[stevehull]

Memphis - the perfect battery is not yet on the drawing boards. What we have today are essentially elegant capacitors. They store charge for a bit, but they lose it internally. The input output inefficiencies will always be there - and even if they are each 95% (very high), you still lose double that as you must come in at 95% and they go out at 95%.

Then there is the aging issue (that you mention). There are only so many life cycles on a battery.

I maintain the best "battery" is actually available - the grid.

A self contained battery (totally off grid) will require some 30-50 kWhrs per day minimum. For those of us in the south, where air conditioning is dominant, then double that. All the chemistry I read about is interesting, but my estimate is that it will take a generation (human) or so to further develop.

Fuel cell technology will likely be a better participant in this as very rapid gains are observed - especially in the many kW situation. Is a natural gas line to your home "off grid"?

The other day I was looking at a physical situation to describe what a mega Whr was. It was hard until I was stopped at a train crossing while a train went by. Turns out that a diesel locomotive is about 1 mW at full output. So that engine, pulling a long trainload of cars for one hour is about 1 mWhr.

I mention this as 33 kWhrs per day (minimal consumption) for a month is about one mWhr. A tremendous amount of energy.

Yes, I know that many here can survive and do quite well on less than 30 kWhrs/day, but will the average Joe/Suzy and family do so? My experience is that they want their electricity sucking appliances AND they want it now at the flick of a switch.

Yes, we can scrounge packs from smashed up Volts and Bolts and that is what people on this forum love to do. I have a friend doing exactly that right now (and am helping him test each cell as it comes out). But internal losses, aging/cycling problems and input output inefficiencies make this maybe a solution for a couple years.

NOT trying to be a wet blanket, but I maintain we do already have a "battery" - and a very efficient one at that.

Steve