After years of looking at motorbikes, riding some, dreaming about owning or buiding one, I have finally settled on building a cafe racer/tracker style electric motorcycle. I've just bought a 1986 Honda CBX250 rolling frame and am currently investigating all electric components.
I've looked into Lithium Ion batteries from a company called LifeBatt but the costs are high. The batteries are roughly $2000 NZ (US$1400) each and apparently also require a battery protection module (NZ$1000). They've also quoted NZ$2000 for a compatible charger. For my total budget of $5000 this is waay to expensive, so I think I'll have to go for deep cycle lead acid batteries. I'll keep investigating Lithium Ion possibilities but at the moment Lead is winning.
I've found a good site at EVAmerica for pretty much all the components required and even though frieght will cost almost NZ$1000 after tax it's still the best option.
Any help or suggestions are welcomed.
lifebatt is the most expensive LiFePO4 battery on the market.
only go to them if you either need large power (and you cant get hold of the better A123) or you need a long warranty (as distinct from just long service life).
fist off, how much power do you need, and what is the heaviest battery pack you can fit?
44 x 60Ah TS cells will put out around 35kw in ~100kg for US$2900 + shipping + BMS (~US$950)
how fast do you need to charge?
this will dictate charger cost.
fewer cells, less cost, lighter, less power, less range.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Hi Matt,
I'm not too sure how much power I will need.. I would like something a bit faster than your average bike but not as fast as a racebike. Maybe I could get away with less than 35KW?? I would also like a range of about 30 miles (40 - 50km) and would be happy with a charge time of about 8 hours at the moment. I could realistically fit the equivalent of 3 or maybe 4 car size batteries onto my frame, the less the better, for looks and performance.
I've just discovered a company in Australia that sell some components which would reduce my costs, making lithium ion cells a possibility again.. still to find a cheap supplier nearby tho. They sell PMG132 DC Motor 24 - 72V and AL300 or 450 controllers. I've inquired about price so waiting on that.
Here's a pic of the starting bike..
Here's the stripped frame..
You don't want lead in a racer. Less weight = better acceleration to get the jump on the opposition. Easier to win from in front :)
Have a look at EVworks in W.A.
http://www.evworks.com.au/index.php?product=BAT-LFP60AHA
bike looks like it has a reasonable amount of room. how much weight can it carry?
35kw is what i get from my 250, if i rev its tits off, and work the gearbox hard.
if you can get this much power over a wide range, it will feel much faster than a 250.
4 yellow tops (or similar) will give you:
25Ah at 48v (1.2kwh), max power of ~32kw.
1.2kwh will give you around 20km.
weight would be ~100kg.
IIRC those batteries cost around AUS$300 ea.
out of curiosity, which company?
a pmg132 + AL450 with a gearbox and battery pack that can supply 35kw will feel just like a 4-cyl 250.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Thanks for the link, have looked at all their components and seems like they offer the best prices.
Not sure how much weight the frame could take but I reckon it could easily cope with about 250- 300kg.
After getting the link to an Australian company that provides all the components for a pretty good price I've re-thought my plan. I'd like to use their lithium ion 60Ah cells and was thinking about stepping down to a 48v setup. This would knock about $1500 off my costs which would be nice.
I like your previous comparison to a 4cyl 250 motorbike Matt.. what do you reckon this setup would be equivalent to? I would be aiming for about 15 3.2V 60Ah cells:
http://www.evworks.com.au/index.php?product=BAT-LFP60AHA
with a 48V motor:
http://www.evworks.com.au/index.php?product=MOT-MARS-ME0708
I figure I'll be using the bike for short trips around the city so will not really need to go much faster than 60km/h (38m/h) but would like it to have a bit of get up and go.
my suzuki across weighs around ~200kg.
60Ah cells are a good idea.
just remember, the more volts you have, the more power you can get through your motor.
that motor at 48v (after sag) applied with 300A, will give you around 11.2kw at 3000rpm.
thats equivalent to a 100cc motor.
for true 48v, you will actually need 16 cells.
60kmh doesn't require much continuous power.
if you plan on gearing so max powerpoint happens at 60kmh (would mean a top speed of around 70kmh), then this will be plenty of power.
if you retain the gearbox (don't steal battery space to do it though), then the bike will be very usable.
for chargers, have a look at kipoint:
http://cgi.ebay.com/Lead-Acid-Battery-Charger-10Amp-48Vdc-230Vac-New_W0QQitemZ380190263702QQcmdZViewItemQQptZLH_DefaultDomain_0?...
i own 2 of those chargers, great units.
with the EVWorks BMS, that charger will work fine.
on 60Ah cells, charge time will be ~6hrs from dead.
also get a cycleanalyst:
http://www.ebikes.ca/drainbrain.shtml
the high current version should do you, unless you plan on holding battery current down to 100A (limits peak power to ~5kw), then you can use the standard version.
This will become your fuel gauge, and is one of the best pieces of instrumentation money can buy.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
For the price, that gauge looks pretty damn handy.
Check out my blog for updates, I've just put a components list up.
http://visforvoltage.org/blog/otto