Originally Posted by
350htrr
I believe that is what I used, to get the same amount of Ah out of the $382 battery you would need 1.6-2.3X $382 batteries for the 60% and 40% used from the bigger batteries. But maybe my math is not as good as it needs to be...
Maybe I'm not following your calculation, or missing what you're getting at. Can you clarify?
1; 48v 10Ah, $382. at 80% used can go 19.2 miles - how many charge cycles to 80%?
2; 48v 15Ah, $533. at 60% used can go 21.6 miles. - how many charge cycles to 60%?
3; 48v 20Ah, $658. at 40% used can go 19.2 miles - how many charge cycles to 40%?
cost per Ah = battery cost / (charge cycles * (percentage charge * battery capacity))
The
Battery University paper had it at:
400 charges to 100%
1200 charges to 80%
3200 charges to 60%
(they didn't list 40%)
So using their claim, the cost per Ah:
for the 10Ah, 100% is $382/(400*1*10) = 9.5 cents/Ah used
for the 10Ah, 80% line is $382/(1200*.8*10) = 4 cents/Ah
for the 15Ah, 60% line is $533/(3200*.6*15) = 1.9 cents/Ah
It looks to me like the lifetime cost is half as much for the 15Ah @60% battery as for the 10Ah @80%, and almost one fifth the cost of using the 10Ah with full charging.