Ok guys-

Trying to gear up for SEFF 09' and be able to have some electrons available to me..

I was thinking about picking up a generator, but it there has been some opposition from those who will be my neighbors while there..

So.. instead of upsetting anyone, I'm trying to think of decent ways to charge..

I'd hate to buy 2 deep cycle batteries when I could just as easily buy a Harbor Freight 1,000W generator..

So, (and I'm going to try and test it out tomorrow) but I'm thinking - it would be cheaper than buying a generator and much quieter if I just let my car idle and run a setup off of it.. We'll see if it works..

in the mean time..

What is everyone else doing?

I've got several 6S and 4S packs I plan on using.. along with the typical 3S and 2S packs..


Just curious....

Jeff
www.CommonSenseRC.com

I can understand the complaints, some of those generators are extremely loud. But I've seen some mechanically minded people modify their generators to be significantly quieter by doing things like adding an extra resonator or car muffler. During an extended power outage that happened in my area recently, I did actually use my car as a generator at times. Never more than a couple hours at a time. It didn't use that much gas (more than a dedicated generator for sure), but I personally didn't like putting that much wear and tear on my engine. I'd recommend investing in chargers and charging as many batteries simultaneously as possible. It should definitely work for you though.

If you got a Honda EU1000i/2000i I seriously doubt anyone will be complaining. Expensive, but worth it. I would expect to see quite a few of them there.

Check with your local tool rental stores and perhaps you can rent one for the event. Better yet, see if you can rent one near the event so you don't have to cart it back and forth.

Yeh, I've thought about putting a new muffler on a generator if I get one..

I've got the chargers covered.. I generally charge at home before I go to the field.. For SEFF, I'll be flying for 3 days in a row and need a way to run the chargers..

Would letting the car idle be excessive wear and tear on the engine over driving it? You'd think letting it idle wouldn't be near as bad on it as running full tilt down the interstate..

I don't know what you have for chargers but I have been looking for another one recently and I am seeing several that have some type of Low Input Voltage Cutoff so they won't leave you stranded with a dead car battery.

You may also find that you could go through a charge cycle and then only need to run the car for a few minutes to bring the car battery back up.

I would also think that letting your car idle from time to time should not be a big deal with the electronics they have today. Its not like old carburetors that you had to take out on the interstate and "clean them out" oh, the good ole days.

Another option may be to share a generator. Does anyone know how many chargers may be able to run off an 18a power supply and if so, how many amps the power supply would draw? I ask because I would like to try to figure out how many chargers may be able to run off my 5000 watt generator that is in my motor home. Of course, if it is hot and my wife want to run the AC we will lose almost 20a of usable charging power (no SEFF without happy wife). I also want to extend the exhaust to above the roof line, I wonder at what point if any I may be able to use PVC?

Rob

Well, the number of chargers off an 18A power supply would be dependent upon how many amps each charger was pulling..

It would be able to run 18 chargers - each pulling 1 amp..
It would be able to run 36 chargers - each pulling .5 of an amp..
It would be able to run 3 chargers - each pulling 6 amps..

Get the generator and a hand full of little foam ear plugs to provide to anyone that gripes.

Originally Posted by Hypersprint

Does anyone know how many chargers may be able to run off an 18a power supply and if so, how many amps the power supply would draw?

Depends on what you are charging - chemistry, number of cells, charging current?

Bill

Originally Posted by PeteB

If you got a Honda EU1000i/2000i I seriously doubt anyone will be complaining. Expensive, but worth it. I would expect to see quite a few of them there.

Check with your local tool rental stores and perhaps you can rent one for the event. Better yet, see if you can rent one near the event so you don't have to cart it back and forth.

Agreed, quietest generator I've seen. Personally own one for camping and you can hardly hear it when its just outside the trailer unless it kicks up, and even then it is still VERY quiet for a high RPM engine.

Joel

Any of you Honda boys wanna let me borrow one? LOL otherwise, it's out of the question even if it's silent... Just cannot justify the cost...

I know Tram is aware of this Thread

http://www.rcgroups.com/forums/showt...7#post11380585


however I would like to point out to others that post #91 - #95 there cover some key points with real data.

Placing a watt meter or flight data logger between your power source battery and charger(s) is a lot more accurate to determine how many AHs you really use / need. Remember as the voltage drops you will pull more amps. / AHs.


I was tempted to go with a Honda 2000 as it along with my Iota 45 amp. PS will run a bunch of chargers and I do have more power supplies also.
I just could not convince myself that $1000 for a generator was a wiser investment that $150 worth of deep cycles which are more than enough for my normal usage.

If I found myself at an event with deep cycles getting near 50% I would not hesitate to run the Blazer for 30 min. or so at a time to pump them back up. My alternator will put out 55 amps. at idle. It takes nearly half of this to support the vehicle but 30 amps. into the deep cycles brings them up fairly fast. One problem using the vehicle's alternator to recharge aux. batteries is that as soon as the main (starting)battery comes up in volts the alternator stsrts cutting back. You really need a means to prevent this. There are several but that gets to be a whole other subject.


Charles

hi there from Toledo

When I go to SEFF or NEAT or even a day at the field I charge exclusively with the alternator and battery of the family minivan. I run the engine about 1/2 hour at noon, mid afternoon, and at dinner time and also bring jumper cables just in case. This has served me well over the years. And yes I occassionally need to use the cables, so it goes. Just be sure that you run the car's engine before every one else leaves, so you don't get stranded.

ciao -rjf

Originally Posted by Tram

Well, the number of chargers off an 18A power supply would be dependent upon how many amps each charger was pulling..

It would be able to run 18 chargers - each pulling 1 amp..
It would be able to run 36 chargers - each pulling .5 of an amp..
It would be able to run 3 chargers - each pulling 6 amps..

Is everyone at Common Sense RC as funny as you?

Rob

Originally Posted by Tram

Any of you Honda boys wanna let me borrow one? LOL otherwise, it's out of the question even if it's silent... Just cannot justify the cost...

Did you read my post about trying to rent one?

Originally Posted by Hypersprint

Is everyone at Common Sense RC as funny as you?

Rob

I apologize, I didn't mean to offend...

In order to find the answer to your 18A question, you need to know what you are going to be asking of the unit...

What type packs will you be charging?

I'm not sure what the charger will need as far as power, I'm still learning all this stuff myself..

I *think* - If you are charging 2100mah packs, you could run almost 9 chargers at 2.1A of draw if you charge at 1C..

4 chargers if you charge the same packs at 2C (4.2amps)..

Off an 18amp power supply..

Jeff
www.CommonSenseRC.com