Lead _is_ toxic. They have systematically banned it from most uses (like
paint and solder.) The writer makes an excellent point. They still use
lead-acid 12 volt batteries mainly a matter of tradition and convenience
and cost. If they invented them today, they could not go into production
because of the environmental concerns.
50% of lead production comes from recycled sources, the rest is mined.
Lead-acid batteries use 80% of that total lead production. The
difference, 30%, ends up in the environment. Simple math. You just look
at the lead association's own figures.
The lead-acid battery industry claims 95% (up to 99%) material recycle
rate, but they fail to mention that only counts the batteries that
actually make it through the gates of the recycling facility. Great PR.
Bad math.
Bill D.
On 12/26/2013 5:03 AM, brucedp5 wrote:
% 'Lead-acid batteries = toxic' = writer's misinformation %
http://www.plugincars.com/why-do-electric-cars-have-lead-acid-12-volt-batteries-when-lithium-lighter-129118.html
Why Do Electric Cars Have Lead-Acid 12-Volt Batteries When Lithium Is
Lighter?
By David Herron · December 20, 2013
[image
http://www.plugincars.com/sites/default/files/P1129300%20copy.JPG
A 12 volt battery (lower right) under the Nissan Leaf hood.
]
Modern electric cars were made possible by lithium-ion batteries. But look
under the hood of any electric vehicle and you'll find a second battery, a
lead-acid battery, whose purpose is to power the 12-volt system. A reader
asked us why isn't this a lithium-ion battery as well?
Lead-acid batteries have an obvious problem: their weight. Specifically, the
energy density, or kilowatt-hours of energy storage per kilogram of weight.
Using a lithium-ion battery instead of a lead acid battery for the 12 volt
system would reduce the car's weight, improving its overall efficiency.
Another problem with lead acid batteries is toxicity. Some of us buy
electric cars because they're kinder on the environment, and lead acid
batteries are not exactly clean nor kind to the environment. Lead itself is
toxic, especially to young children, and there are several toxic chemicals
used in lead battery manufacturing.
The 12-volt battery stores the power for the 12-volt system that runs
components like the lights, entertainment system and the heating/cooling
system. This battery is kept charged by a DC-DC converter which produces a
12-volt source from the main battery pack. There's nothing magic about the
12-volt system which makes lead-acid batteries technically better. Since
automakers obviously know how to design and build a high-voltage lithium ion
pack for the traction battery, they could obviously do so for the accessory
battery as well.
Clearly it would be nice on at least two fronts to use something other than
lead-acid batteries for the 12-volt system. A quick glance at the price of
lithium ion versus lead-acid batteries though tells us why automakers use
12-volt lead-acid batteries: cost.
Unfortunately, we don't know the cost automakers pay for batteries. We can
estimate the cost difference between lithium ion and lead-acid 12-volt
batteries with the ALM-12V7, manufactured by A123 Systems. This is a a
plug-and-play replacement for for the industry standard 12-volt, 7 amp-hour
sealed lead-acid batteries that are used in a wide range of equipment. The
cost for the ALM-12V7 is $129 and its weight is only 1.875 lbs, while the
cost for 12-volt 7 amp-hour lead-acid batteries is in the $10-20 range,
weighing about 4.5 lbs.
Lithium Pros is another maker of 12-volt lithium batteries, which are direct
replacements for typical car batteries and provide the kind of power output
required to turn a starter motor. The prices we found for their batteries
carry an even higher premium. The Lithium Pros 12-volt, 20 amp-hour battery
weighs only 9 lbs, but costs over $1000, which is much lighter than the
equivalent lead battery, but at a very high cost.
Another gain is the engineering resources that would have to be spent to
design a suitable 12-volt lithium ion battery. All the automakers have
access to a ready supply of 12-volt lead-acid batteries from a long list of
manufacturers. It's a classic buy-versus-build decision, where it's cheaper
to buy a component than to design and manufacture it yourself.
[© plugincars.com]
For all EVLN posts use:
http://electric-vehicle-discussion-list.413529.n4.nabble.com/template/NamlServlet.jtp?macro=search_page&node=413529&query=evln&sort=date
Here are today's archive-only EV posts:
EVLN: Cities can save big money by switching to EVs
EVLN: OpConnect keeps U.S. Navy EVs Charged
EVLN: Vending machine dispenses Chinese Kandi @$3.25hr r:75mi ts:50mph
EVLN: China Tesla website and dealership are up, and taking pre-orders
+
EVLN: EVs dominate the bus lanes into Oslo.no, more EVs than EVSE
{brucedp.150m.com}
--
View this message in context:
http://electric-vehicle-discussion-list.413529.n4.nabble.com/EVLN-Why-Do-EVs-have-12V-PbSO4-Aux-Batts-When-Li-ion-Is-Available-tp4666905.html
Sent from the Electric Vehicle Discussion List mailing list archive at
Nabble.com.
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
