Search found 10944 matches

by Hillhater
Jan 14 2021 5:20pm
Forum: Electric Watercraft
Topic: Shamrock, 25 foot sailboat electric conversion with an ebike hub motor
Replies: 40
Views: 2924

Re: Shamrock, 25 foot sailboat electric conversion with an ebike hub motor

. ........I don't know where to find one, but the Albin Vega (a similar sized boat) came with a variable pitch feathering prop which strikes me as being pretty great for an EV sailboat. I posted this link earlier in the thread.. https://oceanvolt.com/solutions/systems ... ail-drive/ They also say t...
by Hillhater
Jan 13 2021 9:28pm
Forum: Alternative Energy
Topic: Generating Power 24/7 by using Tides
Replies: 15
Views: 312

Re: Generating Power 24/7 by using Tides

Well, since you are so smart, why dont you develop a simulation or run the FEA maths to check the viability. ...or did you miss out on those techniques....unlike real engineers who use them every day as part of their skill set. Do it, it will save you wasting time and money building a pilot that wou...
by Hillhater
Jan 13 2021 4:50pm
Forum: Alternative Energy
Topic: Generating Power 24/7 by using Tides
Replies: 15
Views: 312

Re: Generating Power 24/7 by using Tides

You are not a civil engineer , are you ? :roll:
Build one to prove the concept !
by Hillhater
Jan 13 2021 4:43pm
Forum: Battery Technology
Topic: Imbalance When Empty?
Replies: 14
Views: 276

Re: Imbalance When Empty?

AAhhh ! ...do i detect the old “Top vs Bottom”. Balance debate re-surfacing again ??
by Hillhater
Jan 12 2021 5:37pm
Forum: General Discussion
Topic: New ebike build problem
Replies: 10
Views: 257

Re: New ebike build problem

Do you have the display operating manual ?
https://www.fatbikeshop.fi/wp-content/u ... -SW900.pdf
It suggests 24/36/48v are the factory options....but other voltages are possible ?
Suggest you contact one of those suppliers as to how to reconfigure for 72v
by Hillhater
Jan 12 2021 5:07pm
Forum: General Discussion
Topic: New ebike build problem
Replies: 10
Views: 257

Re: New ebike build problem

Its hard to comment when you do not tell us the make or model of the display
Suggest you Email/contact the manufacturer for information ?
by Hillhater
Jan 11 2021 10:01pm
Forum: Battery Technology
Topic: jonescg's cylindrical cell build thread
Replies: 24
Views: 1299

Re: jonescg's cylindrical cell build thread

Is it obviously the weld failing on the Nickel, or is the Nickel/zinc layer separating from the Al ?
I guess some late night reading of the spot welding threads may be needed ?
by Hillhater
Jan 11 2021 5:02pm
Forum: Items for Sale - New
Topic: Why doesnt prismatic pouch batteries come up in these conversations about batteries.
Replies: 1
Views: 104

Re: Taking Charge: Let's Develop the Products That We Want!

I think that would be classed as a commercial advertisement cleverly cloaked in some propaganda about an unavailable battery technology.
Come back and let us know the full spec and price of these wonder cells, ....
.....but not until they are commercially available .! :roll:
by Hillhater
Jan 11 2021 7:36am
Forum: Battery Technology
Topic: Imbalance When Empty?
Replies: 14
Views: 276

Re: Imbalance When Empty?

Thats what I thought also but I forgot to mention that it's a 16P pack which logically should make all the little imbalances and capacity changes between cells all averaged. So is this a 52v, 16s, 16p pack, ? And those voltage readings are from each 16 cell parallel group ? If so, those voltages te...
by Hillhater
Jan 10 2021 4:44pm
Forum: E-Vehicles General Discussion
Topic: Bosch Motorsports e-GoKart Powertrain Young Star
Replies: 7
Views: 631

Re: Bosch Motorsports e-GoKart Powertrain Young Star

While racing karts may be not exactly the sweet spot for this idea (not the product), maybe with some refinement this conect can be well used for Rental karts (swap batteries, check the motor, limit speed/acceleration for beginners and more), and for rental karts the excess weight won't be that muc...
by Hillhater
Jan 10 2021 6:35am
Forum: E-Vehicles General Discussion
Topic: Bosch Motorsports e-GoKart Powertrain Young Star
Replies: 7
Views: 631

Re: Bosch Motorsports e-GoKart Powertrain Young Star

Back to the original subject of the Bosch EKart... ..from the info link you get this b0110cks.. BRS can generate electricity while slowing the kart by spinning the motors backward. This makes sense, if you think about it. When the motors spin forward, expending electricity from the onboard batteries...
by Hillhater
Jan 08 2021 8:34pm
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

VTOL is certainly a very different ball game to winged craft, but you wont have the back up of a unpowered “glide” down if you run out of power.
Even if only hovering a few feet up in my back yard,.. I would certainly want a very noticeable alert at 25% capacity level. :shock:
by Hillhater
Jan 08 2021 6:57pm
Forum: E-Vehicles General Discussion
Topic: Bosch Motorsports e-GoKart Powertrain Young Star
Replies: 7
Views: 631

Re: Bosch Motorsports e-GoKart Powertrain Young Star

From that Bosch gokart article..... When it goes into production next year, the road-going version of this system, known as the Boost Recuperation System (BRS), will provide an extra 15 kW (20 hp) and 150 Nm (110 lb.ft) to compact petrol-powered cars during acceleration. According to its creators, t...
by Hillhater
Jan 08 2021 4:54pm
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

As you are discovering, battery packs are a whole area of potential problems.. I hav never bought a 1 kWh pack of any type,..only smaller individual RC lipo packs or 48v packs for EBikes etc So my financial risk is not great, and using multiple smaller RC packs allows me to replace a single failed p...
by Hillhater
Jan 08 2021 9:07am
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

Battery packs are a big gamble unless it is a known reputable vendor, using known brand quality cells and components.
There is a lot of fake product in the market.
Whilst the capacity is ok, that is not the full story for pack performance.
You need to know full cell specs
by Hillhater
Jan 07 2021 8:25pm
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

how did you calculate the battery weight of 220+ pounds? It will vary somewhat depending on the choice of pack chemistry and build method.. But at best you can expect 260 W per kg theoretically at cell level with low current draw. But as i pointed out above to solarsail, once you put a load on a ce...
by Hillhater
Jan 07 2021 6:50pm
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

Ok.. so from that.. 490lb thrust needs 14 motors at 3.1 kW each (75% throttle,..55% output) For 30 mins run time (max..20 mins + safety ),.. each motor would need 1.55kWh od battery...22kWh total. At 10+ lbs /kWh, that is 220 + lbs of battery , leaving <270 lbs for everything else, including pilot. ...
by Hillhater
Jan 07 2021 5:25pm
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

Where/how did you obtain those thrust figures ?
Are there “power” (kW) figures associated with the “% throttle” data ?
by Hillhater
Jan 07 2021 5:26am
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

Solarsail,... as i said, we have to be realistic, not idealistic. 30kW to hover ..OK so presumeably more to climb and manouver etc ?..maybe 40kW as you previously suggested ? Cells... Samsung 50E are one of the best cells, but at 2C (10A) thay can only provide 4.5Ah,..or 16Wh. https://lygte-info.dk/...
by Hillhater
Jan 07 2021 12:47am
Forum: Electric Aircraft
Topic: Suggested battery capacity for 30 min flight?
Replies: 24
Views: 658

Re: Suggested battery capacity for 30 min flight?

We did this before on your other thread. The estimate was for 40-50kW of power ...and a 20 min flight time. Assuming you can find motors to do that, you will need 20 kWh of battery minimum, distributed and connected as you desire. but..as AW said, you dont seem to recognise the scale of the battery ...
by Hillhater
Jan 06 2021 6:09pm
Forum: General Discussion
Topic: Why my lights, tv, and everything else isn’t flickering.
Replies: 7
Views: 222

Re: Why my lights, tv, and everything else isn’t flickering.

Re: Why my lights, tv, and everything else isn’t flickering. Being ac and 60hz what keeps the current continuous? Regardless of the frequency. Your lights ARE flickering, it is just your brain “smooths” the vision so you do not notice it. Even DC powered LED lights “flicker” ..but at a higher frequ...
by Hillhater
Jan 05 2021 11:56pm
Forum: EV Business World
Topic: Toyota’s Solid State EV battery
Replies: 1
Views: 292

Toyota’s Solid State EV battery

... Toyota’s Solid State EV battery There is a lot of noise on the jungle drums about Toyota going full commercial in 2021 with a solid State battery in a new EV Japanese car maker Toyota will introduce a solid state battery that can recharge to full in just 10 minutes 2021, a move that could revolu...
by Hillhater
Jan 05 2021 11:51pm
Forum: Battery Technology
Topic: Thread for new battery breakthrough PR releases
Replies: 1668
Views: 253084

Re: Thread for new battery breakthrough PR releases

... Toyota’s Solid State EV battery There is a lot of noise on the jungle drums about Toyota going full commercial in 2021 with a solid State battery in a new EV Japanese car maker Toyota will introduce a solid state battery that can recharge to full in just 10 minutes 2021, a move that could revolu...
by Hillhater
Jan 05 2021 11:39pm
Forum: Battery Technology
Topic: What batterie should work min. 48V
Replies: 5
Views: 260

Re: What batterie should work min. 48V

Good batterys are not cheap. But For cheap, quality cells, from a reliable supplier in Europe,..i would suggest considering Timich here.. https://endless-sphere.com/forums/viewtopic.php?f=31&t=61608 To save the difficulty, time, hassle and risk of building your own pack, he has 48v 21Ah packs fo...