Shit Robert, it will be tought to catch you and require some battery investment.
I have an old Esurf battery that is 63v 50Ah, perhaps I need to use that one to catch up.
Did 19,5kms today with 27% left, so I have no chance to catch you with small efoil batteries.
55mins in one go is pretty much the limit for my knees and feet as well.
Impressive!
Make it 25kms next time and I will post, but that is as far as I will go. Rode the veloce M today, first time in a year. Have to say that my preferences have changed greatly as i have advanced as a rider. It is quite good and loose setup actually.
My only complaint is that the lift is a bit uncontrolled over 35kmh. Otherwise almost as agile
Huge range! Looks like the power required for 30 kmh is roughly 3500W, this includes all the energy loss( mainly heat?), so actually engine output is somewhat less.
Was out for your record today, but had to stop with 17% battery left. Was riding in nice evening swell. I loose the feeling in my feet after 60min. Then my kid started calling like crazy, so i had to stop.
I think I migjt be able to tie you Robert with my 8p magic battery. Just need to loose some more weight and get below 70w/km…
16S 100kv 7”FR Veloce M/surf stab.
Im 100kg, so fighting to get same efficiency as you with gong setup.
Not really magic battery, but very compact for its energy. Im using 16s8p samsung 50E crammed into a max04 box. It gets quite hot as this is not high discharge variants.
Just had a new record for me with my new battery (14s10p P42A)! 17miles (27km) in about an hour (to a completely empty battery, I swam the last little bit in when it got below 3.0V a cell). My gross estimate of efficiently is 110W/mi (68W/km) with slingshot 84cm wing.
I had it set to 40 or 42V (~3.4-3.5V a cell for 12S) to start the cutoff and 36-38V to end (~3V a cell for 12S). I swap out 12S and 14S batteries so I don’t have an easy way to change the cut off. So I just monitor my remote until I am near 46V (3.3V) and come in, after 3.3V a cell it drops really quickly.
3.3-3.5 is a good start of cutoff and 2.7-3.0V a cell is a good end of cutoff.
Did a long run on my happy foil and 14S, efficiently was way worse, but I was going about 19-20mph the whole time with a couple runs hitting 23mph. Battery lasted about 40 minutes and I went 12.2 miles.
…10p will allow a very short cruise time, the battery will drain very quickly. I think cruise time is the most important parameter of the e-foil propulsion system, so it is better to increase the number to …14p. I am planning 13s20p (or 14s20p).
Weight and max current are also important parameters to tetermine the battery. More capacity means more weight. Batery pack max current depends on the individual cell max current and number of parallel cells. Number of S depends also on the KV of your motor and max speed you want to achieve. If you want to run it without bms, an even number is better because you can split them into two 6 or 7S packs. If you use high current 18650 cells like samsung 30Q, everything from 12s8p to 14s 16p works. With 21700 cells like molicel p42A even 12s6p would work. Personally, I would not go above 14S 40Ah nominal capacity (2000wH). This results in a 10kg battery. As a reference—I use a 12S8P pack (split in 2x6S8P) from MolicelP42A with a 63100/130KV motor, a flite prop and RL wing. Max speed is 40km/h, range is almost 19km @69Wh/km. Total battery weight is 7kg, riding time around 50min.
Depends on 18650 or 21700 battery also. I have a 12s12p 18650 Samsung 30q and a 14s10p 21700 p42a battery. Both work well but the p42a has more energy for a longer ride.
14s20p is huge and will be a beast of a battery in both weight and ride time. Probably the biggest pack that I’ve seen on here. I prefer to be able to swap batteries and keep it lighter.
Yes, I agree, for a regular e-foil (e.g. v1) a low battery weight is better. However, I’m building a slightly different concept of e-foil - in it the battery will be placed firmly, without the possibility of pulling out - the goal is to achieve a cruising time of 2 to 3 hours.
However, it is possible that I will need a smaller battery, maybe just a 13s16p. The number of parallel cells will depend on the parameters of the propeller and wing, which I will design myself. So the main goal is to get the longest cruise time possible, so that I don’t have to wait for annoying recharging after a short cruise, and so that I don’t need another spare battery.
Interesting 20p , I was happy with my 8p12s already , conception choice is challenging with other limits : motor and controller running for hours and the legs !