andylaurence wrote:You can circumvent the requirement for pump fuel by adding a 50cc engine for recharging!
Cheers,
Andy
Nice one.
What classes did you race your last car in?
Floydster
ChrisB wrote:andylaurence wrote:ChrisB wrote:andylaurence wrote:.........156v @100Ah is 15.6KWh, which is enough energy for the application I have in mind. I was converting the required energy into the number of lead-acid batteries I'd need as a real world example. I wouldn't want to use 12v for the car. Imagine the current!
Agreed, but watch out , not sure if its a typo but you've said 156v@100Ah is going to give you 15.6KWh, you cant really say that as it all depends on the batteries you use and the Wh they will give you. I'm almost 100% sure you cant just calculate KWh from voltage and Ah
ChrisB
I'd have thought that those were the only things you can calculate KWh from. The batteries are rated at 100Ah and 12v. 156v is 13 x 12v batteries, still at 100A. 15.6KWh is 156v @100A for one hour. 156v x 100A = 15600VA = 15.6KVA =~ 15.6KW. The batteries can supply this current for 1 hour, hence they collectively have a capacity of 15.6KWh (ignoring the difference between KVA and KW). If I have this wrong, I'd really like to develop my understanding and learn why.
Cheers,
Andy
Ahhhh common error, it does really depend on what batteries you are going to use, there are few batteries that will supply the 1hr rating known as C1 some of the modern Li-ions are pretty good at this though.
Battery ratings are a big bone of contention, and are easily missunderstood.
Lets take say a Yuasa 12v 17Ah sealed LA, if you look at the figures it may appear to be able to supply 17A for an hour when actually its 17Ah @ C20 which works out that it will actually supply 0.85A for 20hrs but that is its guaranteed output.
Yes it will supply more and will supply several hundered amps for a few mins but your unlikely to get 17amps from it for 1 hr or if you do you will be damaging the batteries long term life and you wont get its its full life cycle from it.
Different batteries have different spec, and we havent even touched on the purket effect
Hope that helps a little ??
ChrisB
floydster wrote:andylaurence wrote:You can circumvent the requirement for pump fuel by adding a 50cc engine for recharging!
Cheers,
Andy
Nice one.
What classes did you race your last car in?
Floydster
EVguru wrote:I've been building a Speed Hillclimb EV on and off for more years than I like to admit to.
My discussions in the past with the Bugatti Owners Club (Prescott Hillclimb) and the RACMSA were quite helpfull. Prescott will allow demonstration runs (as they have in the past) and the MSA suggested they would form an EV class as soon as there were vehicles to run. One possibilty would be a handicap class where a wide range of vehicle could compete.
Frank Wykes ran his Enfield (uprated to 120volt) at Prescott and his unofficial time was similar to that of a standard 1500 MG midget.
When I was involved with racing in the USA we ran a converted Porsche 914 and once shared track time with NASA (National AutoSports Association). The NASA cars were RX7s, 3 series Beemers (318, 325), and low end Porsche 911s. Many of these were running about 50hp of NOX to keep them smog legal. In the open practice session, our power limit was 36hp in order to last a 23 mile race, but with better suspension and tires and a good driver we could circulate as fast as any of the gas cars.
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