EV Drag Racing

[allen_okc]

and this is the recommended wire size from altrax controllers...

[allen_okc]

I thought the same, but, .. i believe he is trying to stay below the 49v class limit ?

..and yes, the Nanotech lipo would still save a bunch of weight ... ( 60lbs of lead vs 10lbs of lipo !) .. give more power , and cost less !
What is 50lbs weight reduction worth in terms of ET ??[/quote]


50lbs in terms of ET depends on what his power to weight ratio is currently, and I don't know either to make an estimate from.

49v class limit? Charged lead is going to be ~53ish right?



from what im understanding, which i could be wrong - but the four 12 volt, 17ah odessy batteries will push out 640amps, more than enough to drive this bike down the 1/8 mile strip...

[AussieJester]

to break speed records cost lots and lots of money, which i dont have... i have too many other expenses to deal with.

Indeed it does, your aim is pure enjoyment not breaking records do what you can afford
mate, if and when you can upgrade great if not really doesn't matter if your gettin a buzz with what you have
Not all of use can drop 4k on a half a pallet of nano techs just for the hell of it. All the best
mate following with EXTREME interest, plan on a couple of these Mars motors in a very long and light drag bike
thankfully have a sponsor so none of my money is being spent LoL..

KiM

[allen_okc]

well said kim - im really pulling for you too. i've seen your projects and i know you will succeed at that 9 second bike...

if anything, out of the fun of racing, comes the knowledge of an overdue technology - by next year i intend to be totally pulled away from the fossil fuel trap...

we have so many different ways of powering a vehicle, like the plasma engine, hydrogen, electric and magnetic, its just crazy not to explore the possibilities... you all are definitely ahead of the game...

[liveforphysics]

from what im understanding, which i could be wrong - but the four 12 volt, 17ah odessy batteries will push out 640amps, more than enough to drive this bike down the 1/8 mile strip...

640amps would be 37C discharge from lead-acid.
Maybe they can if you just short the pack down to a dead-short, that's how the rate the "cranking amps" on a lead battery, despite it offering you no power when shorted to 0v (because power is amps x volts, so 1000amps x 0volts = 0 watts).

As a rule of thumb, all damage to batteries and safety concerns aside, if you're discharging the pack hard enough to sag below 50% of it's resting voltage, you're getting less power out of the pack than you would be at less current draw. Just keep that in mind if you see the pack voltage drop from 50v to 25v (or lower), you know you could be running harder dialing back the current a bit.

Also, you're batteries are going to be getting heated during discharge, BUT, they are NEVER going to deliver the current you want if you start with them cold. Ideally, you're going to want some powerful heating pads between those batteries, and while you're charging up in the pits, you're going to want a separate cord getting that lead as hot as possible.

You can seriously double the performance of a lead acid battery if you get those batts so hot they are uncomfortable to touch before you start your race. And likewise, on a cold morning or something if you don't have pack heaters, your performance is REALLY going to be saggy.

[allen_okc]

i have a gauge on the bike that will tell me if she drops to low, plus the controller has a processor that will tell me how the amps and the voltage hold out... so i'll keep an eye on it to see how it does...

thats some of the things i cant seem to grasp is that whole "C" thing - i understand "ah" a bit, boy the mysteries of the lithium...

i'll learn for sure, but right now i have a starting place with the battery thing...

Thank You Liveforphysics...

[allen_okc]

im told i'll get two good runs off the four dry cell 12volt 17ah bats... when i get to the track i'll top off the batteries, that should heat them up a bit...

[Hillhater]

you have lost me here ...
....after much discussion and advice from LFP , AJ, and others , you said..

...i'll go with kim and liveforphysics batteries...

and..

, i will definitely use the lipho batteries -

..then , a few days later you decide to buy the lead batterys ! WHY ?
not cost.....because the LiPo's would have been cheaper !
not performance ...the LiPo's would be better !
not weight.... LiPo's would save you 50lbs !

so why ???

....im told i'll get two good runs off the four dry cell 12volt 17ah bats...

who is advising you on these lead batts ? ..sounds like sales talk !

[liveforphysics]

im told i'll get two good runs off the four dry cell 12volt 17ah bats... when i get to the track i'll top off the batteries, that should heat them up a bit...

The person you're getting battery advice from is an idiot. I wouldn't put those batteries in an electric wheelchair for my Grandma, because I would just have to listen to her complain about the weight and low performance.

If your charging heats the lead, you're damaging it, and it's not going to perform nearly as well as if you heated it with a heating pad, and just charged it appropriately.

And I understand having a tight budget, but this really is a very very poor choice in battery that will cripple the performance of your machine (both in weight and power) until you buy something suited towards racing.

In other words, you're just going to end up re-buying the batteries if you want it to perform worth a damn, and this time you will have even less money because you wasted some of it on lead.

Take it from a guy who has played the re-buying it game in racing more than his share of times. So, in the Honda racing scene, the axles are a weak-link. You can spend anywhere from $89 for Napa free replacement axles clear up to $6,000 for custom axles. So, like most folks, I started out being more interested in spending money making more power, and wanted to just spend as little money as possible on things like axles. My goal was to just spend the least amount to get something that would work. So, buying 2 sets of the free replacement Napa axles seemed like a good idea, because when they break you bring it back and get a new one free. One of the local racing shops had advised me to buy the stage 5 axles right from the start for $2200usd... I was like, you guys are nuts! I'm never paying that much for stupid axles, they are $89 at Napa and when they break you get to swap it out for a new one!

So, the Napa axles kinda work on street tires but it's annoying to have so many trips at the track botched from needing to pull your axles, drive to the store, exchange them, put them back in, try to run again, break them again, go back to the store etc... So, I ended up buying 3 sets of them at $89 each thinking I could get them to work for me, and having spares on hand for quick replacement as they broke. So, $534 in axles, and I could generally last a full saturday of racing if I didn't mind swapping them out multiple times at the track.

But, when you switch to slicks, you can't get a single pass down the strip on the Napa CV-joint axles anymore,
Time to buy some after-market axles. Find the cheap pair of no-name "racing axles" for $350 (so now I've spent $534+$350 on axles). Go to track, start burn-out to heat up tires, on the roll-out of the water box, TING! Axle breaks, car does a little 45deg spin in the water box. lol Normally the Napa axles can at least get to the starting line before they shatter...

Ok, look for the cheapest reputable racing axles... They are $550 for the Stage II axles that are suposed to be twice as strong as the stock axles yadda yadda special alloys, bigger bearings etc. Buy them, install them, and go racing. Burn-out/waterbox is all fine, make 6 passes down the track on saturday, I'm happy. More tuning Saturday night, improve the tune a bit, come out Sunday, first pass my fancy $550 axles shatter. Damn Damn Damn. Now I've spent $534+$350+$550 on axles, and I still can't get a weekened of racing in...

So, I'm looking at the different racing axle options... and I see the Stage 5 axles for $1850 bucks, and then you have to buy custom machined hubs for another $350 so these giant axles can fit. I'm thinking to myself, damn, that would be so stupid to spend $2200usd on axles... The stage 2 axles lasted a day for me, so I will bite the bullet and jump up to the stage 4 axles for $950 bucks, and I should be set for life. So, they come, they are beefy, I'm happy, I run them for a couple track weekends, many street passes, and I'm pleased. But... on the second month of owning them, they snap at the track again.... I called the company and told them I'm making less than the 700hp they are supposed to handle, and I only had them for 2 months, and yadda yadda, and they of course said that the shock loading from launching on slicks can put huge stress on things etc etc (like I didn't know that lol) and that nothing for racing can be warrantied etc. So, at this point I've spent $534+$350+$550+$950 on axles, which is $2,384, and I still don't have an axle that works for my car... I was pretty damn bummed about it. The car sat for about 6 months while I saved up and thought about WTF to do about it.

So, finally, I bit the bullet and bought the custom billet hubs made to accept the enormous custom axles that cost $1850 bucks + $350 for the custom hubs that allow them to fit. That extra $2,200 on top of all ready spending $2,384 on axles really hurt the budget. Ended up paying $4,584 to end up with the $2,200 axles...
But, they don't break anymore, the car works, it can run full events as often as I want on those axles, and they have held up like a champ, no signs of stress cracks or anything on them yet.


So, I learned a lesson from this axle ordeal.
When you're racing, it's often cheaper to only buy the best right from the beginning, and only have to buy it once.



So, later, when myself and buddies were breaking gears in the tranny (because racing is always about pushing harder/faster etc), some friends bought the $800 cheapo racing gear sets, I just saved my money, and after a while, I bought the best PPG $4,500 straight-cut dogbox gearset on the market. And still do this day, it's held up great, and never missed a shift for me, while other buddies are on cheapo gear-set number 3-4 by now, and have to bring a spare tranny to the track with them for each event that they are serious about.



Take it from somebody with a little experience in this racing and battery game. You buy the lead blocks, you're not going to be happy with it, and you ARE going to end up buying it over again. Save yourself the long term money, wait and save up if you have to, but buy it right the first time and you will be a lot happier guy in the long run.

Best Wishes,
-Luke

[Hillhater]

Luke,
what makes it worse is those Odyssey 680 batts cost $130 + each, vs $104 each for the 6s Nano-tech Lipo. !
and i dont see where he would need more than 4 of the lipo's ( 12s, 2P ) to give him 45 v, 10 Ahr of 90C good stuff !

[liveforphysics]

Luke,
what makes it worse is those Odyssey 680 batts cost $130 + each, vs $104 each for the 6s Nano-tech Lipo. !
and i dont see where he would need more than 4 of the lipo's ( 12s, 2P ) to give him 45 v, 10 Ahr of 90C good stuff !

LOL, you're right. It's cheaper to go Nano-Tech!

This battery:

http://www.batterymart.com/p-odyssey-pc ... onShopping

That says 680 cranking amps (warm), means when SHORTED OUT on a carbon pile loadbank, the battery can do 680amps discharge (or at least that's the claim, most lead claims are totally full of sh*t.)

That number is useless for your application, as the current it discharged when shorted would indicate the torque it could put on a starter motor, but it's useless for an EV application where you need power not just torque.

[Hillhater]

Even if someone is giving you those lead batterys for free... they are still not doing you any favours as they will simply slow you down compared to the lipo.
HINT :- IF you are being given them...sell them quick and buy the lipo !

[allen_okc]

i hear you kim - i used to race moto and hair scrambles myself - i spent more money on carburetors...

the issue is - i have little knowledge of the lithium bat - the weight issue would definitely be better in the weight ratio with them - but the understanding of the lithium batteries seem to be more dangerous to me, especially when i have little knowledge of them - plus trying to understand exactly how many of the lithium i need on top of whether to use lithium ion or lithium poly is totally foreign to me - im not building a long distance runner or a grocery getter - im building a drag scooter short run for 15 seconds at most, torque gears and horsepower is what makes the difference, of course horse power measured by amps and watts...

im not mad or crazy, just confused - so im just using what i know, when i get a better understanding of the lithium battery i will definitely use them. right now time is running out - for now i will be using the dry cell battery this year, even though no one seems to appreciate them, it worked for the white zombie and it will work for me too...

next year i will be going to the lithium battery - by then i will have a better understanding of them and all the equipment required to maintain them...

right now the lead bat will do for now - my concerns at this point is mounting the motor, which will be ordered next week and finding a motorcycle wheel that fits, looks and perform. frame structure safety, a gear ratio, on top of a quality of sprocket and pinion gear and chain to use on top of satisfying NEDRA NHRA with their safety reg's.

like i said - i just want to have fun on the track, experience the scooters performance and improve on it by next year...

so weither it fry's the bat and the cables or burns to the ground - she will be out there doing it. your advices are very important to me, and i do listen - but i can only do what i can do, because im the one who will be sitting at the starting line on the drag strip with my scooter, waiting for the green light to give it full throttle, because thats what its all about...

[Arlo1]

interesting

[mdd0127]

I will tearing my smashed turnigy packs apart in the next week or so to replace the damaged cells and will probably end up with 10-15 dented but electrically functional 5000mah 25c cells. I want a few of them but would definitely donate a few to your cause. Maybe there are others that can do the same. With your application, you can keep an eye on them and will be more hands on so they should be fine. I just don't want to cram them in a tight space and go trekking out into the woods unless they're perfect. Then you could get some LVC boards from tppacks, a couple of meanwells and charge controller instead of the lead.

Somehow, I totally missed the lead part of the thread??? Lipo on the brain I guess. I know you can definitely have a little fun with the big old batteries but if you're out there exposing electric vehicles to the public, it's best for the image and everyone if it performs REALLY well. I'd be happy to contribute cells or advice...whatever I can do.

[allen_okc]

i appreciate your offer, but like it was mentioned earlier, cost compared of the lead bat to the lithium, the lithium would be cheaper and lighter, which is awesome... but the equipment for charging and balancing the batteries is expensive - and i need a better understanding of the batteries - i went to the thread that kim recommended, and it made me even more confused.

i just need a book soley about lithium battery types for dummy's, care of handling charging storing, even understanding the rating of the bats in "C", it would be a lot to learn before i use them...

i dont need to come home and find my house burnt down while i was at work, or have them blow up in my face, simply because i did something wrong at the wrong moment... i saw liveforphysics video, which was awesome, but it also shows how dangerous they are...

im sorry everyone - the bike will do just fine... lithium bats are on the list, but only when i have the right equipment for them...

[vanilla ice]

At least the lead will let you focus more attention to the non-battery stuff and ease in to things. And afterward you will be able to give a solid quantitative comparison of both types of battery!

[gogo]

Devil's advocate argument: The weight of the lead = better traction = less wheel spin = getting up to speed quickly = low ET. At some point air resistance will overshadow the penalty of accelerating the added weight of lead.

I'd think it should be possible to get a tire sticky enough that wheel spin wouldn't be much of an issue and in that case lithium will clearly be better. I think it'll be interesting to see just how much difference lithium vs. lead will make.

[AussieJester]

like i said - i just want to have fun on the track, experience the scooters performance and improve on it by next year...

because im the one who will be sitting at the starting line on the drag strip with my scooter, waiting for the green light to give it full throttle, because thats what its all about...

Of all the people telling you what you should be doing your the only one actually doing it (on the drag strip)
with an electric vehicle, all well and good for us to sit here and tell you what you should be doing but we are not the ones risking injury. I think we should all being giving Allen props for being out there and at least having a go rather than giving
him attitude about his battery choice.. Hes on a budget, he already has the lead.

You have the bike running and your having fun on it when you get the $$$ and are comfortable you have the knowledge get some Lithium Polymer packs. They aren't difficult to use and they aren't dangerous if used correctly. Majority of the fires in the past have been from incorrect charger settings/over charging packs. This was also years past new tech Lipo are a hell of alot more robust Allen and also not that expensive to get chargers for. Meanwel PSU (are used as a chargers) a good RC charger is under 200. I would definitely suggest bulk charging your packs at the track this would require a few of the 30 dollar meanwels paralleled. If your running 44v lipo you need to charge to 49.5-50V simply set your meanwels to 50v plug it in to your pack and walk away. You can balance (if ever needed) at home during the week with a cheapo RC charger. You will find they will rarely need it though if ever lipos stay extremely well balanced if treated correctly.

All the best buddy.

KiM

[Hillhater]

Allen,
I think you have psych'd yourself out of the Lipo's with some misunderstandings.
Have you actually bought the lead batts yet ? ...if yes , thats ok, decision made.
...but If not, consider the following...
# for racing, battery choice is probably MORE critical than motor choice !!
# weight is a HUGE factor in ET & speed on the strip...even more so in the lower power classes
..( and forget the BS about needing weight for traction ..if you cannot hook up 18kw you have other problems ).
#charging lipo is NOT dangerous if you use the correct equipment
#you can buy a charger for <$20 to SAFELY maintain lipo. ( more money buys faster charge time)
#charging lead can blow up your house if you do it wrong !
#riding your bike down the strip is a far bigger risk than any potential battery charging issue.
Correction :-- driving to the track is a far bigger risk than charging lipo..

[allen_okc]

i havent bought the bats yet - but can anyone direct me to a good lithium pack for a 48 volt 300amp motor 4,500watt 15hp...

i need to know exactly how many and what type... im not going to geuss about this, cause if i do then i'll get the lead bats instead...

i agree that the lithium is a superior battery, but im not paying 500 dollars for a battery charger - 150 is my limit... and the "C" thing, i understand it stands for current, but what is 37c compared to "17ah"...

if someone can lay out the whole package i need to get including the charger and everything else i need, then i will use them instead and learn from that - remember i need a lot of amps for at least 15 seconds...

liveforphysics gave me the info that was good, but he keeps thinking im doing 80volts, if he is suggesting 80 volts for a 48 volt motor and controller then im curious as to why... remember im lithium stupid here...

i was looking at these - http://www.electricmotorsport.com/store ... s_20ah.php

[Arlo1]

i havent bought the bats yet - but can anyone direct me to a good lithium pack for a 48 volt 300amp motor 4,500watt 15hp...

i need to know exactly how many and what type... im not going to geuss about this, cause if i do then i'll get the lead bats instead...

i agree that the lithium is a superior battery, but im not paying 500 dollars for a battery charger - 150 is my limit... and the "C" thing, i understand it stands for current, but what is 37c compared to "17ah"...

if someone can lay out the whole package i need to get including the charger and everything else i need, then i will use them instead and learn from that - remember i need a lot of amps for at least 15 seconds...

liveforphysics gave me the info that was good, but he keeps thinking im doing 80volts, if he is suggesting 80 volts for a 48 volt motor and controller then im curious as to why... remember im lithium stupid here...

i was looking at these - http://www.electricmotorsport.com/store ... s_20ah.php

You can run the motor at any voltage you want (with in reason) so if you run it at 80 volts it will spin faster and because you are using more volts the watts will go up which increases your HP at the same rpm but because you upped the rpm the HP is up from that as well.
100 amps at 48 volts is 4800watts but 100 amps at 80 volts is 8000 watts watt/746=HP So 4800/746=6.43 HP and 8000/746=10.72HP
You are building a bike to compeat with so in order to compeat you need to try every thing you can to make it faster.
If you up the volts as hi as you can you will go faster.
Remember the volts will determin the max rpm of the motor so if you up it you will have to gear down to lower the top speed of the bike but this is a GREAT thing because it multiplies the torque going to the rear wheel to make you even faster!!!!

Trust me I am one who has felt it a electric motor will accelerate faster and have a higher top speed with more volts and make the system more efficient!
I would go as high as you can afford with the volts
As for the nano tech lithium its not an option its the best battery and its the lightest and in some casess its the cheepest!!!!
PS my lipo charger is $40 pluss 4 Mksppro balancers.

[allen_okc]

well i just purchased stuff for the rear wheel and i got a good deal on it all, its all off a FZX 700 yamaha - 15" X 3" wheel...

the wheel
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0522179123

the cush hub flange
http://cgi.ebay.com/ebaymotors/ws/eBayI ... MEWNX%3AIT

the cush
http://cgi.ebay.com/ebaymotors/ws/eBayI ... MEWNX%3AIT

sprocket
http://cgi.ebay.com/ebaymotors/ws/eBayI ... MEWNX%3AIT

the axle
http://cgi.ebay.com/ebaymotors/ws/eBayI ... MEWNX%3AIT

[allen_okc]

Thank You Arlo - i still need a configuration and specifics on the lithium bats - the charger sounds more reasonable than what the electric motor sports is trying to sell me... over 500 dollars...

[Arlo1]

Thank You Arlo - i still need a configuration and specifics on the lithium bats - the charger sounds more reasonable than what the electric motor sports is trying to sell me... over 500 dollars...

Go to one of the hobby king links luke give you or just serch Kobby King go to their battery section > lithium polymier>turnigy nano tech
Then find the Highest C rating with the most MAH and as manny cells in a pack as you can
the S is the number of cells
the C is timesed by amp hours to get max amps
Now onething to know is they rate their batteries on a 3.7volt per cell nominal voltage and in all realaty they are near dead at that voltage so you will find they over produce what they are rated at and as luke has seen some times over 2x the max rated amps/
So a 6s 6000 mah 45-90c pack is 6x3.7 22.2 nomnal (but charges to and is used at 25.2 volts) its 6 ah times 90 which gives you peak distarge of 540 amps!!!
And luke will tell you he has seen times when it can be more then double that imagine a 25 volt battery with 1000 amps !!!!! thats 25000 watts out of one little 1/2 lb pack!!!

But remember the highes C number and amp hour number (but #1 is the C rating) you can get will win because then you need less batteries in total!!!!