Quote:
Originally Posted by teoman
From memory... a small gasoline car draws about 6A @ 13V. That is 78W.
Lights are 50W each.
Your cells are 3.6V 2Ah -> 7.2 Wh each. (Probably)
With 1 cell and a boost converter. You can run your car for 7.2Wh/78W = 0.09h = 5 mins(roughly). (Assuming the batt can deliver 24A for 5 minutes, and that the boost converter is %100 efficient)
That is how I do the calculations. Obviously a single cell does not have the amps to run your car.
To run for an hour, you would need 12 cells.
1 hour car consumes 78Wh
78/7.2 = 10.8 cells.
But you want something divisible by 4 in order not to need a boost or buck converter. So 12 cells for 1 hour and no lights or blower or radio.
|
That's interesting our estimates came out similar, though why do you assume a buck-boost converter when 4 in series
the (4s) in the 4s4p, gives 14.8V easy. (Really it is 16.4V when fully charged, though like lead acid, the nominal voltage is given, ~12V or 14V for lithium )
Can you check my added maths above, in my last post, as I edited the post before seeing you had just replied.
It's a strange thing that 14 V li-ion batteries for RV usage, aren't commonplace, can't seem to find them to compare prices with, while sure it is a little more volatile of chemistry than the lithium iron phosphate that everyone is selling in the RV role, but at exorbitant prices for a 50 A.h battery...but we have the former chemistry, in our laptops and they run just fine. Don't discharge all the way(iron phosphate's advantage) and longevity is close enough between Li-ion and Lithium iron phosphate, to not really matter. Especially in this role.