Power consumption?

[whitepony]

i finally decided to go through with it and build my own e-board with abec 11 flywheels as contrast to my awesome 50km evolve carbon AT touring machine .. also aiming for more power and a top speed of nearly 50kph with the "DIY" board (not sure if you can still call it DIY with all the awesome buy & be happy solutions around the net - diyskateboards, enertion, aliendrivesystems all have really great polished products).

anyways, my landyachtz top speed 36 will arrive shortly and then I can immediately start with the cell layout - problem is that I lack experience with the crazy outrunners that people are usually using. the evolve sucked pretty much 350watt on average - now these double outrunner apparantly can suck up to 4.4k+ watt in peak moments - so Im really wondering which cells to use for my battery.

maybe some of the expert users here, ideally those that develop for the DIY community did some tests to share some numbers. ideally Im interested in a power consumption as function of velocity to get a rough idea what the individual cell needs to deliver in average and in peak moments.

setup:
10S battery (so i can use my evolve charger)
16/36 gearing
90mm abec 11 flywheels (softest 75A, probably adds some additional load)
double outunners with 4000+ combined peak power consumption


thanks for any input

 

[okp]

landyatchz top speed : what a beauty

I suggest you to go on 12S (4x3S in series)

 

[whitepony]

wanted to use the evolve charger ... even got a spare charging port somewhere. seemed very convenient! 8)

 

[whitepony]

whats the typical range you get with your double 63mm diagonal setup and at which typical average speed (how much Wh does your battery have, discharge capacity also available)? you got one of those giant peak watt setups, so im really curious!

 

[bandaro]

I built a 63mm dual hub motor ride on the 90mm wheels, on a fast but cruisy commute this morning, making about 1300 watts max, I burn about 15watts/km. This is running on 5s.

When I am going harder, it's more like 3-4kw peak, and burn in the low 20's per km.

The max amps pulled can easily go over 100, but I still use a 60 amp plug no worries - It doesn't sit at high amps for more than a few seconds. A higher voltage setup would make a little more power, but I doubt you either would or could use it much. If I pin it from 1/3 throttle it will throw me off. Give it 20% more throttle with weight neutral, it will wheelie. It's a great power level.

 

[whitepony]

after talking to riba, i decided to play it rather safe than sorry - going for high flow cells instead of max capacity.

what do you guys think? buy 12s charger and go for it or stay 10S and use the evolve?

 

[made_in_the_alps_legacy]

whats the typical range you get with your double 63mm diagonal setup and at which typical average speed (how much Wh does your battery have, discharge capacity also available)? you got one of those giant peak watt setups, so im really curious!

https://endless-sphere.com/forums/viewtopic.php?f=35&t=70187

 

[whitepony]

i was actually looking for that cause ive seen it a while ago, but didnt find the thread! thanks a lot

 

[onloop]

after talking to riba, i decided to play it rather safe than sorry - going for high flow cells instead of max capacity.

what do you guys think? buy 12s charger and go for it or stay 10S and use the evolve?

I think 10S3P offer the best outcome... with 190kv & 83mm wheels is perfect

60A peak is fine for a correctly geared drive train.

I would say avg 30A is what you would expect to draw. Probably less. Maybe 500w per motor.

Only during rapid accleration and hill climbing will you get high peaks...

-2kw is plenty of power.
-any bigger battery and weight gets a bit to much for my liking.
-any more cells and length is an issue (depends on wheel base of deck)
-12S do you really need that? It becomes difficult to gear down. Unless you are getting a custom made motor to give your desired top speed.

I am working on a small booster pack for my space cell. It will boost it from 10S3P to 10S4P. It plugs in parallel and gives you an extra 33% capacity. It can be used when you want more range. Or disconnected if you don't need it.

 

[whitepony]

I ordered 42 cells yesterday for a 10S4P setup with 12Ah (2 replacement cells again if i screw something up): http://www.nkon.nl/lg-18650-hg2-3000mah-20a.html

it should fit exactly on the length of the board and cells dont weight much - rather have a few spare kilometers in my battery than stopping early. also more parallel cells = less current per cell. there are next to no drawbacks!

I think your booster pack is a really great idea! I also considered your space cell, it really is good value for money but I felt like the only thing I can actually build myself is the battery, so I wanted to do that myself at least. 8)

 

[onloop]

Yeah 10S4P is not overly large.

What cells will you use?

 

[whitepony]

LG 18650 HG2! riba was pointing in that direction and the reviews i found were very positive! Looks like a very interesting blend of high drain and high capacity.

 

[bandaro]

I hear much better things about the LG cells than other cheaper cells used in these type packs, you should be fine.

Be sure you don't have the controller reset due to low voltage from what the voltage sag leaves the batteries momentarily, I find my FTV esc's occasionally need resetting after a hard slog. Lower drain LIFE could sag more. The 4p was a good idea assuming you are not chasing an ultra low weight build.

 

[chaka]

If you want to get as many cycles out of your 18650's as possible, go with a minimum of 10p. You really don't want to run much more than 1C current draw constant and 3C max/burst or the cells will degrade quickly. It's all about the heat generated during high discharge causing unwanted chemical reactions overtime.

A high capacity battery, from what I have read, can lose it's capacity sooner due to thinner and more tightly wound positive and negative plates reacting more rapidly with each other. Tesla Motors counters this by actively cooling the batteries which helps to prevent unwanted chemical reactions between the cathode and anode during high discharge.

Remember, these high discharge cells are made for power tools. If you flog them uninterrupted till depth of discharge they are going to get hot regardless of what they are rated.