according to their own data sheets.
NiMH would last the life of the car, as they do in the Prius.
These would give up the ghost very rapidly, and that is according to their own specs, as opposed to their wolly claims.
Posted by: Davemart | 18 May 2011 at 01:03 AM
Davemart remember thats a review of the aa battery vs nimh aa batteries. This is talking strictly vs lead acid main battery of a car.
The new battery weighs only 16 lb vs 45 and yet has 2/3rds of the wh of the lead acid battery nand all the starter amprage needed.
Also remember 200 cycles at 100% discharge is MUCH harder then the normal deep cycle which I belive is 80% down to 20% or 90% down to 20% and not full 100.
Also shelf life has nothing to do with self discharge rate it has to do with calendar lifespan.. lead acid dies in 3-5 years most times no matter how you use em.
Posted by: wintermane2000 | 18 May 2011 at 07:29 AM
W-2000 and DaveM: We change car batteries every 8 years (120,000+ Km) and never had a failed one in the last 24+ years. Our current car batteries are guaranteed 108 months (On sale at $79 CAN installed), and that is North of the Border, where it is much colder and more demanding for batteries. We use over sized (energy wise, not physically much larger), extra long life (108 months), higher quality batteries only. It is a low cost option on most made in Japan cars. It is often coupled with over sized generator and starter.
Posted by: HarveyD | 18 May 2011 at 09:03 AM
Heat seems to shorten the life of lead acid car batteries. Some designs isolate the battery from the engine heat and some to not. It is my experience that the ones that do not need to be replaced more often...just some empirical data.
Posted by: SJC | 18 May 2011 at 11:32 AM
Well our batteries tend to poof but that I think is because when it comes to batteries we have the luck of a blind weasel on fire falling into a lake of gasoline on friday the thirteenth.
Posted by: wintermane2000 | 18 May 2011 at 11:55 AM
They spec this battery for starting current. It could become THE battery for a car because there is no deep discharge. It can also be a micro hybrid, if that is a 12v system, which is REALLY micro. BAS was 36v and BAS+ is 100+ volts.
It sounds like it is for start/stop systems that do not want to cost a lot and want to recapture at least SOME regenerative braking energy. There could be a market for this, perhaps in Europe where companies have been offering tiny micro hybrid systems.
Posted by: SJC | 18 May 2011 at 12:42 PM
Well dont forget in the intended market they have MICROcars so a micromicro wouldnt need all that much power to handle the traditional microhybrid needs of say a 500 cc car.
Posted by: wintermane2000 | 18 May 2011 at 03:57 PM
They will go in 2L cars, the idea is the microhybrid does not do much but it does not cost much either. It is the cost effective model that Honda used with the Civic hybrid scaled down even further.
Posted by: SJC | 18 May 2011 at 04:20 PM
w-2000. We could steer (if needed) to a battery store with 108+ months guarantee units. It may cost a bit more than the lowest cost unit from WM, but it would give you much better services.
the most cost effective change (for now) may be improved, more efficient, much lighter ICE machine that should have been built decades ago..
Posted by: HarveyD | 19 May 2011 at 04:55 PM