Hey guys -

Thanks for all the help over the past few weeks. I've successfully converted 2 of my quads over to individual ESCs/PDB and am switching the last two tonight

I'm using a few different PDBs to see what works best

Right now I'm trying to get a APD PDB360 installed and everything is good to go except the current sensor. There is no current sensor on the PDB360

My escs for this quad are the DYS Aria (blheli_32) 70a

Do I have any options to get the current with this set up? anything I need to buy separately?

I'm going to be using a Speedybee F7 v3 fc.

There’s always an external option like these:

Xt60:
https://www.hglrc.com/products/pre-order...ent-sensor

Xt30:
https://www.hglrc.com/products/amass-xt3...eq=uniform

(23-Dec-2022, 02:38 AM)Lemonyleprosy Wrote: There’s always an external option like these:

Xt60:
https://www.hglrc.com/products/pre-order...ent-sensor

Xt30:
https://www.hglrc.com/products/amass-xt3...eq=uniform

Okay sweet, I'm down to grab something like that.

I need current sensor because that's how I'll get my battery voltage on the osd right?

My escs have a "cu" pad on the bottom. Would I be able to use that?

No, a current sensor is not required to display your battery voltage in your osd.

Current sensors can be handy, because if you calibrate them and display the “battery mah drawn” on your osd, it can be a better guide on when to land, or when you should start paying attention to your voltage level. Voltage level varies, for instance sag from a punch out.

Completely different things- current sensor can show you amperage info (how much it has drawn from the pack, peak). Betaflight gets voltage info through different means.
https://github.com/betaflight/betaflight...Battery.md

If you decide to wire in a current sensor, here’s Oscar’s guide to calibrating it:
https://oscarliang.com/current-sensor-calibration/

I’m sorry I can’t answer your fc and esc specific questions, I’m not familiar with either of those boards.

(23-Dec-2022, 04:19 AM)Lemonyleprosy Wrote: No, a current sensor is not required to display your battery voltage in your osd.

Current sensors can be handy, because if you calibrate them and display the “battery mah drawn” on your osd, it can be a better guide on when to land, or when you should start paying attention to your voltage level. Voltage level varies, for instance sag from a punch out.

Completely different things- current sensor can show you amperage info (how much it has drawn from the pack, peak). Betaflight gets voltage info through different means.
https://github.com/betaflight/betaflight...Battery.md

If you decide to wire in a current sensor, here’s Oscar’s guide to calibrating it:
https://github.com/betaflight/betaflight...Battery.md

I’m sorry I can’t answer your fc and esc specific questions, I’m not familiar with either of those boards.

Watch the voltage, not current.  You can manage current with your throttle control... I like to look at a SINGLE CELL voltage, this way I never have a problem... at 3.75v, start coming back!  I haven't seen single cell telemetry in the F7 V3, but I have noticed that it tells you battery percentage remaining.  AND I DON'T KNOW IF WE CAN TRUST THAT - because I never identified what size battery and # of cells. Hopefully it is using the same technology as my chargers that figure it out, but I sure would like to see a single-cell value!  Any ideas?

(02-Jan-2023, 04:11 PM)PBSDMark Wrote: Watch the voltage, not current.  You can manage current with your throttle control... I like to look at a SINGLE CELL voltage, this way I never have a problem... at 3.75v, start coming back!  I haven't seen single cell telemetry in the F7 V3, but I have noticed that it tells you battery percentage remaining.  AND I DON'T KNOW IF WE CAN TRUST THAT - because I never identified what size battery and # of cells. Hopefully it is using the same technology as my chargers that figure it out, but I sure would like to see a single-cell value!  Any ideas?

If your current sensor is calibrated, and you know the size of your lipo pack (ie: 1500mah), watching your mah drawn can be a more reliable way of knowing when you should land or head home.

That said, most of the time I don’t bother calibrating it and I just rely on average single cell voltage.

But, keep in mind that this isn’t an accurate indicator of how much juice is left in your battery, and keep in mind that it is an *average* of all cells.

When we connect a battery via an xt60 connector for example, we are only connecting to the full pack output. The way that your charger can accurately identify (assuming your charger has been calibrated) individual cell voltages and cell count is by reading them individually from that multi pin plug that you connect to the charger in addition to the xt60.

All betaflight is doing is reading the full voltage from the battery pack, determining how many cells it thinks it should have based on that voltage, and then dividing the full voltage by that amount to give you an average cell voltage. This is why if you have your settings wrong, it will sometimes misidentify a HV lipo as a lipo with one more cell, and tell you that the battery voltage is low.

In order to get accurate individual (not average) cell voltage, we’d need a way to plug in that smaller balance lead coming off of a battery as well as a way to measure it.

I pasted in the wrong link to Oscar’s guide to calibrating your current sensor in my post above, here’s the correct link:
https://oscarliang.com/current-sensor-calibration/

And if you’re like me and the poster above me who rely on average cell voltage, here’s Oscar’s guide to calibrating your voltage:
https://oscarliang.com/fix-wrong-voltage-betaflight/

If you’re missing average single cell voltage on your osd, make sure that you’ve selected it in the osd tab in betaflight.
(For analog- I don’t know anything about osd in digital- it gets more complicated and I haven’t had a reason to learn it yet.)

The problem with relying purely on cell voltage is that it can just unexpectedly plummet near to the end of the remaining available capacity (especially if running 6S) and end up ruining your LiPo before you can make it back to your piloting location.

Always use current as the primary indicator of when to start thinking about coming in to land, and use voltage as the secondary indicator (i.e. other than for battery health reasons I don't take much notice of the voltage reading until my available battery capacity is getting near to depletion).

There are a couple of better current sensor calibration options (IMO) in the thread linked to below than the ones detailed in Oscar's guide. The best one as shown in the video of that thread is a little dangerous, but it does seem to work quite well because it actually puts a realistic load on the motor during calibration. The other method I like is in post #4 of that thread.

https://intofpv.com/t-how-to-calibrate-y...ent-sensor