Flipsky multiple battery

EFOIL.builders Electronics (ESC, remote, batteries)
1

hello guys!

Few question about the flipsky 75200 vesc.

First one: there is no user manual when I receive it, can I find it somewhere online? Didn’t find it on Flpsky website.

If I want to connect multiple battery, they’re in parallel right? so if I want to use 72v 30ah I need to choose 3x72V 10ah?

The discharge current rating is the same, so if I have a continuous discharge current rated a 50 amp for one battery, It will be an addition, so 3X 50 amp= 150amps for the 3 correct?

But because I have a 6kw motor so I don’t need 150amps@72v, 100 will be enough. So I can choose 2x 72v 15ah. How I connect 2 batteries to 3 connector to have a good discharge repartition?

the last one, I see on the forum some of you usine passive cooling and some of you use a dedicate pump. Passive is more easy/light/efficient, but it give the same cooling quality or the pump give a good improvement?

Thank you very much for your help!

2

Nobody to help me? :no_mouth:

3

1, the pin outs are printed on the case. the rest of the set up in in VESC TOOL

2, if you connect in parallel your capacity will double and voltage will remain the same, if you connect in series your voltage will double but capacity will remain the same so it depends what you want to do.

3, Correct 150A

4, connect all 3 red cable from the vesc to positive, connect all 3 black cable from the vesc to negative

5, depends on a few things.How big the board is. How much you weighing. What size wing. how good you are - if still learning you will probably overheat the vesc if using passive cooling. I’m my case I use the pump because I’m 115kg on a good day. My friends 80kg ish don’t seem to need to have the pump switched on

2 Likes
4

Thank you very much! :blush:

So in order too:

1- I have the watercooling case and didn’t see any info in it.

2- I talk about the build in cables, the VESC have 3 XT90 battery connector integrated, I just want to be sure they’re factory connected parallel to order the correct battery.
If I can my plan is to take 3X 60v/10ah and connect each to one connector separately.

If they’re not I have to do what’s you’re saying, connect the battery in parallel to one plug and connect all VESC XT90 cable to one.

Ok for the cooling, I will put a pump, it’s more safe. We are around the same weight, can I ask you your board dimension/liters?

5

1, some people use passive cooling but it didn’t work for my heavy ass.

2, the 3 cables are connected in parallel on the vesc but Make sure to use anti spark connectors or your connetors will die over time. Easier to connect all 3 positives together so you can use 1 fuse going to the vesc. But connecting 3 individual batt will work.

My board is 1500mm and 130mm thick

1 Like
6

Some Traps here:
1.) Putting the batteries in parallel is right, but you should do so externally.
The internal connections of the ESC are not made to equalize any significant voltage
difference between the batteries. If you connect two batteries with >0,2V difference
you will immediately burn the VESC.
If you want to split the battery, do that in serial:
I am either using 2x 6s or 2x 7s batteries in series; that way I do not need an BMS but
can charge & equalize with a standard hobby-grade charger (ISDT K4)
Most people here build an external battery and then connect it by using 2 or 3
connectors on the VESC.
2.) The 75V type is good until 16s only - which is 57,6V nominal; 67,2V fully charged.
You need some leeway for the voltage spikes that occur during load changes.
Using a 72V battery will surely burn the ESC very soon.
Also, everything above 60V is getting dangerous, especially in water - so I personally
will not go above 14s. If you go to 16s take extra care when waterproofing.
3.) For the standard Flipsky 65161 “6kW” (more 4,5kW in reality) Motor,
12s is good enough; 14s is plenty.

And last not least: Passive cooling works perfectly if your pipes aren’t obstructed. Even with a 92cm Mast I never get more than 15°C delta between water & ESC temperature (With 24°C water my ESC typically stays below 35°C even during start)
If you want more efficient cooling, go for bigger diameter pipes - this is more efficient than any electric pump.

7

Thank you very much! Yeah I’ve seen on Flipsky website about the 16S max power. I’m not light so I guess I need quit of power… :sweat_smile:
So I’ll probably go for 16S I guess but not fixed yet.

Ok I get it about the equalize voltage, I’m glad I ask here, I’ve think the ESC have a regulator integrated… :skull_and_crossbones:
I’m ok with serial the battery, but in this case I doubt I keep the additional discharge current right? So I need to find 100 amp discharge battery, more expensive and difficult to find compare to the regular 50 amp.

For the cooling I think I’ll put a external pump with separate battery the time I begin, and when I’ll be good enough to keep moving I’ll remove the pump.
But thanks for the info about the pipes size, good to know! I’m thinking about putting rigid aluminium tube in the mast and use flexible only to make the link between tube and ESC.

8

I would recommend to build a battery.
Normal LiPo cells are not up to the task and dangerous as well - also by far not as durable as good LiIo cells.
So safe yourself the trouble and build a proper battery.
P.S. why do you want to go 16s? For an efoil it is not needed, except if you want to do speed records - and for this is seems you have the wrong motor…

9

I’m better for building physical stuff than electronic :sweat_smile:, so it’s more convinient for me to use regular bike battery, and it’s pretty easy to find a 52V 15Ah Li-ion battery with good samsung cell.

Also, I live 0.3 mile from the lake, so I want to have at least 2 maybe 3 battery pack to don’t have any ride limit, it’s more easy to buy directly 6 x 52v 15ah battery than buidling them.

For the 16S… it’s my skateboard experience, maybe it’s a mistake but it’s to not limit myself. I’m not building an E-foil for relaxing ride, I want dynamic one.

When I begin for sure the 14S or even the 12S will be enough, but when you get some skill in general you want to increase difficulty, like speed or carving.

And I don’t want to get limited by the battery and need to replace them.

I did this mistake with my E-skateboard, I buy a first one with 400w power, enough most of the time but sometime I want speed. Then I switch for a 1000w version, I rarelly use it full power, 90% of the time I stay on medium. But when I want I can go faster when condition are good.

Anyway the remote have 3 speed mode, I can limit it if it’s too much.

Elctric motor have rotation speed relate to voltage, so a 52V battery will be more limited than a 60V. I can limit the 60v battery to 52V with the trigger or the limiter, but it’s not possible for a 52V battery to produce 60V That’s my thinking about battery choice.

But maybe I’m wrong, it’s my first foil so it will be a new experience. That’s why I havent order the battery yet… :exploding_head:

PS: why wrong motor? the 120Kv have a lot of power, for what I read here the propeller is more the issue, the flipsky one will be good for begin but with skill I need to switch for FR & co prop.

10

I understand you reasoning; however:
In an efoil the dynamics depend far more on the wing, the propeller and the motor (in that order) than the battery: By far most important for the dynamics & speed of the board is the wing; and lower kV can always be compensated by a higher pitch propeller.
Also, peak power is only needed for starting; once flying you will rarely use more than 1-1,5kW of Power - except if you want to break speed records with speeds above 40km/h…
Last not least: Be carful with e-bike batteries, as the included BMS are usually not able to handle the power needed during startup: For an efoil I would go with 100A BMS (better 150A) minimum; e-bike batteries typically do not have more than a 30A BMS or less.
Last not least:
I started with a 36Ah 12s battery, then build a 56Ah 12s - and now I mostly use a small 24Ah one, because it is easier to handle on land, much better for carving and still gives me about 1h of ride time, which is plenty for my legs… :wink:
The bigger ones I now only use for traing sessions with my kids and when going out on the Ocean.

11

Ok I got it, thanks a lot for you advice they’re really usefull! :blush:

My plan is to stay with the flipsky propeller to begin and then switch for a Fr prop and maybe a smaller wing, I have a 1700cm2 for now.

For the battery I was planing to take 2 set of these in 15ah need to see if they exist with 52V.
The advantage to be parallel is the management of weight/ ride time easily.

https://www.ebay.com/itm/374164657036?hash=item571df3938c:g:9R0AAOSwIsNiwvMG

They’re using samsung cells with a continuous discharge at 50 amps - 90 peak, so for both battery parallel, I’ ll get 100amps continuous and 180 amps peak, far enough I guess.

12

Woooahh… :frowning:
Some remarks here:

  • Same discharge current independent of capacity should make you very, very suspicious…
    Discharge current is a direct function of cells in parallel: So rated discharge cannot be the same for 12/15/…/45Ah types.

  • LiitoKala is one of the worst brands in the industry:I had some of their cells and they were utter scrap; specs grossly overstated. I would be extremely surprised if they use Samung cells or if this pack would be even close to the stated data. Do your own research on this brand…

  • The description clearly states “30A BMS built in” - just like I said:
    This is surely peak, not continous. So to realize reliably 120A for starting (as you will need longer than 10s to fly, you need this to be continous!) You will need at least 6 of those in parallel.

In short: Maybe I am wrong & you can certainly try, but I would be surprised if it works…

Last not least: DO NOT USE the Flipsky Prop!! Look on TinkerCAD you will be able to find much, much better props for 3D printing. With the Flipsky prop you will not get any kind of performance or efficiency; From my experience I would estimate a 50% loss of efficiency with this prop.

13

One last remark: If you absolutely want to try this pack, you have to bypass the BMS for discharge and use it only for charging. Discharge is managed well by the VESC, so no need for the BMS here.
This way you will be able to start without burning the BMS; don’t know about the cells though…

14

Excuse me for taking over this thread, but I have a similar background / idea: not very much into amps and volts, therefor wanting to use ready made battery packs instead of building my own to keep things simple. Maybe someone could put some light on the following, right / wrong, good / bad:

For safety reasons I would like to use LiFePo - I am using two packs with my boat (continues load) and motobike (high start amps) and they work great. I understand that an eFoil - especially fpr getting up - needs much more power, continuously.

Packs I consider buying:
9,9V, 4200mA, 30C constant, 60C peak, 3s1p, weight 365g

Idea to combine them:
5 in parallel, making 3s5p at 9,9V, getting 21A, approx 207Wh
4 of these “fives” in serial, making 12s5p at 39,6V and 21A, approx 831Wh

VESC 75200 says it’s safe for 14-75V and 3-16s - so this should fit, right? I would combine the packs as said and use one of the battery connections of the VESC 75200 only, good?

I know this is not much, cost is almost EUR 1000 and weight below 8 kg. A compromise. Hope this will be enough to get 30+ minutes flying time (I am light weight) …

Questions: what about antispark? What do I buy, where do I put this?
Generally speaking: higher voltage give lower amps, lowers the chance for overheating, right? I wouldn’t go over 50V though …
I’ve got a good charger that is capable of doing 6s so I would charge the “five”-packs at once, should work, right?

Any comment is greatly appreciated! :innocent:
Cheers, Dan

15

For an efoil I would use LiIon cells, they have a much better Wh per weight ratio. 2 6S8P packs from Molicel 21700 P42A or Samsung 21700 40T weight around 7kg with a nominal capacity of 1382Wh. Cost would be less as well. If you balance charge them with a good charger, I don‘t see a big risk. Just use genuine branded cells from a reputable seller like nkon.

16

Thanks Daniel, I understand but would nevertheless go with LiFePo: is the plan of connecting them okay? Does the VESC work with them? What about the antispark?

And one more thing I consider: a killswitch. I have smewhere read (can’t find it anymore) that the Flipsky VESC already has a connector to safely connnect the battery on/off … any hint?

17

Yes 40V works, you won‘t break a speed record, but if the cells deliver enough current you will get on the foil. For the killswitch, some people used a reed contact in the pwm throttle signal path. When the magnet is removed from the reed contact there is no signal and the vesc sets throttle to 0. with FW 5.3 you can also use one of the Inputs for a kill switch. Either with a reed contact or better with a hal sensor. HAL is more reliable as reed contacts sometimes get stuck.

1 Like
18

Ok thanks a lot for the info on the battery, I’m really happy to open this post bedore order one. :sweat_smile:

So for a battery what you will recommand? any advice? My other choice is the hobby king 20ah pack:

I don’t know if 12S, with 2 pack, will be enough for my weight… the other option is to take 4x 4S battery, then I’ll get 16S.
Don’t know if I can mix 6s and 4s when I plug them in series?

19

Not sure what you mean here? Connecting batteries in parallell with slightly different voltages to a vesc does not pose any risk to the vesc - but they will balance discharge into the lowest voltage battery through the connection pads on the vesc (which are made for taking all the input current) with current limited by the internal resistance of the batteries - current will be huge and dangerous if there is any significant voltage difference, but not at 0.2V difference.

An example:
U=ri, i=u/r; with a voltage diff of 0.2v and total battery internal resistance of 38mohm (for two molicel p42a 12s10p batteries connected) gives only 5A current.

20

Just tagging on here since I have a similar question about the same batteries.
on the same Group W7 Water Sports Kit (FSESC75200 and 65161 Motor)
Is there any reason not to use (4) Turnigy 12ah batteries in 2series/2paralell, over (2) 20AH in series?
The cost is 7% more but I would get 20% more capacity. and if a cell fails, I only need to replace 1 smaller pack?
The only downfall I see is requiring more charger outputs.

Dave