Gas Electric Hybrid, Hypothetically

[duivendyk]

Problem is starting the thing,use gen.as motor to start& have some kind of coupling ?.Need high speed gen,motorcycle type could match rpm 5-9 krpm.Best if hearing impaired,I think but would be fun to mess around with.Will it last???

 

[stoppit]

I'd have similar concerns about running an rc motor (namely longevity and noise).
One thing I wanted to make sure of. Is the excess current going to simply pass along through the battery and run the engine at a lower rate, or would the battery charge at a lower rate and the engine run at normal capacity, or am I approaching concept completely wrong?

 

[duivendyk]

No, you are pretty much on track.I'm not 100% sure how this battery management system functions exactly,it "protects" against overcharging by monitoring the cell voltages,that much is clear.They also state that the charge current should not exceed 5 amps,but don't say that it protects against this,which is of importance in our situation,maybe you can pry this out of them.Their charger is good for only 2 Amp,so the problem does not arise normally.
What happens is that if our motor generator is hooked up to the battery& controller&drive motor:the battery receives or supplies the difference between the generator current and the motor current,so let's assume we have the gen. supplying 8Amps,if the motor takes less than that say 6Amps, 2 Amps go to the battery,if the motor takes 12 Amps,the battery supplies 4 Amps and the generator 8 Amps.Of course if you shut off the motor the battery would get 8 Amps,hence my previous query.I have not said anything yet about how to manage the gas engine&generator combination.(fully automatic,manual,automatic with manual override,that's for later.
BTW I have run across another generator candidate on Ebay,it's a Bosch surplus dc motor good for about 300-400W at 50V at 4k rpm plus,as best I can determine (the specs are a bit sketchy as allways on Ebay),pretty much up our alley.There is somebody in NYC who's got a hold on a whole slew of these things apparently and has been dribbling them out. There are a few coming due in the next few days,prices vary all over the place fom $10 to $40 + $18 shipping.Not bad for $50 or so.This thing meets reqds and is pretty compact,they may nor be around forever !, he has disposed of quite a few already.

 

[Flapdoodle]

My new 600 watt motor kit was shipped this morning. The plans is slightly different than discussed here. My back is deteriorating and the e-motor will help get me going so I can pop the clutch to start the HT 80, and it will be back-up in case the gas engine dies or chain breaks, etc.

The kit has three 12v 12AH SLA batteries in series. The motor features electric braking. I will measure the output when the motor is free wheeling and hope to get enough output for charging at least one battery pack. The output of the HT can charge another. This would have to be done using a rather bewildering array of jumpers, but should be manageable.

If successful a relay control may replace the jumpers later.

Will keep you informed here.

 

[duivendyk]

Looks interesting from EE perspective,the motor playing generator should produce anything from 0 to 36 V plus,what you need is a step-up battery charging controller that you can set a certain charge rate with and you'd be all set.You don't need a lot of power,just a few Amps.Maybe this Buck Puck gizmo could do the job,it converts a voltage source,like your motor into a controllable current supply to charge with.It is intended to run LED's with,they need a current source to operate from safely.I don't know the input&output voltage/current ranges.Look in Google for info.

 

[stoppit]

Tried searching for the item you mentioned on ebay. Couldn't find it though. I am a bit tapped out financially (eating lots of ramen) so I can't really be in a rush to build this. However, 50 bucks was a pretty **** good price and possibly doable.

 

[duivendyk]

I see,I have a similar project in mind &might snag one myself.Ebay can be confusing to find something go to Ebay under " Motors" & type in 260406652968 as description that gets you to it.Works for me there's one coming up in 2 days.If you don't intend to bid on it ,let me know,I might,we don't want to start bidding against one another.I think this is actually a pretty good deal.Ramen noodle diet not so great on the long run.What did your battery etc + hubmotor set you back for ?.these Li batt. packs not exactly cheap.

 

[loquin]

The MG set doesn't need to be able to supply enough power to power the bike EMotors under all conditions, as the battery takes care of the power surges needed for acceleration/hill climbing.

The MG set should supply enough to charge the battery and maintain bike speed on level pavement. So, as an estimate, if you need 150 watts to maintain speed on level ground, and 2 amps for charging, a 36V MG set should be able to provide a little over 6 amps, or a bit less than 250 watts at 36V.

 

[Flapdoodle]

I got my 600 watt motor from this guy: http://shop.ebay.com/merchant/qvea
for $375 including batteries, headlight, and shipping. Some dealers want $120 shipping, so I figure it was a bargain. [crosses fingers]

I doctor my Ramen noodles with egg, green onion, crushed red pepper, and maybe some scraps of chicken or ham to give it at least some food value.

 

[stoppit]

That auction is all you man. My big concern is to get the basics up and running first, then work on making it a hybrid. Even though that price is ridiculously low.... Have fun doing whatever it is that you're planning with that thing.

I'm a big believer in the doctored ramen. Like to do mine up with a little vietnamese fish sauce, celery, carrots, bamboo shoots, and a raw egg cracked on top.