lead acid and RC???

[jawshnitzel]

i am about to play with the RC stuff in a gravity bike i built this fall... looking at the turnegy 130 motor and a controller to match.

my only question is, how much battery choice matters to the controller / motor????

say, if i had a supply of deepcycle car style batterys, would an the RC controller and motor run on them fine??? that is, until i can afford something better?

im thinking of running 2 deep cycles in series to make 24V at first.. just to get started rolling.

thanx,

shnitzel

 

[swbluto]

Any battery type is fine, although you'd need a high quantity of lead to power the potential of RC equipment.

Doing so doesn't exactly do much to aid in the lightweight, small characteristics of RC systems. But it may just be fine for your applications... maybe. I'm clueless about gravity racing.

 

[amberwolf]

imy only question is, how much battery choice matters to the controller / motor????

Battery choice is almost everything on a small EV like a bike, because it determines more than anything else your power-to-weight ratio, by how much "fuel" (power) you are carrying vs the weight and volume of carrying it (which will affect the performance and range of your EV).

If gravity racing means primarily downhill racing, then the lead will give you a lot of extra inertia to overcome vs the power you can get out of it, so in a straightaway it won't make much difference (except for the off-the-line start will be slower vs same power and C-rate in lighter batteries), but when you have to change it's speed or direction then it will make a lot of difference, compared to the lighter types of battery.

Two deepcycle car batteries is probably going to be 80 to 100 pounds, making your bike probably heavier than my CrazyBike2 (which weighs in at 150 with all the doodads on it, about maybe 120 without the pods and lights and stuff).

 

[TylerDurden]

FYI: Chemical burns (from the sulfuric acid in flooded car batteries) leave scars that chicks do not dig.

SLA and AGM are better choices for a vehicle that can tip over.

 

[vanilla ice]

Like sw says, the whole point of the RC stuff is that its compact and light weight for any given performance level. You can get just as much power or range or whatever with non-RC stuff but you have to deal with bulkier and heavier equipment. Any case using the flooded bricks negates most of the benefit of the light R/C bits.

If there are specific reasons you must do the lead with the r/c motor, go for it. It should work. Seems a little asswackboards is all. But maybe we're missing something? What kind of bike are you using it on? Pics? You may even be better off budget wise switching it up and going with rc lipo and a non-rc conventional controller/motor. I do that on my razor, lipo with crap cheap brushed parts. Works great.

The R/C motor-controller thing is still kind of a PITA to noobs.. err at least it is to me.

 

[Jeremy Harris]

One of the often overlooked, but rather nice, features of using decent lead acid batteries is their ability to deliver extremely high current for short periods of time from a relatively cheap battery. Sure, their capacity suffers when you do this, but in terms of getting loads of peak current for a modest amount of money lead acid beats all other battery types hands down.

There are downsides though, mainly to do with weight, size and longevity.

I haven't re-done the calculations lately, but a year or so ago it was clear that big lead acid batteries still had the edge over lithium batteries for something like a hill climb car. The ability to deliver very high current outweighed the weight penalty for this particular application, in fact the weight was something of an advantage in some respects, as it could be put in the best place for good traction off the line. They were also a fraction of the price of high rate lithium batteries.

Jeremy

 

[amberwolf]

One of the often overlooked, but rather nice, features of using decent lead acid batteries is their ability to deliver extremely high current for short periods of time from a relatively cheap battery.

Yep. Just ask my chainrings, chains, and rear wheel. Or rather, the pieces thereof lying about.

 

[recumpence]

The new HV160 controller seems to have cured the majority of RC issues. It has current limiting and is FAR more robust. So, even sensorless, this should be a very good year for RC.

I agree that lead acid negates the benefit of the light RC stuff. However, as a means of climbing back up the hill after a gravity race, you might be onto something!

Matt

 

[jawshnitzel]

ah thank you so much! i appreciate your info!

i ordered all my RC parts, after sooo much research, i went with the sentilion... ill probably regret that someday....

got the big turnigy 130 motor, a wattmeter, the signal generator and a twist grip throttle...

i would prefer lithium ion batterys... but being from a small mill community, deep cycle batterys are easy to come by. and cheap... like $2 each when im lucky...

as far as weight, id be stoked to be lighter, but im not to concerned with acceleration.. more rather having a top speed of around 60-80km/h and enough range (not neccesarily at that speed) of about 30km.

im all set up for 48v in the future. but for now, i think ill find 2 deep cycle cheap lead acids, and get rolling!

my bike is very stable at 80km/h. and runs hairpins like a dream... cant wait to be riding up hills!

and yes, im a very cheap bastard!!!!! and i build everything for myself! including::::::

5x8 foot flatbed CNC router
turbo, megasquirt EFI 81 civic
solar thermal collectors,
blah blah.... thank you internet!!!! thank you all!!!!!!!!!!

and thank you endless sphere, without this page, i wouldnt have discovered RC biking .... very happy with my purchase! cant wait to play!

shnitz