# Power tool cells

Discussion in 'Electric Propulsion' started by pictsidhe, Apr 1, 2019.

1. Aug 9, 2019

### proppastie

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so obviously it is not as simple as buying a motor, controler, batteries and hooking them together, or a wrecked scooter......

2. Aug 13, 2019

### GeeZee

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Have you guys seen the e-PPG projects.
One uses Greenworks 80 v 4ah packs ($205ea on Amazon) he’s at “Minne.us” Claims 18hp for the motor he sells. He sells mating connectors for many different brands of batt packs. The other is openppg.com. It uses Bonka 22000mAh 7S LiPo Battery [USA ($250 ea) packs but they use 4 large scale RC motors and props. The 4 motor/prop option would not really apply to an e-ultralight. Hmmm, well maybe a pusher config would work.....

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3. Aug 13, 2019

### pictsidhe

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If you use a complete system such as a scooter, yes, it is simple. The problems come when people start building their own bits and adding features. Wrecked vehicles have often had a hard impact, which may have damaged the battery...

4. Aug 13, 2019

### pictsidhe

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320Wh is less than 1/2h for one hour. 18hp for 5 minutes would probably need 4 packs. They have less capacity under high discharge. 30 minutes, ~23 packs. Amazon puts the pack weight at 5.5lb.

5. Aug 13, 2019

### GeeZee

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For the version that uses the 4 RC motors it looks like they are thinking 8 of the Bonka 2.2AH cells will weight about 48lbs and give them 40-50 min flight time. I’ve noticed in some of the YouTube vids they climb then shut down and glide for a while. As they point out that’s the best reason to go electric with the PPGs. The total silence and assured instant restart.

Last edited: Aug 13, 2019
6. Aug 13, 2019

### GeeZee

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Also, just to be clear I’m not advocating for an e power fixed wing aircraft. I’m just passing on some info.
I seems that maybe there is a practical e-power niche in the PPG arena. It looks like with 8 batt packs a controller, throttle, and motor(s) you would be in the low/mid \$2k range which would be cost competitive with a gas engine. It seems that most people don’t try to go anywhere in these things so maybe a half hour of climbing /gliding and some partial throttle cruising would fit some people’s mission.

7. Aug 13, 2019

### Scheny

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Both the voltages and currents in this projects are way beyond what you should handle if you are not an expert. You will experience arcing and shorting with power behind it you cannot imagine.

At three digit currents also smallest contact resistance can cause connectors to burn, etc...

Be careful

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8. Aug 13, 2019

### GeeZee

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Thanks for your input Scheny. I’m actually fairly interested in the E option PPG. I decided from the start that the batt pack would have to be jettison-able. Pull a pin and the entire batt assembly falls free. I wouldn’t even consider their current setup of strapping/velcroing the packs to the frame.

9. Aug 13, 2019

### proppastie

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I have been told PPG can actually thermal when conditions are right....( really cooking)....so the E option with no torque, easy starts, and very light weight total package looks like a lot of fun. Another plus it seems like they have worked out all the hardware issues for you so there should not be a lot of problems... Might just tie safety wire around the Velcro and connectors for quick ejection.

Last edited: Aug 13, 2019
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10. Aug 13, 2019

### GeeZee

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Yep, whatever method used to jettison the pack would have to be simple and lightweight (and of course reliable) I’m not sure how secure the connectors they use are, if they would unplug reliably just from batt weight or if it’s a twist and pull. I was thinking of Mounting all the packs to a tray that would plug into something that would work like like a home AC disconnect (large high current blades that would unplug with a straight pull).

11. Aug 14, 2019

### Speedboat100

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That is your best choice..in power to weight...and energy density.

12. Aug 14, 2019

### GeneG

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I lean to the Leaf 62kw packs for their ease of use and air cooling. The power density is nearly the same and they will be used by many of the German as well as other car makers in the near future.

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13. Aug 14, 2019

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