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Discussion Starter #1
Hi,
I'm thinking about building an electric vehicle for running errands. I posted on the "I want to build an EV! Where do I start?" thread but it's not getting any action.

I have a '61 Ranchero and a '69 Honda Trail 90 for conversion candidates. The Ranchero weighs ~2400 lb in stock form, and it's a pickup so the batteries would easily fit in the bed.

The Honda 90 is somewhere between a moped and a motorcycle. I'm thinking sidehack so there'd be room for the batteries and a little cargo, plus since I was a kid I wanted but never had a sidehack bike. I'm leery of riding on the streets much, so that'd be for getting my feet wet with EVs, and I'd probably only take it into town (about 4 miles).

I live in the foothills- in Sonora, California. My most common one-way trips are to Twain Harte (about 4 miles), downtown Sonora (about 12 miles), and up to Pinecrest lake (about 25 miles) with my current EV- a canoe with a trolling motor and a deep cycle battery :D. For the Ranchero I could probably get by with a 30-mile range, and a 60-mile range should be good. The Honda 90 could probably get by with 10-mile range, and a 25-mile range should be good.

I'm thinking 60 MPH top speed for the Ranchero and around 40 MPH for the Honda 90.

Performance similar to stock should be good. The Ranchero originally had an ~85 HP straight-six, and the Honda 90 a 90 cc 4-stroke with a top speed of 45-50 MPH, I believe.

Browsing info about EVs can be overwhelming. I'll have to try to dig up a few older EV books I have. I'm looking to do it fairly cheap and simple. From what I've seen here so far a forklift motor and lead-acid batteries sound like what I want. I have no idea on controllers, but I imagine a motorcyclebike versus a car controller are very different.

I have an unhealthy respect for electricity. I have above average auto mechanics and fabrication skills, probably with some access to mills, lathes, welders, etc. I have a '61 Comet that's a propane conversion.

So, some thoughts would be good.

Thanks,
Kurt
 

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Either one sounds like a good candidate. I think the bike might be somewhat easier, due to it's smaller size. If you're just looking to get your feet wet, you might want to do that. The caveat being, due to its smaller size, fitting components may be more challenging. You'll have to measure carefully before buying anything there, and include some room for getting parts in, room for couplers, etc.

The truck would work well too. Thirty miles is definitely doable. Sixty is probably asking a bit much for PbA. Assuming 350 wh/mi, x 60 mi you're looking at 21,000 x 1.5 x 1.2 (Puekert and Depth of Discharge) =37,800 wh. At 144v you'd be looking at 263 Ah batteries, very hard to do. Few batteries are made > 250 Ah that are for mobile applications; you start looking at huge solar storage batteries and such. At 30 you're looking at 132, which is easy. If you go with AGM batteries, you may have shorter battery life, but will need 30% less Ah (only a 20% Peukert effect).

With the motor cycle, you'll get much better range, but will have less space to put in batteries. You can probably count on ~150wh/mi or less, but take a look at EValbum.com and see if anyone else has posted theirs.
 

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Discussion Starter #3 (Edited)
Okay, if I'm correctly following your math here ... I did some calculations. Is it correct that adding voltage (more batteries) lowers the Ah rating needed for the battery? If so, what does increasing the battery pack Voltage do for performance and/or range? What does decreasing/increasing the battery pack Amp-hour rating do for performance and/or range?

What are typical battery pack voltages for motorcyclebikes?

Thanks,
Kurt
 

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Okay, if I'm correctly following your math here ... I did some calculations. Is it correct that adding voltage (more batteries) lowers the Ah rating needed for the battery? If so, what does increasing the battery pack Voltage do for performance and/or range? What does decreasing/increasing the battery pack Amp-hour rating do for performance and/or range?

What are typical battery pack voltages for motorcyclebikes?

Thanks,
Kurt
Yes. Your needs are fixed, i.e. the power to move it, how far you want to move it. Watts (power) = volts x amps. So as you increase volts, you decrease amps a proportional amount.

Increasing voltage doesn't necessarily do anything for range or performance. It's all about power. You can have a 48v monster amp machine that will tear up the track and go forever. Having said that, the easily available components dictate voltage more than anything else. Typically you wouldn't want to go over ~ 168v for a DC conversion, and you would have to pick your motor/controller carefully. Almost every DC motor you would get for this purpose will take 120v at the top end; beyond that, start looking carefully. The parts are available but you want to make sure you pick the right voltage for your motor.

Decreasing Ah decreases range, plain and simple. You only decrease Ah if you're increasing voltage or are scaling back your range.

I can't answer what a typical motorcycle setup is, might check on http://evalbum.com for wha tothers are doing, or look at the garage here.
 
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