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[TurnNBurn]

Do any of you know anything about solar charging? I was thinking of getting a cargo box to cary a portable solar charger. How long do you think it'd take to charge 3 or 4 batteries with a solar charger? I think thinking about getting a large flexible panel that I could sort of drap over the sides of the bike like a cover.

[Bogan]

At a guess, 100W of solar if you get good panels. approx 10kwhr of batteries, is 100 hours for a full charge, or 1% charge every hour.

[TurnNBurn]

Wow. Now I know why solar panels never really caught on. That's no bueno. 6 hours for 6%. That'll get me to the first stop sign. Do you guys know of any other charging methods I haven't considered or have any odball ideas?

[frodus]

Maybe a receptacle at wherever you are?

I mean, they're literally everywhere you go.

Nothing really mobile other than a generator running on propane or natural gas rather than gasoline/petrol..... but receptacles are the best options.

[TurnNBurn]

Maybe a receptacle at wherever you are?

I mean, they're literally everywhere you go.

Not here in vegas. Shocking, actually, since solar energy is so abundant here.

Another question that's been on my mind. I saw a youtube video of an EV bike that had 2 motors. What advantage would having 2 motors give? It seems like a waste. Wouldn't it draw twice the power without giving any extra benefit? Or would the 2 motors ease up the load and require less energy?

-edit-

Found some information here: http://www.bikeforums.net/archive/index.php/t-694962.html

Sounds like a challenge that I would like to accept, especially considering it will increase range.

[frodus]

2 motors splits the power between two motors.... which is better for motor efficiency since the resistive losses would be less than running that motor at twice the amps to get the same power. Say you have one motor and use 100A and compare to 2 motors using 50A each. It's more efficient at the motor due to less loss due to heat. That much is true.

Some things to consider though. 2 motors is a bit of extra weight. And depending on if it's BLDC or AC, you need 2 controllers. And depending on how you couple them together, you might have mechanical losses associated. If you use PM or series wound motors and them in series, it doesn't matter, you still have resistive losses the same as a single motor, it's just running at half the voltage. If the PM or series motors are in parallel, the current is divided and losses go down..... but there's an issue with getting the motors perfectly tuned. If one is just barely built differently and has different coil resistance, the motor with the least resistance gets more current. more current, more heat. More heat, more resistance.... then the other one starts to use more, and you end up creating more heat.

With a sufficiently sized single motor that is built to handle the amps, it's a much simpler system, cheaper, lighter, smaller. Keeping the motor cool will do quite a bit for efficiency.

[frodus]

If you're interested....I think I'll have a new AC15 motor with warranty (or AC20 if you give me a heads up), but with a new out of warranty 1238-6501 controller. This is an AC setup with regen.

[TurnNBurn]

If you're interested....I think I'll have a new AC15 motor with warranty (or AC20 if you give me a heads up), but with a new out of warranty 1238-6501 controller. This is an AC setup with regen.

I havent begun researching motors enough yet i dont know much about the ac15 or ac20. What motors would you guys would recommend for the top speeds i want to achieve with the distance im looking for?

im building a parts list one item at a time. im looking at motor for the speed and efficiency i want, a controller that is compatible and efficient, and batteries to last. Where should i begin researching each and what would you guys recommend for each part?

[TurnNBurn]

Any recommendations for motors and controllers?

Is there any interest in me getting pics? I already have the bike stripped and about the be stripped, primed, and repainted. I'm about to get a list of electrical and mechanical parts I need to  begin assembling.

-edit-
I'm looking at brushless motors, two of them being the PMAC-SS (ME0201014201) which is rated at 19HP. I'm also looking at the PMAC-DS (ME0913) which is rated at 40HP. I have 2 controllers picked out if I go with these motors, but I'd like to ask my next question first.

What about brushes versus brushless motors? What are the benefits of each and which should I be looking at for the speeds and distances I need?

[frodus]

What Controllers do you have matched for each motor respectively? I'd still recommend an AC15 or AC20 for your application. Of your choices, I'd only choose the DS. 19HP might be a bit on the small side for your bike. It's not a tiny bike and you want some fair speeds out of it. The PMAC-SS might take you a bit to get to 75mph... if at all. The DS shouldn't have any issues.

Also, it's not a brushed versus brushless thing, it's power. A sufficiently sized brushed motor could accomplish the same job.

Pro's of Brushed:
Easy to get motors
Less complex (cheaper) controllers
easy to tune the controller

Cons:
Brush maintenance
Slightly less efficiency

Pros of Brushless:
Only bearing maintenance
More efficient (but not always)
More power dense (but not always)

Cons:
More complex (expensive)controller
Harder to tune the controller to match the motor
More expensive/harder to find motors

[TurnNBurn]

For the controllers on the brushless motors I was looking at the Sevcon Gen4 72-80V (180A) or the 72-80V (350A). The price difference is $400 between the two.

For the Brushed motors I was looking at the EMC-RT200 at 38HP and the EMC-R LS (ME1004) at 21HP. Obviously I'm going to want the more HP, but now the question is....brushless or brushed. The EMC RT-200 or the PMAC-DS. The prices on them are almost the same.

At this point it's looking like the PMAC-DS with the Sevcon Gen4 72-80V. But what amp? Are there better controllers to be had for this motor?

[frodus]

Do a quick calculation.... what is (lets say 72V pack voltage) 72V * 350A? it's about 34HP.... but you won't get that out of the controller. 350A is motor side. 72V is battery side. You'll never see 350A in the battery side. You'll get 350A on motor side, but not at 72V.... it's modulated. Let’s assume you CAN get 350A battery side.... that means your batteries need to be able to supply that peak current. Let’s say they're 60Ah CALB cells... that's about 6C, which is OK for pulse discharges, but the sag will be pronounced (something like 2.8V or so).

So a 24-cell pack of 3.2V nominal cells will be 76.8V resting, but 67.2V under load..... so 67.2V * 350A is 23520W, or 31.5HP. The batteries and controller are the bottleneck. If you get batteries that don't sag as much, and you may help that, but not much.


Next:
You’ll absolutely want to get the motor AND controller as a package from someone who sells BOTH as a package. Otherwise you will need to purchase or rent a programmer and set it up yourself, which is not an easy task for many. If this is your first, just get it as a working set before you start the project.

Brushed is much easier to configure. If you can get a decent sized brushed motor and match it with a good Alltrax, Curtis or Kelly, then you’re un business.

If you want something you know works, and puts out the kind of power you want, I have an AC15 motor AND controller that I’d be willing to sell for way under what they go for brand new.

Sevcon Gen 4 350A 72V is : ~$925
ME0913: ~$825
Rental: Unknown if you can even rent it, otherwise it’s ~$900
Total: $1750 without rental/programmer

AC15 motor and 1238-6501 controller: $1900 and I’ll throw in one free rental of a programmer IF you even need it (2 weeks, you pay shipping to/from). It’s a well proven package that most of the online suppliers sell. Not trying to dissuade you, just be honest about what you need to get it working. I just happen to have one, slightly used for a development project that didn’t pan out. Controller is new, motor is only slightly used.

[TurnNBurn]

AC15 motor and 1238-6501 controller: $1900 and I’ll throw in one free rental of a programmer IF you even need it (2 weeks, you pay shipping to/from). It’s a well proven package that most of the online suppliers sell. Not trying to dissuade you, just be honest about what you need to get it working. I just happen to have one, slightly used for a development project that didn’t pan out. Controller is new, motor is only slightly used.

I did find a few retailers that had package deals and they had as an option a few controllers to pick from. I'd definitely take you up on that offer, but right now I'm just putting together my shopping list and hopefully in a few weeks I'll be able to buy the parts. If they're available in a few weeks, I'll surely hit you up.

I'm trying to start selling the CBR parts (engine, exhaust, radiator, etc...) on craigslist. Those funds will go to my motor setup.

[frodus]

Let me know, I haven't advertised it yet and am not in a huge hurry to get rid of it.

Where are you located?

[TurnNBurn]

Let me know, I haven't advertised it yet and am not in a huge hurry to get rid of it.

Where are you located?

I'm in Las Vegas.