Which Batteries? Lipo, Lifep04, headways,turnigy?

[V-spec]

I'm confused guys in which batteries to use, i went and purchased 24 calb se40aha which are quite large and heavy for my bike project. Now after searching through endless sphere and looking into ttxgp technology more people are using Lipo it seems.

Now i have an alltrax 7245 controller and a lynch d135 200 now i want to get some speed and power and feed 72 plus volts and 200amps, im looking to get over 50mph and still have get a distance of 30-50miles.

Ive seen lipo batteries which are only 5000ma but yet have a discharge of 50c continuous!:

http://www.overlander.co.uk/batteries-chargers/lipo-batteries.html

http://www.lipolbattery.com/LiPo%20Battery%207.4V%206500mAh%2050C.html

for example, my question is would these be suitable and better than my lifep04 calb batteries? in terms of weight, placement etc? If so how many would i need to get the power/range i need?

also what about these type of batteries:

http://compare.ebay.co.uk/like/190753167627?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla&crdt=0

they are similar to headways?

http://compare.ebay.co.uk/like/190753167627?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&adtype=pla&crdt=0


before i start building my bike i want to choose the right batteries!

 

[robb]

If you are from the UK and thinking of headways it might be worth looking at http://eclipsebikes.com/headway-lifepo4-38120s-10ah-p-1011.html They are around £13.75 for 10 amp headway cells and £20 for the 15 amp.
RobB

 

[Kirk]

Turnigy or for a few bucks less Zippy 6s 8000mAh will give you some depth. Get at least 30C if you use Zippy. YMMV

 

[dogman dan]

Hoo boy. 50mph for 30 - 50 miles. In a way, you did buy the right battery. You'll need a huge number of watthours to get to that range at 50 mph.

How to carry it on a bike is the main problem. Well, after the tire problem that is, but motorcycle tires and rims solve that.

50 mph for 10 miles is relatively easy though, and Hobby King lipo is the way. Smaller physical size, and slightly less weight Tests with a small affordable lipo pack will show you how big your final battery will need to be to get closer to the range you want. Once you know how many watthours per mile your bike uses to go 50 mph, the math to size the pack is simple.

Follow the rules, don't puncture is a big deal so build safe boxes to protect your lipo.

Headways wouldn't be any smaller or lighter than what you have, once you get to carrying 40 ah of it. A rude dog guess at what you will need for 50 miles at 50 mph will be more than 40 ah. So you really are looking at carrying a gigantic pack as the main problem. You can't do it on an ordinary bike frame. Hopefully you weld real good.

 

[dogman dan]

In case that wasn't clear, the source for the lipo is Hobby King. Buy from the more local warehouse for the batteries themselves. Other stuff can ship from china fine, such as the chargers, wire, connectors, etc etc.

http://www.hobbyking.com/hobbyking/store/index.rc

 

[V-spec]

Man why is this so hard! Dogman i'm using a 2006 aprilia rs 125 as my testing chasis, i think jozztech did the same type of build using headways? Your right is saying ill need a gigantic pack hence why im trying to find something that will suit my needs. At a guess what the hell would i need? so many different battery types, shapes etc. Maybe i should contact Jozzer!

 

[dogman dan]

Pardon me for the laws of physics. It's just that every time you add 1 mph, you add a lot more needed energy to overcome wind resistance. A streamilner helps, but on a relatively upright bike or motorcylce you are screwed. Ever notice people don't go 50 mph with 3 hp motorcylces? About 35 mph is it. Gas or electirc, it takes a lot of power to buck the wind at 50 mph.

I don't know what you will need exactly, but to go 47 mph for ten miles I was carrying 10 ah of 110v. So my best guess is that for a 72v battery you'd need around 50-60 ah.

72v 10 ah of lifepo4 weighs about 15 pounds, so call it a 75 pound battery. At least you have a decent frame to do it with, instead of having the fantasy that a bike frame can deal with that 75 pounds.

That's lifepo4 though. RC lipo will be much smaller and about 25% lighter, so perhaps 40-50 pounds of battery. Slow your expectations down to 50 mph top speed, but only cruise at 40 mph, and the size battery you need gets much smaller. You can do your first experiments with about 15 ah, then see what you get before investing in more.

 

[Doctorbass]

:lol:

And.. who is welling to run 50mph during 30-50miles!!!!... on an electric bicycle!!!! :lol:

and where ????.. in the desert of bonneville.. or somewhere else where no cops can catch you ?

btw.. Turnigy ARE a brand of LIPO.. Turnigy are not a type of cells :wink:

Your cell type would be: LiPo, LiFePO4, LiMn or.. if you like danger: LiCo

Doc

 

[agniusm]

24 Calbs will come to 36 kg, 48 A123 prismatics would be 23.5kg + some weight for assembling the pack. You win 10kg have capable battery to deliver power you need and most likely be smaller for factor.

 

[jonescg]

24 Calbs will come to 36 kg, 48 A123 prismatics would be 23.5kg + some weight for assembling the pack. You win 10kg have capable battery to deliver power you need and most likely be smaller for factor.

Yeah, CALBs are great for very cheap car or motorbike conversions, or stationary power applications. There is so much better out there for EVs.

 

[dogman dan]

Yeah, too heavy. But I wonder how much weight is really going to be saved, since you still need to protect a lithium battery pack somehow. Can't just duct tape naked foil pouches to the bike. Well, too many do anyway.

I just wanted to point out that he won't go 50 mph for even just 30 miles without a huge battery. He's got the size about right, nothing will magically make it take 35 wh/mi.

Slowing down to just 40 mph would cut the wh/mi very significantly.

+ 1 for understanding it takes more than a cheap bicycle from wallmart to do 50 mph on the roads for any distance. He's using a motorcycle frame, for those that didn't notice that.