: Batteries for the masses



Submariner409
06-12-08, 07:35 PM
The evening Wall Street Journal home page has an interesting line on automobile batteries: GM (and Ford some time back) has asked the Fed for more help ($$$$ ???? as in: yours and mine) in developing better technology and batteries for future motive use.

Ummmmmm.........Where the devil were our forward-thinking automobile manufacturers when the first oil supply/demand spikes were hiccuping 20 years ago ??? (and don't use the "Well, Government should have done something" argument. A Congressman can smell money or glory coming or going and isn't reticent about beating his/her own drum about how he/she saved the world from consumer greed.)

BTW, Martha, Just how much will it cost to replace the NiMH batteries in your Widget XP-43? Lots less than the total cost of the oil you saved, right ??? And how much does it cost to recharge that same Widget overnight if you get stuck in traffic ? Who pays that ?

orconn
06-12-08, 07:41 PM
And the question is?

eyekandyboats.inc
06-12-08, 07:50 PM
dont know about nimh bat but they are outdated!.
li-po li-ion or M1 cells are the way to go. I have 30+ packs of enerland lipo-ion batteries ( avg of about $340 a piece). which is the same company that the Tesela roadster uses for there cells.
the ones they use are 32 Ah at 3.7 volts per cell( about $150 a piece). ( about 9/8 inches and .5 tall a inch tall). they are 40C rating which means they can deliver 1280 AMPS of power with out even running in parallel packs ( 2p config).
having a 185 Kw motor it can suck back as much 770 amps given its 240 volt battery capacity.
for a long run time such as this the car is carrying a atomic amount of battery power.

Playdrv4me
06-12-08, 07:58 PM
And the question is?

Man I'm glad I wasn't the only one thinking that LOL. :hide:

dkozloski
06-12-08, 08:59 PM
As unlikely as it might seem; a very efficient way of storing and releasing kinetic energy is by the use of rubber bands. I've seen several serious proposals for their use in transportation.

orconn
06-12-08, 09:09 PM
As unlikely as it might seem; a very efficient way of storing and releasing kinetic energy is by the use of rubber bands. I've seen several serious proposals for their use in transportation.

Might have a problem in Fairbanks with rubber bands ......... they get a bit brittle in very cold temperatures. But, come to think of it, batteries aren't known for their cold temperature efficiency either!

dkozloski
06-12-08, 09:23 PM
Might have a problem in Fairbanks with rubber bands ......... they get a bit brittle in very cold temperatures. But, come to think of it, batteries aren't known for their cold temperature efficiency either!
Synthetic rubber is problematic but natural rubber retains its elasticity in very cold temperatures.

Submariner409
06-12-08, 10:18 PM
eyecandyboats, I believe your battery size, Ah, and drawdown comparisons are wrong.

At what drawdown rate is it possible to extract 1280 Amps from a 32 Ah cell ? If a cell can supply 32 amps for 1 hour at a constant 3.7 volt rate, that says the cell will be fully depleted in less than 4 minutes at a theoretical 1280 Amp load. And, given the size of the cell stated, that load would explode the cell because the internal construction and leads/connectors would overheat instantly.

There's quite a bit of difference in the voltage/loads required to run a radio controlled model boat and a 1,400 lb. car......from an old RC model airplane flyer.......and, yes, I remember rubber band escapements.

dkozloski
06-12-08, 10:30 PM
eyecandyboats, I believe your battery size, Ah, and drawdown comparisons are wrong.

At what drawdown rate is it possible to extract 1280 Amps from a 32 Ah cell ? If a cell can supply 32 amps for 1 hour at a constant 3.7 volt rate, that says the cell will be fully depleted in less than 4 minutes at a theoretical 1280 Amp load. And, given the size of the cell stated, that load would explode the cell because the internal construction and leads/connectors would overheat instantly.

There's quite a bit of difference in the voltage/loads required to run a radio controlled model boat and a 1,400 lb. car......from an old RC model airplane flyer.......and, yes, I remember rubber band escapements.
Rudderbug?

dkozloski
06-12-08, 10:34 PM
eyecandyboats, I believe your battery size, Ah, and drawdown comparisons are wrong.

At what drawdown rate is it possible to extract 1280 Amps from a 32 Ah cell ? If a cell can supply 32 amps for 1 hour at a constant 3.7 volt rate, that says the cell will be fully depleted in less than 4 minutes at a theoretical 1280 Amp load. And, given the size of the cell stated, that load would explode the cell because the internal construction and leads/connectors would overheat instantly.

There's quite a bit of difference in the voltage/loads required to run a radio controlled model boat and a 1,400 lb. car......from an old RC model airplane flyer.......and, yes, I remember rubber band escapements.
The local utility company built an electric car years ago based on a Corvair and Ni-Cad cells. Somebody dropped a Crescent wrench on the battery. The wrench welded itself in position, the battery exploded, and the car burned to the waterline.

orconn
06-12-08, 11:18 PM
The local utility company built an electric car years ago based on a Corvair and Ni-Cad cells. Somebody dropped a Crescent wrench on the battery. The wrench welded itself in position, the battery exploded, and the car burned to the waterline.

Well that's one down for Fairbanks scientific endeavor! I only hope te spirit of the dKoz will propel this inquiry further ....... and who knows what the outcome will be! Ain't America great!!

Submariner409
06-13-08, 07:21 AM
I started off Navy sub duty as an electrician. Wires, bulbs, and batteries. That boat in my avatar is a diesel-electric: 4 Fairbanks-Morse 1680 hp diesel generator sets, 4 parallel/series motors on 2 shafts, and 2 batteries. Each battery (forward and aft wells) was composed of 128 one ton wet cells, each cell approximately 20 inches square by 6 feet tall. Each 2 Volt cell was linked in series by copper bolted bus bars which gave each battery a voltage of 256 at some staggering potential amperage rate. The copper battery bars and cabling was rated at 8,000 amps continuous. The main cables were as big around as George Foreman's arm. AC, where needed, was created by motor/generator sets. The boat could normally stay submerged 36 - 48 hours, until air quality and battery charging requirements forced you to surface (unlike a nuclear boat which may remain submerged indefinitely) and light off one or two main engines for propulsion and charging, which took a carefully monitored day or night. Charging batteries that large produces huge amounts of hydrogen, which is violently explosive and must be contained and either burned or ventilated, so the process was very carefully done, every time, without fail (death). I am very glad that I no longer have to crawl around in semi-darkness, in rubber clothes, to feed the voracious distilled water appetite of those puppies. I learned, early on, that Navigation/Operations was far superior to potential electrocution.

EcSTSatic
06-13-08, 08:38 AM
Rubber bands? In conjunction with large flywheels I hope.

eyekandyboats.inc
06-13-08, 09:21 AM
SUB.
i agree with you there. maybe i am wrong But you need to take into account the cells C rating which is a rating of the capacity the cell can discharge as well as sustain a certain amperage and voltage.
new age lipo cells are not just rated at AH and volts.
the C Rating...
LiPo cells are also commonly given a C or current rating. This is the maximum average recommended discharge current for the cell. For example, the enerland 32,000mAh packs have a 40C rating. To determine the maximum discharge rate multiply the capacity times the C rating. 32,000mAh x 40C = 1,280,000. So the maximum discharge rate would be 1,280,000mA or 1,280 amps. If your application has a higher amp draw, remember that LiPo cells can be wired in parallel, and with 2 cells in parallel each cell sees half the total current. With 3 cells in parallel, each cell see one third the current.

By wiring packs in a combination of series to get the voltage and parallel to achieve the capacity and individual cell current to an acceptable level,
for instance. a real work result which i know for a fact does in deed work because i use it for my application.
I run fast electric RC model boats. Not toys. my boats run in excess of 85MPH
i have a setup that will draw a constant amperage of 105 amps with the given prop and race water conditions.
i run a 4.5 AH lipo battery which is rated for 30C @14.8 volts ( 4s lipo) that pack CAN delivered 135 amps constant. that and the fact it is listed on the battery. with a mere 4.5 amp hours in a RC boat. i can run for roughly 10 mins on this pack. I am not even paralleling my cells. if i was my AH would double. triple... which ever

Submariner409
06-13-08, 12:08 PM
That makes sense......battery technology is far and away better now than even ten years ago........Look at the 3 -4 day runtimes for cell phones. I know exactly what your hobby is....and its fun !

The kicker I was fishing for is "Does anyone know how much it costs, and how often, to replace batteries in a hybrid car?"

Just like the high capacity packs in a model race boat, I betcha it ain't cheap.......

dkozloski
06-13-08, 03:24 PM
I started off Navy sub duty as an electrician. Wires, bulbs, and batteries. That boat in my avatar is a diesel-electric: 4 Fairbanks-Morse 1680 hp diesel generator sets, 4 parallel/series motors on 2 shafts, and 2 batteries. Each battery (forward and aft wells) was composed of 128 one ton wet cells, each cell approximately 20 inches square by 6 feet tall. Each 2 Volt cell was linked in series by copper bolted bus bars which gave each battery a voltage of 256 at some staggering potential amperage rate. The copper battery bars and cabling was rated at 8,000 amps continuous. The main cables were as big around as George Foreman's arm. AC, where needed, was created by motor/generator sets. The boat could normally stay submerged 36 - 48 hours, until air quality and battery charging requirements forced you to surface (unlike a nuclear boat which may remain submerged indefinitely) and light off one or two main engines for propulsion and charging, which took a carefully monitored day or night. Charging batteries that large produces huge amounts of hydrogen, which is violently explosive and must be contained and either burned or ventilated, so the process was very carefully done, every time, without fail (death). I am very glad that I no longer have to crawl around in semi-darkness, in rubber clothes, to feed the voracious distilled water appetite of those puppies. I learned, early on, that Navigation/Operations was far superior to potential electrocution.
What Sub didn't tell you is the reason why sub sailors got extra pay for hazerdous duty. If salt water gets to the battery, huge amounts of chlorine gas are evolved and in a matter of minutes everybody on board is pretty much dead meat. They can get some protection from masks but one good breath and you drown in the fluids that collect in your lungs.

The Tony Show
06-13-08, 03:49 PM
The kicker I was fishing for is "Does anyone know how much it costs, and how often, to replace batteries in a hybrid car?"

Just like the high capacity packs in a model race boat, I betcha it ain't cheap.......

$3,000 to $6,000 depending on the model.

orconn
06-13-08, 04:08 PM
Geez! I think I'll stick with the downside potential of N* engine replacement, get my 18 mpg city and 30 mpg hwy and enjoy the hell out of getting there!

dkozloski
06-13-08, 04:31 PM
$3,000 to $6,000 depending on the model.
If you want that economy you're going to have to pay for it.

Submariner409
06-13-08, 05:38 PM
Chlorine gas drills and movies were very sobering.

As are the (old) pictures of the forward battery explosion aboard the diesel boat USS POMODON, which killed 3 men, one of which was shot 100 feet in the air through the Forward Torpedo Room hatch. The boat was in overhaul at Mare Island Naval Shipyard at the time, conducting a dockside battery charge with jury-rigged ventilation to the battery wells.