It's ALIVE!!! (Twin Star video) - Page 4 - Fuel Economy, Hypermiling, EcoModding News and Forum

Christ · 11-09-2009, 12:48 AM

Quote:

Originally Posted by jjackstone

Christ,

Just finished reading through this post. Possibly I missed the reason you wanted to bring this up to a 12 volt system. Was that just to be able to use standard automotive LED's? Also you'd obviously need to toss in a 12 Volt headlight. If you measured the output of your rectifier and it is as high as 8 volts, then the system is probably charging properly.

I bought my wife a cm200t about 18 years ago to learn on and that bike regularly returned 70 mpg with no mods. Now she's riding a Honda 650 that still gets her around 50-60 mpg.

As far as the lithium idea goes, probably not a good one. Lithium cells in general need to be charged within a specific range depending on their particular type of chemical makeup. Some like being charged a little above 4V(per cell), some prefer around 3.6V/cell. A standard charger would probably toast them. However, you might just disconnect the whole charging system, use a couple of Dewalt 36V batteries paralleled up, get a DC to DC converter to step back down to 12 volts and then pull the batteries to charge them in the standard Dewalt charger. Just another possibility.
JJ

The reason for wanting to upgrade to 12V output was for the ability to use accessories, modern lighting, etc. I've seen how dim the 6V headlight is, and it's just not safe at speed out here on the country roads.

I had also briefly considered what you've suggested with the drill motor batteries, except using the Lithium inline packs and charging them with the normal charger, and it really seems like too much work/money for the minimal power draw the AC generator has on the motor under it's current configuration. I did, however, consider using a microswitch to control a charge relay that will stop the alternator from charging unless the throttle is off (decel).

What about Ni-Cd or Ni-MH batteries? Would either of those accept the type of charge I'd be giving them?

PS - The LED's, it really doesn't matter if I have a 12V or 6V system, I can just wire the panel differently for them. I'm probably going to keep the OEM configuration for lighting, then add in strips of LEDs placed in such a way that they make the size/shape of the vehicle known to other operators on the roads. Since I'm decreasing the profile from slim to anorexic, and smoothing out the body a bit, it might be a little more difficult for motorists to recognize that I'm on the road, so I want to maximize the visibility of the bike without compromising my goals.

jjackstone · 11-09-2009, 01:41 AM

You could probably get by with NICads. I don't remember any really special conditions for charging them and they can pull a strong current for starting the bike. Their normal voltage /cell is 1.2V so you'd need to series up ten of them for 12 V. Looks like the standard lead acid for that bike is 12Ahrs. Don't know that you would absolutely need that much reserve, but probably ought to try to get close to that. The RC guys have some decent posts on how to solder cells together if that is the route you choose.
JJ

Christ · 11-09-2009, 02:02 AM

Quote:

Originally Posted by jjackstone

You could probably get by with NICads. I don't remember any really special conditions for charging them and they can pull a strong current for starting the bike. Their normal voltage /cell is 1.2V so you'd need to series up ten of them for 12 V. Looks like the standard lead acid for that bike is 12Ahrs. Don't know that you would absolutely need that much reserve, but probably ought to try to get close to that. The RC guys have some decent posts on how to solder cells together if that is the route you choose.
JJ

Not awful worried about the electric starter, since once the bike is tuned, I'll primarily be kick starting it anyway.

I was thinking about doing 6-8 packs of 5 in series for a total of 6v per pack, then wiring those packs in parallel for now, then in series when I get the 12V stator coil I need.

The cool thing is that I can get NiCad and NiMH batteries from salvage electronics... things such as cordless phones often use a 3 cell pack of them, at 3.6V. Take the pack apart, and you've got 3 AAA batteries that will run your remotes and such, and you can recharge them easily.

For the bike, I'll probably buy new, though.

Thanks for the input, it's much appreciated, especially after hearing from my Father in Law all about how it's stupid to run both pipes into a collector, I'm making too much work of the bike, blah blah blah, as though it's any of his business, or trying to sound like he actually knows anything about how engines work. He's another one that thinks putting higher octane gas into an engine means it will fire up easier...

jjackstone · 11-09-2009, 02:15 AM

Cool, hope it works well. JJ

Christ · 12-02-2009, 02:59 AM

BAM!

Got a deal on some Prius GenII battery modules, one of which will become the new battery for the TwinStar!

Also, changed the bars to those from a 1985 CB125S, Since they're shorter, and less "Japanese School Boy".

Working on other designs in my head, but I've basically removed the aero idea from my plans for right now, and I'm just working on tucking everything and whatnot. Need to get a shorter clutch cable, some other stuff, and do up some wiring that isn't "up to par" as far as I'm concerned, like the glass tube fuse.

Haven't started on the intake manifold yet, haven't been able to source a cheap decent merge collector, either. Still working on that part, though... Don't really want to run with two open pipes under the engine.

Also, checking to see if I can retrofit a custom hitch plate from a 1978 GoldWing I bought recently.

Have also been feeling out for really cheap bikes to fix up for Spring, so I can get some cash flow in the Spring.

orange4boy · 12-02-2009, 05:18 AM

Prius deals all round!

How are you going to charge those? Don't know if you know but they have to be clamped tight and charged VERY carefully. Not to freak you out or anything but you don't want to do this:

From here:Prius Battery Photos

Sweet score. I'm looking too.

Christ · 12-02-2009, 04:41 PM

I'm not sure, I was kinda hoping I could case it in metal and just let it charge off the AC generator on the bike.

I guess that won't work out?

I actually wonder if 7VDC at 3.3A will even charge the battery, or if it will only get a charge when I'm at higher engine speeds? Maybe I won't be able to use these...

Christ · 12-02-2009, 06:42 PM

Specs on the alternator of the TwinStar:

At 5K rpm the output should be 7.0 Volts at 3.3 amps
10K rpm 8.3 Volts with a max current of 6.0A

orange4boy · 12-03-2009, 04:00 PM

I think the damage in the pic was done over several hours. I doubt your average bike trip would be that long.

You might just have to keep an eye on it, or a hand, to make sure it's not overheating. Warm is fine as far as I know. My NiMH cordless drill packs get warm to the touch when charging.

Christ · 12-03-2009, 04:02 PM

I've decided that I'm going to mount it flat, with a clamp plate over the exposed side, holding it with a fair amount of clamping force. I'm figuring about 3-4 bolts on both 11" sides, and 2 bolts on the 5" sides, with 3mm plates of aluminum as clamp plates. That should help keep it cool, as well?