Noob question thread! 2020_Summer

Didn’t take me too long but you could also just ride around in circles :stuck_out_tongue_winking_eye:

1 Like

this sounds like a job for “wheelie-mode” @xsynatic

2 Likes

So I’m a complete noob to this hobby. I’m a highschooler looking to build my own electric longboard, since I’ve built an fpv drone. I have two questions. I was going to build a dual belt drive with flipsky 6355 190kv motors, but I’m not sure if those are any good or reliable. I’m trying to stay on the cheap end, since I do not have a lot of money to spend. Also I’m looking to get a 10s2p battery at an affordable price, but it seems that I can’t find one that is cheap or legit. Any help would be appreciated.

2 Likes

I would buy these over Flipsky: https://diyelectricskateboard.com/products/electric-skateboard-motor-6355-190kv

For a budget-oriented 10s2P, you’re better off sourcing from Meepo, Ownboard or Wowgo, since they offer free shipping. Get the best cell you can afford.

3 Likes

Noobish Question, If I bypass the Switch on the Unity, do I lose Roll to Start and Shutdown after X capabilities?

You’re not crazy for suspecting that. But it doesn’t sound like a BMS problem

Are you sure you aren’t just seeing the exact correct behavior for a float charger? I think you are expecting the outcome of using a trickle charger but actually have a float charger, which is usually better.

If you plug a fuel gauge into the charger (without an esk8 plugged in) and it jumps from OFF to 50.4V to OFF to 50.4V to OFF to 50.4V endlessly then you have a float charger. If it goes to 50.4V and stays there, then you have a trickle charger. So find this out first.

1 Like

Thanks for the help.

Amazon 1.5A and diy 4A both would not charge it yesterday. Actual voltage was 48.9. Today charged up and I removed it. Just checked metr and down to 50.3. Plugged in and 4A kicked on immediately.

I guess I’d need a female 2.1 to female 2.1 to test the charger. Or maybe I don’t understand.

4A just turned off at metr indicated 50.5 and “fuel gauge” at 50.3.

It doesn’t sound like anything is wrong

2 Likes

Maybe not. Lol. But wouldn’t you expect either charger to work when the voltage is down over 1V?

And then it magically works today when only down .1V?

Adapters will be here tomorrow

Nah sometimes they don’t kick on until it goes down a few volts

If you look at a discharge graph, you’re talking about 99.98% full versus 99.99% full :rofl:

The graph right near full (on the left) goes almost vertical

3 Likes

I don’t think you ever need that.

These are super-handy to have

It’s easy to make with a battery gauge, some JB Weld, a female 5.5x2.1, and a male 5.5x2.1

2 Likes

Yah what the chart shows is basically different constant discharge rates and that most of the power is between 3.0-3.8V that little bit when voltage goes way up goes away very quickly when discharging at any rate. With slower discharge rate you get more Ah out of a given cell (less is “burning off” as heat from internal resistance in the cells).

3 Likes

That said it is good to let balance chargers fill up the battery occasionally so they can get all the cells up to the same charge (generally balancing happens at the end of the charge cycle)

2 Likes

I missed part of that picture. Makes sense now.

My gauge.

1 Like

I still don’t understand why it wouldn’t charge when over a full volt down but today had no problem turning on 1/10V down.

Okay, I’ve looked at those motors, but they were more expensive than other motors. I guess I could get those instead for reliability.
Do you know of any voltage sag for those batteries and if they are reliable?

Yah if you are talking with plugging in a brick style charger to a barrel jack on a battery that has BMS attached or otherwise (basically relying on the brick part to detect voltage of the battery) I think it is good to plug in the brick part first to the wall (the AC->DC) before plugging in the battery otherwise I have had situations where it doesn’t go into charging mode… If this is a bad idea someone let me know :smiley:

What charger?

1 Like

Couldn’t find any info on it. Has a fan.

2 Likes

Do TB110s come with bearings and spacers?