Pure fantasy right now but sounding board time :-) LOW power electric hybrid??

[Nerys]

Ok first this is PURE fantasy dreaming right now. I don't have the $600 for the pack or $600 for the controller etc.. to do this its just "sounding board" time.

IE reality check to see if my fantasy is even feasible.

I want an EV. I can't afford one and a Lead powered one will not work for me (commutes too long 54 miles)

but one thing I have been thinking about is a "sort of" hybrid of sorts. I have a wee trailer for my mouse and I was thinking maybe I could make that trailer into an electric car that attached to my mouse and use it to "assist" me.

the idea would be this. when I let off the gas to slow down I kill the engine. at the light engine off. when its green engine off use the electric to accelerate to speed and then restart the gasoline engine and turn off the electric motor.

if I can do that right there I should be able to boost my fuel economy to 75-80mpg maybe even 90mpg (I am currently getting 49-50 in the winter 54-55 in the summer on E10)

so I have been trying to figure out a way to make a non lead affordable battery pack.

I found this interesting battery pack for around $150. 37volts 5000mah 15c

Now do I understand this 15c thing right. this pack can output 675 amps or power?

if I am correct on that this means 4 of these would get me a 148volt pack with 5 amps of capacity and these batteries can dump that full 15c or 675 amps for around 8 minutes.

if 1c is normal discharge over 1 hour IE 5 amp load them 15c would be 1/15th of an hour or around 8 minutes.

if it takes me 30 seconds to accelerate from 0 to 45-50mph (my normal cruising speed) that means 16 full accelerations IE more accelerations than I need to get to work. (figure I need 9 to 15 acceleration depending on how well I time the lights and or lucky I get :-)

since this would be an AC system I could even use REGEN.

am I doing my math right or did I really screw something up? that would be only a $600 battery pack !!! thats almost within range of being doable for me !!!

maybe I could even do a DC system 74 volts would only need 2 packs or still get 4 and have 16 minutes of full power but no regen. (and go gentler on the packs)

I must be doing the math wrong seems like too good to be true or something.

I mean at 8 minutes per set of 2 at 74 volts that means $3000 worth of lithium packs would get me my full 54 miles to work even if I drew 100% 15c from them the whole time which I won't off course so probable a $2000 pack would do the job.

feedback?

[todayican]

Was there to be a link in that post?
What kind of batteries are we talking about?
Thanks

[b13bliss]

I like your thinking, especially the idea of using plug-in electric power for brief, high demand loads without needing to pack $20k worth of batteries around.

I'm no expert, but my understanding of C ratings on battery packs is that you multiply the C rating by the amp hour capacity to get the highest safe discharge rate in amps. A 5000mAH battery has 5 amp hour capacity times the C15 rating= 75 amp max rate of discharge. The total capacity of the battery is 37v x 5AH, so at a 75 amp discharge rate it would empty in 5/75ths of an hour (or 1/15 of an hour) which equals 4 minutes (4x15=60.) Your 4 battery pack would output about 11kw (148 volts times 75 amps). I don't think you would get acceptable acceleration from it, but I don't really know. You also don't want to use the battery's full capacity, so subtract 1 minute to leave the bottom 30% unused.

Cool idea, but the cost might still be prohibitive. I would really like to use batteries, but they're heavy and expensive and have a fairly short life span in terms of miles per dollar spent. If your metro cruises along using 10KW of power at 60 mph steady state, you would use about 9KWh to go your 54 miles
and would need at least a 13KWh battery pack. That would be about 70 of the batteries you mentioned at $150 each or $10,500. Say they were the greatest battery and you get 3000 cycles out of them, then you would go about 162,000 miles before replacing them. The cost of battery ownership would be about 6.5 cents per mile not including the electricity they use. Right now your cost of fuel at 50mpg is about 6 cents per mile. Electricity is cheap, but battries are not. That being said, I still would like to incorporate them into a reasonable scheme.

[nimblemotors]

I'm starting to sound like a broken record, but this is what the Prius does.
It has a very small battery pack, only good for a few minutes of power, but that is all that is needed to get the car up to speed from a stop, and then it recharges it from the gas engine once up to speed (and when braking) so its ready for the next time you come to a stop.
This is how they can get 50-60mpg in city driving.

So I don't quite understand why everyone wants to "dream" up the same thing that is already been done and proven to work very well.
Just trying to do it cheap? Get a used Prius or the used parts from one.

Originally Posted by Nerys

Ok first this is PURE fantasy dreaming right now. I don't have the $600 for the pack or $600 for the controller etc.. to do this its just "sounding board" time.

IE reality check to see if my fantasy is even feasible.

I want an EV. I can't afford one and a Lead powered one will not work for me (commutes too long 54 miles)

but one thing I have been thinking about is a "sort of" hybrid of sorts. I have a wee trailer for my mouse and I was thinking maybe I could make that trailer into an electric car that attached to my mouse and use it to "assist" me.

the idea would be this. when I let off the gas to slow down I kill the engine. at the light engine off. when its green engine off use the electric to accelerate to speed and then restart the gasoline engine and turn off the electric motor.

if I can do that right there I should be able to boost my fuel economy to 75-80mpg maybe even 90mpg (I am currently getting 49-50 in the winter 54-55 in the summer on E10)

so I have been trying to figure out a way to make a non lead affordable battery pack.

I found this interesting battery pack for around $150. 37volts 5000mah 15c

Now do I understand this 15c thing right. this pack can output 675 amps or power?

if I am correct on that this means 4 of these would get me a 148volt pack with 5 amps of capacity and these batteries can dump that full 15c or 675 amps for around 8 minutes.

if 1c is normal discharge over 1 hour IE 5 amp load them 15c would be 1/15th of an hour or around 8 minutes.

if it takes me 30 seconds to accelerate from 0 to 45-50mph (my normal cruising speed) that means 16 full accelerations IE more accelerations than I need to get to work. (figure I need 9 to 15 acceleration depending on how well I time the lights and or lucky I get :-)

since this would be an AC system I could even use REGEN.

am I doing my math right or did I really screw something up? that would be only a $600 battery pack !!! thats almost within range of being doable for me !!!

maybe I could even do a DC system 74 volts would only need 2 packs or still get 4 and have 16 minutes of full power but no regen. (and go gentler on the packs)

I must be doing the math wrong seems like too good to be true or something.

I mean at 8 minutes per set of 2 at 74 volts that means $3000 worth of lithium packs would get me my full 54 miles to work even if I drew 100% 15c from them the whole time which I won't off course so probable a $2000 pack would do the job.

feedback?

[Nerys]

because a used prius is still about 19 thousand dollars more than I can dream of affording and thats not counting the roughly 10 thousand dollars in finance charges AND gets WORSE fuel economy than I am getting right now so what would be the point?

even my WINTER fuel economy is better than a prius.

I got my metro for $600 AND EVEN THAT was more than I could afford but thank god he took payments :-)

thats why. If I had the cash to afford a prius without a second thought I would not be worried about fuel prices you can be sure of that :-) hehehe

also I am sorry the battery I am looking at is 45c with bursts to 90c. but even at 45 c thats 225 amps 450 amps burst (I am not sure where I got the 675 amps from ??)

so I would definitely need to go 4 packs serial parallel 74volt and net 450 amps continuous and 900amps burst. safer yet 3 "2 unit" packs (6 packs total $900) this way I get a much better 675 continuous amps (coincidence that number I did something wrong to get 675 the first time) and 1350 amps burst. should be more than enough for a 2600 pound loaded metro.

would I get my 8 minutes of power on that setup? oddly enough charging would be easy on this setup - each pack has its own secondary connector for charging. I just plug a separate charger into each one and slow charge them (I will always have at least 8-10 hours to let it charge so no worries their)

right now I spend roughly $2240 a year in gas. if this got me to 75mpg (and I think I could get even higher)

with this setup I would only have to pay out $1493 a year in gasoline a savings of $747 or about $700 after paying for the electricity

IE the whole system could break even in 3 years. not a bad ROI at all. I can also keep buying "sets of 3 packs" to up my range.

the trick is affording that initial "lump sum" :-(

here is a link to the battery.
http://www.hobbyking.com/hobbyking/s...dProduct=14617

$161 but if you "sit" on the site for a few minutes it pops up and says hey you have been watching this for a while buy now and we will give it to you for $152 :-) hehe

its only 1447 grams for the entire pack. so 6 would mass at 20 pounds. thats not heavy at all.

[gabi]

i cannot post a link since is my first post ,but there're some new lithium capacitors out there you might try
ioxus, it'll come up from a simple search
dont know about the prices tough,but you might find out

they look like a good alternative to bateries,
i like your idea,let us know how it goes

[gor]

Originally Posted by gabi

i cannot post a link since is my first post ,but there're some new lithium capacitors out there you might try
ioxus, it'll come up from a simple search
dont know about the prices tough,but you might find out

they look like a good alternative to bateries,
i like your idea,let us know how it goes

.ioxus.com/data-sheets
•1000F "Snap-In" Hybrid Capacitor

Wh 0.735
kW/kg 1.57
------------------
batt:
hobbyking.com/ Turnigy_nano_tech_5000mah_10S_45_90C_Lipo_Pack

wh/kg: 127
kw/kg 5 -11

[Ryland]

What might be closer to your budget is to get a DC/DC converter, a few of those packs and pull your alternator belt off then use the lithium packs to keep your lead acid battery fully charged.
I worry about drawing 75 amps from those batteries, the wires just don't seem large enough to handle it and at 90 amps those wires are going to start melting insulation.

[gone-ot]

...if they can ever get "super-cooling" compact enough, then a super-cooled electric motor would be BOTH efficient and compact! Talk about R-A-N-G-E!