[clett]

Anyone heard of Zinc matrix before? Looks like they've cracked the dendrite problem and can get zinc batteries to recharge:

http://www.zmp.com/tech.html

Result is a non-flammable, non-toxic battery capable of up to 240 Wh/kg. Nice! 8)

100 kg of this in a Prius would store 24 kWh - enough for about 120 miles EV range.

I guess we just have to see how much this tech costs and whether it can compete with the forthcoming A123 high energy battery....

 

[jdenenberg]

After a quick review.

Interesting but they only claim 100 deep cycles (our NiMh and some Lithiums are rated at 1000 deep cycles). Their high energy (lab experiments only) cells are tested to 60 amps with a significant voltage drop. We need 100 to 150 amps in both directions with almost no voltage drop.

As i said interesting, but no yet ready for prime time.

JeffD

 

[Jeffand]

If you can't get the current out of the battery you need. You simply double the voltage. Because energy is equal to watts. So if you can't get the current you need. Then up the voltage until you get the power you require.
:shock:
:arrow: Volts x Amps = Watts
:wink:

 

[Jeffand]

Some new battery technology for electric vehicles.
Yes it seems every couple of weeks some new news on battery technology comes out.

Well it seems those new nano lithium batteries will be soon be installed in electric scootters. Oh by the way they also recharge in 15 minutes.


:arrow: http://www.evworld.com/view.cfm?section=communique&newsid=12952&url=

 

[DanMan32]

I wonder what they meant by

The scooter employs a pack of nanometer battery cells of 5.8 Ah, 2.2 V. with a capacity equal to or greater than 720W/L

especially W/L. Did they mean Wh? 750 isn't a whole lot.

As I mentioned before, even if a battery could be charged instantly with whatever you can throw at it, you still have to move that energy from the source to the battery. That means watts, which means volts * amps. So if you have a 1KWh battery, that means if it can be charged in 15 minutes, you need to deliver 15KW to the battery. At 15V, that would mean 1000 amps. If you have 10A cables, then that means 1500 volts.

Electricity isn't an easy form of energy to move and store, compared to liquid fuels.

 

[clett]

[Oops, duplicate post]

 

[clett]

To charge a 1 kWh battery in 15 mins would need 4 kW, about a third that required by an ordinary electric shower.

By the way, I think the scooter press release is wrong - 2.2 V x 5.8 Ah is only 13 Wh, about the same as two AA-sized batteries.

Two AA batteries wouldn't push a scooter very far!

Maybe they meant 22 V?

 

[DanMan32]

I think they were referring the capacity of one cell (or pack), where the scooter has multiple cells (or packs).

Similar to the Prius having 7.2V packs, but has 18 of them.

For a scooter, you could get away with 1KWH for an all electric, but not for a sedan.
Consider how inflexible the power cord is to the hot water heater. For a car, you would probably need a cable 15x the capacity.

 

[clett]

Not really, this is what the cable for a 50 kW EV charger looks like:

A 50 kW charger like this could charge a 10 kWh PHEV pack (40 miles range) in 12 minutes.

 

[DanMan32]

Fascinating!

 

[Jeffand]

The scooter employs a pack of nanometer battery cells of 5.8 Ah, 2.2 V. with a capacity equal to or greater than 720W/L

The 720 Watts / Liter which would indicate the storage capacity per volume. Since the space for a battery in EV is limited A key factor in storage capacity would be the space available, and charge density of the battery.


As for what determines the rate of charge or discharging the battery is what is called the internal resistance. The lower the internal resistance of the battery the faster the charge can be moved in or out of the battery.
So a battery with a low internal resistance will except a higher bulk rate charge.

 

[DanMan32]

First off, a liter is a measure of fluid. I have never seen it used as a measure of dry volume.

Second, it wasn't clear if the 5.8Ah was total charge capacity, or just for one cell, in which case the total capacity and/or number of cells wasn't given.

 

[Jeffand]

KW/L or KiloWatts per Liter is often used express the power being produced per liter of displacement of an internal combustion engine.

This would be the same as Horse power per cubic inch.
Instead they are using metric units for volume.
A liter is a unit of displacement volume.
So a KW/L is the amount of energy that can be stored in a liter of storage area.

 

[DanMan32]

Yes, I know Liter is metric. I have never heard it used for non fluid measure though.

 

[Jeffand]

Here is a link to an example that shows engine power in kilowatts, and engine displacement in Liters.

http://www.deere.com/en_US/rg/images/emissionsinfo/fueleconomy/PTP_90_Load.jpg

 

[DanMan32]

Engine displacement in Liters makes sense. We're talking about gas fluid(air/fuel mixture) displacement. This fluid volume is in a different category than dry (solid) volume.

But if you take a cardboard box, its storage capacity isn't measured in Liters from what I know.