Tec wrote:I've lost count of the number of reports of various groups who announce batteries with improved energy densities, charging rates, or other desirable quantities, but then they seem to fade out of existence.
I think the trouble is that solving ONE of these problems is only solving part of the problem and in order to do it, some other desirable feature has to be sacrificed. Unfortunately these sacrifices are rarely mentioned in the announcement
I wonder if it would be possible to quantify our assessment of what is and what isn't a 'good' battery by making a rough individual assessment of each feature and adding the total. I suggest this be pretty coarse - say -2 to +2, eg:
-1 Worse than average
+1 Better than average
This could be applied to the following features:
Lousy Poor Usable Good Fine
Energy density 100 175 225 300 500 (Wh/kg)
Cost 1000 700 500 300 100 ($/kWh)
Charge rate 0.05 0.2 1.0 3.0 20.0 (C, continuous)
Discharge rate 1 3 6 10 20 (C, instantaneous)
Temp. tolerance 10 30 50 70 100 (range, K)
Charge cycles 300 1000 3000 6000 10000 (to 80%)
Losses in cycle 50 10 3 2 1 (%)
Degradation 1 3 8 12 30 (years)
Safety Explodes Burns Sputters Outgasses Stable (?)
I've abandoned average as it moves.
An at spec EESU would be in the top category in all of these except the first, I think.
Last edited Mon, 04 Apr 2011, 5:41pm by WalksOnDirt
Deasil is the right way to go.