Quote:
Originally Posted by Furyous
I couldn't find anything about this on the web, but I am running 6 8v lead acid batteries in my golf cart based commuter. During acceleration, as expected, voltage drops and then rises and stabilizes when I get to top speed.
My question is whether I can effectively increase the range (and potentially the life of the batteries) by installing car audio capacitors across every 12v bank of batteries to reduce voltage sag? My guess is that it would improve performance as well.
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Hi Furyous,
Audio caps for cars are rated at car battery voltage (16 volt is the nearest standard voltage), so there doesn't seem to be an efficient way to use them for a 48 volt system.
And...
Each farad can store about 100 joules at battery voltage (about 14.5 volts) 1 joule is 1 watt-second. So 1 F could store 100 watt-seconds. That's if you can convert the whole charge down to 0 volts. I guess you'd better assume you could use the top 30%, 14.5 volts down to 10 volts - you need 3 times as many capacitors.
The
Stinger seems to be a combo capacitor & lithium battery which emulates 50 F.
If you attached 60 of these to pairs of batteries, 15 for each pair, you'd gain 750 farad at 48 volts. If you could use about a third of that (14.5 v down to 9.6 v) it would provide about 25,000 watt second. Or 20 amps at about 48 volts for 26 seconds. 20 amps might be noticeable and 26 seconds might be how long you want help accelerating. Or it could provide as an additional 100 amps for 5.2 seconds for climbing short steep driveways.
And that would only cost $11,700.
-mort