Nickel-Iron SLI Battery
Starting Lighting Ignition (SLI) battery feasibility check:
reqs for a typical commercial battery: http://en.wikipedia.org/wiki/SLI_battery#Terms_and_ratings CCA will be particularly hard to do with nife due to the problems that it experiences at low temperatures and high discharge rates e.g. the sulfides accumulating on the electrode surfaces http://en.wikipedia.org/wiki/Peukert%27s_Law maybe we coudl use a capacitor
example car battery with ratings:
http://www.apexbattery.com/ford-aerostar-battery-1986-mt-option-car-batteries-ford-batteries.html will need to be a lot bigger for bigger engines of course $160 Amp-hour 16 (probably a 20 hour rating) so about 192 Wh CCA: 220 (what is this OE CCA stuff?)
total conld cranking power output ofr 30 seconds: 7.2 volts or so ( a bit more actually) * 220= 1584 Watts or 8.25 C
for 30 seconds it only needs to deliver 1/120 *1584=13.2 Wh. which is only 6.8% of the total battery capacity. Presumably we want the capacity to crank several times, though, and there still has to be enough juice to run lights, onboard computer etc. left over. However when it is only 13.2 Wh maybe a supercapacitor in paralell with a battery would be fine.
If the nife battery can be *sold* at $0.2 per Wh then we would get 800 Wh for this price. The battery would only have to discharge at 2 C, hypothetically. That is not too hard at all, the battery in the sealed testing doc did 6 C without major problems. However low temperatures might be a problem, the battery could potentially be designed to cope adequately.
Need to check changhong high rate batteries to see what they can do and if they are pocket plates. How much does it cost to do with other battery types, though? The thing is that there is relatively little potential to save the customer money, and existing NimH or Ni-ion might be just fine Now, how much does it cost to do with ni-mh? says 37 cents per Wh or so so $71.1 price for nimh batteries according to wikipedia: They woudl have to be high rate cells though, check prices for high rate cells
for Litium iron phosphate, the thindersky lithium batteries are 40 cents a Wh but don't know if they could support the current (they are rated for 2 C though), but price would be $76.8.
Interesting. The CCA is at -18 degrees C. That might effect the nimh adversely but not litium ion that much.
Specific batteries capable of spporting the discharge rates involved at the temps involved would need to be identified first.
Important: nimh and Li-ion and nife have a much longer life than lead acid. Therefore the acceptable cost here is much higher. A li-ion pack could cost twice as much and still save you money.
Although sites like http://auto.howstuffworks.com/under-the-hood/vehicle-maintenance/often-replace-car-battery.htm and http://www.answerbag.com/q_view/1808823 indicate lead acid last surprisingly long in this useage pattern, which is something I have heard before, unfortunately. Clearly they last for a far larger number of cycles than the 800 usually quoted in a solar power system context, which should be no surprise actually as the vibration will mix the electrolyte and they like being in the full state of charge to some degree. Nevertheless a lithium ion could last for mugh longer han 4 years easily, same with nife and nimh.
However I remember seeing batteries for less than that at wal-mart so these people might be charging too much. this thread :http://www.topix.com/forum/autos/ford-explorer/TO70FAM7B9268PDV2 suggests $50 is more typical if you shop around Further investigation is needed, but I suspect that as usual there is no real legitimate reason to keep doing this environmentally harmful thing. The real reason is that they can charge $160 on a 192 Wh lead acid battery ($0.83/Wh) which only costs them a lot less than $38.2 ($0.2 per Wh) to make, since that is what you can buy the batteries for in other contexts already, and from my reasonable degree of knowledge of the chemistry and material costs involved in this and other battery types it is *not* the case that a car lead acid battery (high rate battery) is any more than marginally more expensive than other types of lead acid.
In fact, probably less than $0.06 given that document from harvard that described a nife battery production process that produced nife batteries at $50/kWh and the other documents that described batteries which the (very well informed) authors expected to cost in that price range. I have not done such in depth reasearch on lead acid but these are fairly authoritative estimates for nife battery cost, and it will inevitably be cheaper for LA.
In other words, the cost of the battery is not the issue to the consumer, only to the manufacturer. They make what they want to sell, not what we want to own. If destroying the environment saves them literally a few cents per Wh they will do it if we let them.
Edit: okay http://www.canadiantire.ca/AST/browse/4/Auto/StartingCharging/BatteriesCables/PRD~0102472P/Motomaster%252B72%252BBattery.jsp?locale=en for example shows what is supposedly a 750 CCA for $80. capacity unknown though. So I might have been burned here by people whose prices were out of line. But, they don't tell you what the battery actually is so cant know for sure.
All these LA car batteries seem to be vent regulated. Nimh and lithium ion prices are for sealed batteries that are maintenance free.
Also had a look around for mnimh and li-ion starter batteries, and there are some for sale now but the manufacturers are charging way too much, clearly they have a massive profit margin right now as they would likely be considered a luxury product only for sale to wealthy eco hippy types and for sport cars etc. The prices probably mean nothing about the manufacturing cost. Porche sells theirs in the thousands of dollars range.
as usual ebay has more reasonable prices http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=220752266666&viewitem=&sspagename=STRK%3AMEWAX%3AIT only 120 amps 10 second pulse for motorcycle starter for $200 buy it now. Check other sources to determine the cost of the cells themselves, they are probably much lower. It is only 55 Wh We would need 2 or 3 apparently for a good minivan starter (the aerostar is a minivan) at a cost of $400 ot $600
"The only one in the entire world that uses environmentally friendly A123 A grade Nano LiFePO4 cells from the original manufacturer which are totally compliant with RoHS standards. BMS, nickel sheet and casing are fully designed and manufactured in Taiwan." A123 26650 Cell Specification:
* Nominal voltage: 3.3V * Nominal capacity: 2.3Ah * Core cell weight: 70 grams * Internal impedance: (1kHz AC) 8 mΩ typical * Typical fast charge current: 10A to 3.6V CCCV * 70A continuous discharge * 120A, 10 sec pulse discharge Cycle life at 10C discharge, 100% DOD: over 1,000 cycles
12V Lithium Ion Starter Battery Technical Specification
Nominal capacity and voltage：4.6Ah, 12V Recommended standard charge method：5A , 50min Recommended fast charge current：20A , 10min Maximum continuous discharge：130A, 30C Pulse discharge：230A, 50C Operating temperature range：-22°F to +140°F /-30℃to +60℃ Storage temperature range：-58°F to +140°F /-50℃to +60℃ Battery weight：1.914 lb/870 grams Size：11.7cm(W) X 10.5cm(H) X 7cm(D) (It can put side down!) Casing material：Transparent Acrylic Motorcycle：4S2P/4.6Ah is suitable for 500cc and under.
http://www.rcdude.com/servlet/the-1405/A123-Li-dsh-Ion-26650-Nanophosphate/Detail sells the cells for $17 each, sinc it takes about 8 cells to make the battery above, it would be $136 for the cells alone, and those rcdude people are probably charging a generous profit margin themselves. I think we start to see how this goes now. Clearly the profit margin on batteries varies dramatically.
this guy http://cgi.ebay.com/12-battery-A123-factory-original-high-power-26650-/190459825031?pt=US_Batteries&hash=item2c584a4b87 is selling the battery with the same rating, 8 cell for $107 (free shipping too) Now the starter battery is $300 to $400. So twice the price, but it lasts longer.
It seems apparent that the off-grid energy system battery should probably be first priority for the NIFE battery, but we shoudl still keep an eye to making the SLI battery with mostly the same parts if possible. http://www.changhongbatteries.com/Pocket_type_Ni-Fe_rechargeable_battery_p52_m2.2.1.html says that the changhong high rate *pocket plate* batteries are used for starting : With more than 30 year’s development, Changhong pocket type low discharge rate and medium discharge rate Ni-Fe rechargeable batteries are widely applicable as stand by and DC controlling power supply for utility and electricity industries, telecommunication, locomotive, railway, metallurgy, mining industry emergency lighting, UPS, switchgear tripping and closing, etc. In addition, they are also used as storage power supply for wind, solar photovoltaic and other renewable energy application. ****Changhong pocket type high discharge rate Ni-Fe rechargeable batteries are mainly used as the starting power supply for diesel engine, DC generator and the DC standby power supply for trail transit application.****
so they figured out a way to do it without sintered electrodes anyway, for what it's worth.