e-power - some operational parameters to consider.

[Keith Black]

Here are some comments on a few of Eric's points.

2. No real idle or purr for stall turns and spin entry control.
This could easily be handled with a throttle up switch or flight profile.

3. Twitched in the air when gunned.
Should be easy to deal with with throttle curve/expo. The bigger planes I've seen fly were smooth as silk.

5. No RX pack required
Actually some of the serious electric flyers with bigger power plants do us a separate RX pack.

8. Lots of wires - battery connector a weak point  -got hot
True, but if separate pack is used for RX worst case is a dead stick.

11. When the battery "dumped" it was LAND NOW!
Again, with separate RC pack this is no worse than a dead stick. Even when using a BEC without a separate RX pack electrics give you an indication of when the battery is fading. Furthermore, when the BEC kicks in if you throttle down you almost always can throttle back up and get a short run before it stops again, this certainly isn't the case for an IC engine when it goes dead stick.

12. Needed spare 12 V battery - one or two charges and your car will not start after the inverter was finished producing 30v DC from your car battery. 
Carrying a spare 12 V battery is normally done by serious electric guys, but in lieu of doing this you can just start your car and charge off of the alternator rather than running your battery down. Carrying the spare 12 V battery is a hassle since they are heavy, but with electrics you don't need to carry a starter, a starter battery, chicken stick or glow starter. You do however end up with more chargers. FYI, most guys just leave the big 12 V in their trunk and never need to lug it to the field. To charge you just take your battery pack to the car, not the entire plane.

14. The packs did not really cool down enough to charge at the field - even using blower tube.
I share your concern here, but there electric guys I know never have an issue here, especially with three batteries.

16. Extreme care of TX required when motor armed - lose a finger at any time without warning if throttle just nudged 
Very good point, this is dangerous and difficult for IC guys to get used to. I've seen many people retrieve electric planes after landing and grab the prop, or near the prop. VERY DANGEROUS!. On the big engines it's a common practiced to use an arming plug so the radio can be activated but the engine will not be armed until the moment just before taking off. Likewise the FIRST thing you do when retrieving the plane is remove the arming plug, then pick up the plane. 

17. Ran low-throttle failsafe from bench installation onwards.
I would disagree with this because if you did loose radio contact and the plane crashed the electric engine would keep running until it tore itself up. One thing that IC engine guys don't consider is that after a crash, flip over, etc. that electric engine will keep running until the throttle stick is brought down, even after the prop hits the ground. Newbies to electric are used to the engine stopping when the prop hits the ground, not so with electric. 

18. Test "burp" in workshop to show wife, blew pliers and squares and wrenches clear off the bench. - Big dust cloud in shop...
Clearly an indication of not realizing how powerful these engines are ;-)  Keep in mind that with a flip of a circuit inside the speed control electric motors can go from cold to power that exceeds the top end of a DZ in an instant!

Another interesting point about electric motors that differs from IC motors. With IC motors you have to find the "right" prop that pulls enough but doesn't bog down the motor. With electric you can keep adding more prop and it will just draw more power. Your only limitations are how much battery you have (i.e. flight time) and how many amps your speed control and motor will tolerate. 

Something that no one has mentioned, with electric you don't need a throttle servo.

Having spent time around electrics there's no question in my mind that electrics are far preferable assuming the following: 
1) Cost of batteries is reasonable, (remember you have to have multiple batteries), 
2) Flight durations are equal to IC flight times (15+ minutes), and 
3) Power is consistent throughout the flight (in other words as the battery drains the engine will be less powerful). This is actually related to #2 flight duration.

Last observation, the best way to convince most people of the potential of electrics is to see one fly in person.

Keith
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