I was measuring the noise in the current waveform for the MeanWell led drivers. I had found a couple of research papers that found that there was increased degradation in the cell cycle life, when there was high amplitude + high frequency ripple in the charging current.
I do believe the paper I was referencing back then was this:
There are couple relevant graphs that demonstrate their findings. Basically, cycle life degraded faster with the higher frequency AC charging current, power delivery capability decreased faster and cell ran hotter indicating higher internal resistance.
Which found and concluded that AC harmonics have no effect on cell degradation and cycle life, so now I don’t exactly know which one is more relevant to our use case. That being mentioned, they didn’t go to such high AC ripple frequencies as on the first article.
So maybe cell manufacturing and technology has gotten better over the few years, or maybe they didn’t go into high enough ripple current frequencies like the first article did, and therefore concluded that the lower frequency AC ripples have less effect on cell degradation? although the first article did find degradation even at the low ripple frequencies…
That first paper subjects the cells to huge levels of AC ripple current. It seems to make sense that current like that would degrade the cycle life of a cell as it’s essentially being charged/discharged by the AC current. The results could also be unique to those specific cells (construction, chemistry, etc.) and only for levels that huge.
IMO, the AC ripple current levels present in the power supplies and chargers used by the esk8 community are tiny compared to the levels used in that first paper.
Just guessing based on the ripple/noise level specs for these supplies though.
It would be interesting seeing a good cycle life comparison of a few cells using a good “quiet” charger and some piece of junk with lots of noise/ripple on its output.
Hello I’m new here and I just finished my first electric longboard.
I charge the 6S LiPo battery with a balance charger and this project is great to switch to a standard charger! So I’d like to buy the FlexiBMS Lite and the Metr Pro (or Metr Pro CAN?).
I’m running a Flipsky Mini Vesc 4.20 (based on 4.12 hw) and a 6S 4Ah LiPo battery. Can someone show me how to wire all the devices together? VESC + FlexiBMS Lite + Metr Pro.
I’m already using an anti-spark switch between the battery and the VESC as you can see in the picture: https://i.imgur.com/Xm0CBZb.jpg
atm there isn’t a loop-key to physically open the circuit but I’m considering to install it (in addition to the anti-spark switch) in order to cut the electronics absorption even when the switch is turned off.
Another question: Can I solder a 6S JST balance connector in the pcb or it needs a full 12S connector and adapt it for my battery’s JST cable?
I think you might need to reverse the rx Tx pins on the metro pro cable as I got a feeling the flipsky VESC 4 is one of the VESC that have them reversed.
The RX / TX pin are swapped in the Flipsky VESC schematic compared to the VESC shown in the Metr Pro setup guide. Do I need to wire like this: RX-RX and TX-TX ? In some applications it needs to be reversed if I’m not wrong.
Thanks dude, that was exactly the info i needed. Just gotta hope now i can adjust the current a little with the charger itself. Don’t particularly want to be chatging at the full 10a.
@SimosMCmuffin I haven’t been following that closely and couldn’t find in a qucik look, but does the newest firmware already has support to the VESC BMS data structure?
